Abdelgadir Ibtihal S, Phillips Robert S, Singh Davinder, Moncreiff Michael P, Lumsden Joanne L
Paediatrics, Sidra Medical and Research Center, PO Box 26999, Doha, Qatar.
Centre for Reviews and Dissemination, University of York, York, UK, YO10 5DD.
Cochrane Database Syst Rev. 2017 May 24;5(5):CD011413. doi: 10.1002/14651858.CD011413.pub2.
Direct laryngoscopy is the method currently used for tracheal intubation in children. It occasionally offers unexpectedly poor laryngeal views. Indirect laryngoscopy involves visualizing the vocal cords by means other than obtaining a direct sight, with the potential to improve outcomes. We reviewed the current available literature and performed a meta-analysis to compare direct versus indirect laryngoscopy, or videolaryngoscopy, with regards to efficacy and adverse effects.
To assess the efficacy of indirect laryngoscopy, or videolaryngoscopy, versus direct laryngoscopy for intubation of children with regards to intubation time, number of attempts at intubation, and adverse haemodynamic responses to endotracheal intubation. We also assessed other adverse responses to intubation, such as trauma to oral, pharyngeal, and laryngeal structures, and we assessed vocal cord view scores.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and trial registers (www.clinicaltrials.gov and www.controlledtrials) in November 2015. We reran the search in January 2017. We added new studies of potential interest to a list of 'Studies awaiting classification' and will incorporate them into formal review findings during the review update. We performed reference checking and citation searching and contacted the authors of unpublished data to ask for more information. We applied no language restrictions.
We included only randomized controlled trials. Participants were children aged 28 days to 18 years. Investigators performed intubations using any type of indirect laryngoscopes, or videolaryngoscopes, versus direct laryngoscopes.
We used Cochrane standard methodological procedures. Two review authors independently reviewed titles, extracted data, and assessed risk of bias.
We included 12 studies (803 children) in this review and meta-analysis. We identified three studies that are awaiting classification and two ongoing studies.Trial results show that a longer intubation time was required when indirect laryngoscopy, or videolaryngoscopy, was used instead of direct laryngoscopy (12 trials; n = 798; mean difference (MD) 5.49 seconds, 95% confidence interval (CI) 1.37 to 9.60; I = 90%; very low-quality evidence). Researchers found no significant differences between direct and indirect laryngoscopy on assessment of success of the first attempt at intubation (11 trials; n = 749; risk ratio (RR) 0.96, 95% CI 0.91 to 1.02; I = 67%; low-quality evidence) and observed that unsuccessful intubation (five trials; n = 263) was significantly increased in the indirect laryngoscopy, or videolaryngoscopy, group (RR 4.93, 95% CI 1.33 to 18.31; I = 0%; low-quality evidence). Five studies reported the effect of intubation on oxygen saturation (n = 272; very low-quality evidence). Five children had desaturation during intubation: one from the direct laryngoscopy group and four from the indirect laryngoscopy, or videolaryngoscopy, group.Two studies (n = 100) reported other haemodynamic responses to intubation (very low-quality evidence). One study reported a significant increase in heart rate five minutes after intubation in the indirect laryngoscopy group (P = 0.007); the other study found that the heart rate change in the direct laryngoscopy group was significantly less than the heart rate change in the indirect laryngoscopy, or videolaryngoscopy, group (P < 0.001). A total of five studies (n = 244; very low-quality evidence) looked at evidence of trauma resulting from intubation. Investigators reported that only two children from the direct laryngoscopy group had trauma compared with no children in the indirect laryngoscopy, or videolaryngoscopy, group.Use of indirect laryngoscopy, or videolaryngoscopy, improved the percentage of glottic opening (five trials; n = 256). Studies noted no significant difference in Cormack and Lehane score (C&L) grade 1 (three trials; n = 190; RR 1.06, 95% CI 0.93 to 1.21; I = 59%).
