Abstract
INTRODUCTION: Hypotensive fluid resuscitation has a better effect before and during surgical intervention for multiple trauma patients with haemorrhagic shock. However, it is questionable whether hypotensive fluid resuscitation is suitable after surgical intervention for these patients, and whether resuscitation with different mean arterial pressure (MAP) targets after surgical intervention can obtain different results. The aim of this study was to investigate these questions and to explore the underlying mechanisms. METHODS: A total of 30 anesthetized piglets were randomly divided into 3 groups (n = 10 per group): low MAP, middle MAP, and high MAP, which had MAP targets of 60, 80, and 100 mmHg, respectively. All animals underwent femur fracture, intestine and liver injury, haemorrhagic shock, early hypotensive resuscitation, and surgical intervention. Then, the animals received fluid resuscitation with different MAP targets as mentioned above for 24 hours. Hemodynamic parameters and vital organ functions were evaluated. RESULTS: Fluid resuscitation in the 80 mmHg MAP group maintained haemodynamic stability, tissue perfusion, and organ function better than that in the other groups. The 60 mmHg MAP group presented with profound metabolic acidosis and organ histopathologic damage. In addition, animals in the 100 mmHg MAP group exhibited severe tissue oedema, organ function failure, and histopathologic damage. CONCLUSIONS: In our porcine model of resuscitation, targeting high MAP by fluid administration alone resulted in a huge increase in the infusion volume, severe tissue oedema, and organ dysfunction. Meanwhile, targeting low MAP resulted in persistent tissue hypoperfusion and metabolic stress. Hence, a resuscitation strategy of targeting appropriate MAP might be compatible with maintaining haemodynamic stability, tissue perfusion, and organ function.