Continuous positive airway pressure (CPAP) for apnoea of prematurity

BACKGROUND: Apnoea of prematurity (AoP) is defined as a pause in breathing for 20 seconds or longer, or for less than 20 seconds when accompanied by bradycardia and hypoxaemia, in a preterm infant. An association between the severity of apnoea and neurodevelopmental delay has been reported. Continuous positive airway pressure (CPAP) is a form of non-invasive ventilatory assistance that has been shown to be relatively safe and effective in preventing and treating respiratory distress among preterm infants. It is less clear whether CPAP treatment is safe and effective in the prevention and treatment of AoP.

OBJECTIVES: 1. To assess the effects of CPAP on AoP in preterm infants (this may be compared to supportive care or mechanical ventilation). 2. To assess the effects of different CPAP delivery systems on AoP in preterm infants.

SEARCH METHODS: Searches were conducted in September 2022 in the following databases: Cochrane Library, MEDLINE, Embase, and CINAHL. We also searched clinical trial registries and the reference lists of studies selected for inclusion.

SELECTION CRITERIA: We included all randomised and quasi-randomised controlled trials (RCTs) in which researchers determined that CPAP was necessary for AoP in preterm infants (born before 37 weeks). Cross-over studies were also included, provided sufficient data were available for analysis.

DATA COLLECTION AND ANALYSIS: We used the standard methods of Cochrane and Cochrane Neonatal, including independent assessment of risk of bias and extraction of data by at least two review authors. Discrepancies were resolved by involvement of a third author. We used the GRADE approach to assess the certainty of evidence for the following outcomes: 1) failed CPAP; 2) apnoea; 3) adverse effects of CPAP.

MAIN RESULTS: We included four single-centre trials conducted in Malaysia, Spain, Germany, and North America, involving 138 infants with a mean/median gestation of 26 to 28 weeks. Two studies were parallel-group RCTs and two were cross-over trials. None of the studies compared CPAP with supportive care. All trials compared one form of CPAP with another. Two compared a variable flow device with ventilator CPAP, one compared two different variable flow devices, and one compared a variable flow device with bubble CPAP. Interventions were administered for periods ranging between six and 48 hours, with pressures between 4 and 6 cm H2O. We assessed all trials as having a high risk of bias for blinding of participants and personnel, and two studies for blinding of outcome assessors. We found a high risk of a carry-over effect in two studies where the washout period was not adequately described, and a high risk of bias in a study that appeared to use an analysis method not generally accepted for cross-over studies. Comparison 1. CPAP and supportive care compared to supportive care alone We did not identify any study for inclusion in this comparison. Comparison 2. CPAP delivered by different types of devices 2a. Variable flow compared to ventilator CPAP Two studies were included in this comparison. We are very uncertain whether there is any difference in the incidence of failed CPAP, defined as the need for mechanical ventilation (risk ratio (RR) 0.16, 95% confidence interval (CI) 0.01 to 2.90; 1 study, 26 participants; very low-certainty). We are very uncertain whether there is any difference in the frequency of apnoea events (mean difference (MD) per four-hour interval -0.10, 95% CI -1.30 to 1.10; 1 study, 26 participants; very low-certainty). We are uncertain whether there is any difference in adverse events. Neurodevelopmental outcomes were not reported. 2b. Variable flow compared to bubble CPAP We included one study in this comparison, but it did not report our pre-specified outcomes. 2c. Infant Flow variable flow CPAP compared to Medijet variable flow CPAP We are very uncertain whether there is any difference in the incidence of failed CPAP (RR 2.62, 95% CI 0.91 to 7.53; 1 study, 80 participants; very low-certainty). The frequency of apnoea was not reported, and we do not know whether there is any difference in adverse events. Neurodevelopmental outcomes were not reported. Comparison 3. CPAP compared to mechanical ventilation We did not identify any studies for inclusion in this comparison.

AUTHORS' CONCLUSIONS: Due to the limited available evidence, we are very uncertain whether any CPAP device is more effective than other forms of supportive care, other CPAP devices, or mechanical ventilation for the prevention and treatment of AoP. The devices used in these studies included two types of variable flow CPAP device: bubble CPAP and ventilator CPAP. For each comparison, data were only available from a single study. There are theoretical reasons why these devices might have different effects on AoP, therefore further trials are indicated.