Effect of Blood Transfusions on Intermittent Hypoxic Episodes in a Prospective Study of Very Low Birth Weight Infants.

Objectives To compare the number of intermittent hypoxia events before and after packed red blood cell (pRBC) and non-pRBC transfusions in very low birth weight infants, and to compare the time spent with saturations of <= 85% before and after transfusions in the same population. Study design This prospective observational study was conducted from April 2014 to August 2017. It included 92 transfusions (81 pRBC, 11 non-pRBC) from 41 very low birth weight infants between 23(0/7) and 28(6/7) weeks of gestation. The primary outcome was number of intermittent hypoxia events. Secondary outcomes included the percent time of Peripheral capillary oxygen saturation (SpO2)of <= 85%, 80%, and 75%. A mixed ANOVA model was used to examine the relationship between event rate and covariates. Results The mean number of intermittent hypoxia events per hour decreased from 5.27 +/- 5.02 events per hour before pRBC transfusion to 3.61 +/- 3.17 per hour after pRBC transfusions (P < .01) and intermittent hypoxia did not change after non-RBC transfusions (before, 4.45 +/- 3.19 vs after, 4.47 +/- 2.78; P = NS). The percent time with saturations of <= 80% and <= 75% significantly decreased after pRBC transfusions (P = .01). The time with saturations of <= 85% did not significantly change after non-pRBC transfusion. Conclusions In very low birth weight infants with a hematocrit of 20%-42%, pRBC transfusions are associated with decreased frequency of intermittent hypoxia. No such diminution of intermittent hypoxia events was observed in infants who had received a non-pRBC transfusion. This finding suggests that the observed beneficial effects of RBC transfusions on apnea and its clinical manifestations of intermittent hypoxia are mediated through an enhanced oxygen carrying capacity.