Brimacombe J, Keller C
Department of Anaesthesia and Intensive Care, University of Queensland, Cairns Base Hospital, Australia. 100236,
Acta Anaesthesiol Scand. 2000 Nov;44(10):1258-60. doi: 10.1034/j.1399-6576.2000.441012.x.
We test the hypothesis that oropharyngeal leak pressure (OLP) and fibreoptic position (FP) are stable for the laryngeal mask airway (LMA) during anaesthesia with and without nitrous oxide.
Forty paralysed anaesthetised patients (ASA 1-2, aged 18-80) were randomly allocated to receive 100% oxygen (O2 group) or 33% oxygen in nitrous oxide (O2-N2O group) for maintenance. In vivo intracuff pressure (CP) using a size 5 LMA was adjusted to 60 cm H2O. OLP, FP and CP were measured every 5 min for 30 min.
CP was higher in the O2-N2O group than the O2 group, other than at time zero (all: P<0.0001). CP increased every 5 min in the O2-N2O group (all: P<0.0001), but not in the O2 group. There were no differences in OLP and FP between groups at any time. There were no significant changes in OLP or FP with time within each group. There were no changes in OLP greater than 1.5 cm H2O and no change in FP for any patient.
We conclude that OLP and FP are stable for the LMA during anaesthesia lasting 30 min with or without nitrous oxide.
我们检验了以下假设，即在有和没有氧化亚氮的麻醉过程中，口咽漏气压（OLP）和纤维光学位置（FP）对于喉罩气道（LMA）是稳定的。
40例麻痹的麻醉患者（ASA 1-2级，年龄18-80岁）被随机分配接受100%氧气（O2组）或33%氧气与氧化亚氮混合气体（O2-N2O组）进行维持麻醉。使用5号LMA时，将体内套囊压力（CP）调整至60 cm H2O。每隔5分钟测量一次OLP、FP和CP，共测量30分钟。
除了在时间零点外，O2-N2O组的CP高于O2组（所有情况：P<0.0001）。O2-N2O组的CP每隔5分钟升高（所有情况：P<0.0001），但O2组没有。两组在任何时间的OLP和FP均无差异。每组内OLP或FP随时间均无显著变化。任何患者的OLP变化均不超过1.5 cm H2O，FP也无变化。
我们得出结论，在持续30分钟的麻醉过程中，无论有无氧化亚氮，LMA的OLP和FP都是稳定的。
