Introduction and aims: Balloon sinuplasty has been the object of recent discussions and papers. It is believed that the use of these tools can bring benefits, when compared with traditional endoscopic sinus surgery. Although there already are papers on the efficacy of this new instrument in the literature, there is no study in our country with a series of cases and follow-up of patients undergoing sinuplasty. Our study aims to review the information of 10 patients who underwent balloon sinuplasty, alone or in combination, discussing the indications, complementary therapy and follow up evaluation.retrospective study.Of 10 patients, 6 were males and 4 females. Their ages ranged from 7 to 58 years. All patients had chronic rhinosinusitis without nasal polyps, of which 8 are associated with allergic disease. 3 patients underwent sinuplasty only, and 7 had other procedures done during the same procedure. Follow-up ranged from 2 to 7 months. Of the 10 patients, 9 showed symptoms improvement in imaging studies.sinuplasty was successfully performed in all patients, without major technical difficulties or complications. This instrument can become an alternative surgical treatment for some groups of patients. Endonasal endoscopic surgery (EES) is the current method of choice for the surgical treatment of patients with nasosinusal inflammatory diseases who have clinical complaints and changed exams even after maximum clinical treatmentThe goal of EES is to increase ventilation and drainage of the paranasal sinuses (PNS) involved, enabling the proper functioning of mucociliary movements in the nasal and PNS mucosa, thus facilitating the drainage of these cavities and enabling the penetration of medication and solutions for nasal flushingThis method, despite bearing numerous benefits when compared to the conventional open procedures, still has some inherent challenges and limitations, especially because it ends up removing bone tissue and nasal mucosa fragments, which can cause bleeding, temporary physiological changes to the nasosinusal mucosa, especially the paradox reduction of mucociliary movements in the post-operative period and local scar fibrosis, which can cause re-obstruction of the treated PNSThe recent finding of high levels of nitric oxide (NO) in the nose and PNS in healthy persons in comparison with the tracheobronchial tree is also a current object of study; nonetheless, very little is known about the role of this gas in the nose and PNS, and which are the clinical and surgical implications of this substance in the upper airways. What is known is that the larger openings of the PNS ostia can significantly reduce the concentration of this gas inside these cavitiesConsidering these and other complications, many are the patients who currently undergo EES, including children, whom could benefit from potentially less invasive methods than EES.As of 2006, a new device gained the lights in our specialty: the possibility of doing a balloon dilatation of the PNS ostia. This device came up with great fuzz in the USA for the enlargement of PNS ostia, especially the maxillary, frontal and sphenoidal sinuses for the treatment of nasosinusal inflammatory diseasesThis device dilates PNS ostia and its adjacent structures, causing local micro-fractures, through the use of a balloon capable of withstanding high pressures. It is believed that after this dilation with the micro-fractures there is a remodeling of the treated PNS system drainageIn some recently published papers, it is believed that these devices may cause benefits, when compared to conventional EES, in reducing surgery time, hospital stay and the use of other materials, such as nasal packingAlthough we already have papers in the world literature on the efficacy of this new device, with patient follow up of up to 2 yearsa)To review the information of 10 patients who were submitted to surgery for the treatment of inflammatory nasosinusal diseases in which this approach was used alone or in combination with other techniques: PNS balloon dilatation.b)To discuss the indications and complementary treatment of these patients.c)To assess the post-operative follow up of these patients.Our goals were:After approval from the Ethics Committee of the Institution (021/2009), we carried out a retrospective study assessing the information present in the clinical, surgical and anesthetic charts and complementary exams of the 10 patients, all submitted to surgical treatment for nasosinusal inflammatory diseases.The inclusion criteria for these patients was the use alone or combined of some other surgical procedure involving balloons for the dilation of the natural drainage ostia of the PNS, the sinuplasty carried out under transillumination  with theWe analyzed patient data such as demographics, surgery indication, prior surgeries, paranasal sinuses treated during the procedure, other procedures carried out in the same surgery, use of nasal packing and other materials, surgery duration, hospital stay duration, technical difficulties, possible complications and post-op follow up.All the patients were submitted to surgery in the same institutions, done by three different surgeons from March through August of 2009. All the procedures were done under general anesthesia .Table 1PDemographics:Of the 10 patients, 6 (60%) were males and 4 (40%) were females. Their ages varied between 7 and 58 years, mean of 28.6 years.Indications:The indication for using balloons, after discussions with the patient or Family members was left in the hands of the surgeons who performed the procedures; however, all the patients had chronic rhinosinusitis (CRS) and no nasal polyps; 8 (80%) of them had nasosinusal disease associated.The most common symptom found was frontal headache, followed by nasal secretion with postnasal drip and facial pain.Previous nasosinusal surgeries:Of the 10 patients, 8 (80%) had never been operated to treat inflammatory nasosinusal diseases. In two cases (20%) the dilations were carried out through EES, and they had recurrence of their clinical complaints and of the alterations in complementary exams (nasofibroscopy and CT scan). These two patients had allergic characteristics.Treated paranasal sinuses:In the 10 patients, 13 PNS were catheterized and treated with sinuplasty: 8 frontal sinuses  and 5 maxillary sinuses . Of these, even after balloon dilatation, 2 PNS were open in the traditional way: 1 maxillary sinus (left) in the same surgery and the frontal sinus of another patient - but this one in another surgery in which the Draf III procedure was carried out.Surgical procedures carried out:In 3 patients (30%), sinuplasty was carried out alone and in 7 patients (70%) one septoplasty  was carried out in the same surgery. All the patients who had undergone septoplasty had never been submitted to any nasosinusal surgical treatment.Of the patients who had undergone septoplasty, 1 underwent partial middle turbinectomy to treat bullous middle turbinate. No patient was submitted to inferior turbinectomy.Nasal packing and other materials:Of the 10 patients, 2 (20%) had Merocel® nasal packing in the middle meatus region. These two patients were submitted to traditional PSN opening after sinuplasty.One patient had Merocel® inferior nasal packing. In the seven patients in whom septoplasty was carried out, one nasal “splint” was placed and fixed at the end of the procedure, and it was removed at the return visit.Surgery time:In order to evaluate the surgery time, we reviewed the anesthesia notes of the 10 patients. We did not take into account only the time it took for the procedure to be made, but also the beginning and end of the surgery, according to the form filled out by the anesthesiologist. This time varied between 40 and 120 minutes, mean time of 70 minutes per patient.Hospital stay period:Of the 10 patients, 7 were discharged on the day following surgery. Three patients we discharged on the very day of the procedure. These three patients were the same ones submitted to sinuplasty only, without other simultaneous procedures.Technical difficulties and complications:All PNS previously defined for treatment were successfully catheterized and dilated. There were no major technical difficulties in doing the sinuplasty and there were no intraoperative complications. There was one immediate post-operative bleeding with the need for inferior nasal packing.Postoperative follow up:All the patients returned for a post-op visit and the follow up varied between 2 and 7 months. Of the 10 patients, 9 (90%) improved in their symptoms - according to answers from the patients, and had better image studies (CT scan). No patient had late post-operative bleeding, nonetheless, 7 patients had nasal obstruction on the first week of post-op. These were the patients who suffered concurrent septoplasty.In two patients, more frequent nasal cleanings were carried out because of nasal crusts. These patients were submitted to traditional procedures, even after PNS dilation.One patient had bilateral frontal sinus re-obstruction. This patient had already undergone prior EES.The use of these new devices in patients has already been