Efficacy of resuscitative infusion with haemoglobin vesicles for severe
postpartum haemorrhage in pregnant rabbits: An animal research study
Abstract
Objective. To investigate the resuscitative efficacy of haemoglobin
vesicles (HbVs) for severe postpartum haemorrhage (PPH) using pregnant
rabbits. Design: Animal research study Setting: Animal laboratory,
National Defense Medical College, Japan Population: Twenty-five female
New Zealand white rabbits at late gestation Methods. Pregnant rabbits
underwent caesarean section; uncontrolled haemorrhage was induced by
transecting the uterine artery to establish a severe PPH model. During
the first 30 min (or until the bleeding volume reached 100 mL), all
rabbits received 6% hydroxyethyl starch (HES) infusion. Thereafter,
rabbits received any of the three isovolemic fluid resuscitations every
5 min: red blood cells (RBCs) with platelet-poor plasma (RBC/PPP)
(vol/vol=1:1, n=8), 6% HES (n=7), or HbVs with 25% human serum albumin
(vol/vol=4:1, n=10). After 60 min (or when the bleeding volume reached
200 mL), we performed surgical haemostasis and monitored the rabbit
survival for 12 hours. Main Outcome Measures: Survival time for severe
postpartum haemorrhage Results. During the first 30 min, all rabbits
showed severe anaemia (Hb <6 g/dL) that eventually developed
to severe PPH. All rabbits that received only HES infusion died within 6
hours, whereas those that received RBC/PPP transfusion survived.
Furthermore, 8 of the 10 rabbits received HbV infusion 6 hours after
PPH. Overall survival of HbV group was markedly improved compared with
that of HES group (p=0.01) but was significantly worse than that of
RBC/PPP group (p<0.01). Conclusions. HbV infusion for severe
PPH effectively prevented lethal haemorrhagic shock in a pregnant rabbit
model, making it a feasible alternative modality.