Hypotensive resuscitation combined with polydatin improve microcirculation and survival in a rabbit model of uncontrolled hemorrhagic shock in pregnancy.

Background: Obstetric hemorrhage remains a leading cause of maternal death internationally. Polydatin is an effective drug in ameliorating microcirculatory insufficiency and increasing survival rate in non-pregnant animal model of controlled hemorrhagic shock. In the present study, we investigated the effects of hypotensive resuscitation combined with Polydatin administration on microcirculation and survival rate in a clinically relevant model of uncontrolled hemorrhagic shock in pregnancy.

Materials And Methods: Twenty anesthetized New Zealand white rabbits at mid and late gestation were anesthetized, and an ear chamber was prepared to examine microvessels by intravital microscopy. Shock was induced by transecting a small artery in mesometrium, followed by blood withdrawal via the femoral artery to a mean arterial pressure (MAP) of 40-45 mm Hg. Animals were randomly divided into two groups (n=10 per group): 30 min after hemorrhage induction, hypotensive resuscitation with Ringer's solution to MAP of 60 mm Hg, followed by a single volume infusion of 4 mL/Kg of normal saline or Polydatin at 60 min after hemorrhage induction (group NS, PD). Finally all the animals received hemorrhage control and resuscitated with half of the heparinized shed blood and Ringer's solution to MAP of 80 mm Hg.

Results: At the end of resuscitation, compared with group NS, group PD showed significantly improved capillary perfusion as indicated by increased arteriole diameter [0.95±0.02 of baseline (PD), 0.71±0.05 of baseline (NS); P=0.000] and higher functional capillary density[95.3% ± 2.6% (PD), 57.2% ± 4.1% (NS); P=0.000]. Median survival time was significantly longer in group PD than that in group NS [4 d (PD), 2 d (NS); P=0.000].

Conclusions: On the basis of hypotensive resuscitation, Polydatin administration improved microcirculation and prolonged survival time in pregnant rabbit model of uncontrolled hemorrhagic shock.