CPAP vs.Unsynchronized NIPPV at Equal Mean Airway Pressure

Overview

This study seeks to determine if standard continuous positive airway pressure, known as CPAP is as effective as a more complicated approach that generates intermittent increases in airway pressure applied to the nostrils via a breathing machine. The latter is known as NIPPV and requires costly equipment to operate. Previous studies did not ensure that the average pressure applied to the lungs was equal and thus did not make for a fair comparison. The investigators believe that when the same average pressure is applied with the two techniques, CPAP is just as effective as NIPPV and may have fewer side effects, such as blowing air into the stomach. Each baby will receive CPAP or NIPPV in a random sequence for a period of 12 hours, followed by 12 hours on the alternate technique.

This is a pilot clinical trial to evaluate the comparative effectiveness of two commonly used types of non-invasive respiratory support. Preterm infants \< 34 weeks gestational age, who are stable on either of the two modalities of support will be studied in a cross-over study design, such that each subject acts as his/her own control. The study will assess the relative efficacy of these modalities when used with equal mean airway pressure comparing measures of oxygenation, CO2 removal, apnea/bradycardia/desaturation events and work of breathing. The initial phase of the study is complete and preliminary analysis supports the hypothesis that there is no difference between the modalities when the mean airway pressure is equal. However we recognized that use of the RAM cannula, which does not transmit pressure effectively is an important study limitation. The findings are valid, but may only be applicable to this interface, which is widely used, but increasingly recognized as flawed. We are now extending the study to determine if the findings will be the same when short bi-nasal prongs are used.