Comparison of Intubating Conditions Between Direct Laryngoscopy and C-MAC Video-laryngoscopy in Patients With Simulated Cervical Spine Immobilization: A Systematic Review and Meta-analysis.

Intubation of patients requiring cervical spine immobilization can be challenging. Recently, the use of C-MAC video laryngoscopes (VL) has increased in popularity over direct laryngoscopy (DL). We aimed to conduct a systematic review and meta-analysis to evaluate the efficacy of C-MAC VL as compared with DL for intubation in C-spine immobilized patients. A systematic search of electronic databases, including PubMed, Cochrane Library, Embase, and Web of Science was performed. Time taken to intubate was the primary outcome whereas the use of optimization maneuvers, laryngoscopy view, first-pass success rates, and difficulty of intubation were secondary outcomes. Seven trials involving 490 patients were included in the analysis. There was no significant difference between the 2 groups in terms of time taken to intubate, standardized mean difference 0.65 (95% CI, -2.55, 3.86). The certainty of evidence for the primary outcome, time taken to intubate, was low, with high heterogeneity (I 2 =97%). The C-MAC VL group had higher first-pass success rates (odds ratio 2.92 [95% CI, 1.14, 7.49]) and a lower incidence of a poor laryngoscopy view (odds ratio 0.21 [95% CI, 0.07, 0.66]). There was no difference in terms of the difficulty of intubation and the use of optimization maneuvers. Overall, C-MAC VL did not reduce the time taken to intubate, although the strength of this finding is limited by wide confidence intervals. C-MAC VL significantly improved laryngoscopy views and first-pass success rate as compared with DL.