Crossover Comparison of Tidal Volume Delivery During Nasal Intermittent Positive Pressure Ventilation in Preterm Infants: Infant Cannula vs. Nasal Continuous Positive Airway Pressure Prongs

Bedside crossover study of neonates with mild respiratory distress receiving NIPPV. Infants serve as their own controls and are randomized to initial interface of either RAM® infant cannula or Miniflow® nCPAP prongs. Infants are instrumented with the following monitoring equipment: Edi orogastric tube to measure electrical activity of the diaphragm, transcutaneous monitor to measure transcutaneous CO2 and O2, pulse oximeter to measure heart rate and oxygen saturation, and respiratory inductance plethysmography (RIP) bands around the chest and abdomen to measure breathing movements and relative Vt (arbitrary units, a.u.). Data are continuously and simultaneously acquired using a data acquisition system. After 10 minutes of stabilization, infants receive 5 minutes of NIPPV on each of a sequence of four commonly used pressure settings (expressed as peak inspiratory pressure / positive end expiratory pressure): 16/5, 16/8, 20/5, 20/8. This sequence is not randomized and is constant between interfaces. Subjects are then placed on the alternate interface, and the sequence is repeated. Events ("breaths") are separated into 3 types: patient effort synchronized with NIPPV breaths (type I), NIPPV breaths without patient effort (type II), and patient effort without NIPPV breaths (type III).