431 Predictors of Decreased Fluid Tolerance in Vlbw Infants

Abstract

Objective: The goal was to elucidate predictors of decreased fluid tolerance (DFT) in very low birth weight (VLBW) infants. We hypothesized that the fluid retention is linked to severity of pulmonary problems and prolonged respiratory support, especially to nCPAP treatment. Methods: The investigation was carried out at Tampere University Hospital between years 2001 and 2006. The study population comprised 74 very low birth weight (VLBW) infants born at 29.21 (24.57-34.14) weeks of gestation. Median of birth weight was 1175 (575-1490) grams. We measured plasma and urine osmolality and 24 hour urine volume to calculate free water clearance (FWC) for each infant. If FWC was less than 30 ml/kg/day the infant was classified as having a DFT. Results: There were 38 (51.4%) infants with an abnormal FWC (AFWC) in the study population. The median duration of observed DFT period was 14 (4-44) days. The gestational age at birth was lower for AFWC infants compared to infants with normal FWC (NFWC), 28.29 (24.57-32.86) vs. 30.00 (25.57-34.14) weeks (p=0.001). AFWC infants also needed longer ventilator treatment, 2 (0-23) vs. 0.50 (0-23) days (p=0.046), nCPAP treatment 30 (0-100) vs. 3 (0-41) days (p< 0.0001) and longer oxygen supplementation 22 (0-74) vs. 47 (0-163) days (p=0.011) than NFWC infants. Conclusions: Decreased fluid tolerance seems to be frequently connected with exacerbation and prolongation of pulmonary problems in VLBW infants. Fluid restriction might be a more beneficial treatment than diuretics in VLBW infants with prolonged respiratory problems and DFT.