proven safe, with good results, being specifically indicated for patients with CRSOne of the most promising indications for sinuplasty is patients with CRS. Doing EES in children with CRS is not common and is controversial as far as its indication and efficacy are concerned, hence the difficulty of having a series of cases with a large number of pediatric patients. Nonetheless, in a recent paper, 30 children were submitted to sinuplasty. No complication was seen and good postoperative results were obtained from this less invasive techniqueAll the patients, even those who had already been submitted to EES, were treated with specific medication in the pre-operative period, for the time advocated in the literature.Numerous papers illustrate the fact that patients with allergies tend to have more complaints of recurrent symptoms, both with clinical treatment and even after EESThis patient did only sinuplasty, without other procedures associated. Nonetheless, this same patient had already been submitted to numerous previous surgeries to treat frontal CRS, always having local re-obstruction and recurrent symptoms. It may be that the failure of the sinuplasty is more associated with a possible incorrect and inaccurate indication than the technique and devices used. Three months after doing the sinuplasty, the patient had to be submitted to traditional EES (Draf III) to drain an abscess in the frontal sinus region.The other patient who underwent revision surgery using only sinuplasty in a region previously altered by EES, so far has improved on his symptoms and in the image exams (CT Scan), without alterations, even being the bearer of allergic characteristics.It is important to mention that in these allergic patients, even after doing sinuplasty, clinical treatment continues to be done with specific medication.Among the non-allergic patients submitted to sinuplasty, 1 had had chronic sinus disease for 6 months, after a dental implant - This patient had, upon CT scan, small bone-density images inside his right maxillary sinus and complete blurring of the same PNS and in his ipsilateral anterior ethmoidal region. These small images corresponded to fragments of the bone graft done by the dentist in order to elevate the maxillary sinus floor to anchor the dental implants .Figure 4In this patient, even after sinuplasty and exhaustive flushing of the maxillary cavity, with abundant oozing, we did a broad maxillary antrostomy, since the surgeon needed to be sure of the complete removal of all the bone fragments. After the broad antrostomy and visualization of the maxillary cavity with an angled endoscope, there was no need for further flushing to remove eventual residual bone fragments.In another patient without allergic disease, there was an important anatomical alteration (bullous middle turbinate) which would be a potential cause of right-side middle meatus obstruction and, consequently, obstruction to the drainage of the right-side frontal and maxillary sinuses. This patient was submitted to partial middle turbinectomy with removal of the meatal pars of the right-side middle turbinate and later right-side maxillary and frontal sinuplasty . It may Sinuplasty may be very interesting in patients who have problems concerning postoperative dressings, such as children and those with some type of mental impairmentNot removing tissue from the nose and paranasal sinuses can represent a major advantage, having seen that problems such as transitional postoperative changes in the nose and PNS mucociliary movements, scar fibrosis and subsequente local re-stenosis, synechia and postoperative bleeding are much less frequent in patients submitted to these dilatations, according to papers recently publishedWe noticed this in those patients who underwent sinuplasty without other associated procedures. In them, sinuplasty alone enabled opening the PNS drainage , postopeAll the patients were submitted to the procedures under general anesthesia, although recent publications discuss the possibility of doing sinuplasty procedures safely under local anesthesia in an outpatient basis, with or without sedationAs to surgery duration, it is important to stress that it is not only the surgical procedure time, but also the entire anesthesia time, taken from the charts which were filled out by the anesthesiologists in the operating rooms. We did not carry out any comparative study as to surgery duration in those patients who underwent conventional EES versus sinuplasty. However, we can say that the surgery time was shorter in the three patients who were submitted to sinuplasty alone, when compared to those whom, besides sinuplasty were also submitted to other concurrent surgical interventions, such as septoplasty and middle turbinectomy. Even then, the maximum time duration of the anesthesia for these procedures was of 120 minutes, which is similar to EES duration- in accordance with the literatureAlthough in the 10 patients of this series we were able to successfully catheterize and dilate all the PNS attempted, there were patients outside of this series in whom we were unable to catheterize the left frontal sinus because of anatomical and technical difficulties pertaining to the surgeon and the patient. In this case, a conventional EES was carried out. Some authors have also faced a similar problem, especially in cases of nasosinusal hypoplasiaAs to the reduced number of patients included, it is important to stress that this is a pioneering study in our country, with a device that is relatively new in the world and it was only approved in Brazil in 2009. There are similar reports in the literature, with an even lower number of patientsEach patient used a different set of dilatation balloons; however, when necessary, in the same patient, the same balloon was used in different PNSs. Although there are comparative cost analyses in the literature showing that the cost of sinuplasty is similar to that of conventional EES in the United StatesThere is a general consensus that the surgeries are indicated when there is maximal clinical treatment failure, or in special cases, with associated anatomical alterations. Surgery is carried out so that we can open the PNS ostia to promote ventilation, proper secretion drainage and penetration of topical medicationThere is no consensus on the size or shape of the PNS openings; nonetheless, we know that the ventilation and the use of topical medication are better with broader openings.In a recent publication, a group of researchers tried to identify the minimum size of the maxillary antrostomy so that both ventilation and topical medication were efficient. This size was of 3.96 mm in diameterIn a recent publication, a group of physicians assessed the long term results of the bullous middle turbinate treatment by only crushing the bullous component, without tissue removal. In most of the patients assessed who used this technique, the bullous component of the turbinate recurred. Although there is no evidence for such, the authors extrapolated the result for possible implications such as sinuplasty, theorizing that simple dilatation or crushing structures such as the agger-nasi could represent a temporary solutionAs far as symptoms are concerned, we did not use specific evaluation questionnaires concerning quality of life or symptoms. In our study, symptoms improving or worsening were based on the notes from the charts of the 10 patients who answered the questions of the physicians in outpatient visits.As to the patients who underwent other procedures in the same sinuplasty, 7 underwent septoplasty and one of them also underwent medium partial turbinectomy. These other procedures were previously indicated by the surgeons to correct septal deviations seen upon CT scans and also to help visualize the middle meatus region. All these patients had not undergone previous surgeries. On the 3 patients who underwent only sinuplasty, but not septoplasty, 2 had already been submitted to previous septoplasty and 1, despite a septal deviation, it was a 7-year-old child, did not undergo septoplasty.In these 10 patients who were submitted to sinuplasty alone or in combination with other techniques, after 7 months, 9 (90%) improved in their symptoms and in their exam images. The most frequent indication to use this new device was in patients with CRS, with or without allergies, not responsive to maximum clinical treatment.Sinuplasty was successfully carried out in all the patients, without major technical difficulties or intraoperative complications. We also did not notice post-operative complications. Nonetheless, the comparative analysis of the surgical time and costs was not carried out. This device can become an interesting alternative to the surgical treatment of some groups of patients, since it introduces a minimally invasive procedure which enables nasal and paranasal sinuses mucosa preservation. Nonetheless, prospective studies and case series studies are required, with a larger number of patients and longer follow up is necessary for a better understanding of the role of sinuplasty in the treatment of paranasal sinuses inflammatory diseases.


