Kiryachkov Yu Yu, Petrova M V, Loginov A A, Skvortsov A E, Artemov K A, Parfenov A L
Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia.
Hum Physiol. 2020;46(6):645-650. doi: 10.1134/S0362119720050060. Epub 2021 Jan 25.
The aim of the study was to develop an informative method for assessing chemoreflex sensitivity and to evaluate its prognostic capacity for restoring spontaneous breathing in patients with brain damage of various etiologies. The study included 16 healthy volunteers and 38 patients on prolonged mechanical ventilation (VE) after a traumatic brain injury, anoxic brain damage, and cerebrovascular events. The external respiration variables were assessed from the initial level to the development of the first episode of desaturation with spO in the range of 90-80% against the background of normobaric hypoxia as indicators reflecting the development of adaptive ventilatory response and characterizing the state of peripheral chemoreflex sensitivity (PCS). The peripheral chemoreflex sensitivity index (PCSI) was calculated using the equation: PCSI = [RR(e) : RR(i)] × [Vt(e) : Vt(i)] × [VE(e) : VE(i)] × Vt(e) × VE(e), where PCSI is the peripheral chemoreflex sensitivity index in L/min; RR(i) and RR(e); Vt(i) and Vt(e); VE(i) and VE(e) are the respiratory rate, tidal volume, minute ventilation initially (i), before a functional stress test, and during a functional test of normobaric hypoxia with spO in the range of 90-80% (e). With the PCSI values ≥15.6 L/min, successful weaning from ventilators and recovery of spontaneous breathing are predicted. The sensitivity and specificity of PCSI were 78.57 [95% CI: 49.2-95.26] and 83.3% [95% CI: 62.6-95.26], respectively. The sensitivity and specificity of the traditional indicator of the success rate of weaning from ventilators and recovery of spontaneous breathing, Rapid Shallow Breathing Index (RSBI), in this cohort of patients was 69.23 [95% CI: 38.6-90.9] and 28.0% [95% CI: 12.03-49.3], respectively. A predictor of the patient's weaning from mechanical ventilation is the assessment of peripheral chemoreflex sensitivity, which can be measured by a simple non-invasive bedside test based on measuring the difference in external ventilation parameters before and during a functional normobaric hypoxic trial.
本研究的目的是开发一种用于评估化学反射敏感性的信息性方法，并评估其对各种病因脑损伤患者恢复自主呼吸的预后能力。该研究纳入了16名健康志愿者和38名在创伤性脑损伤、缺氧性脑损伤和脑血管事件后接受长时间机械通气（VE）的患者。在常压性缺氧背景下，将外部呼吸变量从初始水平评估至首次出现血氧饱和度（spO）在90% - 80%范围内的去饱和发作，以此作为反映适应性通气反应发展并表征外周化学反射敏感性（PCS）状态的指标。外周化学反射敏感性指数（PCSI）使用以下公式计算：PCSI = [RR(e) : RR(i)] × [Vt(e) : Vt(i)] × [VE(e) : VE(i)] × Vt(e) × VE(e)，其中PCSI是以升/分钟为单位的外周化学反射敏感性指数；RR(i)和RR(e)；Vt(i)和Vt(e)；VE(i)和VE(e)分别是初始（i）、功能应激测试前以及在常压性缺氧功能测试期间血氧饱和度在90% - 80%（e）时的呼吸频率、潮气量、分钟通气量。当PCSI值≥15.6升/分钟时，预测可成功脱机并恢复自主呼吸。PCSI的敏感性和特异性分别为78.57 [95%置信区间：49.2 - 95.26]和83.3% [95%置信区间：62.6 - 95.26]。在该组患者中，传统的脱机成功率和自主呼吸恢复指标——快速浅呼吸指数（RSBI）的敏感性和特异性分别为69.23 [95%置信区间：38.6 - 90.9]和28.0% [95%置信区间：12.03 - 49.3]。患者脱机的一个预测指标是对外周化学反射敏感性的评估，这可以通过基于在常压性缺氧功能试验前后测量外部通气参数差异的简单非侵入性床边测试来测量。
