Continuous Monitoring of Dynamic Pulmonary Compliance Enables Detection of Endobronchial Intubation in Infants and Children

Abstract

Auscultation of breath sounds is used routinely to confirm tracheal placement of endotracheal tubes (ETT). In infants and children, this method is limited by the conduction of breath sounds bilaterally, despite endobronchial intubation. Although several methods of detecting endobronchial intubation have been described, none is both simple and reliable. In this investigation, we determined whether changes in pulmonary compliance and airway pressures, measured using continuous side stream spirometry, can reliably detect endobronchial intubation in pediatric patients. Forty patients aged 1 month to 6 years were included. After endotracheal intubation the ETT was incrementally advanced as two observers monitored breath sounds and spirometry (Pressure-Volume Loops). Changes in pulmonary compliance, peak inspiratory pressure, or auscultation were reported, at which point ETT position was confirmed by fiberoptic bronchoscopy. Endobronchial intubation decreased measured pulmonary compliance by 45 +/- 11% (mean +/- sd; P < 0.001, Range 26%-66%) and increased peak airway pressures by 26 +/- 17% (mean +/- sd; P < 0.001, Range 0-87). Changes in peak airway pressures were smaller and more variable when compared to changes in compliance. Breath-sound auscultation failed to detect endobronchial intubation in 7.5% of cases. Pulmonary compliance changes are a sensitive and an accurate indicator of endobronchial intubation in infants and children. Both increased peak airway pressures and changes in breath sounds are less sensitive indicators of endobronchial intubation.