Chapter 23: Nasal CPAP

SCOPE

DISEASE/CONDITION(S)

Prevention/reduction of bronchopulmonary dysplasia.

GUIDELINE OBJECTIVE(S)

Recommendations for initiation of continuous positive airway pressure (CPAP); define CPAP failure and identify strategies to prevent failure; recommendations for weaning of CPAP.

BRIEF BACKGROUND

In the past decade, the incidence of bronchopulmonary dysplasia (BPD) has remained relatively unchanged despite improvements in neonatal intensive care, which have enhanced survival. Since the earliest identification of BPD by Northway et al. in 1967, development of BPD has been associated with exposure to mechanical ventilation. A seminal paper by Avery et al. in 1987 reported a decreased incidence of BPD at Babies Hospital in New York compared with seven similar centers; they hypothesized that this decreased incidence resulted in part from avoidance of mechanical ventilation through the use of CPAP. Consequently, several randomized controlled trials and meta-analyses have sought to answer the question of whether CPAP use compared to standard intubation and surfactant administration can prevent BPD.

RECOMMENDATIONS

MAJOR RECOMMENDATIONS

Randomized trials and meta-analyses demonstrate that early, routine CPAP use significantly reduces the combined outcome of BPD or death in preterm infants. However, the treatment effect remains disappointingly small with an incidence of BPD in survivors still at ∼40%. This lack of treatment effect may result from a high proportion of CPAP failures, which result in need for mechanical ventilation. Thus work is ongoing to investigate how to improve implementation of CPAP and prevent CPAP failure.

INITIATION OF CPAP

1) Provided that the neonate demonstrates spontaneous respiratory effort, CPAP can be initiated in the delivery room via nasal prongs or mask in any weight infant. 2) Distending pressures of 5−8 mmHg and flow rates of 5−10 L/min of warmed, humidified gasses are sufficient.

IDENTIFYING CPAP FAILURE

CPAP failure may be defined as FiO₂ requirement >60% (controversial) to maintain SpO₂ >89%, pCO₂ >65 mmHg, pH <7.2, or apneic episodes requiring positive pressure ventilation or frequent stimulation. Strategies to avoid CPAP failure are targeted at delivering effective distending pressure and include appropriate size nasal prongs, proper positioning of nasal device to infant’s nose and face, use of chin straps and pacifiers to minimize air leak, placement of feeding tube to permit gastric decompression, and frequent monitoring of device, device positioning, and infant’s respiratory status by neonatal nurses and physicians.

WEANING CPAP

Three weaning methods are commonly used in clinical practice—sudden removal of CPAP, gradual reduction of pressure, and gradual reduction in time off CPAP (aka “sprinting”). No significant benefits of any one strategy have been demonstrated. Infants >30 weeks post menstrual age with stable respiration on CPAP (4–6 mmHg vs <9 mmHg) with 21% FiO₂ should be ...