Objective: To test whether early blood administration combined with crystalloid solution infusion may prolong survival in a clinically relevant model of ongoing uncontrolled life-threatening hemorrhage.
Methods: Light anesthesia was induced with halothane in 24 rats, and spontaneous breathing was maintained. Uncontrolled hemorrhagic shock was induced by withdrawal of blood at 2.5 mL/100 g over a 15-minute period, followed by 75% tail amputation. At 10 minutes after tail cutting, rats were randomized into four groups (n = 6 each): group 1, receiving 3 mL of shed blood for 5 minutes followed by 9 mL of lactated Ringer's (LR) solution for 15 minutes; group 2, receiving 9 mL of LR solution for 15 minutes followed by 3 mL of shed blood for 5 minutes; group 3, receiving 9 mL of LR solution only for 15 minutes; group 4, receiving neither of shed blood nor LR solution. Rats were then observed until death or a maximum of 180 minutes.
Result: Mean survival time was 138 +/- 30 minutes, 108 +/- 22 minutes, 79 +/- 13 minutes, and 55 +/- 18 minutes for groups 1, 2, 3, and 4, respectively (p < 0.05 among the four groups). Additional blood loss from the tail stump did not differ significantly between the three treatment groups.
Conclusions: In a model of uncontrolled hemorrhagic shock in rats, a resuscitation regimen using crystalloids agent alone is not ideal, and even a brief delay in blood administration worsens survival. Early blood administration combined with crystalloid solution infusion seems ideal.