The aims of this study were to understand and to do a critical analysis of the different indigenous systems and practices of waste management to inform waste management policy development in Lesotho. To achieve these aims, the objective was to assess community perceptions of the impact of the indigenous systems and practices of solid waste management on the environment and human wellbeing. A simple random sampling method was employed. The primary data were collected through observations and survey questionnaires that were distributed among the communities in the study areas. The sample size was 693 participants from a total estimated population of 6917 in May 2021 in the Matsieng, Koro-Koro and Rothe constituencies. The data were analysed quantitatively by using the International Business Management Statistical Package for Social Science version 25.0. The descriptive method was used to interpret the results. For validity, the interview questions were set towards answering the study research questions. For reliability, open- and close-ended questions were designed. The research clearly indicated that indigenous systems and practices are culturally accepted in areas lacking formal waste collection services by the local authorities. The tradition, culture, values, and belief of the communities play a major role in the systems and practices implemented. Although some people convert waste items into useful products, the practices of general disposal were often unsafe from the human wellbeing and environmental perspectives. In Lesotho, a lack of awareness about conservation and sustainable use of natural resources could be attributed to flawed education at the grassroots level in schools. The Kingdom of Lesotho is a small, mountainous country that is surrounded by South Africa. The population stands at about 2.2 million people of which an estimated 60% live in rural areas. Maseru is the capital city with a population of about 120,000, of which an estimated 6917 reside in rural villages . FurtherHowever, waste management in Lesotho remains a challenge with indiscriminate dumping on roadsides, at markets and other public places being a common practice . The 2]2] has esThe knowledge gaps bridged by this study emphasize the connection between waste, the environment, health, and the Matsieng, Koro-Koro and Rothe constituencies’ (MKRC) communities. The gap in knowledge was identified to guide future policy development and improve health and wellbeing as it relates to individual rural areas. Seeman et al.  stated tIn this article, we describe the methodology employed in this study and pay special attention to explaining the methodological approach and the data collection. We explain the quantitative descriptive design, ethnographic design, and the direct observation design. We further discuss data collection and data analysis. Next, we present the results of the study and provide the discussion where we focus on the perceived understanding of the community on the indigenous practices of SWM in the MKRC, the impact of indigenous solid waste on the environment, and the impact of indigenous solid waste on human wellbeing. This is followed by types of solid waste generated in the MKRC. Next is gaps in knowledge and then conclusions.This paper builds on the paper by  which ouMap of the study country, Lesotho.Map illustrating some of the study areas indicated by arrows.We employed quantitative, qualitative and observations in this study. The primary data were collected with the assistance of four field workers and secondary data such as population estimates in the study areas were sourced from Lesotho government documents. From the internet, we accessed information on the description of the study country, the geographical location of the rural areas under investigation, and Lesotho demographics such as population, education, life expectancy at birth , povertyThis study employed quantitative descriptive, ethnographic, and direct observational designs and they are discussed below.To answer the research questions about the real-life situation in the rural communities of Maseru, a quantitative descriptive technique was used . The cloThe qualitative ethnographic method was applied because researchers wanted to interact with respondents in their real-life environment. The interaction assisted to gain acceptance from the community so that they would freely respond to the questions without any hesitation. Furthermore, we aimed to generate knowledge about the behaviours, social structures, and shared beliefs of the rural communities of Maseru, Lesotho. Semi-structured interviews were conducted to obtain detailed information about the participants’ personal feelings, perceptions, and opinions. Participants were observed during their daily activities. Their activities were assessed and critically analysed to understand their indigenous practices and systems of SWM. This method was chosen to investigate the background of the research problem and collect qualitative data necessary for an explanatory analysis of the sample used for the study.Direct observation refers to a research design where the researcher collects data by observing what the participants do but also being mindful to not alter their environment or activities . This isData were collected over a 40-day period between April and June 2021 and involved a questionnaire containing open- and close-ended questions, semi-structured interviews, and observations. Interviews were conducted during the week from Mondays to Fridays between 07:00 and 17:00 daily. Two additional focus group meetings involving ten  former employees of the Maseru City Council (MCC) with the knowledge of waste management from a government perspective. These meetings were called to fill the knowledge gap when authorities in the Ministry of Environment in Lesotho declined to participate. The former employees were recruited through WhatsApp invitations and the meeting was held at a local high school. We used the quantitative method to collect numerical data, and an Excel spreadsheet was used to record the transferred raw data obtained from the survey questions. Qualitative findings were expressed in words, and this approach was chosen to allow the researchers to interview participants one-on-one using semi-structured open-ended questions. Observations were chosen to observe participants’ behaviour in terms of their practices. Semi-structured interviews were chosen because it was necessary for the researchers to prepare the questions. Researcher should prepare questions that are relevant to the study, that will be understood by respondents and that will not consume time for both respondents and the researcher. Using these types of interview questions provided us with an opportunity to structure the questions in the format we preferred. The researcher worked towards a flexible structure and reliable qualitative data; therefore, the use of semi-structured open-ended interviews was an advantage. This study was conducted in Lesotho, and because of COVID-19 regulations, the researchers had to complete the data collection. To avoid multiple interview rounds, semi-structured interviews were conducted to gather detailed information using twelve questions. In this study, these types of questions were meant to subjectively analyse participants’ opinions in terms of how they understand indigenous SWM; seek participants’ opinions on translating useful ISPs into effective SWM; and understand participants’ opinions.For quantitative analysis, we checked for missing data, outliers were removed, and raw data were transformed into significant and understandable information using the following three steps: data validation, data editing, and data coding. Data were analysed in terms of ISPs of SWM. To communicate the results, a percentage was used to determine the number of respondents. For qualitative analysis, we focused on language, pictures, and observation. One-on-one interviews were transcribed, and a thematic analysis method was employed. Data were coded before identifying and reviewing the themes that were examined separately to gain an understanding of participants’ perceptions of ISPs of SWM and their motivations. We used the software International Business Management Statistical Package for Social Science version 25.0.The number of respondents indicated as the sample size relative to the population in the study area is indicated in For this section, the number of responses varied for each question as participants did not always answer all the questions. The first question (E1.1) with 463 responses asked whether waste is stored and the purpose of the storage. Six scenarios were provided for respondents to indicate their understanding on a Likert scale . Out of E1.1 explored people’s perception of the impact of indigenous SWM on the environment. The analysis asserts that the majority agreed or strongly agreed that they understand waste must be stored properly in buckets, bags, and other containers before its disposal. It is concluded that buckets and bags used to store waste before disposal are ideal for containing waste. These containers store waste that is intended to be used in the future; participants claimed they protect the waste from rain which can cause contaminated runoff. From the minority of participants who disagreed or strongly disagreed, it can be interpreted that they had limited knowledge of the usefulness of waste and how it can contaminate the environment if not properly managed. E1.2 stated, “People in this community store dry cow dung to use as fuel”. Responses confirm participants were from typical rural areas where people engage in farming and raise domestic animals such as cows, horses, sheep, and goats. A majority depended on their herd of cattle for sources of fuel. The minority could be members of the communities without domestic animals. Most of those who used cow dung for fuel lacked knowledge of the health implications of the smoke generated when cow dung is burnt, indicating they are susceptible to respiratory diseases. E1.3 sought responses to: “People in this community use cow dung to run a generator”. This analysis asserted that the rural communities use cow dung as a valuable source for cooking and heating their homes only, and not for any other purposes. It also means that they rely more on traditional resources than modern resources. E1.4 concerns itself with “People in this community store dry cow dung to light up their houses”. This analysis suggests that raw cow dung was not an ideal source of renewable energy. Alternative approaches, such as training the communities to convert cow dung into electricity, can benefit the MKRC communities. E1.5 stated: “People in this community store waste that is capable of being decomposed by bacteria to use as garden manure”. Most participants agreed or strongly agreed. It is evident that most participants understood waste cannot be converted into manure without the biological activity of microorganisms such as bacteria. This means they can