AUTHORS' CONCLUSIONS: Evidence suggests that indirect laryngoscopy, or videolaryngoscopy, leads to prolonged intubation time with an increased rate of intubation failure when compared with direct laryngoscopy (very low-quality evidence due to imprecision, inconsistency, and study limitations). Review authors had difficulty reaching conclusions on adverse haemodynamic responses and other adverse effects of intubation, as only a few children were reported to have these outcomes. Use of indirect laryngoscopy, or videolaryngoscopy, might lead to improved vocal cord view, but marked heterogeneity between studies made it difficult for review authors to reach conclusions on this outcome.
直接喉镜检查是目前用于儿童气管插管的方法。它偶尔会出现意想不到的不佳喉镜视野。间接喉镜检查是通过非直接直视的方式观察声带，有可能改善插管结果。我们回顾了当前可用的文献，并进行了一项荟萃分析，以比较直接喉镜检查与间接喉镜检查或视频喉镜检查在有效性和不良反应方面的差异。
评估间接喉镜检查或视频喉镜检查与直接喉镜检查在儿童插管方面的有效性，包括插管时间、插管尝试次数以及气管插管时的不良血流动力学反应。我们还评估了插管的其他不良反应，如口腔、咽部和喉部结构的创伤，并评估了声带视野评分。
我们于2015年11月检索了Cochrane对照试验中心注册库（CENTRAL）、MEDLINE、Embase、护理及相关健康文献累积索引（CINAHL）以及试验注册库（www.clinicaltrials.gov和www.controlledtrials）。我们在2017年1月重新进行了检索。我们将潜在感兴趣的新研究添加到“待分类研究”列表中，并将在更新综述时将其纳入正式的综述结果中。我们进行了参考文献核对和引文检索，并联系了未发表数据的作者以获取更多信息。我们未设语言限制。
我们仅纳入随机对照试验。参与者为年龄在28天至18岁的儿童。研究者使用任何类型的间接喉镜或视频喉镜与直接喉镜进行插管操作。
我们采用Cochrane标准方法程序。两位综述作者独立审阅标题、提取数据并评估偏倚风险。
我们在本综述和荟萃分析中纳入了12项研究（803名儿童）。我们确定了3项等待分类的研究和2项正在进行的研究。试验结果表明，使用间接喉镜检查或视频喉镜检查而非直接喉镜检查时，需要更长的插管时间（12项试验；n = 798；平均差异（MD）5.49秒，95%置信区间（CI）1.37至9.60；I² = 90%；极低质量证据）。研究人员发现，在评估首次插管成功率方面，直接喉镜检查和间接喉镜检查之间无显著差异（11项试验；n = 749；风险比（RR）0.96，95% CI 0.91至1.02；I² = 67%；低质量证据），并且观察到间接喉镜检查或视频喉镜检查组的插管失败率显著增加（5项试验；n = 263）（RR 4.93，95% CI 1.33至18.31；I² = 0%；低质量证据）。5项研究报告了插管对血氧饱和度的影响（n = 272；极低质量证据）。5名儿童在插管过程中出现血氧饱和度下降：1名来自直接喉镜检查组，4名来自间接喉镜检查或视频喉镜检查组。2项研究（n = 100）报告了插管的其他血流动力学反应（极低质量证据）。一项研究报告间接喉镜检查组在插管后5分钟心率显著增加（P = 0.007）；另一项研究发现直接喉镜检查组的心率变化显著小于间接喉镜检查或视频喉镜检查组（P < 0.001）。共有5项研究（n = 244；极低质量证据）观察了插管导致创伤的证据。研究人员报告，直接喉镜检查组仅有2名儿童出现创伤，而间接喉镜检查或视频喉镜检查组无儿童出现创伤。使用间接喉镜检查或视频喉镜检查可提高声门开放百分比（5项试验；n = 256）。研究指出，在Cormack和Lehane评分（C&L）1级方面无显著差异（3项试验；n = 190；RR 1.06，95% CI 0.93至1.21；I² = 59%）。
有证据表明，与直接喉镜检查相比，间接喉镜检查或视频喉镜检查会导致插管时间延长且插管失败率增加（由于不精确、不一致和研究局限性，证据质量极低）。综述作者难以就血流动力学不良反应和插管的其他不良反应得出结论，因为仅有少数儿童报告出现这些结果。使用间接喉镜检查或视频喉镜检查可能会改善声带视野，但研究之间存在明显异质性，使得综述作者难以就此结果得出结论。
