A randomised comparison of C-MAC™ and King Vision® videolaryngoscopes with direct laryngoscopy in 180 obstetric patients

Abstract

Background: Current evidence suggests that there is uncertainty about which videolaryngoscope performs best in obstetric anaesthesia. The aim of this study was to compare C-MAC and King Vision® videolaryngoscopes and direct laryngoscopy for tracheal intubation of patients undergoing caesarean section.

Methods: One hundred and eighty women were randomly assigned. The primary outcome was the time to tracheal intubation. Secondary outcomes were the time to the best laryngeal view, grade of Cormack and Lehane view, overall and first-pass success, intubation difficulty, the number of intubation attempts and optimisation manoeuvres; and complications.

Results: The time to successful intubation, first-pass and overall success rates did not differ between the devices. The difficulty of intubation was less for C-MAC than King Vision® (P <0.001). No difference was observed between King Vision® and direct laryngoscopy (P=0.06) or C-MAC and direct laryngoscopy (P=0.05). King Vision® required the longest time to best laryngeal view (9 ± 6 s, P=0.028), had the highest rate of grade 1 view (47 (80%) patients, P <0.001), and the highest need for optimisation manoeuvres (59 (100%) patients, P <0.0001). Five minor complications were recorded with King Vision® and one with direct laryngoscopy.

Conclusions: Compared to direct laryngoscopy, C-MAC and King Vision® did not prolong the time to intubation, supporting these videolaryngoscopes as primary intubation devices in obstetric anaesthesia. The C-MAC was easier to use and needed fewer additional manoeuvres than the King Vision®. The C-MAC may be better suited for tracheal intubation of obstetric patients undergoing caesarean section.

Keywords: Anaesthesia; Caesarean section; Intubation; Obstetric; Videolaryngoscope.