distinguish between the types of waste capable of decomposing and that such waste cannot be disposed of anywhere; it can contaminate the environment if not disposed of safely. E1.6 relates to: “People in this community store waste that is not capable of being decomposed by bacteria to produce new items”. The analysis suggested that most community members did not consider waste as something that is unwanted but as an item that can be reused or converted to make new items. Conversely, the analysis asserted that the minority of participants who disagreed or strongly disagreed with this statement might be individualists who were conscious of the negative effects of rodent and cockroach infestations caused by the long-term storage of non-degradable waste. They would not like to have rodents and cockroaches in their homes as they transmit diseases to them and their families.No measurements, such as the weighing of waste, were made in the study areas because of a lack of equipment. Percentages obtained from government of Lesotho documents  are compThere is an understanding amongst the community members in the study areas that culture does not support the disposal of waste on the ground. This is evident from the responses of a majority who disagreed or strongly disagreed with this statement. This analysis asserted that for some members of the community, culture may be disappearing, so it is reasonable to encourage communities not to ignore their cultural beliefs and waste management practices because cultural beliefs have an influence on present waste disposal methods. In addition, cultural beliefs may contribute positively to alleviating indiscriminate waste disposal problems. Not everyone lived in proximity to natural resources. This analysis asserted that there were natural resources in the MKRC ancestral territories, but these were somehow exploited. It is clear then that there is a need to enhance environmental sustainability through interdisciplinary and multidimensional approaches such as cultural constructs, Furthermore, MKRC communities were not bonding with their natural resources, or they had limited natural resources that were accessible to a certain portion of community members. This analysis concluded that it is important to illustrate effective systems and practices of SWM through human interconnectedness, the environment, and sustainable development. Most community members still followed the footsteps of their ancestors when it came to waste management. It shows that most community members understand their culture, thus they continue observing their rituals.There were 464 respondents to the questions interrogating the culture and social systems in the study area. In response to the question if indigenous systems of managing solid waste in their area could be attributed to peoples’ cultural beliefs 62.5% agreed  while 24.6% disagreed  D1.1 in . On quesParticipants in the study areas indicated that they used waste items such as old tyres to make chairs , plasticWhen asked if waste disposal practices cause damage to the environment F1.1, , 464 parThe first question under this sub-category was whether a lack of knowledge of the consequences of poor SWM had increased the occurrence of infectious diseases. There were 463 responses, and 75.6% strongly agreed, 11.4% agreed, 4.1% were neutral, 1.7% disagreed, while 7.1% strongly disagreed. On the question of whether infectious diseases include those that are caused by various vectors such as rodents and mosquitoes, there were 464 responses, and 76.5% strongly agreed, 13.4% agreed, 9.3% were neutral, 0.6% disagreed, and 0.2% strongly disagreed. When participants were asked whether offensive odours from heaps of solid waste affect human beings, 464 responded, and 88.89% strongly agreed, 10.11% agreed, 0.6% were neutral, 0.2% disagreed, and 0.2% strongly disagreed. The last question was whether human health problems are caused by ignorant waste generators. There were 464 responses, 74.4% of which strongly agreed, 16.2% agreed, 7.3% were neutral, 0.2% disagreed, and 1.9% strongly disagreed. Lack of knowledge on the consequences of poor SWM has increased the occurrence of infectious diseases. This study revealed that communities generate infectious waste such as used nappies and waste from slaughtering animals. Infectious waste contributes to infectious disease through environmental and water contaminants as well as rats and mosquito infestations. Communities in the study areas are denied access to municipal services, some of which include health education on how best to handle solid waste to prevent the occurrence of infectious diseases. Infectious diseases include those that are caused by various vectors such as rodents and mosquitoes. When waste is disposed of improperly and remains there for a long time, the result is rodent and mosquito infestations. Rodents and mosquitoes transmit infectious diseases if not controlled or prevented. We suggest that many communities keep waste in one place for a long time, causing infectious diseases. As illustrated in Amongst the three analysed constituencies, Rothe was found to be the only one that did not have evidence of stored corrugated iron sheets, tyres, cow-dung and garden waste and the questions are: What do they do with these types of waste that they have generated? Is there a common place where they dispose of these types of waste that was not observed by the researcher during data collection? The most common heavy metals linked with the types of waste generated were from the highest to lowest: Lead (Pb) was found to be associated with a few wastes generated, followed by cadmium (Cd) and then copper (Cu) and zinc (Zn) with equal levels of concentration. Chromium (Cr) was followed by arsenic (As). Barium (Ba) and nickel (Ni) have equal levels of concentration in solid waste, then magnesium (Mg). The last four heavy metals with equal levels of concentration were mercury (Hg), silver (Ag), iron (Fe) and cobalt (Co). We did not find literature that links corn stalk with any of the heavy metals mentioned in this article. Corrugated iron sheet contains Cu, As and Zn . DorenfeWaste containing these heavy metals can contaminate water sources if disposed of in the landfill site; hence, there is a need to avoid landfill disposal of solid waste. It is clear therefore, that water bodies could be contaminated by the metals found in leachate. It is concluded that in the rural areas like MKRC where most community members are unemployed, there is small amounts of waste biodegradable waste generated, the leaching behaviour may not be easy to determine. It was observed during data collection that the type of household waste that is generated in the MKRC is not disposed of into the environment, but it is used to feed animals such as pigs, dogs, and cows. Pigs and dogs are fed from kitchen food waste while cows are fed from garden waste. Papers/card box are used to make fire for cooking; plastics are reused to neat hats, mats, and handbags. This explains that non-biodegradable waste in the rural areas of MKRC is not disposed of but used for various purposes. The study’s findings reflected 12 themes related to ISPs of SWM, and these are discussed as follows: Theme 1: Understanding ISPs of SWM—The findings show that, in general, people understand ISPs of SWM from cultural, norms and customs perspectives. People in their respective areas use various pathways to manage their waste including the implementation of a waste hierarchy (reusing and recycling) and local management systems and practices. This is consistent with what  wrote inTheme 2: Recognising ISPs of SWM in addressing local environmental issues—the findings reveal that in the study areas, there were different opinions, potentially attributed to individual levels of education and lack of understanding and knowledge of the impact caused by improper handling and disposal of solid waste. Participants indicated that some community members recognise ISPs of SWM in addressing local environmental issues, while this is not the case for others. However, this is inconsistent with what  found inTheme 3: Enhancing communal waste management—this study found that it is a common practice for many rural communities to engage in unsafe SWM practices. Common practices include digging holes in the backyards of homes, burning the waste, or disposing of waste in the streets. Participants indicated that each member of the community manages waste in the way most suitable for them unless the headmen instruct community members to engage in cleaning campaigns. Suitable methods include the collection of recyclable items such as bottles and aluminium cans, which are then sold to a recycling company at Ha Mantsebo in the outskirts of Maseru City. This is consistent with literature, where  referredTheme 4: Preventing the breeding of mosquitoes and other health problems—the findings show that where there were no municipal solid waste collection services, people dispose of the waste anywhere they find a space to do so and, in many cases, this becomes a source of mosquitoes, which then transmit diseases. The participants claimed that decomposed waste is a source of mosquito breeding, which causes certain health problems in humans. This is consistent with previous studies conducted by  who founTheme 5: Preventing bad smells from decomposed waste—a lack of municipal waste collection services results in bad smells emanating from decomposed waste. The participants confirmed there were no municipal solid waste removal services in their areas. A lack of municipal services accounts for unpleasant odours. This is consistent with what  stated iTheme 6: Converting waste into useful items—various items are recycled to produce new products. In other parts of the world, cast-offs are donated to destitute communities. The participants in the study areas indicated that they used waste items such as old tyres to convert them into chairs, plastic into hats, and animal skins into Basotho blankets, among others. There is consistency in these systems between the findings and observations in literature. Dorenfeld et al.  claimed Theme 7: Managing kitchen waste—in some African countries like Egypt, communities feed kitchen waste to animals, such as pigs and dogs. In some European countries, like Sweden, kitchen waste is disposed of in drains. The participants mentioned that waste from the kitchen is used to feed domestic animals such as pigs and dogs. In support, Azmat  indicateMusa paradisiaca Linn is valuable in healing wounds. The difference identified here is that this study’s participants explained ash is broadly used in treating diseases, while the literature confirmed the use of ash is specific to wound treatment. This study concludes that ash is an important resource for preventing and destroying garden and farm pests in certain countries across the globe. It is also a useful resource for treating unknown diseases. Theme 8: Translating useful ISPs into effective SWM—molora (ash) is mostly used for pest control in gardens