Abdominal Aortic and Junctional Tourniquet release after 240 minutes is survivable and associated with small intestine and liver ischemia after porcine class II hemorrhage.

BACKGROUND

Uncontrolled hemorrhage is a leading cause of tactical trauma-related deaths. Hemorrhage from the pelvis and junctional regions are particularly difficult to control due to the inability of focal compression. The Abdominal Aortic and Junctional Tourniquet (AAJT) occludes aortic blood flow by compression of the abdomen. The survivability of tourniquet release beyond 120 minutes is unknown and fluid requirements to maintain sufficient blood pressure during prolonged application are undetermined. We therefore compared 60-minute and 240-minute applications and release of the AAJT for 30 minutes, with crystalloid fluid therapy, after a Class II hemorrhage.

METHODS

Sixty-kilogram anesthetized pigs were subjected to 900-mL hemorrhage and AAJT application for 60 minutes (n = 5), 240 minutes (n = 5), and fluid therapy only for 240 minutes (n = 5) and reperfusion for 30 minutes.

RESULTS

The AAJT application was hemodynamically and respiratory tolerable for 60 minutes and 240 minutes. Cumulative fluid requirements decreased by 64%, comparable to 3000 mL of crystalloids. Mechanical ventilation was impaired. AAJT increased the core temperature by 0.9°C compared with fluid therapy. Reperfusion consequences were reversible after 60 minutes but not after 240 minutes. A 240-minute application resulted in small intestine and liver ischemia, persisting hyperkalemia, metabolic acidosis, and myoglobinemia, suggesting rhabdomyolysis.

CONCLUSION

The AAJT application for 240 minutes with reperfusion was survivable in an intensive care setting and associated with abdominal organ damage. Long time consequences and spinal cord effects was not assessed. We propose an application time limit within 60 minutes to 240 minutes, though further studies are needed to increase the temporal resolution. The AAJT application may be considered as a rescue option to maintain central blood pressure and core temperature in cases of hemorrhagic shock from extremity bleedings, if fluid therapy is unavailable or if the supply is limited.

LEVEL OF EVIDENCE

Therapeutic study, level II.