Department of Women's Anesthesia, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, 229899, Singapore.
Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
BMC Anesthesiol. 2020 Aug 26;20(1):213. doi: 10.1186/s12871-020-01132-5.
Pregnancy is associated with higher incidence of failed endotracheal intubation and is exacerbated by labor. However, the influence of labor on airway outcomes with laryngeal mask airway (LMA) for cesarean delivery is unknown.
This is a secondary analysis of a prospective cohort study on LMA use during cesarean delivery. Healthy parturients who fasted > 4 h undergoing Category 2 or 3 cesarean delivery with Supreme™ LMA (sLMA) under general anesthesia were included. We excluded parturients with BMI > 35 kg/m, gastroesophageal reflux disease, or potentially difficult airway (Mallampati score of 4, upper respiratory tract or neck pathology). Anesthesia and airway management reflected clinical standard at the study center. After rapid sequence induction and cricoid pressure, sLMA was inserted as per manufacturer's recommendations. Our primary outcome was time to effective ventilation (time from when sLMA was picked up until appearance of end-tidal carbon dioxide capnography), and secondary outcomes include first-attempt insertion failure, oxygen saturation, ventilation parameters, mucosal trauma, pulmonary aspiration, and Apgar scores. Differences between labor status were tested using Student's t-test, Mann-Whitney U test, or Fisher's exact test, as appropriate. Quantitative associations between labor status and outcomes were determined using univariate logistic regression analysis.
Data from 584 parturients were analyzed, with 37.8% in labor. Labor did not significantly affect time to effective ventilation (mean (SD) for labor: 16.0 (5.75) seconds; no labor: 15.3 (3.35); mean difference: -0.65 (95%CI: - 1.49 to 0.18); p = 0.1262). However, labor was associated with increased first-attempt insertion failure and blood on sLMA surface. No reduction in oxygen saturation or pulmonary aspiration was noted.
Although no significant increase in time to effective ventilation was noted, labor may increase the number of insertion attempts and oropharyngeal trauma with sLMA use for cesarean delivery in parturients at low risk of difficult airway. Future studies should investigate the effects of labor on LMA use in high risk parturients.
The study was prospectively registered at clinicaltrials.gov ( NCT02026882 ) on 3 January 2014.
妊娠与更高的气管插管失败发生率相关，并因分娩而加重。然而，分娩对剖宫产时喉罩（LMA）气道结果的影响尚不清楚。
这是一项关于剖宫产时使用 LMA 的前瞻性队列研究的二次分析。纳入禁食>4 小时、接受全身麻醉下 Supreme™ LMA（sLMA）行 2 类或 3 类剖宫产的健康产妇。我们排除了 BMI>35kg/m2、胃食管反流病或潜在困难气道（Mallampati 评分 4 分、上呼吸道或颈部病变）的产妇。麻醉和气道管理反映了研究中心的临床标准。快速序列诱导和环状软骨加压后，按照制造商的建议插入 sLMA。我们的主要结局是有效通气的时间（从拿起 sLMA 到出现呼气末二氧化碳描记术的时间），次要结局包括首次插入失败、氧饱和度、通气参数、黏膜创伤、肺吸入和 Apgar 评分。使用 Student's t 检验、Mann-Whitney U 检验或 Fisher's 确切检验测试分娩状态之间的差异，具体取决于情况。使用单变量逻辑回归分析确定分娩状态与结局之间的定量关联。
共分析了 584 名产妇的数据，其中 37.8%处于分娩状态。分娩并未显著影响有效通气的时间（分娩时的平均值（SD）为 16.0（5.75）秒；无分娩时为 15.3（3.35）秒；平均差异：-0.65（95%CI：-1.49 至 0.18）；p=0.1262）。然而，分娩与首次尝试插入失败和 sLMA 表面有血有关。未观察到氧饱和度或肺吸入减少。
尽管没有观察到有效通气时间的显著增加，但在低困难气道风险的产妇中，分娩可能会增加 sLMA 用于剖宫产时的插入尝试次数和口咽创伤。未来的研究应调查分娩对高危产妇 LMA 使用的影响。
该研究于 2014 年 1 月 3 日在 clinicaltrials.gov（NCT02026882）前瞻性注册。
