Continuous infusion of small-volume fluid resuscitation in the treatment of combined uncontrolled hemorrhagic shock and head injury

Abstract

Objective: To determine the effect of continuous limited fluid resuscitation on the hemodynamic response and survival in rats in a model of uncontrolled hemorrhage shock due to massive splenic injury (MSI) and head injury (HI).

Design: An experimental study.

Place and duration of study: Dicle University Animal Research Laboratory, Turkey, between January and February 2005.

Subjects and methods: Seventy Sprague-Dawley rats were used in this study. Group 1 rats (n=10) was sham-operated. In group 2 (n=10), only Massive Splenic Injury (MSI) was performed and untreated. In group 3 (n=10), only head injury (HI) was performed and untreated. In group 4 (n=10), HI and MSI were performed and were untreated. In group 5 (n=10), HI and MSI were performed and 15 minutes later treated with 7.5% NaCl. In group 6 (n=10), HI and MSI were performed, and rats were treated with Ringer's Lactate (RL) solution. In group 7 (n=10), HI and MSI were performed, rats were treated with 0.9 % NaCl. In groups 2,4,5,6 and 7 midline incision was reopened and splenectomy was performed at 45 minutes.

Results: In group 4 rats, Mean Arterial Pressure (MAP) was decreased from 104 +/- 6.1 mmHg to 75 +/- 19.5 mmHg at 15 minutes; heart rate decreased from 357 +/- 24.9 beats/min to 321 +/- 62.1 beats/min and hematocrit decreased from 46 +/- 1.3 % to 43 +/- 2.5 % (p<0.01). Similar early changes in MAP, heart rate and hematocrit were observed in groups 5, 6, and 7, at 15 minutes. At 45,60 and 120 minutes, in fluid resuscitated rats (group 5,6,7) MAP, heart rate and hematocrit values were measured higher than group 2 and 4 (p<0.01 for all). At 120 min. in group 6, hematocrit was higher than group 4, 5 and 7, in group 6, total blood loss after splenectomy was calculated at 20 +/- 2.4% of blood volume and was the best value compared to other fluid resuscitated group 5 and 7 (28% and 27% of blood volume) (p<0.01). Mortality was lower in all fluid resuscitated groups when compared to group 3 and 4 (p<0.05). The median survival time was again higher in fluid resuscitated groups.

Conclusion: Continuous infusion of 7.5% NaCl, RL and 0.9 % NaCl following uncontrolled hemorrhagic shock with massive splenic injury and combined head injury resulted in better survival and RL did not increase abdominal bleeding before splenectomy was performed.