Preterm infants with hypotension (mean arterial blood pressure [MABP] < gestational age [GA]) are treated with volume expansion and/or dopamine to ensure adequate cerebral perfusion/oxygenation. We used near-infrared spectroscopy to analyze the effects of volume expansion and dopamine on cerebral oxygenation in hypotensive preterm infants without patent ductus arteriosus (PDA).
Among 390 infants, 71 (GA < 32 weeks) were hypotensive and eligible for inclusion. Thirty-three infants received volume expansion only (NaCl 0.9%; 20 mL/kg), and 38 received additional dopamine (5 μg/kg per minute). Nine and 11 infants initially treated with dopamine subsequently needed 7.5 and 10 μg/kg per minute, respectively. Seventy-one infants without hypotension were individually matched to serve as controls. MABP, regional cerebral oxygen saturation (rSco2), fractional tissue oxygen extraction (cFTOE), and arterial saturation (Sao2) were monitored 15 minutes before and 30 and 60 minutes after volume or dopamine and at comparable postnatal ages in controls.
No changes in MABP, rSco2, or cFTOE were found 30 minutes after volume expansion. MABP increased 60 minutes after 5 μg/kg per minute dopamine (median [range]: 28 [19–32] vs 33 [23–46] mm Hg; P < .001). There was a small increase and decrease, respectively, in rSco2 (63 [43–84] vs 66 [46–87]%; P < .05) and cFTOE (0.33 [0.14–0.56] vs 0.31 [0.07–0.54]1/1; P < .05). However, no differences were found at any time point between controls and infants treated with volume or additional dopamine (5, 7.5, and 10 μg/kg per minute) for rSco2 or cFTOE.
Volume expansion and additional dopamine do not cause any significant change in rSco2 or cFTOE in hypotensive preterm infants without PDA. We speculate that very preterm infants with hypotension but without signs of a compromised cerebral oxygenation and systemic perfusion might not be in need of antihypotensive therapy.