Acute kidney injury in stable COPD and at exacerbation.
BACKGROUND
While acute kidney injury (AKI) alone is associated with increased mortality, the incidence of hospital admission with AKI among stable and exacerbating COPD patients and the effect of concurrent AKI at COPD exacerbation on mortality is not known.


METHODS
A total of 189,561 individuals with COPD were identified from the Clinical Practice Research Datalink. Using Poisson and logistic regressions, we explored which factors predicted admission for AKI (identified in Hospital Episode Statistics) in this COPD cohort and concomitant AKI at a hospitalization for COPD exacerbation. Using survival analysis, we investigated the effect of concurrent AKI at exacerbation on mortality (n=36,107) and identified confounding factors.


RESULTS
The incidence of AKI in the total COPD cohort was 128/100,000 person-years. The prevalence of concomitant AKI at exacerbation was 1.9%, and the mortality rate in patients with AKI at exacerbation was 521/1,000 person-years. Male sex, older age, and lower glomerular filtration rate predicted higher risk of AKI or death. There was a 1.80 fold (95% confidence interval: 1.61, 2.03) increase in adjusted mortality within the first 6 months post COPD exacerbation in patients suffering from AKI and COPD exacerbation compared to those who were AKI free.


CONCLUSION
In comparison to previous studies on general populations and hospitalizations, the incidence and prevalence of AKI is relatively high in COPD patients. Coexisting AKI at exacerbation is prognostic of poor outcome.
['Barakat|M F|MF|', 'McDonald|H I|HI|', 'Collier|T J|TJ|', 'Smeeth|L|L|', 'Nitsch|D|D|', 'Quint|J K|JK|']
D058186:Acute Kidney Injury D000368:Aged D000369:Aged, 80 and over D016208:Databases, Factual D018450:Disease Progression D005260:Female D005919:Glomerular Filtration Rate D006760:Hospitalization D006801:Humans D015994:Incidence D053208:Kaplan-Meier Estimate D016015:Logistic Models D008297:Male D008875:Middle Aged D015999:Multivariate Analysis D011379:Prognosis D029424:Pulmonary Disease, Chronic Obstructive D012189:Retrospective Studies D012307:Risk Factors D012720:Severity of Illness Index D012737:Sex Factors D006113:United Kingdom
mortality acute renal failure chronic bronchitis emphysema prognosis