Rhabdomyolysis after gastric bypass: severity and outcome patterns.

Background: Rhabdomyolysis (RML) is a recently recognized complication of bariatric operations, but it is not known whether creatine kinase (CK) levels along with clinical markers are able to define the course and outcome.

Methods: Bariatric patients (n=324) were reviewed retrospectively. Substantially elevated plasma CK after operation was identified in 4.9% (16/324). The affected population was divided into Group I (n=11, 68.8%) with CK 1050-8000 IU/L and no conspicuous muscle pain, weakness or swelling, and Group II (n=5, 31.2%) displaying CK >8000 IU/L and severe pain and dysfunction. The main outcome measures were CK concentration, frequency of renal failure, need for hemodialysis and mortality.

Results: Group I subjects compared to Group II were younger (37.7 +/- 10.9 vs 44.0 +/- 5.5 years, P<0.05) and predominantly females (72.7% vs 40.0%, P<0.05). Peak CK values were definitely lower (2811 +/- 952 vs 28136 +/- 19000 IU/L, P<0.001), and none progressed to renal failure (0% vs 40.0%, P<0.05). No difference was detected regarding preoperative BMI (50.8 +/- 8.1 vs 54.6 +/- 7.0 kg/m(2), NS), duration of operation (5.3 +/- 1.6 vs 5.6 +/- 2.1 hours, NS) or types of anesthetic drugs (basically fentanyl, nitrogen oxide and halothane/isoflurane).

Conclusions: 1) Demographic features, nominally gender and age, were different between the two degrees of RML; 2) Renal failure and hemodialysis were a danger only in patients with massive CK elevation and muscle pain; 3) Moderate CK increase was very well tolerated and rarely entailed major clinical symptoms; 4) Early diagnosis, fluid replenishment and general supportive therapy probably contributed to avert mortality.