Platelet function as measured by the thromboelastrogram in end stage renal failure patients presenting for surgery – a pilot study.

Abstract

Chronic renal failure patients develop a coagulopathy primarily due to reversible platelet dysfunction. This coagulopathy makes certain anaesthetic techniques and procedures such as neuraxial anaesthesia and invasive line placement possibly contra-indicated or risky. There is no evidence to suggest that the degree of platelet dysfunction is proportional to the degree of renal dysfunction. In this research project the platelet function of 39 end stage renal failure patients, who received regular dialysis and who presented to theatre for vascular access, was assessed using the thromboelastogram. A bleeding time was also performed pre-operatively. A linear regression model was used to determine if the bleeding time, plasma urea, plasma creatinine or creatinine clearance could predict maximum amplitude (and therefore clot strength) on the thromboelastogram. No such regression could be found. The clinical implication of this result is that there exists no "safe" plasma urea or creatinine, below which it is safe to perform procedures which are contra-indicated in coagulopathies. The degree of renal dysfunction did not predict the degree of platelet dysfunction. Since dialysis reverses the platelet dysfunction, the question that should be asked before performing such a procedure is not "how severe is the renal dysfunction?" but rather "has the patient been receiving regular dialysis?"