Effects of hypotensive resuscitation on uncontrolled hemorrhagic shock in rats

Objective To study the effects of hypotensive resuscitation and larger volume fluid resuscitation on uncontrolled hemorrhagic shock and survival in rats with a standardized massive splenic injury model (MSI).Methods Following establishment of MSI model,fifty Wistar rats were randomly and equally divided into five groups, group 1: sham operated group, group 2: shock untreated group, group 3: normal MAP resuscitation group (during acute resuscitation phase MAP was kept at 80mmHg),group 4: hypotensive resuscitation group(during acute resuscitation phase MAP was kept at 60mmHg±5mmHg), group 5: larger volume fluid resuscitation with hypotensive resuscitation group(during acute resuscitation phase MAP was kept at 60mmHg±5mmHg, simultaneously infused SNP at 5μg·kg -1 ·min -1 ).Results The mean survival time in group 1～5 was 180, 73.50±8.04, 114.30±31.33, 146.70±28.07 and 171.60±15.74(min), respectively. Statistic significances were seen in each group ( P 0.05),except between group 1 and group 5 ( P =0.0671).The amount of bleeding in group 2～5 (during acute resuscitation phase ) was 3.79±1.39,17.41±8.88,8.67±4.59 and 10.33±4.31(ml·kg -1 ) respectively. The loss of blood in group 3 was significantly more than other groups ( P 0.05). Group 4 and group 5 enhanced the blood loss significantly compared with group 2 ( P 0.05).Conclusion Hypotensive resuscitation and adding SNP at a proper dose additionally could improve tissue metabolism and prolong survival time during hypotensive resuscitation from uncontrolled hemorrhagic shock. It is a more ideal resuscitation method compared with normal blood pressure resuscitation.