Effects of hemorrhagic shock and rhabdomyolysis on renal microcirculation, oxygenation and function in a female swine model.

ABSTRACT

BACKGROUND: Hemorrhagic shock (HS) and rhabdomyolysis (RM) are two important risk factors of acute kidney injury (AKI) after severe trauma, however the effects of the combination of RM and HS on kidney function are unknown. The purpose of this study was to determine the impact of RM and HS on renal function, oxygenation, perfusion and morphology, in a pig model. METHODS: Forty-seven female pigs were divided into 5 groups sham, RM, HS, HS and moderate RM (RM4/HS), HS and severe RM (RM8/HS). RM was induced by intramuscular injection of Glycerol 50% with a moderate dose (4 ml/kg for RM4/HS group) or a high dose (8 ml/kg for RM and RM8/HS groups). Among animals with HS, after 90 min of hemorrhage, animals were resuscitated with fluid followed by transfusion of the withdrawn blood. Animals were followed for 48 hours. Macro and microcirculatory parameters measurements were performed. RESULTS: RM alone induced a decrease in creatinine clearance at 48 hours (19 (0-41) vs 102 (56-116) ml/min for RM and SHAM respectively; p = 0.0006) without alteration in renal perfusion and oxygenation. HS alone impaired temporarily renal microcirculation, function and oxygenation that were restored with fluid resuscitation. RM4/HS and RM8/HS groups induced greater impairment of renal microcirculation and function than HS alone at the end of blood spoliation that were not improved by fluid resuscitation. Mortality was increased in RM8/HS and RM4/HS groups in the first 48 hours (73% vs 56% vs 9% for RM8/HS, RM4/HS and HS groups respectively). CONCLUSIONS: The combination of HS and RM induced an early deleterious effect on renal microcirculation, function and oxygenation with decreased response to resuscitation and transfusion compared with HS or RM alone.