and farms. In the study area, it is used for various purposes, including treating unknown diseases, as a symbol for death in the house, and others. To ensure sustainable vegetable production, waste items such as ash, bones, cans, and animal dung are added to what is referred to as “Lentloane”. This practice is employed in the study areas and by international organisations such as food and agricultural organisation’s UKaid and USAID. The participants reported that they had several ways in which they translated useful ISPs into effective SWM. The findings were based on both quantitative and qualitative methods of data collection on uses of molora (Ash), and they are as follows: As one of the ingredients to manufacture traditional paint for their homes; to destroy mafokololi (caterpillars) in the gardens or fields; applied to windows to symbolise a death in the house; applied to the human body to treat unknown skin diseases; it is spread on the skin of newly slaughtered animals to prevent flies. The thotobolo (ash heap) is used to accommodate a copper pole with forks to prevent lightning strikes. There is consistency in the use of molora for home gardens and agricultural farms between this study’s findings and literature. Ramraj and Ramsingh  explaineTheme 9: The disappearance of the ISPs of SWM—considering that there are no municipal waste collection services in all geographical areas, ISPs of solid waste will never disappear. The findings showed that ISPs in the MKRC will never disappear if there are no municipal waste collection services. Besides, the ISPs of SWM are culturally accepted. This is consistent with literature  on ruralTheme 10: Relevance of the ISPs of SWM for the conservation and sustainable use of natural resources—ISPs of SWM are relevant to conservation and the sustainable use of natural resources, but education on the topic at the grassroots level is flawed in schools. The findings showed that ISPs in the MKRC will never disappear if there are no municipal waste collection services. Besides, the ISPs of SWM are culturally accepted. This is consistent with literature  on ruralTheme 11: Facilitation of cheap, effective, and sustainable community environmental cleanliness—clean-up campaigns are cheap and can be participated in by everyone, young and old, men and women, from any private or public sector. They can be organised and implemented at any time during the year. The report  stated tTheme 12: Exhibition of cultural beliefs and values through the practice of the indigenous systems of SWM—the participants expressed their understanding of ISPs of SWM across all age groups. The participants referred to cultural mores, traditions, and practices as important parameters throughout the waste management process in their respective areas. It is evident from the findings of this study that communities in the study areas listen to their authorities (headmen) when instructed to participate in a cleaning campaign in their respective areas. This study’s emphasis on cultural mores is consistent with what transpired in the literature, where studies mentioned ISPs of SWM. Panta  referredThe knowledge gaps bridged by this study emphasize the connection between waste, the environment, health, and the MKRC communities. The gap in knowledge was identified to guide future policy development and improve health and wellbeing as it relates to individual rural areas. Gaps identified during the data collection in the MKRC include a lack of Waste Information Systems, a lack of health education on the proper management of waste, a lack of legislative frameworks that govern SWM, insufficient management of solid waste due to a lack of implementing existing laws and policies, negative impacts on human wellbeing and the environment. There were no previous studies found which could be used to provide solutions to help the MKRC communities overcome the barriers in their management of indigenous solid waste. Moreover, the rural communities on the outskirts of Maseru are not covered by The study’s findings reflected 12 themes related to ISPs of SWM, and these are summarized below. Theme 1: Understanding ISPs of SWM—the findings show that, in general, people understand ISPs of SWM from cultural, norms and customs perspectives. People in their respective areas use various pathways to manage their waste. Theme 2: Recognizing ISPs of SWM in addressing local environmental issues—the findings reveal that in the study areas, there were different opinions, potentially attributed to individuals’ level of education and lack of understanding and knowledge of the impact caused by improper handling and disposal of solid waste. Theme 3: Enhancing communal waste management—this study found that it is a common practice for many rural communities to engage in unsafe SWM practices. Common practices include digging holes in the backyards of homes, burning the waste or disposing of waste in the streets. Theme 4: Preventing the breeding of mosquitoes and other health problems—the findings show that where there were no municipal solid waste collection services, people dispose of the waste anywhere they find a space to do so and, in many cases, this becomes a source of mosquitoes, which then transmit diseases. Theme 5: Preventing bad smells from decomposed waste—a lack of municipal waste collection services results in bad smells emanating from decomposed waste. Theme 6: Converting waste into useful items—various items are recycled to produce new products. In other parts of the world, cast-offs are donated to destitute communities. Theme 7: Managing kitchen waste—in some African countries like Egypt, communities feed kitchen waste to animals, such as pigs and dogs. In some European countries, like Sweden, kitchen waste is disposed of in drains. Theme 8: Translating useful ISPs into effective SWM—molora (ash) is mostly used for pest control in gardens and farms. In the study area, it is used for various purposes, including treating unknown diseases, as a symbol for death in the house, and others. To ensure sustainable vegetable production, waste items such as ash, bones, cans, and animal dung are added to what is referred to as “Lentloane”. This practice is employed in the study areas and by international organizations such as food and agricultural organization, UKaid and USAID. Theme 9: The disappearance of the ISPs of SWM—considering that there are no municipal waste collection services in all geographical areas, ISPs of solid waste will never disappear. Theme 10: Relevance of the ISPs of SWM for the conservation and sustainable use of natural resources—the ISPs of SWM are relevant to conservation and the sustainable use of natural resources, but education on the topic at the grassroots level is flawed in schools. Theme 11: Facilitation of cheap, effective, and sustainable community environmental cleanliness—clean-up campaigns are cheap and can be participated in by everyone, young and old, men and women, from any private or public sector. They can be organised and implemented at any time during the year. Theme 12: Exhibition of cultural beliefs and values through the practice of the indigenous systems of SWM—exhibiting cultural beliefs and values by engaging in ISPs of SWM is an indication of shared collective values by a specific community. The ISPs of SWM will never disappear because, for indigenous communities, the practice is culturally accepted, people can manage it, and people do not have the support of municipal authorities for waste collection. The ISPs are relevant for conservation and the sustainable use of natural resources; however, basic education seems to be a can of worms. Therefore, the problem in the study areas is not ISPs of SWM, per se, but a lack of education and training to community members by authorities in Lesotho on how to engage positively in systems and practices of SWM. The environment can simultaneously be conserved and upheld through indigenous methods of waste management.A critical analysis of ISPs of SWM in the rural communities of Maseru, Lesotho, and its impact on the environment and human wellbeing is significant to identify appropriate control measures for the following reasons: There is a need for authorities in Lesotho to plan for SWM in the rural areas surrounding Maseru City. To help protect human wellbeing and land from pollution and degradation, regulatory measures  must be established to control the effects of inappropriate handling and disposal of solid waste in the MKRC. Current ISPs of waste disposal are inappropriate and may pose a threat to human health and the environment; appropriate waste management methods must be understood and adopted by all communities in the MKRC, and education on this topic should be provided, as the literacy rate is low in the study areas. Ultimately, appropriate SWM methods should be sustainable and benefit the MKRC communities in the long term. It is therefore important to investigate and use municipal by-laws since SWM tools may be relevant to address the issue of inappropriate systems and practices of SWM. The study will contribute information and knowledge towards rural planning in SWM and sustainable development in the MKRC. Newly developed rural municipal by-laws could be used to promote good waste management programmes that mitigate adverse effects on human wellbeing and the environment. Literature has shown that rural areas in Lesotho are not provided with municipal solid waste services; therefore, this study was the first research conducted to investigate whether municipal by-laws can be developed and implemented in the rural areas surrounding Maseru to offer alternative SWM systems and practices. This alternative could be achieved by incorporating the waste management hierarchy into ISPs. The analysis of the waste management systems in question will promote a valuable understanding of how ISPs of SWM could contribute to maintaining human wellbeing and the environment. Furthermore, to empower the MKRC communities, this study will provide insight and information on the process of ISPs so they can seek solutions for their problems. Using the results from this study, authorities in Lesotho may leverage findings to develop ISP improvement programmes by initiating cultural, values and belief factors that contribute to maintaining the traditional practices the MKRC communities prefer. Data collected from this study will be utilised to help policymakers in Lesotho make decisions on the most appropriate indigenous SWM systems and practices required according to the MKRC’s geographical location. The communities will be better equipped to accept that changes are needed to develop the rural areas in terms of SWM. They will also be encouraged to take the lead in rural policy development to ensure rural communities receive municipal waste collection services. This study may also benefit the MKRC communities by providing information on job creation opportunities, such as using stored waste to make new items; for example, plastic hats and chairs made from old tyres.


