Background: Rhabdomyolysis (RML) is caused by muscle injury, this may cause kidneys overload and lead to acute renal failure (ARF). The risk factors for RML in bariatric surgery (BS) are operative time (OT) >4 h and high BMI. The frequency of RML in BS varies from 12.9 to 37.8%. This study has the objective of describing the characteristics associated with RML and ARF in BS.
Methods: We studied retrospectively 114 patients submitted to BS. Criteria for RML were CPK level >950 IU/l (five times the normal value). The variables were BMI, OT, age, intraoperative hydration and diuresis, CPK, creatinine, arterial hypertension, peripheric vascular disease, diabetes, open and laparoscopic techniques--inclusion criteria: patients submitted to gastric bypass; exclusion: renal failure and statins use.
Results: RML incidence was 7%. The factors associated with RML in the bivariate analysis were hepatic steatosis, high BMI, high weight, higher excess weight, and prolonged OT. The risk factor for RML in the multivariate analysis was BMI > or = 50 kg/m2. When the OT was below 2 h the incidence of RML was zero, but this was not significant in the multivariate analysis. The factors associated with a higher risk of CPK elevation (multivariate analysis) were hypertension and open technique.
Conclusion: BS is safe, with low incidence of RML/ARF. High BMI is associated with a higher risk of RML. Probably a longer OT is associated with a higher risk of RML not statistically demonstrated in this study. The factors associated with a higher risk of CPK elevation were hypertension and open technique.