///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Primary Choice of Laryngoscopy Blade & Risk of Difficult Intubation in Parturients undergoing Cesarean Delivery

Abstract Number: T2A-170
Abstract Type: Original Research

Broughton Kirbie MD1 ; Justin Morello MD2; Allison Clark MD3; Andrew King n/a4; Bobby Nossaman MD5

Introduction: Securing the parturient airway in a safe and timely manner is essential during general anesthesia for cesarean delivery. The goal of any therapeutic intervention is to increase the probability of success or decrease the probability of harm. These probabilities are expressed as ratios or as risks in which the outcome event is compared in one or more groups (1). The purpose of this study was to calculate the odds ratios and relative risk of difficult intubation during primary laryngoscopy with the use of three commonly available laryngoscopy blades: Miller, Macintosh, or videolaryngoscope. Difficult intubation is defined as more than two attempts at securing the maternal airway or an exchange to a different airway tool during this process (2).

Methods: Following institutional review board approval, data from 468 electronic medical records in parturients undergoing general anesthesia for cesarean delivery were extracted over a 6-year period. Key associations, odds ratios, and relative risks included 95% confidence intervals (CI). The role of these blades used during primary laryngoscopy on the incidence of modified Cormack-Lehane views and on the incidence of difficult intubation were analysed with statistical tests set at the more stringent P<.005 value to minimize the risk of false discovery rates (3,4).

Results: The incidence of difficult intubation was 4.2% (CI 2.7-6.5%) with three failed intubations recorded (airways managed with LMA or mask ventilation). When the modified Cormack-Lehane views observed during primary laryngoscopy were grouped into III & IV versus I & II cohorts; there were no significant differences in the incidence of difficult laryngoscopic views (II I& IV) provided by the type of blade (Macintosh: 4 CI 2-9%; Miller: 6 CI 3-10%; Videolaryngoscopy: 4 CI 2-10%; P=.7738). However, odds ratios and relative risks for difficult intubation were dependent on the type of blade used during primary laryngoscopy (Table 1).

Discussion: This analysis suggests that although similar incidences of modified Cormack-Lehane III & IV laryngoscopic views were provided by these three blades; Miller blade laryngoscopy provided the lowest odds ratio and relative risk for difficult intubation during general anesthesia for cesarean delivery.


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SOAP 2019