To create and validate a model for predicting septic or hypovolemic shockfrom easily obtainable variables collected from patients at admission to anintensive care unit.A predictive modeling study with concurrent cohort data was conducted in ahospital in the interior of northeastern Brazil. Patients aged 18 years orolder who were not using vasoactive drugs on the day of admission and werehospitalized from November 2020 to July 2021 were included. The DecisionTree, Random Forest, AdaBoost, Gradient Boosting and XGBoost classificationalgorithms were tested for use in building the model. The validation methodused was k-fold cross validation. The evaluation metrics used were recall,precision and area under the Receiver Operating Characteristic curve.A total of 720 patients were used to create and validate the model. Themodels showed high predictive capacity with areas under the ReceiverOperating Characteristic curve of 0.979; 0.999; 0.980; 0.998 and 1.00 forthe Decision Tree, Random Forest, AdaBoost, Gradient Boosting and XGBoostalgorithms, respectively.The predictive model created and validated showed a high ability to predictseptic and hypovolemic shock from the time of admission of patients to theintensive care unit. Earlyidentification of the condition and prompt initiation of treatment have been themost effective measures to reduce mortality associated with shock. However, the workdynamics in ICUs, especially when there is a high occupancy rate and a large numberof critically ill patients, can be a barrier to the identification of signs of shockwithin the ideal time window. This difficulty, often observed in routine ICUs, hasbeen a stimuli for the expressive growth of tools that can optimize time andresources to obtain better clinical results in patients in intensivecare.The evolution of a patient to shock is one of the main concerns of health teams inintensive care units (ICUs), as it represents one of the most frequent causes ofdeath in these units. Inaddition to the high death rate, the occurrence of septic shock is associated withthe development of physical and cognitive sequelae, resulting from a long stay inthe ICU, as well as a reduction in the quality of life with constanthospitalizations and a significant increase in health costs.,5 Hypovolemic shock, in turn, despite having lower overallmortality, is also a cause of death, especially in the ICUs of trauma hospitals,with a mortality rate approaching 19%.Septic shock may affect up to 35% of patients admitted to the ICU, and mortality inthese cases reaches 63%.,8 In individuals with sepsis and hypotension, forexample, the infusion of fluids results in improved perfusion and increased meanarterial pressure (MAP), whichmay reduce the chance of progression to in-hospital death by up to 2.7% for each 1%extra fluid administered, provided that the identification of the condition and theinitiation of treatment occur in a timely manner. Likewise, the immediate initiation of antibioticsin cases of sepsis significantly reduces the risk of death, as mortality ratesincrease by 10% for every hour of delay in starting treatment. These data demonstrate the needfor identification and prioritization in the surveillance of patients with highpotential for evolution to shock in ICUs, which can be strongly supported by a toolthat is easy to apply and with high accuracy.The infusion of intravenous fluids and the rapid initiation of antimicrobial therapyare considered effective in reducing the risk of evolution to shock in high-riskpatients. They are usedto predict several clinically relevant conditions, including sepsis and septicshock. However, themodels used to predict shock use a large number of variables, which are generallydifficult to obtain and may be difficult to reproduce in other scenarios. Some models use variables thatare more easily collected but are exclusive to the prediction of septic shock andwith predictor variables collected after patient admission. These characteristics make theapplication of these models in the daily clinical practice of ICUs limited due tothe lack of practicality and unavailability of data when necessary.The predictive models created from machine learning algorithms are used as a basisfor the creation of tools with increasing application in the health carefield.Thus, this study aimed to create and validate a model for predicting septic orhypovolemic shock with easily obtainable variables collected at admission frompatients admitted to the ICU. throughthe KoCoCollect Android app. The collected data were audited daily to avoid loss orerror in their collection or entry.This was a predictive modeling study conducted with data from patients admitted tothe ICU of a hospital located in the northeast region of Brazil. At the time of thestudy, the unit had 20 beds and received patients with various clinical and surgicalconditions. All patients aged 18 years or older who were not using vasoactive drugs(VAD) on the day of admission and were admitted to the ICU between November 2020 andJuly 2021 were included in the study. Patients are incomplete data for any of thevariables used in the study were excluded from the analyses. Data collection fromthe medical records was performed daily, from admission to discharge of the patientfrom the ICU, with the aid of a questionnaire prepared by the research team on theKoBoToolbox platform for the present study, shockwas assessed only by the use of VAD during hospitalization. This strategy wasused due to the absence of lactate levels for most patients. Although there isthe possibility of overestimating the number of patients with shock, the needfor VAD is an alert condition that can be avoided as long as it is signaled in atimely manner for the implementation of measures that can prevent shock. Thetarget variable consisted of a dichotomous variable, with yes or no values forthe use of VAD during hospitalization, except for admission.The occurrence of septic or hypovolemic shock was assessed using VAD,norepinephrine and/or vasopressin at some point during hospitalization in theICU. Although the definition of septic shock is the use of VAD to maintain MAPgreater than 65 mmHg and serum lactate greater than 2mmol/L, Patients with missing datawere excluded from the analyses. We chose not to perform data imputation becauseonly a small number of patients had missing data, with no impact on thepredictive capacity of the model.The mining step of the predictor variables was restricted to the data availableon the date of admission of the patient to the ICU, which resulted in theidentification of 12 variables: “age”, “presence of infection”, “use oforotracheal tube”, “use of urinary catheter”, “use of central venous catheter”,“use of catheter for invasive blood pressure monitoring”, “sedation”,“Simplified Acute Physiology Score III (SAPS)”, “temperature”, “systolic bloodpressure”, “comorbidities” and “heart rate”. The variables “temperature”,“systolic blood pressure” and “heart rate” were used as continuous variables,while the variable “SAPS” was categorized into ≤ 57 and > 57,according to a Brazilian study, in which the cutoff ratio of 57 showed bettersensitivity and specificity in predicting hospital mortality.For the construction of the model, the data were imported into the JupyterNotebook software, and the Pandas, Scikit-Learn and Matplotlib libraries of thePython language were used to create the model. The Decision Tree, Random Forest,AdaBoost, Gradient Boosting and XGBoost algorithms were tested in the search forthe best result in the prediction of septic and hypovolemic shock. Otheralgorithms, such as artificial neural networks and logistic regression, weretested and presented inferior results with precision and recall less than 60%,while tree-based algorithms presented results greater than 80% in the evaluationmetrics.k-fold cross validation method wasused. In this method, the database was subdivided into five datasets. In each ofthe five validations, a different part of the model was randomly chosen torepresent the test group, and the rest of the data formed part of the trainingset. The final evaluation metrics are the arithmetic means of the five resultsobtained at the end of each validation. Although the dataset is not unbalanced,we chose not to use accuracy; therefore, the metrics of recall, precision andarea under the curve were used (AUC) Receiver Operating Characteristic (ROC) formodel evaluation. These metrics were chosen with the aim of reducing the numberof false-positives, given the severity of the condition to be detected, as wellas false negatives, to reduce the possibility of inadequate allocation ofresources in the ICU.For model validation, the Universidade Federal da Bahia, Multidisciplinary Instituteof Health - Campus Anísio Teixeira, under number38332720.4.0000.5556. The application of the Free and Informed Consent Form(ICF) was waived as all information was collected from the medical records andwith minimal risk to patients.This study was approved by the Research Ethics Committee of theA total of 731 patients met the study inclusion criteria, of whom 11 were excludedbecause they had missing data on one or more predictor variables, which resulted inthe inclusion of 720 patients for the analyses. The demographic data and generalcharacteristics of the study population are described in recall and thus the lowestnumber of false negatives were observed with the Gradient Boostingand XGBoost algorithms. The evaluation metrics of the models aredescribed in Among the models compared, the best XGBoost algorithm presented better performancewhen considering the three evaluation metrics, with an ASC-ROC of 1.00. Theimportance of the variables for the predictive model was measured by calculating themean and standard deviation of the decrease in impurity in each generated tree usingthe attribute feature importance. The variables that most contributed to theprediction in this algorithm were infection, urinary catheter, orotrachealintubation and temperature; the importance of the variables for the model isdescribed in The model with the Based on easy-to-obtain data, we developed and validated a prediction model that wasable to correctly classify 99% of patients who would progress to septic orhypovolemic shock at some point during their stay in the ICU.The direct correlation between the time of onset of symptoms, introduction oftherapeutic actions and mortality associated with shock is a concept widelydisseminated among intensive care teams. However, in the routine of an ICU, it isnot uncommon for there to be a delay in the identification of the initial signs ofshock and in the triggering of the set of measures that can reduce the chance ofevolution to death. This delay may be related to both work overload and failures inthe planning and systematization of care. Consequently, despite knowing when and howto act, the ideal time for diagnosis can be missed. Among the main potentials of ourshock prediction model is its possibility of application as a support tool in theorganization of the care process in the ICU, such as in defining the number andinterval of nursing visits to the bed of a patient, based on his or her risk ofevolution to shock, as well as the expansion of infectious surveillance, withmonitoring of temperature, WBC and C-reactive protein, in addition to constantreview of antimicrobial therapy, with escalation, when necessary. Thus, theidentification of a patient at risk of shock appears to be essential for theinitiation of fluid resuscitation, which results in improved patient outcomes anddecreases the risk of late hypotension. However, such conduct should be performedwith caution so that there is no water overload or harm to critically illpatients. Therefore,the model that we validated in the present