Comparison of different rates of artificial ventilation in preterm neonates with respiratory distress syndrome.

The effectiveness of three different ventilator rates of artificial ventilation (30, 60 and 120/min) was studied in 32 preterm infants, all of whom were suffering from the Respiratory Distress Syndrome (16 were paralysed). Ventilator pressures, I:E ratio and MAP were kept constant at each rate. Increase in rate from 30 to 60 and to 120/min was well tolerated and not associated with episodes of hypotension. The only significant improvement in oxygenation was amongst the non-paralysed infants and at a rate of 120/min (p less than 0.01) this was associated with synchronous respiration. Two different ventilators were used in the study and a significant change in PaCO2 (reduction) occurred only in non-paralysed infants ventilated at a rate of 120/min by Sechrist ventilators (p less than 0.05). This difference may be a direct reflection of differences in ventilator performance at fast rates.