The effect of high flow nasal cannula therapy on the work of breathing in infants with bronchiolitis.
The main physiological impact of high flow nasal cannula (HFNC) therapy is presumed to be a decrease in work of breathing (WOB). To assess this, diaphragmatic electrical activity and esophageal pressure changes were measured off then on HFNC delivered at 2 L/kg/min, in 14 infants with bronchiolitis and 14 cardiac infants. Electrical activity of the diaphragm (Edi) was measured using an Edi catheter with calculations of signal peak (EdiMAX ) and amplitude (EdiAMPL ). Pressure-rate and pressure-time products (PRP, PTP) were calculated from analyses of esophageal pressure. Changes in end-expiratory lung volume were measured using respiratory inductance plethysmography (RIPEEL ). The EdiMAX and EdiAMPL were significantly higher in infants with bronchiolitis than in cardiac infants (P < 0.05). Within the bronchiolitis group, both were significantly reduced between HFNC states from 27.9 µV [20.4, 35.4] to 21.0 µV [14.8, 27.2] and from 25.1 µV [18.0, 32.2] to 19.2 µV [13.3, 25.1], respectively (mean, 95% CI, P < 0.05). A less prominent offload of the diaphragm was observed in cardiac infants (P < 0.05). WOB decreased in both groups with a significant reduction of PRP and PTP (P < 0.05). RIPEEL increased significantly in bronchiolitis only (P < 0.05). HFNC offloads the diaphragm and reduces the WOB in bronchiolitis. A similar effect was demonstrated in cardiac infants, a group without signs of airway-obstruction.
Paediatric Critical Care Research Group, Mater Research Institute, The University of Queensland, South Brisbane, QLD, 4101, Australia.|School of Electrical Engineering and Computer Science, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Trang M T
TM
Pham
Paediatric Critical Care Research Group, Mater Research Institute, The University of Queensland, South Brisbane, QLD, 4101, Australia.
Lee
L
O'Malley
Paediatric Critical Care Research Group, Mater Research Institute, The University of Queensland, South Brisbane, QLD, 4101, Australia.|The School of Nursing and Midwifery, The University of Queensland, Brisbane, QLD, 4006, Australia.
Sara
S
Mayfield
Paediatric Critical Care Research Group, Mater Research Institute, The University of Queensland, South Brisbane, QLD, 4101, Australia.
Simon
S
Martin
Paediatric Critical Care Research Group, Mater Research Institute, The University of Queensland, South Brisbane, QLD, 4101, Australia.
Andreas
A
Schibler
D001988:Bronchiolitis / Q000503:physiopathology / Q000628:therapy*; D003964:Diaphragm / Q000502:physiology; D004947:Esophagus / Q000502:physiology; D006330:Heart Defects, Congenital / Q000503:physiopathology; D006801:Humans; D007223:Infant; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D010991:Plethysmography; D011312:Pressure; D011446:Prospective Studies; D014939:Work of Breathing / Q000502:physiology*
breathing pattern; electrical activity of the diaphragm; end expiratory level; esophageal pressure; oxygen therapy; respiratory distress