study may be valuable input for thedecision-making of the care team about vigorous hydration of a patient in the ICU,even before the onset of the initial signs of hypotension or shock.Fluid administration is one of the main interventions for increasing tissue perfusionand reducing the progression to shock. This measure is used not only to avoid septicshock but also hypovolemic shock. Although the definition of the best fluid to beused remains under discussion, there is already sufficient evidence demonstratingthat the earlier the infusion, the better the patient outcomes. Intravenous fluidtherapy in patients who have sepsis without shock was responsible for the increasein MAP and was associated with shorter mechanical ventilation and ICUstay.Thus, the development of a prediction model composed of a reduced number of easilyobtainable variables allows its reproduction in other hospitals, including thosewith limited resources.Some models have been proposed for the prediction of sepsis and septic shock in theICU. However, these models have reproducibility limitations, mainly due to theirdependence on a large set of variables. Some models include up to 20 differentvariables, some of which are impractical to obtain in the usual routine of an ICU,such as fibrinogen levels. Although asignificant percentage of patients require VAD at the beginning of hospitalization,those who experience shock after the first 48 hours remain in the ICU for a longerperiod of time. Therefore, ourmodel has the widest application potential and the possibility of contributing tothe reduction of ICU length of stay.A predictive model for the use of VAD, which also uses easily obtainable variables,was recently developed. However, its prediction concerns the use of vasopressorswithin 24 hours after ICU admission to aid in the initial management of thesepatients, as the predictors were vital signs that are usually available before ICUadmission.machine learning algorithmsto create predictive models in the health care field is about the interpretabilityof these tools. A model isconsidered interpretable when its decision-making process is easilyexplainable. The bestmodel for predicting septic and hypovolemic shock in the present study was achievedusing the XGBoost algorithm, a poorly interpretable algorithm. However, thevariables used in our model are known to be associated with shock, and therefore,although the model is difficult to understand, the included variables make the modeleasily understandable for the end user in the decision-making process. Thischaracteristic expands the possibility of practical application of the modelvalidated in this study.A recent discussion regarding the use of Our study has some limitations. One of them was the use of VAD alone to define shockdue to the lack of serum lactate values; therefore, the number of patients withshock may be overestimated. However, the use of VAD already characterizes a scenariowith the need for greater monitoring and care. Another limitation of our study isthe number of patients included in the model. However, because it was aprospectively fed database with constant auditing of the data, there was a minimalloss of information, which resulted in variables with a high degree of completenessand, consequently, a reduction in the potential for bias produced by the size of thepopulation studied. Likewise, the values obtained in the evaluation metrics suggestthat the number of patients did not affect the performance of the model. In additionto the number of patients included, because this was a single-center study, it isnot possible to say that our model can be applied to other ICUs. Therefore, it willbe necessary to test its accuracy in different scenarios until it can be applied asa tool to support decision-making.The creation and validation of a predictive model based on an XGBoost classificationalgorithm showed high accuracy in predicting septic and hypovolemic shock from themoment of admission of patients to the intensive care unit based on variables thatcan be easily collected. This tool has the potential for application in the dailypractice of intensive care teams as support for the organization of the care processto reduce the chance of evolution to shock in patients admitted to the intensivecare unit. In addition, the model can be easily used to develop an application thatcan be accessed by professionals during their work routines.


The course of the COVID-19 pandemic has given rise to many disease trends at various population scales, ranging from local to global. Understanding these trends and the epidemiological phenomena that lead to the changing dynamics associated with disease progression is critical for public health officials and the global community to rein in further spread of this and other virulent diseases. Classic epidemiological modeling based on dynamical systems are powerful tools used for modeling and understanding diseases, but often necessitate modifications to the classic compartmental models to reflect empirical observations. In this paper, we present a collection of extensions to the classic SIRS model to support public health decisions associated with viral pandemics. Specifically, we present models that reflect different levels of disease severity among infected individuals, capture the effect of vaccination on different population groups, capture the effect of different vaccines with different levels of effectiveness, and model the impact of a vaccine with varying number of doses. Further, our mathematical models support the investigation of a pandemic’s trend under the emergence of new variants and the associated reduction in vaccine effectiveness. Our models are supported through numerical simulations, which we use to illustrate phenomena that have been observed in the COVID-19 pandemic. Our findings also confirm observations that the mild infectious group accounts for the majority of infected individuals, and that prompt immunization results in weaker pandemic waves across all levels of infection as well as a lower number of disease-caused deaths. Finally, using our models, we demonstrate that, when dealing with a single variant and having access to a highly effective vaccine, a three-dose vaccine has a strong ability to reduce the infectious population. However, when a new variant with higher transmissibility and lower vaccine efficiency emerges, it becomes the dominant circulating variant, as was observed in the recent emergence of the Omicron variant. The COVID-19 pandemic has brought into focus the importance of being able to predict the trajectory of viral pandemics, and how such forecasts can be valuable in guiding public health policies. Over the course of the past few years, the world has grappled with numerous challenges associated with the SARS-CoV-2 coronavirus , and looking back reveals a plethora of unfortunate scenarios where public health officials struggled with difficult challenges, ranging from the lack of sufficient resources in public hospital systems, to the importance of testing kits for detecting and identifying patients and “carriers” of COVID-19, and to the emergence of many different variants of the original COVID-19 virus. This latter scenario is perhaps one of the most disconcerting, as it causes public health officials to worry whether the waves of COVID-19 will continue in perpetuity, potentially requiring significant investment in public health infrastructures, as the SARS-CoV-2 virus has evolved through numerous mutational variants that have demonstrated more potent disease pathology. It further highlights the importance of being able to create forecasts that go beyond a single disease variant, but that can capture the dynamics and competition between variants.After two years following the onset of the pandemic, the global health community has been able to amass significant data regarding the impact that COVID-19 has had locally and globally on public health. There are now numerous reports and articles analyzing the pandemic trends, which have explored different approaches to understand the pandemic’s trajectory. Mathematical modeling has been quite useful in illustrating what the world has experienced over the past two years and predicting what the future of the pandemic might look like.In this paper, we first explore various aspects of the pandemic that have been analyzed and interpreted using COVID-19 transmission dynamics modeling. This includes models that study the disease’s severity level, explore the emergence of new variants, investigate the impact of vaccination strategies, and those that explore the impact of different social behaviors, such as social distancing and lockdown, on the pandemic trends ,11,12.Afterwards, we use the epidemiology of COVID-19 to develop a collection of compartmental mathematical models that illustrate the pandemic’s trend and anticipate its trajectory for different situations. The models we present can be helpful in illustrating potential disease trajectories that might arise in different scenarios and to predict the pandemic’s trend based on the status of vaccination efforts and the emergence of variants of concern.The remainder of the paper is organized as follows. In In this section, we survey a collection of papers that provide extensions to classic compartmental models and explore various aspects of the COVID-19 pandemic to anticipate the disease’s trajectory. The papers in this section were chosen for their similarities in using epidemiological modeling to investigate pandemic trends, as well as for their differences in the specific aspects of the pandemic they studied.The authors in  estimateIn , the autThe authors in  extend tTo capture the durability of immunity, the authors in  offer a Another SEIR-based model extension is presented in  in whichThe authors in  simulateIn , the autThe authors in  modify aIn another example of modifying classic models, the authors of  provide In , the autIn a different approach, the authors in  use an aIn the first extension, we present a model with three different infectious compartments, each representing a different severity level for the disease. Using empirical data associated with the early phase of the COVID-19 pandemic, in which patients experiencing milder disease recovered from infection quicker than more severe cases, we show through simulations that most infections will be mild, although mildly infected individuals retain less durable resistance post-recovery. The recovered patients in this model and all of our other extensions are assumed to return to the susceptible compartment, in contrast to , which aIn our second extension, we build upon the first model to arrive at a model that includes multiple compartments for varying levels of disease severity, as well as a protected compartment to represent individuals who have been vaccinated. We assume different vaccine effectiveness across different disease severity levels. Further, we include a time-dependent vaccination rate in our model to account for the effect of vaccination initiation time on the pandemic trajectory. Our model and results support the observation that early vaccination reduces the severity of pandemic waves across all severity levels of infection.The third extension we present models a vaccination strategy that uses multiple vaccines with varying availability and immunization efficacy, and shows through simulations that vaccine availability and distribution is a major contributor to the timing and peak of the second wave and subsequent waves of the pandemic. This model offers the epidemiologist a tool to explore the impact that additional investments in vaccine production and distribution can have on the progression of the disease through the population.The fourth extension