Comparison of CPAP Machines With Reusable vs Disposable Circuits

The study aims to assess the basic functionality of a newly designed CPAP machine with reusable circuits to existing machines with disposable circuits, for treatment of newborn infants diagnosed with respiratory distress syndrome. The assessment will compare a comprehensive list of physiological parameters over the first 72 hours of treatment, and will also monitor rates of side effects and adverse events. The null hypothesis is that infants treated on the two categories of machine (reusable vs disposable) will not differ in relation to key physiological parameters by more than 0.63 standard deviations.

One of the commonest sources of serious newborn morbidity and mortality is difficulty with breathing. When this occurs, three main types of supportive therapy are available to increase the provision of oxygen to cells: a) passive provision of oxygen-enriched gases (i.e., higher than the 21% O2 found in the earth's atmosphere) through tubes in the nostrils, or by putting a hood over the baby's head and enriching the gases under that hood; b) provision of room air or oxygen-enriched gasses under pressure, frequently performed using a method called continuous positive airway pressure \[CPAP\] therapy; and/or c) by using a machine that is able to breath on behalf of the baby, most commonly referred to as mechanical ventilation \[MV\].

Passive therapy is the least invasive method but is also of limited benefit, particularly for infants born preterm. CPAP is more effective than passive methods because continuous distending pressure to the lungs allows better oxygen exchange; however, the distending pressure increases the risk of damage to the lung. MV is the only method that can be used on babies without a neurological impulse to breath, but the mechanical breathing action can damage the lungs, and MV is usually provided through a tube inserted into the lungs which increases the risk of lung infection; MV machines are also significantly more expensive than CPAP machines.

In high resource settings, CPAP is now the preferred method of providing oxygen for infants where passive therapy is insufficient, because of the lower infection risk, lower risk of lung damage, and relative ease of clinical care. CPAP is increasingly recommended for low resource settings, but the CPAP machines used in high resource settings are too expensive for low resource settings due to high-priced consumables ($US50-200/baby), and are usually unusable in low resource settings because they require 'medical air' (clean air in a cylinder, or through a piped wall system) with which to blend 100% oxygen. Low cost 'indigenous' machines ('jury-rigged' by hospital staff) have also been developed, but these do not provide the heated, humidified and blended gasses, that are recommended for CPAP.

This study seeks to evaluate a novel CPAP machine that provides heated, humidified, blended gasses, in line with recommendations for high-resource settings, while massively reducing costs by including re-usable tube sets and humidifiers that can be autoclaved, and with an on-board air-compressor to allow use in a broader range of clinical settings. By reducing the cost per CPAP treatment, such a machine can dramatically increase the number of hospitals in low resource settings that can provide high quality CPAP treatment.

Eligibility Criteria:
Inclusion Criteria:

1. Infants born at Ramaiah Medical College hospital ('inborn infants');
2. Infants born elsewhere, and admitted to Ramaiah Medical College hospital under 6 hours of age ("outborn infants");
3. Infants with a gestational age at birth (weeks +days) in the range ≥ 28+0 to ≤ 36+6;
4. Infants thought to have RDS (clinically diagnosed after onset of respiratory distress \<6 hours of age, sometimes confirmed by X-ray showing homogenous bilateral opacity) who would routinely be provided CPAP therapy; and
5. Infants \<24 hours old at the time of fulfilling other inclusion criteria.

Exclusion Criteria:

1. Infants with a 1-minute Apgar score \<3 (as a marker of severe birth asphyxia);
2. Infants who received MV prior to randomisation;
3. Infants with suspected meconium aspiration syndrome will be excluded to avoid any imbalance in this condition across groups;
4. Infants clinically suspected to have another specified serious condition as their main disease process, diagnosed prior to randomisation, specifically: cardiac anomaly, other congenital malformation with respiratory sequelae, septicaemia, pulmonary haemorrhage, pneumothorax, meningitis, poor respiratory effort or recurrent apnoea, or brain haemorrhage (IVH Grades III or IV);
5. Infants who have an airway abnormality precluding the use of the standard CPAP interface proposed for this study (e.g., Pierre-Robin sequence, cleft lip or cleft palate) or who have a neuromuscular condition that interferes with respiration;
6. Any infant whose treating clinician believes should not be randomised due to some other condition, or for any other reason (reason to be documented).