A randomised cross-over study showed no difference in diaphragm activity during weaning from respiratory support

We measured electrical activity of the diaphragm (Edi) to compare the breathing effort in preterm infants during weaning from respiratory support with high-flow nasal cannulae (HFNC) or nasal continuous positive airway pressure (nCPAP).

This randomised cross-over study was carried out at St Olav's University Hospital, Trondheim, Norway, from December 2013 to June 2015. We gave 21 preterm infants weighing at least 1000 g HFNC 6 L/minute for four hours and nCPAP 3 cmH₂ O for four hours with a one-hour wash-out period. Measurements included diaphragmatic load, Edi, vital signs and a modified Silverman-Andersen Retraction Score.

We found no differences in HFNC and nCPAP in the median Edi peak (8.0 μV versus 7.8 μV, p = 0.095), median Edi min (1.1 μV versus 1.2 μV in, p = 0.958) or mean heart rate (157 versus 159, p = 0.300) in the 21 infants who took part. The mean respiratory rate was significantly lower during HFNC than nCPAP (47 versus 52, p = 0.012). The modified Silverman-Andersen Retraction Score showed no significant differences.

This study of preterm infants found no difference in the breathing effort measured by Edi between HFNC 6 L/minute and nCPAP 3 cmH₂ O. HFNC could replace nCPAP when preterm infants are ready for weaning.