Objective: We assessed the safety and studied the influence of short-term helium-oxygen (heliox) mechanical ventilation (MV) on respiratory function, gas exchange and oxygenation in infants with bronchopulmonary dysplasia (BPD) or at high risk for BPD.
Design: A pilot, time-series study.
Setting: Neonatal intensive care unit.
Patients: Infants with severe BPD who required MV.
Interventions: MV with helium-oxygen and air-oxygen mixtures.
Main outcome measures: Respiratory parameters, acid-base balance, oxygenation and vital signs were recorded at five time points: initially during MV with air-oxygen, after 15 and 60 min of helium-oxygen MV, and 15 and 60 min after return to air-oxygen MV.
Results: 15 infants with BPD were enrolled. Helium-oxygen MV was well tolerated and was associated with a statistically significant increase in tidal volume, dynamic compliance and peak expiratory flow rate. An improvement in oxygenation and a decrease in fraction of inspired oxygen was also observed. During helium-oxygen MV there was a significant decrease in the oxygenation index and alveolar-arterial oxygen tension difference. The PaO2/fraction of inspired oxygen (FiO2) ratio increased significantly during helium-oxygen ventilation. A decrease in PaCO2 and an increase in pH were also observed during helium-oxygen administration, however this was not statistically significant. After ventilation with helium-oxygen was discontinued, the infants' respiratory function and oxygenation deteriorated and supplemental oxygen requirements increased accordingly.
Conclusions: Helium-oxygen MV is safe and resulted in improvement of respiratory function and oxygenation in infants with severe BPD requiring MV.
Keywords: Intensive Care; Neonatology; Respiratory.