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

AIM: 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).

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.