Our team has conducted a thorough analysis and meta-study of research papers published from 2013 to 2023. This study aims to compare the first-pass success rates of video and direct laryngoscopy techniques in endotracheal intubation procedures. Our analysis included five randomized controlled trials (RCTs) and three observational studies. Airway management in critically ill individuals in non-operative settings presents significant challenges and is frequently associated with potentially life-threatening complications. Notably, the incidence of difficult endotracheal intubations in the intensive care unit (ICU) surpasses that observed in the operating room. The prevalence of challenging intubations in critically ill patients ranges from 10% to 22% [11]
Furthermore, tracheal intubation is one of the most frequently conducted procedures within the intensive care unit (ICU). Video laryngoscopes are recommended to enhance airway management within the ICU. There is an emerging suggestion that video laryngoscopes can mitigate the incidence of challenging intubation [12]. The occurrence of difficult intubations was studied through a comprehensive analysis of eight studies that shared a common PICO. The studies included 3036 patients and compared the success rate of the first attempt between video and direct laryngoscopy. We also looked into the potential adverse effects of both techniques across all the studies included. In 2013, De Jong conducted a study on 70 patients, which showed that video laryngoscopy had a higher success rate than direct laryngoscopy, with 55 patients experiencing a successful first pass. The study also found some adverse effects, such as severe hypoxemia (RR of 2.25 [0.91,5.58]), severe hypotension (RR of 1.50 [0.54,4.16]), and cardiac arrest (RR of 0.28 [0.01,5.42][13]. A study by Lakticova in 2015 reported a first-pass success rate of 199 out of 252 patients, with a relative risk (RR) of 1.47 [1.25, 1.74]. The study also noted severe hypoxemia with an RR of 1.85 [0.91, 3.79] and severe hypotension of 2.22 [0.76, 6.52]. However, no data was provided on cardiac arrest.[14] Silverberg M published a study in 2015 that reported a first-pass success rate of RR 1.80[1.27, 2.55], a severe hypoxemia RR of 0.42[0.09, 2.08], and a severe hypotension RR of 0.79[0.29, 2.13]. However, no data was reported on cardiac arrest.[15]. Two studies were conducted in 2016. The first study, led by Janz D, had a first-pass success rate of 58 out of 74 patients. The RR ratios were as follows: 1.10 [0.90, 1.33] for severe hypoxemia, 0.90 [0.47, 1.71] for severe hypotension, and 1.03 [0.07, 16.12] for cardiac arrest.[16]. The second study, led by Hypes C, reported a first-pass success RR of 1.23 [1.08, 1.40]. The RR ratios for severe hypoxemia and severe hypotension were 0.70 [0.51, 0.98] and 1.81 [0.79, 4.11], respectively. No data was available regarding cardiac arrest.[17]. A study conducted in 2017 by Lascarrou J.B. reported a first pass rate with RR 0.96 [0.84, 1.10]. The study also looked at the incidence of severe hypoxemia with RR 0.99 [0.55, 1.79], severe hypotension with RR 1.99 [0.61, 6.49], and cardiac arrest with RR 8.85 [0.48, 163.28].[18] In 2023, two additional RCT studies were published. The first study by Prekker M. E. et.al (1) reported a first-pass success rate with an RR of 1.15 [1.08, 1.23] but did not provide any data for severe hypoxemia, hypotension, or cardiac arrest.[19] The second study by Prekker M. E. et.al (2) reported a first-pass success rate with an RR of 1.20 [1.14, 1.27]. Additionally, the study reported an RR of 0.94 [0.68, 1.30] for severe hypoxemia, an RR of 0.71 [0.41, 1.24] for severe hypotension, and an RR of 1.10 [0.20, 4.99] for cardiac arrest. These findings were presented in Study [6]
We analyzed data from eight studies using Review Manager (version 5.3; Copenhagen) to determine the success rate of intubation using video laryngoscopy versus direct laryngoscopy as the primary outcome. The results showed a 95% confidence interval of 1.191 (1.10, 1.21) with a p-value < 0.00001, indicating moderate heterogeneity (I2 = 70%). Figure 1 confirms that video laryngoscopy had a higher success rate than direct laryngoscopy. Our study analyzed seven research papers focusing on severe hypoxemia as a secondary outcome, and concluded that the use of video laryngoscopy (VL) or direct laryngoscopy (DL) has no significant impact on severe hypoxemia. The results showed a non-significant trend, with a 95% confidence interval of 0.99 [0.74, 1.33] and a p-value of 0.97, as presented in Figure 2. We also examined severe hypotension across the same seven studies, and found no significant difference, with a 95% confidence interval of 1.19 [0.83, 1.72] and a p-value of 0.35. However, there was a minimal level of heterogeneity with I2 at 0%. Based on our analysis, it seems that using VL or DL has no significant impact on severe hypotension, as shown in Figure 3.
We also investigated the prevalence of cardiac arrest as a secondary outcome by examining four research papers, including three randomized controlled trials and one observational study. The results showed a slight decrease in the incidence of cardiac arrest with the use of VL, although this decrease was not statistically significant. The confidence interval was 1.17 [0.37, 3.70], and the p-value was 0.79. It is worth noting that there was no observed heterogeneity. Our findings indicate that the use of VL or DL has no effect on cardiac arrest since the results were not statistically significant.
Based on our thorough analysis, we recommend using video laryngoscopy as it has displayed a much higher success rate on the initial attempt. Our analysis suggests that there is no significant correlation between using VL or DL and the adverse effects of severe hypoxemia, hypotension, and cardiac arrest, as all the forest plots for these adverse events were non-significant.
Limitation:
This meta-analysis is subject to several limitations that should be considered when interpreting the findings. Firstly, the included studies exhibited heterogeneity, which may have influenced the overall results. Variations in study settings, types of laryngoscopes used and patient characteristics could have contributed to this heterogeneity, potentially affecting the generalizability of the findings. It is crucial to highlight that the likelihood of bias in the studies that were incorporated could significantly affect the precision of the results. The assessment of study quality revealed varying degrees of methodological limitations and potential sources of bias, which may have influenced the overall outcomes. Thirdly, the assessment of publication bias indicated the potential for selective reporting and publication of studies, introducing the possibility of bias into the overall conclusions. Unpublished studies or those with negative results may be missing from the analysis, potentially affecting the overall findings. Lastly, the generalizability of the findings is limited to critically ill patients and emergency orotracheal intubation settings. The results may not be directly applicable to other patient populations or non-emergency intubations. Further research is needed to address these limitations and provide more comprehensive insights into the effectiveness and safety of video laryngoscopy versus direct laryngoscopy in diverse clinical scenarios.