全麻诱导期头高15°斜坡位对无通气安全时限的影响

Effect of 15°Head-up Tilt Position during Pre-oxygenation and Induction of General Anaesthesia on Duration of non-hypoxic Apnoea

目的观察全麻诱导期头高15°斜坡体位能否延长无通气安全时限。方法择期全麻患者40例,随机分为头高位组(T组)和对照组(C组),每组20例。T组采取头高15°斜坡位,C组采取去枕平卧位。诱导前2min开始面罩吸入纯氧,静脉诱导插管,诱导期间不采用辅助或控制通气,记录无通气安全时限(呼吸停止至SpO2降至90%)后再机械通气。记录入室后、诱导后、插管后、SpO2降至90%时的血压(mmHg)、心率(b/m);分别于吸氧2min时、SpO2降至90%时抽血行血气分析;术中观察胃胀气情况。结果T组无通气安全时限为(562.3±96.6)s,C组为(462.0±136.1)s,二者有显著差异(<0.05)。动脉血气分析、心率、血压变化无统计学差异。2组均无胃胀气发生。结论全麻诱导期采取头高15°斜坡位,可以延长无通气安全时限。

Objective To observe the effect of the 15° head-up tilt position during pre-oxygenation and induction of anaes- thesia upon the duration ofnon-hypoxic apnoea. Methods Forty patients undergoing general anesthesia were randomly divided into two groups, group T and group C （control, N=20 each）. Patients in group T were in a 15° head-up tilt position,while patients in group C in supine position. All patients breathed spontaneously before and during induction without control or assistant ventilation. Two minutes before intravenous induction, patients began to inhale 100% O2 via face mask continuously. After induction and intubation, all patients were not ventilated until SpO2 decreased to 90%. The duration ofnon-hypoxic apnoea （from breath stopping to SpO2 of 90%） was recorded. Blood pressure and heart rate were monitored before oxygen inhalation, after induction, after intubation and at the time of SpO2 reaching 90%, respectively. Arterial blood gas analysis was performed before induction（after 2 min of oxygen inhalation） and at the time of SpO2 to 90%. Stomach inflation was judged by surgeon during operation. Results The duration ofnonhypoxic apnoea was significantly longer in group T than that in group C （562.3±96.6s vs. 462.0±136. Is, P〈0.05）. No statistical difference in arterial blood gas analysis was found between the two groups. The blood pressure and heart rate in the two groups were similar, and no stomach inflation occurred in any case of the two. Conelusion The application o fthe 15 o head-up tilt position during induction of anesthesia prolongs the safe duration ofnon-hypoxic apnoea without side-effects.