Perioperative chronic use of statins and the risk of muscle complaints in patients undergoing knee and hip endoprosthesis surgery.

STUDY OBJECTIVE: To assess whether regular statin therapy enhances muscular and hepatic deterioration and muscle complaints in patients undergoing elective arthroplasty. DESIGN: Prospective, case-controlled, observational study. SETTING: Tertiary-level university teaching hospital in Eastern Finland. PATIENTS: 48 ASA physical status I, II, and III patients, aged 51 to 84 years, 24 of whom were scheduled for hip arthroplasty (12 pts with and 12 without statin therapy) and 24 patients who were to undergo knee arthroplasty (12 pts with and 12 without statin therapy). INTERVENTIONS: Before and after surgery, all patients were interviewed for muscular and hepatic symptoms and signs. MAIN MEASUREMENTS: S-creatine kinase, S-alanine aminotransferase, P-creatinine, S-lactate dehydrogenase, P-potassium, S-myoglobin, and U-myoglobin were measured at baseline and at 6, 24, and 72 hours after surgery. MAIN RESULTS: S-creatine kinase and S-myoglobin increased in all study groups at 6 hours after surgery and remained elevated for 72 hours, with no differences noted in patients treated with or without statins. There was no increase in the amount of muscular or hepatic complaints after surgery. CONCLUSION: Long-term statin therapy does not appear to increase the risk of muscular adverse effects in patients receiving major endoprosthesis surgery.

Potentially detrimental effects of N-acetylcysteine on renal function in knee arthroplasty.

Ischaemia/reperfusion induces systemic inflammation and oxidative stress and thereby remote organ injury in the kidney. In a double-blind, placebo-controlled clinical trial of 30 patients undergoing knee arthroplasty with tourniquet, this study evaluated the effect of N-acetylcysteine (NAC) infusion on renal function by measuring urine alpha-1-microglobulin, N-acetyl-beta-D-glucosaminidase (NAG), glutathione-S-transferase-alpha and -phi and serum creatinine and cystatin C concentrations up to 24 h post-operatively. Compared to the baseline, urine alpha-1-microglobulin/creatinine increased in both groups and was higher in the NAC group than in the placebo group at tourniquet deflation and at 3 h thereafter. Urine NAG/creatinine increased at deflation and at 3 h thereafter in the NAC group and the ratio was higher than in the placebo group. The two sensitive indicators of proximal tubular damage and function used in the present study suggest that use of NAC in clinical setting of ischaemia/reperfusion injury may increase the risk of remote kidney injury.