Abstract

Two methods of providing assisted ventilation were compared in infants severely ill with hyaline membrane disease (HMD). 10 infants were assigned to each group. One group received ventilation with a volume-cycled respirator, and the other was ventilated using a pressure-limited ventilator and reversed I:E ratio. Both groups were well matched for severity of illness in terms of pH and blood gases. pH and PO2 were quickly corrected by both ventilators. However, the pressure-cycled ventilator group had higher survival and lower complication rates. PAO2 after one hour was substantially improved at the same FIO2 in the pressure-limited group and after 8 hours the FIO2 required to maintain a PaO2 of 50--70 mmHg (6.6--9.3 kPa) was significantly decreased compared with the volume-cycled group. No effects on blood pressure were detected in either group. The study shows that the pressure-limited method is significantly better.