Objective. In adults, a single dose of 250 mg of caffeine may decrease cerebral blood flow by 30%. In preterm infants, caffeine is commonly used for the treatment and prophylaxis of apnea. The purpose of this investigation was to assess effects of caffeine on circulatory parameters in preterm infants.
Methods. We studied 16 preterm neonates with a mean gestational age (mean ± standard deviation) of 31 ± 1.2 weeks (range: 29–33 weeks), birth weight of 1400 ± 380 g (range: 625-2060 g), and postnatal age of 24 to 72 hours before and 1 and 2 hours after an oral loading dose of 25 mg/kg pure caffeine. We investigated left ventricular output (LVO), cerebral blood flow velocity (BFV) of the internal carotid artery (ICA) and the anterior cerebral artery, and intestinal BFV of the celiac artery and superior mesenteric artery by Doppler sonography.
Results. Mean BFV in the ICA decreased significantly 1 (17%) and 2 hours (22%) after caffeine administration. Mean BFV in the anterior cerebral artery showed a reduction of 14% after 2 hours. The mean BFV in the superior mesenteric artery decreased significantly 1 and 2 hours after caffeine administration (30%). Mean BFV in the celiac artery showed a significant reduction of 14% 1 hour after caffeine. No changes were observed in LVO, blood pressure, and heart rate.
Conclusion. Oral administration of a high loading dose of caffeine results in marked reduction of cerebral and intestinal BFV, without changing LVO, blood pressure, and heart rate.