Desaturations with or without Bradycardia are Associated with Cerebral and Abdominal Hypoxemia: Secondary Analysis of a Randomized Clinical Trial

Objective To determine if episodes of desaturation, either with or without bradycardia, are associated with cerebral and abdominal hypoxemia in preterm infants. Study Design Secondary analysis of a single center pilot randomized clinical trial including preterm infants <29 weeks’ gestation on positive pressure respiratory support. Rates of cerebral hypoxemia (<55% for ≥10 seconds) and abdominal hypoxemia (<40% for ≥10 seconds) on near-infrared spectroscopy corresponding with episodes of desaturation (oxygen saturations (SpO2) <85% for ≥10 seconds) either with or without bradycardia (<100 bpm for ≥10 seconds) were compared using a generalized estimating equation to address repeated events from the same subject. Results Twenty-five infants with a gestational age (mean+SD) of 24w 6d±11d and birth weight 645±142 grams were included. Desaturations with and without bradycardia were both associated with cerebral hypoxemia and abdominal hypoxemia (all p<0.05). Cerebral hypoxemia was more strongly associated with desaturations with bradycardia compared to episodes without bradycardia (adjusted odds ratio (aOR), 95% confidence intervals (CI): 0.34, 0.25-0.47; p<0.001). There were also more episodes of abdominal hypoxemia during desaturations with bradycardia versus desaturations with no bradycardia (aOR, 95% CI: 0.35, 0.26-0.46; p<0.001). The rate of concurrent cerebral and abdominal hypoxemia was also higher during desaturations with bradycardia. Conclusions Desaturations, whether occurring with or without bradycardia, are associated with cerebral and abdominal hypoxemia in very preterm infants. Cerebral and abdominal hypoxemia are more likely during episodes of desaturation with bradycardia than during episodes without bradycardia.