Continuous positive airway pressure to reduce the risk of early peripheral oxygen desaturation after onset of apnoea in children: A double-blind randomised controlled trial.

J M Santos Neto ,Lívia Barboza De Andrade,Raphaella Amanda Maria Leite Fernandes,Rebeca Gonelli Albanez Da Cunha Andrade,Thiago Santos ,Clístenes Crístian De Carvalho ,Flávia Augusta De Orange

doi:10.1371/journal.pone.0256950

Abstract

Continuous positive airway pressure (CPAP) during anaesthesia induction improves oxygen saturation (SpO2) outcomes in adults subjected to airway manipulation, and could similarly support oxygenation in children. We evaluated whether CPAP ventilation and passive CPAP oxygenation in children would defer a SpO2 decrease to 95% after apnoea onset compared to the regular technique in which no positive airway pressure is applied. In this double-blind, parallel, randomised controlled clinical trial, 68 children aged 2-6 years with ASA I-II who underwent surgery under general anaesthesia were divided into CPAP and control groups (n = 34 in each group). The intervention was CPAP ventilation and passive CPAP oxygenation using an anaesthesia workstation. The primary outcome was the elapsed time until SpO2 decreased to 95% during a follow-up period of 300 s from apnoea onset (T1). We also recorded the time required to regain baseline levels from an SpO2 of 95% aided by positive pressure ventilation (T2). The median T1 was 278 s (95% confidence interval [CI]: 188-368) in the CPAP group and 124 s (95% CI: 92-157) in the control group (median difference: 154 s; 95% CI: 58-249; p = 0.002). There were 17 (50%) and 32 (94.1%) primary events in the CPAP and control groups, respectively. The hazard ratio was 0.26 (95% CI: 0.14-0.48; p<0.001). The median for T2 was 21 s (95% CI: 13-29) and 29 s (95% CI: 22-36) in the CPAP and control groups, respectively (median difference: 8 s; 95% CI: -3 to 19; p = 0.142). SpO2 was significantly higher in the CPAP group than in the control group throughout the consecutive measures between 60 and 210 s (with p ranging from 0.047 to <0.001). Thus, in the age groups examined, CPAP ventilation and passive CPAP oxygenation deferred SpO2 decrease after apnoea onset compared to the regular technique with no positive airway pressure.

Highlights

General anaesthesia largely alters the physiology of the respiratory system
We aimed to evaluate whether Continuous positive airway pressure (CPAP) ventilation and passive CPAP oxygenation would defer oxygen saturation (SpO2) decrease to 95% after apnoea onset in children compared to the regular technique in which no positive airway pressure is delivered
The median for T1 was 278 s in the CPAP group and 124 s in the control group

Summary

Introduction

Paediatric patients have the highest risk of desaturation during anaesthesia induction [5,6,7,8], because of their physiological characteristics (lower FRC and greater oxygen consumption). Their anatomy (proportionally large head and tongue, tonsil and adenoid hypertrophy, small and narrow hypopharynx, upper larynx, slanted vocal cords, Ushaped inverted epiglottis, and short airway radius) may complicate airway management. Other preventive strategies have been evaluated; an ideal technique has not been determined far [13,14]

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