David Guevorkian1, Sebastien Mur2, Eric Cavatorta3, Laurence Pognon2, Thameur Rakza4, Laurent Storme5. 1. Neonatal Intensive Care, Department of Neonatology, Marie Curie Public Hospital, Charleroi, Belgium; Department of Neonatology, Jeanne de Flandre Hospital, University Hospital of Lille, F-59000 France. 2. Department of Neonatology, Jeanne de Flandre Hospital, University Hospital of Lille, F-59000 France; National Reference Center for the Rare Disease Congenital Diaphragmatic Hernia, Member of the European Reference Network on inherited and congenital anomalies ERNICA, University Hospital of Lille, F-59000 France. 3. Neonatal Intensive Care, Department of Neonatology, Marie Curie Public Hospital, Charleroi, Belgium. 4. Department of Neonatology, Jeanne de Flandre Hospital, University Hospital of Lille, F-59000 France; National Reference Center for the Rare Disease Congenital Diaphragmatic Hernia, Member of the European Reference Network on inherited and congenital anomalies ERNICA, University Hospital of Lille, F-59000 France; EA4489, Perinatal Environment and Health, University of Lille, F-59000 France. 5. Department of Neonatology, Jeanne de Flandre Hospital, University Hospital of Lille, F-59000 France; National Reference Center for the Rare Disease Congenital Diaphragmatic Hernia, Member of the European Reference Network on inherited and congenital anomalies ERNICA, University Hospital of Lille, F-59000 France; EA4489, Perinatal Environment and Health, University of Lille, F-59000 France. Electronic address: laurent.storme@chru-lille.fr.
Abstract
OBJECTIVE: To investigate the effects of distending pressures on respiratory mechanics and pulmonary circulation in newborn infants with congenital diaphragmatic hernia (CDH) and persistent pulmonary hypertension (PPHN). STUDY DESIGN: In total, 17 consecutive infants of ≥37 weeks of gestational age with CDH and PPHN were included in this prospective, randomized, crossover pilot study. Infants were assigned randomly to receive 2 or 5 cmH2O of positive end-expiratory pressure (PEEP) for 1 hour in a crossover design. The difference between peak inspiratory pressure and PEEP was kept constant. Respiratory mechanics, lung function, and hemodynamic variables assessed by Doppler echocardiography were measured after each study period. RESULTS: At 2 cmH2O of PEEP, tidal volume and minute ventilation were greater (P < .05), and respiratory system compliance was 30% greater (P < .05) than at 5 cmH2O. PaCO2 and ventilation index were lower at 2 cmH2O than at 5 cmH2O (P < .05). Although preductal peripheral oxygen saturation was similar at both PEEP levels, postductal peripheral oxygen saturation was lower (median [range]: 81% [65-95] vs 91% [71-100]) and fraction of inspired oxygen was greater (35% [21-70] vs 25% [21-60]) at 5 cmH2O. End-diastolic left ventricle diameter, left atrium/aortic root ratio, and pulmonary blood flow velocities in the left pulmonary artery were lower at 5 cmH2O. CONCLUSIONS: After surgical repair, lower distending pressures result in better respiratory mechanics in infants with mild-to-moderate CDH. We speculate that hypoplastic lungs in CDH are prone to overdistension, with poor tolerance to elevation of distending pressure.
RCT Entities:
OBJECTIVE: To investigate the effects of distending pressures on respiratory mechanics and pulmonary circulation in newborn infants with congenital diaphragmatic hernia (CDH) and persistent pulmonary hypertension (PPHN). STUDY DESIGN: In total, 17 consecutive infants of ≥37 weeks of gestational age with CDH and PPHN were included in this prospective, randomized, crossover pilot study. Infants were assigned randomly to receive 2 or 5 cmH2O of positive end-expiratory pressure (PEEP) for 1 hour in a crossover design. The difference between peak inspiratory pressure and PEEP was kept constant. Respiratory mechanics, lung function, and hemodynamic variables assessed by Doppler echocardiography were measured after each study period. RESULTS: At 2 cmH2O of PEEP, tidal volume and minute ventilation were greater (P < .05), and respiratory system compliance was 30% greater (P < .05) than at 5 cmH2O. PaCO2 and ventilation index were lower at 2 cmH2O than at 5 cmH2O (P < .05). Although preductal peripheral oxygen saturation was similar at both PEEP levels, postductal peripheral oxygen saturation was lower (median [range]: 81% [65-95] vs 91% [71-100]) and fraction of inspired oxygen was greater (35% [21-70] vs 25% [21-60]) at 5 cmH2O. End-diastolic left ventricle diameter, left atrium/aortic root ratio, and pulmonary blood flow velocities in the left pulmonary artery were lower at 5 cmH2O. CONCLUSIONS: After surgical repair, lower distending pressures result in better respiratory mechanics in infants with mild-to-moderate CDH. We speculate that hypoplastic lungs in CDH are prone to overdistension, with poor tolerance to elevation of distending pressure.