Factors Predicting Spontaneous Closure of Patent Ductus Arteriosus in Very Low Birth Weight Neonates

Abstract

Background: Management of hemodynamically significant patent ductus arteriosus (hsPDA) in very low birth weight (VLBW) neonates remains a challenge. Accurate prediction of spontaneous PDA closure could allow selective medical treatment and prevent unnecessary medical intervention. This study aims to evaluate potential variables as predictors of spontaneous closure of hsPDA in VLBW infants. Methods: We conducted a retrospective review of VLBW infants born from 2006 to 2014 at our institution. Infants included in the study were diagnosed with moderate to large hsPDA on echocardiogram in the first week of life. We divided our population into 2 study groups: PDA closure before discharge without medical/surgical treatment (spontaneous closure) and PDA closure by medical or surgical treatment warranted by critical clinical status. Relevant baseline data and PDA-related parameters were extracted from the medical records. Statistically significant variables were further analyzed using a multiple logistic regression model to identify potential independent predictors of spontaneous closure. Results: 108 infants were included in the study; 52 had spontaneous PDA closure and 56 required treatments. Of the baseline characteristics, only gestational age and mode of delivery differed significantly between infants with spontaneous closure and those who required treatment. Significant variables included hematocrit and fluids received on day 1 of life, pre-diagnosis mean pH, PCO2, serum bicarbonate, average fluid goal, and average urine output. After multiple logistic regression analysis, controlling for statistically significant and clinically relevant variables, Cesarian section (OR, 0.18, 95% CI, 0.06-0.55; P=.003), average pre-diagnosis PCO2 (OR, 0.92; 95% CI, 0.86-0.98; P=0.008) and pre-diagnosis daily fluid received (OR, 0.96; 95% CI, 0.94-0.99; P=0.03) were independent predictors of spontaneous closure. Sensitivity and specificity analysis of predictor variables revealed highest sensitivity cut-off points of 40 mm Hg (71.2%) for PCO2, 104 mL/kg/d (71.2%) for fluid goal and highest specificity cut-offs of 64 mm Hg (91.1%) and 158 mL/kg/d (96%), respectively. Conclusion: In our study of VLBW infants, lower average pre-diagnosis CO2, lower daily fluid goal, and vaginal birth were associated with increased likelihood of spontaneous hsPDA closure.