Prediction of infant extubation using surface diaphragm electromyography

Abstract

Aims: The diaphragm electromyogram (dEMG) recorded via oesophageal catheter has been used to predict extubation in adults and children. We sought to assess whether non-invasive transcutaneous measurement of dEMG could be used to predict extubation success in ventilated infants. Methods: Once the clinical team had decided the infants were ready to be extubated, the dEMG was recorded before extubation using three surface electrodes (H59P Cloth Electrodes, Kendall) and a physiological amplifier (Dipha-16, Inbiolab BV, Netherlands) transmitting to a bedside computer (PolyBench, Applied Biosignals, Germany). If infants remained extubated at 48 hours then extubation was deemed successful. Assuming a 25% failure rate, a sample size of 72 would allow detection of one standardised difference in dEMG amplitude between those who successfully extubated and those who did not. Results: 72 infants, 33 male (46%) were studied. They were born at a median gestational age (GA) of 28.4 (range 23.4 – 42.1) weeks, with birthweight (BW) 1118 (470 – 5000) grams and were studied at a postnatal age of 6 (1 – 213) days. The dEMG amplitude and area under the dEMG curve were not significantly different between those who were and were not successfully extubated. GA, BW, weight, tidal volume and the inspired oxygen concentration (FiO2) were better predictors than the amplitude or area under the dEMG curve (Table 1.) Conclusion: The surface diaphragm EMG was not a better predictor of successful extubation than readily collected clinical variables.