Ventilation by mask before and after the administration of XXXX : a pragmatic non-inferiority trial.

@entity1 @entity4094 @entity30147
BACKGROUND: Test ventilating prior to administration of @entity4094 ( @entity4094 ) in order to avoid a cannot intubate-cannot ventilate situation is a classic anesthesia teaching. The primary aim of our study was to show that facemask ventilation ( @entity30147 ) after @entity4094 was not inferior to @entity30147 prior to @entity4094 with respect to exhaled gas volumes before and after their administration. METHODS: This study was approved by the University of Washington @entity1 Subjects Division (Seattle, Washington, USA). Written informed consent was obtained from all @entity1 . Measurements of tidal volume (Vte) as well as other respiratory parameters during @entity30147 were made for 60 s after induction of anesthesia and again after @entity4094 . Difficult, impossible, inadequate, and dead-space only mask ventilation was graded using published definitions. Difficult intubation was defined as >2 attempts at intubation. The primary outcome was non-inferiority in Vte during both study periods defined as a mean difference of <50 mL. Multivariate analysis was performed to assess for interaction between operator experience, @entity1 risk factors for difficult mask ventilation, exhaled volumes, and use of airway adjuncts. RESULTS: Two-hundred and ten @entity1 were studied. Overall, @entity30147 improved after NMBD. The mean (SD) Vte in mL/breath increased from 399 (169) to 428 (166) (mean dif. 30 mL, p   =   0.001) and the minute ventilation in L/min from 5.6 (2.5) to 6.3 (2.5) (mean dif. 0.6, p   <   0.001). No @entity1 who was difficult to ventilate after induction became impossible after @entity4094 . DISCUSSION: In @entity1 at risk for or judged to be a difficult @entity30147 by clinical grading scales, tidal volumes improved after administration of NMBDs. None of these @entity1 exhibited a decline in ventilation or became impossible to ventilate after NMBDs. Several limitations are noted, including the use of hand-delivered breaths and inability to account for time-related changes in ventilation conditions independent of NMBDs. CONCLUSION: We conclude that @entity30147 is no worse after @entity4094 than before and is likely to improve airway conditions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02237443 . Registered August 28, 2014.
