Dopamine infusion for postresuscitation blood pressure support after profound asphyxia in near‐term fetal sheep

Abstract

Dopamine is commonly used for blood pressure support in the neonate, but has limited empirical evidence to support its use. We tested the hypothesis that after near-terminal asphyxia in utero, dopamine infusions would prevent secondary hypotension. Fetal sheep (122-129days of gestation; term is 147days) received umbilical cord occlusion for 15 min or sham occlusion (n=5). If the mean arterial blood pressure fell below 90% of baseline within 6 h after occlusion, fetuses were randomized to either dopamine infusion starting at 4μgkg(-1)min(-1) and titrated according to mean arterial blood pressure up to a maximum of 40μgkg(-1)min(-1) (n=5) or to the same volume of normal saline (n=5). Dopamine infusion, initiated at a median of 180 min after occlusion (range 96-280min), was associated with a marked but transient increase in mean arterial blood pressure and fall in femoral blood flow compared with saline. Terminal hypotension developed later in four of the five fetuses that received maximal dopamine infusions than in five of five receiving saline infusion [517 (range 240-715) versus 106min (range 23-497) after the start of infusions, P<0.05]. In conclusion, dopamine infusion delayed but did not prevent terminal hypotension after severe asphyxia.