Bariatric surgery: Rhabdomyolysis after open Roux-en-Y gastric bypass: a prospective study.

BACKGROUND: Rhabdomyolysis (RML) is a recently recognized complication of bariatric surgery (BS). The aim of this prospective study was to determine frequency, risk factors, and clinical relevance of RML in morbidly obese patients treated with open Roux-en-Y gastric bypass (RYGBP).
METHODS: A total of 23 consecutive patients with morbid obesity undergoing primary open RYGBP were included prospectively in the present study. The following parameters were recorded: age, gender, BMI (kg/m(2)), comorbidities (presence of known hypertension and diabetes), duration of surgery, levels of serum creatine phosphokinase (CPK) measured before surgery and daily after until the values were clearly tending towards normal, and the presence of neuromuscular symptoms in the early post-operative period. RML was defined as post-operative CPK >1000 IU/l (5 times the normal value). Patients were divided into two groups according to the presence or absence of RML.
RESULTS: The study sample consists of 16 females (69.6%) and 7 males (29.4%). RML was diagnosed in 7 (30.4%) patients with CPK levels greater than 5000 IU/l in 3 patients (42.9%). BMI was identified as an independent risk factor for RML (P = 0.031). The best cut-off value of BMI as a predictor of RML was 55.88 kg/m(2) giving sensitivity of 100% and specificity of 80.7%. Other variables (age, sex, comorbidities, and duration of surgery) did not have a significant predictive effect on the rate of RML.
CONCLUSION: After open bariatric surgery with RYGBP, the risk of RML increases in obese patients specially when BMI >56 kg/m(2). In such patients, CPK, which is an inexpensive easily done test, should be performed routinely to guarantee early diagnosis and consequently preventive treatment of RML complications.