includes separate compartments for vaccinated and unvaccinated individuals and is designed to reflect immunization with multiple vaccine doses. This model allows one to explore scenarios in which the population receives varying amounts of vaccine doses, such as occurred with the Pfizer and Moderna mRNA vaccines. The concept of having multiple compartments for different susceptible groups based on their immunization status is similar to ,5. HowevFinally, our fifth model extension accounts for the emergence of new variants with different levels of transmissibility and vaccine effectiveness. We utilize recent data for the Delta and Omicron variants of COVID-19, and show through simulations that the more transmissible and less-severe Omicron variant, which provides cross-reactive humoral immunity to the Delta variant, will ultimately become the dominant variant. This model provides a mathematical tool for the public health community to explore the dynamics that might arise in the competition between variants.In this paper, we present multiple extensions to the SIRS epidemiological model that can be used to investigate COVID-19’s trajectory, and which allow an epidemiologist to examine varying aspects related to a disease’s trajectory. Unlike the above-mentioned papers, which present a single model and approach, we start from a baseline mathematical model and demonstrate how one can introduce different compartments and population flows within the model to examine aspects of the pandemic’s behavior. We present five different models in this paper and employ these models to investigate various questions about the pandemic’s trajectory:In the following sections, we first review the classic SIR and SIRS models and examine how they estimate COVID-19’s trends; afterwards, we present our collection of SIRS extensions, which facilitate investigating the COVID-19 trajectory across different aspects of the disease. These factors include the severity of the disease, the effectiveness of multi-dose immunization, and the impact of emerging new variants, but they exclude age and social distancing policies. We note that our model can be extended to include specific subpopulations, such as the elderly or those with pre-existing conditions, by introducing a separate population subcompartment for that particular demographic.S, I, and R. t. S to the infectious class I with the rate of R with the rate of A series of papers by Kermack and McKendrick ,15,16 inHowever, in many viral infections, the permanent immunity assumed in the SIR model is not always accurate for a variety of reasons, including virus mutation and waning immunity. Therefore, in this paper, we adopt the SIRS model as our starting point, shown in N. In other words, the initial value for the fraction individuals that are infectious is I. We also assume that the remainder of the population is totally susceptible; thus, the initial value for the fractional susceptible is In this section, we provide simulation results for the classic SIR and SIRS models in which the underlying rate parameters have been tailored to match the early phase of the COVID-19 pandemic (when there was a single variant). We assume a constant population of ν=5 days ,5,18, wiyears in ,5. Moreoyears in , 1 year Over the course of the COVID-19 pandemic, the medical and public health communities have been able to identify many characteristics associated with the virus’s pandemic behavior that we were not aware of originally, and which warrant inclusion into epidemiological models. For example, since the start of the pandemic, we are now cognizant of the importance that asymptomatic infectious individuals have upon disease spread, the challenges associated with the development and deployment of multiple vaccines with various levels of efficacy and durability, as well as the emergence of new variants with higher transmissibility.These and other observations necessitate introducing tailored extensions to the classic SIRS model in order to reflect and explore the more complex dynamics associated with each phenomenon. In the following sections, we present a variety of extensions to the classic SIRS model.Our first extension to the classic SIRS model aims to introduce modifications that allow for a mathematical model that reflects different levels of disease severity. In S) is in contact with any infectious individual , they may become infected with varying levels of severity. We assume that an individual contracts COVID to become an asymptomatic carrier of the disease with a rate of For the model depicted in D corresponding to a deceased subpopulation.In the figure, we depict the entire population of infected individuals For members of the asymptomatic subgroup An estimation of 29%  of early29% , it was orted in . However 18 days .The simulation results for our extended SIRS model, which incorporates three levels of disease severity, is shown in The availability of vaccines has been one of the most successful tools used for protecting public health and in preventing the spread of many diseases. Therefore, it is natural to explore how the availability of vaccines can be incorporated into epidemiological models.The next extension to the SIRS model that we present is depicted in Equation , which iOther forms of Because vaccination confers a temporary protection, we include an outflow of people from the vaccinated subgroup to return to the susceptible compartment. This outflow is captured by the rate parameter The following set of differential equations represents the dynamical system associated with this model: Throughout most of the remainder of this paper, discussion involving vaccines and a vaccinated subpopulation will primarily draw upon early data associated with the Pfizer-BioNTech and Moderna mRNA vaccines, and the single-dose Janssen (Johnson & Johnson) vector virus vaccine against the wild type COVID-19 variant. When it is necessary for the discussion to examine questions related to disease variants and booster administration, we will utilize more recent vaccine data and will clearly reference the newer data and assumptions.We will draw upon early-stage data regarding the efficacy of different vaccines in preventing disease corresponding to the manufacturers’ results involving a comparison between a placebo arm and vaccinated arm of a clinical trial. The Moderna vaccine has a nfection , while tefficacy , and theefficacy . While [efficacy ,26,27 prefficacy  that thevaccine,  reports y study,  reports In We were interested in exploring the potential impact that earlier or later vaccination could have had on the population dynamics. In order to facilitate this, the third, fourth, fifth, and sixth rows of the figure are zoomed in to focus on the second and subsequent waves of the pandemic. A comparison of panels a, b, and c shows that early immunization would result in weaker pandemic waves in all levels of the infection. The effect of vaccination initiation on the number of deaths is then compared in I and suppose that susceptible individuals are immunized at variable rates with either of the two accessible vaccines In our next SIRS-based extension, we model the effect of deploying a vaccination strategy that employs multiple vaccines of varying immunization efficacy and durability, as depicted in The dynamics of this model is represented by the set of equations below: Extensions to this model that involve more than two vaccines are straightforward.We were interested in understanding the impact that employing more than a single vaccine type could have on the disease trajectory. We used infection parameters and vaccine-related parameters specified in Over the course of the pandemic, one of the major questions that the public health community has been facing is centered on how and when multiple doses should be deployed for the Pfizer and Moderna mRNA vaccines. In particular, initial deployments involved a two-dosage strategy, which eventually was updated to three doses for select subgroups of the population . Questions, such as when to initiate the third dose, and the implications should a third dose reduce the availability for first and second shots, have been at the forefront of the public health discussion.To examine such questions, in this section, we extend the SIRS model to capture immunization with multiple doses, while including separate compartments for vaccinated and unvaccinated individuals. Equation  to incluThis model reflects the efficacy of each dose of the vaccine  is monitoring 12 variants, which include the most recent two, Delta and Omicron, which are variants of concern . Therefo variant .The dynamics of this model is represented by the set of equations below: In addition to the assumptions for the wild type variant provided in gh as 10 . Moreovegh as 10 , we assuThe simulation results for our modified SIRS model with two variants, and employing a vaccine with different effectiveness against each variant, are shown in fections , we can In this paper, we explored a variety of aspects associated with the COVID-19 pandemic through the lens of epidemiological modeling. This survey includes models that study the severity of the disease, those that explore the emergence of new variants, those that investigate the impacts of vaccination strategies, and those that look into the impact of different social behaviors on pandemic trends, such as social distancing and lockdowns. Building upon the methods presented in our survey, we proposed a collection of useful compartmental models that extend the classical SIRS model, allowing to further analyze the dynamics that arise in the presence of different levels of disease severity, capturing the effects of vaccinations on different subgroups of infected populations, as well as different vaccines with different levels of effectiveness, modeling the impact of a vaccine strategy involving multiple doses, yielding progressively-enhanced effectiveness and durability, allowing one to investigate pandemic trends as new variants emerge, in combination with a corresponding decrease in vaccine effectiveness to emergent variants. We used publicly available real-world data and applied parameters associated with the wild type variant for many of our models, as early pandemic data are now widely available. Further, for our studies related to multiple co-existing variants, we used specifications for the newer Delta and Omicron variants of concern. In our simulations, we also assumed vaccine data from Moderna, Pfizer, and Janssen. When the natural immunity interval is short, our simulated results show that a steady-state condition will arise in which a fraction of the population is consistently infected. Our findings also show that mild infectious groups make up the majority of infected people, and that early immunization causes pandemic waves to be weaker across all illness severity levels, and the number of disease-caused deaths to be lower. Our results also show that a three-dose vaccine has a strong chance of reducing the infectious population when dealing with a single variant and having access to a highly efficient vaccine. When a new variant with lower vaccination efficacy emerges, however, it quickly becomes the dominant circulating variant, which is consistent with observations associated with the Omicron variant out-competing the Delta variant. Finally, we should note that the models that we have presented are quite flexible and can allow the public health modeler to explore many problems that were not directly examined in this paper. Notably, evolving trends in vaccination efforts, such as the impact of vaccine saturation and hesitancy on how the disease propagates through a population, can be explored using simple modifications to our compartmental models.