Video Versus Direct Laryngoscopy for Intubation: Updated Systematic Review and Meta-Analysis

Direct laryngoscopy (DL) is a modality commonly used in endotracheal intubation (EI). Video laryngoscopy (VL) was introduced to further facilitate the procedure with enhancement in glottic views, which captures the video image of the vocal cords to be projected onto a screen, providing enhanced visualization. This real-time video projection aids in accurately placing the endotracheal tube (ETT) through the vocal cords. In emergency and critical care settings, both laryngoscopes are used for intubations. This study assesses the efficacy of both modalities by comparing success rates in first-attempt tracheal intubation in critically ill patients.  PubMed, EMBASE, and Scopus were searched and all randomized controlled trials (RCTs) and observational studies until 2023 were included. Studies included patients in critical care settings undergoing EI under the guidance of either DL or VL. The primary outcome was the first attempt at successful tracheal intubation. The secondary outcomes assessed the comparative safety of DL and VL by comparing the rates of severe hypoxemia, severe hypotension, and cardiac arrest occurring during each modality. P-values were considered of statistical significance if below 0.05. Statistical analysis was performed using RevMan v5.4 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). The results were displayed in the form of forest plots.  A total of eight studies were included with a total of 5348 patients, with 1780 in the DL group and 3568 in the VL group. Analysis revealed that in emergency situations, the success rate of intubation on the first attempt was significantly higher for VL than DL [81.5% vs 68%; RR= 1.19; 95% CI: 1.10, 1.29; p <0.00001; I2=70%]. There was no significant correlation between VL and severe hypoxemia [13.4% vs 11.6%; RR= 0.99; 95% CI: 0.74, 1.33; p =0.97; I2=46%], severe hypotension [6.09% vs 4.78%; RR:1.19; 95% CI: 0.83, 1.72; p =0.35, I2-15%], and cardiac arrest, [0.8% vs 0.4%; RR= 1.17; 95% CI: 0.37, 3.70]; p =0.79; I2=0%]. Our meta-analysis confirmed that VL has a higher success rate for first-pass intubation than DL. Furthermore, our analysis has shown no significant evidence linking VL to any adverse events.