Prediction of infant extubation success using the diaphragmatic electromyography (EMG) signal during a spontaneous breathing test (SBT)

Abstract

Introduction: Prolonged mechanical ventilation in infants can result in ventilator associated lung injury. Premature extubation, however, can be associated with cardiorespiratory compromise. Identification of an accurate predictor of extubation success is, therefore, essential.

Aim: To determine if diaphragmatic electrical activity during an SBT could predict extubation success in ventilated infants.

Methods: Infants deemed ready for extubation by the clinical team were assessed. The SBT was performed when infants were on endotracheal CPAP for 5–10 minutes (mins). A failed SBT was recorded when the heart rate dropped < 100bpm or a desaturation to 85% for > 15 seconds, despite a 15% increase in FiO2. The diaphragmatic electrical activity was assessed using surface electrodes 10 mins pre, during and 10 mins post SBT. The clinical team were unaware of the SBT or the diaphragmatic EMG analysis results. Infants failed extubation if they were reintubated within 48 hours.

Results: Twenty-eight infants, median (IQR) gestational age of 26.9 (25.2-28.4) weeks and post menstrual age (PMA) 30.5 (27.9–35.4) weeks, were studied. During the SBT, the infants had increases in the mean EMG amplitude (3.6 versus 2.2 μV, p<0.001) and mean area under the curve (MAUC) (5.3 versus 4 μV.s, p<0.05). Seven infants failed extubation and had a greater percentage increase in the MAUC (40.4 versus 6.3 %, p<0.05). A 29.6% increase in the MAUC during SBT had 71.4% sensitivity and 85.7% specificity in predicting extubation failure.

Conclusion: The diaphragmatic EMG signal during SBT might have a role in predicting extubation failure in ventilated infants.