Lewis SR, et al. – This study assessed videolaryngoscopy versus direct laryngoscopy for tracheal intubation in adults, focusing mainly on intubation failure and complications. Researchers found no evidence suggestive of the ability of videolaryngoscopes in attenuating the number of intubation attempts or the incidence of hypoxia or respiratory complications or influencing the time required for intubation, nevertheless, videolaryngoscopes showed potential to reduce the number of failed intubations, particularly among patients presenting with a difficult airway and laryngeal/airway trauma via improving the glottic view.

Methods

• Researchers searched CENTRAL, MEDLINE, Embase and clinicaltrials.gov up to February 2015, and conducted forward and backward citation tracking.
• They included randomized controlled trials that compared adult patients undergoing laryngoscopy with videolaryngoscopy or Macintosh laryngoscopy.
• They did not primarily intend to compare individual videolaryngoscopes.  

Results

• This analysis included 64 studies (7044 participants).
• It was demonstrated in moderate quality evidence that videolaryngoscopy reduced failed intubations (Odds Ratio (OR) 0.35, 95% Confidence Interval (CI) 0.19-0.65) including in participants with anticipated difficult airways (OR 0.28, 95% CI 0.15-0.55).
• Researchers found no evidence of reduction in hypoxia or mortality, but few studies reported these outcomes.
• They noted that videolaryngoscopes reduced laryngeal/airway trauma (OR 0.68, 95% CI 0.48-0.96) and hoarseness (OR 0.57, 95% CI 0.36-0.88).
• Furthermore, they found that videolaryngoscopy increased easy laryngeal views (OR 6.77, 95% CI 4.17-10.98) and reduced difficult views (OR 0.18, 95% CI 0.13-0.27) and intubation difficulty, typically using an ‘intubation difficulty score’ (OR 7.13, 95% CI 3.12-16.31).
• Data reported that failed intubations were reduced with experienced operators (OR 0.32, 95% CI 0.13-0.75) but not with inexperienced users.
• Researchers identified no difference in number of first attempts and incidence of sore throat.
• Heterogeneity around time for intubation data prevented meta-analysis.
• They found evidence of differential performance between different videolaryngoscope designs.
• As per observations, lack of data prevented analysis of impact of obesity or clinical location on failed intubation rates.