Resuscitation of severe but brief haemorrhagic shock with PFC in rabbits restores skeletal muscle oxygen delivery and does not alter skeletal muscle metabolism

Abstract

Studies have demonstrated that perfluorocarbon (PFC) emulsions associated with hyperoxia improved whole body oxygen delivery during resuscitation of acute haemorrhagic shock (HS). Nevertheless the microcirculatory effects of PFC and the potential deleterious effects of hyperoxic reperfusion are still of concern. We investigated (i) the ability of a newly formulated, small sized and highly stable PFC emulsion to increase skeletal muscle oxygen delivery and (ii) the effect of hyperoxic reperfusion on skeletal muscle metabolism after a brief period of ischaemia using an original, microdialysis-based method that allowed simultaneous measurement tissue oxygen pressure (PtiO2) and interstitial lactate and pyruvate. These measurements were carried out in anaesthetised and ventilated (FiO2 = 1) rabbits subjected to acute HS (50% of blood volume withdrawal) and either resuscitated with a PFC emulsion diluted with a 5% albumin solution (16.2 g PFC per kg body weight) (n = 10) or with a modified fluid gelatin solution (Gelofusine) (n = 10). We found no difference between the two groups for the haemodynamic and haematological variables (except for the venous oxygen partial pressure). However, a significant difference was observed in the slope of the regression linear relationship exhibited between the mean arterial pressure (MAP) and the PtiO2, PFC group showing a much steeper slope than Gelofusine group. In addition, PtiO2 values increased linearly with decreasing haematocrit (Hct) values in PFC-resuscitated animals and decreased linearly with decreasing Hct values in Gelofusine-resuscitated animals. There were no differences between the two groups concerning the blood and interstitial lactate/pyruvate ratios suggesting no deleterious effect of hyperoxic resuscitation in skeletal muscle. In conclusion these results suggest that resuscitation of severe, but brief, HS with PFC increased skeletal muscle oxygen delivery without measurable deleterious effects.