Case report: Rhabdomyolysis in morbidly obese patients: anesthetic considerations

We report the presentation and management of rhabdomyolysis involving shoulder girdle and upper arm muscles in a morbidly obese patient after prolonged laparoscopic surgery.

A 41-yr-old morbidly obese woman presented for laparoscopic abdominal hysterectomy. She had hypertension and type II diabetes which were controlled on regular medications. She also had obstructive sleep apnea. Her clinical examination and investigations revealed no abnormality except morbid obesity (body mass index 54 kg·m(-2)) and left ventricular hypertrophy on transthoracic echocardiogram. Standard general anesthesia was administered under baseline non-invasive monitors. Succinylcholine was used to secure the airway during anesthetic induction. Surgery was performed with the patient positioned with a 15° head-down tilt, and it took six hours to complete the procedure as technical difficulty was encountered due to her body habitus. Her trachea was extubated and she was transferred to the postanesthetic care unit (PACU) without incident. In the PACU, the patient complained of severe bilateral arm pain and weakness an hour after surgery. On physical examination, she exhibited limited movement of her arms against gravity while complaining of tenderness in her shoulder girdle muscles and both arms. Clinical suspicion of rhabdomyolysis based on her signs and symptoms was confirmed by an elevated serum creatinine kinase (CK) of 18,392 IU·L(-1) and serum potassium of 5.3 mmol·L(-1). Intravenous crystalloids and mannitol were administered for 24 hr for renal protection, and her clinical symptoms and serum CK levels improved over seven days. The patient was discharged to home on the tenth postoperative day, and she continued to improve over the three-month follow-up period.

Morbidly obese patients who undergo prolonged surgery are at risk for rhabdomyolysis, and early diagnosis and therapy are required to prevent severe complications.