Experimental study of controlled fluid resuscitation in the treatment of severe and uncontrolled hemorrhagic shock.

Background: Hemorrhagic shock is a common clinic emergency case. The fluid resuscitation method in the presurgical care of hypotensive trauma patients is open to debate. This study was conducted to evaluate the general and pathophysiologic effects of controlled fluid resuscitation in the treatment of severe and uncontrolled hemorrhagic shock.

Methods: A model of rat with severe hemorrhagic shock and active bleeding was established in 32 Sprague-Dawley rats. The rats were randomly divided into the control group, no fluid resuscitation group (NF group), controlled fluid resuscitation group (NS40 group), and aggressive fluid resuscitation group (NS80 group). Each group contained eight rats. The changes of survival, blood loss, blood platelet, hemoglobin, hematocrit, and serum lactate level were dynamically monitored in the "prehospital phase". In addition, the apoptosis in the liver, kidney, lung, and small intestinal mucosa of survivors after hemorrhage and resuscitation was detected by light microscopy in hematoxylin-eosin stained tissue sections, flow cytometry, and terminal deoxynucleotidyl transferase dUTP nick end labeling. Via the above-mentioned indexes, the curative effects of three fluid resuscitation methods were compared.

Results: Compared with the survival in the NF group (3 of 8), the higher survival rate of the NS40 and NS80 groups (14 of 16) showed significant difference (p < 0.05). After fluid resuscitation, serum lactate levels in the NS40 and NS80 groups obviously decreased (p < 0.01 compared with control and NF groups). The shed blood loss from bleeding tail in the NS80 group was obviously increased (p < 0.01 for the NS80 group compared with the control, NF, and NS40 groups). Compared with that of the control, NF, and NS40 groups, the hemoglobin, hematocrit, and blood platelet of the NS80 group quickly descended in the prehospital phase and showed statistical differences. At the same time, there was some apoptosis in the liver, kidney, lung, and small intestinal mucosa of all survivors. Compared with that of the NF and NS40 groups, the apoptosis of liver, kidney, and small intestinal mucosa of the NS80 group was obviously increased, and showed statistical differences.

Conclusions: In severe and uncontrolled hemorrhagic shock, some fluid must be given in proper time to improve tissue perfusion and avoid early death. Among three fluid resuscitation methods, controlled fluid resuscitation can effectively decrease additional blood loss, avoid excessive hemodilution and coagulopathy, improve the early survival rate, and reduce the apoptosis of visceral organs in rats with severe and uncontrolled hemorrhagic shock. This model supports the concept that when surgical care is not readily available, controlled fluid resuscitation should be considered in the treatment of uncontrolled hemorrhagic shock.