无痛分娩|海拔会影响笑气镇痛效果吗?

发布于 2021-09-06 06:49

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本文由“小麻哥的日常”授权转载

摘要译文

高海拔和低海拔地区中氧化亚氮用于分娩镇痛的多中心研究

背景：

氧化亚氮（N2O）作为止痛剂在全国范围内的临床中广泛使用。虽然神经轴镇痛仍然是美国最常用的分娩镇痛方式，但分娩中N2O的使用比例正在增加。鉴于较高海拔处气体分压降低，据报道N2O的镇痛性能也降低。然而，目前还没有研究评估海拔高度对N2O分娩镇痛效果的影响。

方法：

我们对4个医疗机构在3年期间收集的N2O登记进行了多中心回顾性数据分析。我们比较了海拔高度对50%N2O用于分娩镇痛效果的影响，更改为另一种镇痛方式的比率，副作用发生率和更改镇痛方案的预测因子。多变量回归模型用于比较高海拔和低海拔产妇的临床特征和结果，同时调整种族、教育和年龄进行分类和定量结果的逻辑回归和线性回归。

结果：

共有1856名分娩产妇（年龄18-50岁）被纳入分析。

从50%的N2O更改为另一种镇痛方式的几率在高海拔和低海拔医疗机构之间没有统计学上的显著差异（调整后的比值比[aOR]，1.13；95%置信区间[CI]，0.90-1.42；P=0.3）。

然而，与高原产妇相比，当产妇在低海拔地区转化为N2O时，他们更有可能（aOR，3.03；95%CI，1.59-5.88）选择神经轴镇痛代替其他镇痛方式。这可能是由于低海拔地区的硬膜外镇痛比例较高。

与低海拔产妇相比，当高海拔地区的产妇确实转换为另一种镇痛方式时，他们更有可能【aOR，2.19；95%可信区间（1.14-4.21】因疼痛缓解不足而转换；然而，缺失的数据可能影响了这一发现。

在低海拔地区分娩的个体更容易出现副作用（aOR，2.13；95%可信区间，1.45-3.12）。

在高海拔组和低海拔组中，需要增加产程、辅助阴道分娩或剖宫产的产妇转为神经轴镇痛的频率明显高于通过自然阴道分娩的产妇（P<0.05）。

结论：

这是首次评估50%N2O作为高原分娩镇痛剂的研究。正如预期的那样，我们在高海拔地区N2O镇痛副作用较低，可能是由于N2O分压较低。然而，在高海拔地区，从N2O到另一种镇痛方式的转化率没有统计学上的显著增加，新生儿结局也没有临床上的显著差异。

重点词汇释义

Use for作……用

has been已经

neuraxial轴索的

United States美国; 美利坚合众国; 依宪法而联合起来的州的总称

there is有

in labor分娩，临产

partial pressure分压；部分压力

data analysis数据分析;

原文摘要

Multicenter StudyEvaluating Nitrous Oxide Use for Labor Analgesia at High- and Low-AltitudeInstitutions

Background: Nitrousoxide (N2O) has been used nationally as an analgesic in many clinical settings.While neuraxial analgesia is still the most commonly used labor analgesic inthe United States, there is increasing use of N2O in labor. Given the reductionin the partial pressure of gases at a higher altitude, N2O has been reported tohave reduced analgesic properties. However, there is no study to dateevaluating the impact of altitude on labor analgesia and N2O.

Methods: Weconducted a multicenter retrospective data analysis of a N2O registry collectedfrom 4 institutions over a 3-year period. We compared the impact of altitude on50% N2O administration for labor analgesia, conversion rates to anotheranalgesic modality, as well as collected side effect frequencies and conversionpredictors. Multivariable regression models were used to compare clinicalcharacteristics and outcomes between parturients at high and low altitudes,while adjusting for race, ethnicity, education, and age (logistic and linearregressions for categorical and quantitative outcomes, respectively).

Results: A total of1856 laboring parturients (age 18-50) were included in the analysis. The oddsof converting from 50% N2O to another analgesic modality had no statisticallysignificant difference between high- versus low-altitude institutions (adjustedodds ratio [aOR], 1.13; 95% confidence interval [CI], 0.90-1.42; P = .3). Yet,when parturients at low altitude converted from N2O, they were more likely(aOR, 3.03; 95% CI, 1.59-5.88) to choose neuraxial analgesia instead of anotheranalgesic modality when compared to high-altitude parturients. This is possiblydue to higher epidural rates at the low-altitude institutions. When parturientsat high altitude did convert into another modality, they were more likely (aOR,2.19; 95% CI, 1.14-4.21) to convert due to inadequate pain relief compared tolow-altitude parturients; however, missing data may have affected this finding.Laboring individuals at low altitude were significantly more likely toexperience side effects (aOR, 2.13; 95% CI, 1.45-3.12). Those requiring laboraugmentation, assisted vaginal, or cesarean delivery converted to neuraxialanalgesia significantly more often than those that delivered via spontaneousvaginal delivery (P < .05) in both high- and low-altitude groups.

Conclusions: This isthe first study evaluating 50% N2O as a labor analgesic at high altitude. Asexpected, we found lower side effects at high altitude, likely due to the lowerpartial pressure of N2O. However, there was not a statistically significantincrease in conversion from N2O to another analgesic modality at high altitudeand no clinically significant differences in neonatal outcomes.