Implementation of Bubble Continuous Positive Airway Pressure in the Delivery Room and NICU.

Abstract

Initiating bubble continuous positive airway pressure (CPAP) in the delivery room to spontaneously breathing neonates.Providing postextubation noninvasive respiratory support in the NICU to maintain functional residual capacity.In 1987, 8 intensive care nurseries in large institutions in the United States, including a total of 1,625 infants with birthweights between 700 and 1,500 g, analyzed their rates of chronic lung disease and respiratory support practices. (1) They reported substantial differences in the incidence of chronic lung disease among institutions. One of the participating centers (Columbia University, New York, NY) had the lowest rate of chronic lung disease, which was attributed to initiation of CPAP in the delivery room. (1) Since then, several additional studies have illustrated the benefits of initiating CPAP treatment early in preterm infants, with improved pulmonary outcomes, including decreased number of ventilator days, (2)(3) fewer intubations, (3) less postnatal corticosteroid use, (3) and decreased risk of bronchopulmonary dysplasia. (4) Based on these studies, the American Academy of Pediatrics Committee on the Fetus and Newborn published a policy statement that concluded that the use of CPAP immediately after birth in extremely preterm infants may lead to decreased duration of mechanical ventilation and postnatal corticosteroid use. (5)CPAP can be administered using a continuous or variable gas flow system. (6) Examples of continuous flow system CPAP include CPAP delivered via a ventilator or a bubble apparatus. In this system, pressure is generated by using a valve (as in ventilator CPAP) or a water seal (as in bubble CPAP) to block the expiratory limb of the respiratory circuit. (6) In contrast, with the variable flow CPAP system, a flow opposition system is created with reversal of fluid flow during expiration. (7)Bubble CPAP consists of humidified, warm room air or air blended with oxygen that is delivered to the infant through a nasal mask, prongs, or nasal cannula and is preferably delivered through a low-resistance interface. (8) Positive end-expiratory pressure (PEEP) is generated by immersing the expiratory limb under water and the amount of PEEP delivered is equal to the depth of the immersion. Bubble CPAP is hypothesized to produce low-amplitude, high-frequency oscillations that may enhance gas exchange. (6)(8) Clinicians should consider a chin strap to improve pressure delivered via bubble CPAP if there is loss of pressure when the infant’s mouth is open, which can be detected by absence of bubbling in the water chamber in the presence of an appropriate nasal interface seal. This simple maneuver of closing the mouth with a chin strap can increase pharyngeal pressure by 2 to 3 cm H2O. (8)Some units have chosen to use bubble CPAP instead of ventilator CPAP because of its practical, simple, space-saving design, making it user friendly while being cost effective. Bubble CPAP allows for maintenance of consistent distending pressure from initiation in the resuscitation room to the NICU and for the duration of the infant’s NICU course. Evidence suggesting that any one CPAP approach is superior to another in reducing bronchopulmonary dysplasia is limited. (7) A recent systematic review of meta-analyses comparing bubble CPAP with other forms of CPAP found that the rate of CPAP failure was lower with bubble CPAP compared to ventilator CPAP; the authors did not find any difference between bubble and infant flow CPAP. (9) One study suggested that bubble CPAP may be preferred for postextubation use in infants who had been intubated for up to 14 days. (10) Further comparison studies are needed to determine the most optimal form of CPAP.For delivery of a preterm infant at less than 32 weeks’ gestation, prepare all necessary equipment including: Bubble CPAP delivery system (set up as per manufacturer’s instructions, attach to a transport isolette or transport pole; setup guideline/videos are available from commercial manufacturers)Various sizes of occlusive nasal interfaces (mask or prongs; we recommend low-resistance interface rather than high airway resistance RAM cannula system [Neotech, Valencia, CA])Nasal tubing (we recommend wide-bore tubing)Bonnets for placement of interface, if neededMeasuring tape for assessing bonnet sizeOxygen tubingSterile water for CPAP generator/chamber (sterile water should be placed immediately before expected use in the resuscitation room)T-piece resuscitator or flow-inflating bagFor use of bubble CPAP in the NICU, the equipment can be used with the system connected to a pole.Apnea or poor respiratory effort (11)Congenital diaphragmatic hernia (11)Esophageal atresia (11)Choanal atresia, both unilateral and bilateral (11)Cleft palate (11)Severe cardiovascular instability (11)Bubble CPAP is set up as per the manufacturer’s directions (Fig 1)Radiant warmer is set up with T-piece resuscitator (or flow-inflating bag) and bubble CPAP attached (Fig 2)After the infant is placed on the radiant warmer, assess the appropriate size of mask (or nasal prong) interface required for infant (Fig 3)Apply occlusive CPAP interface immediately, and if infant has an appropriate heart rate with spontaneous respirations, measure occipitofrontal circumference, place cap, and complete application of CPAP (Fig 4)If the infant has significant bradycardia or apnea requiring positive pressure ventilation, transition to the T-piece resuscitator (Fig 5A) or flow-inflating bag (Fig 5B); if the infant has a return of spontaneous respirations and improvement in heart rate, transition back to bubble CPAPAn example of applying bubble CPAP in the delivery room is shown in the Video.Pneumothorax. (12)(13) CPAP at a median rate of 8 cm H2O was found to be associated with an increased incidence of pneumothorax in infants with a birth gestational age of 25 to 28 weeks in the Continuous Positive Airway Pressure or Intubation at birth trial (COIN trial). (12) Another study did not find an increase in pneumothorax in infants receiving CPAP versus mechanical ventilation; in this study, infants had a gestational age between 24 and 27 6/7 weeks and the initial PEEP was 5 cm H2O although the maximum PEEP was not reported. (3) A Cochrane review estimated that 11 preterm infants have to be treated with CPAP for 1 preterm infant to develop a pneumothorax. (14)Nasal septal breakdown. (13) This needs to be regularly assessed.Feeding intolerance due to gastric distention. (13)Cardiovascular compromise secondary to increased intrathoracic pressures and impaired venous return, if excessive CPAP is needed. (13)Excessive lung volumes leading to impaired ventilation and compromise of pulmonary blood flow, which may worsen ventilation/perfusion mismatch and lead to impaired oxygenation. (13)