2 | METHODS
We prospectively studied gastric emptying in very low birth weight (VLBW) infants treated with either MD-nCPAP or bCPAP from May 2018 to March 2020. The study was approved by Northwell Health Institutional Review Board (Manhasset, NY). Informed consent was obtained from parents before enrollment. Inclusion criteria included infants 25-34 weeks of gestational age (GA) at birth receiving full enteral feedings and treated with either MD-nCPAP or bCPAP for RDS. Infants with major congenital anomalies, gastrointestinal disease or surgery, and those treated with systemic antibiotics or GIT motility medications were excluded from the study.
Per NICU protocol, infants who are not mature enough to nipple feed are fed by bolus every 3 hours via orogastric tube (OGT). After minimal enteral trophic feedings are tolerated for 1-2 days, the feedings are increased daily by ~20 mL/kg/day until full enteral feeding volumes of 160 ml/kg/day are achieved. Feedings are fortified to 24 kcal/oz using Similac Human Milk Liquid Fortifier (Abbott Nutrition, Abbott Park, IL, USA) when enteral feeding volumes reach ~60 ml/kg/day. Parenteral nutrition (PN) support is discontinued when infants tolerate ~120 mL/kg/day of enteral feeding. Gavage feedings were provided over a feeding pump for 60 minutes period. The stomach is decompressed by opening the OGT to straight drainage 30 minutes after completion of feeding. All infants are examined every 3 hours for vomiting, abdominal distention, bowel sounds, bowel movement and abdominal wall softness. Gastric residuals or aspirates are checked only when an OGT is placed or replaced, or if there is a clinical indication. Feeding intolerance was defined as the withholding of feedings by the attending physician because of one or more of the following: bilious emesis, significant abdominal distention, abnormal bowel auscultation or abnormal vital signs.
Treatment of apnea of prematurity and RDS includes administration of IV or PO caffeine together with either MD-nCPAP or bCPAP. During the study period, our NICU was transitioning from using MD-nCPAP to bCPAP, with the choice dependent solely on the availability of bCPAP at the time of patient’s admission. MD-nCPAP was delivered by AVEATM(Vyaire Medical, Inc., Chicago, IL, USA) mechanical ventilator and administered through RAM cannula® (Neotech, Valencia, CA, USA). Bubble CPAP was delivered by a commercially available system (Fisher & Paykel Healthcare Ltd., Auckland, New Zealand) connected to Babi.Plus® nasal prongs (Respiralogics, NV, USA). Oxygen saturations were maintained between 88% and 95% as per NICU protocol. Upper airways and mouth were gently suctioned on an as-needed basis to keep them clear. Infants’ necks were kept in slight extension.