|Burrin, Douglas - Doug|
Submitted to: Pediatric Research
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2008
Publication Date: 4/1/2008
Citation: Burrin, D.G., Gay, A.N., Stoll, B., Naik-Mathuria, B., Olutoye, O.O. 2008. Can abdominal NIRS detect changes in intestinal blood flow and risk of NEC in premature piglets?. Pediatric Research. E-PAS 635819.3 Interpretive Summary:
Technical Abstract: Necrotizing enterocolitis (NEC) is major gut disease in preterm newborns. Intestinal ischemia may be an early contributing factor that precipitates NEC. Near-infrared spectroscopy (NIRS) is a non-invasive method of measuring local tissue oxygen saturation and indicator of blood flow. Our aim was to determine trans-abdominal NIRS measurements of StO2 correlate with changes in intestinal blood flow, and the onset of NEC in premature neonatal piglets. In study 1, neonatal (2 d-old, n=10) pigs were implanted with vascular catheters, and an ultrasonic flow probe on the superior mesenteric artery. After 7 d recovery, piglets were anesthetized and the rate of SMA flow and abdominal StO2 were measured continuously during a 10 min baseline (saline infusion), and 20 min treatment (25 g/kg bolus glucagon-like peptide 2, GLP-2). In study 2, premature (10 d preterm, n=17) piglets were delivered by cesarean section given total parenteral nutrition (TPN) for 72 h, and thereafter fed a milk-based formula (15 ml/kg) every 3 h for 48 h. All pigs were monitored for clinical signs of NEC and intestinal biopsies were examined for histopathology. In study 1, as predicted, the mean (+/-SD) SMA flow (ml/min) was significantly higher during the GLP-2 (155 +/- 22) than saline baseline (76 +/- 15) the mean. The mean StO2% was also higher during the GLP-2 (82.0 1.1), compared to the saline baseline (74.6 +/- 1.9) period; the increase in StO2% occurred rapidly within 2 min GLP-2 treatment. Regression analysis indicated that the changes in StO2% were highly correlated with SMA flow (R2=0.45, P<0.001). In study 2, the NEC incidence was 18% (3/17) and was associated with abdominal distension, lethargy, villus erosion, and intestinal pneumatosis within 24 h of formula feeding. The mean StO2% at birth in healthy pigs was 30% , and increased gradually to 50-60% during the course of TPN, and enteral feeding. The mean StO2% in NEC pigs was significantly lower (21 +/- 20 vs 53 +/- 15) than healthy pigs. Trans-abdominal StO2 are significantly correlated with changes in intestinal blood flow in neonatal pigs. Evidence from premature pigs suggests that low trans-abdominal StO2 during the perinatal period may be a useful indicator of NEC risk.