Effect of caffeine on superior mesenteric artery blood flow velocities in preterm neonates

Objective: To investigate the effect of caffeine infusion on superior mesenteric artery (SMA) blood flow velocities (BFV) in preterm infants.

Methods: Prospective observational study on 38 preterm neonates 28–33⁺⁶ weeks gestation, who developed apnea on their first day of life, and caffeine citrate infusion was initiated at a loading dose of 20?mg/kg, followed by a maintenance dose of 5–10?mg/kg/day. Duplex ultrasound measurements of SMA BFV were recorded: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI), at 15?min before, 1-, 2- and 6-h after caffeine loading dose, and 2?h after two maintenance doses.

Results: There was a significant reduction in PSV 1-h (p?=?.008), a significant decrease in EDV 1- and 2-h (p?=?.000 and p?=?.005, respectively) and a significant increase in RI 1- and 2-h (p?=?.003 and p?=?.005, respectively) following caffeine loading dose, as compared to values before caffeine infusion. No significant effect of caffeine maintenance doses on SMA BFV was observed (p?>?.05).

Conclusion: Blood flow in SMA is significantly reduced after caffeine citrate infusion at a loading dose of 20?mg/kg. This effect continues for at least 2?h. Meanwhile, SMA BFV seems not affected by maintenance doses.