Background: Preterm infants are at high risk of adverse neurodevelopmental outcomes and this is associated with cardiovascular instability. The first line treatment for supporting preterm cardiovascular function, volume expansion with saline, is ineffective for maintaining blood pressure and does not improve neurodevelopmental outcomes [1]. We hypothesised that early blood transfusion using packed red blood cells (RBC) is more effective than saline for maintaining blood pressure and cerebral oxygenation.
Methods: Preterm piglets (98/115d gestation; similar to a 28wk infant) were randomly assigned to receive either 10 or 20mL/kg of packed RBC, or 10 or 20mL/kg of saline, or no treatment (n=8-11/group) over 1h. Blood pressure, heart rate, oxygen saturation, carotid blood flow, central venous pressure and cerebral oxygenation index (TOI, near-infrared spectroscopy; NIRS, INVOS system) were measured continuously from baseline (~5h PNA) until 6h after treatment commenced. Arterial blood gases were monitored at least hourly.
Results: Blood pressure was maintained at, or above, baseline levels in the transfusion groups, whereas blood pressure in the saline and untreated groups fell below baseline levels. Carotid flow was higher 6h after treatment commenced in the transfusion groups compared to other groups. Cerebral oxygenation was also maintained at, or above, baseline levels only in the transfusion groups but fell to 73% of baseline levels in the saline and untreated groups. Arterial pH and base excess (ABE) 6h after treatment commenced were higher in the 10mL/kg transfusion group compared to the untreated or saline groups. Similarly, end lactate levels were lower in the 10mL/kg transfusion group compared to all other groups.
Conclusion: Volume expansion with saline provides no benefit compared to no treatment. In contrast, volume expansion with packed RBCs is effective for maintaining blood pressure, cerebral oxygenation and acid-base status.