The association between rhabdomyolysis and acute renal failure in patients undergoing cardiopulmonary bypass.

Objective: The authors describe 9 cases of rhabdomyolytic acute renal failure (ARF) as a complication of cardiopulmonary bypass.

Experimental Design: Retrospective research between June 1992 and March 1994.

Setting: Department of Cardiac Surgery.

Patients: 931 consecutive patients undergoing major cardiac surgery.

Interventions: Patients affected by rhabdomyolytic ARF were treated with pharmacological therapy and/or plasmapheresis/continuous arteriovenous hemofiltration. In seven patients indirect cannulation of the femoral artery was used.

Measures: Incidence, risk factors of syndrome results obtained with pharmacological treatment, CAVH and plasmapheresis were evaluated. Statistical analysis was performed with ANOVA, Tukey Kramer test and chi2 test (p<0.05 as significant).

Results: The syndrome occurred in 0.96% (9/931 patients) of the total cases; 11.3% (6/53 -p<0.0000) in patients undergoing a direct femoral artery cannulation for cardiopulmonary bypass and 9.5% (2/21, p<0.01) in patients in which the aortic balloon pump was used. Six patients develop acute anuric renal failure and underwent plasma exchange and hemodialysis (1 case) or CAVH (5 cases); 3 patients underwent early medical treatment and developed developed acute renal failure (ARF) with preserved diuresis. Early medical therapy appeared to prevent the evolution towards anuric ARF. The indirect cannulation of the femoral artery does not seem to produce a rhabdomyolytic ARF syndrome. In patients with direct femoral artery cannulation risk factors appear to be: arteriopathy (p<0.001), prolonged extra corporeal circulation (p<0.001), low cardiac output syndrome (p<0.001), continuous i.v. infusion of epinephrine (p<0.0001).

Conclusions: Rhabdomyolytic acute renal failure is a severe complication, early identification of patients ¿at risk¿ is most important. The preventive measures and the therapy adopted proved efficient.