October 2006 Case of the Month

MH Hotline
800MH-HYPER or 800-644-9737
available 24/7
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Topic: Postoperative rhabdomyolysis

A 50-year-old male weighing 500 pounds  had an uneventful laparoscopic gastric banding lasting 3 hours. Principal anesthetic agents were propofol and succinylcholine for induction followed by desflurane by endotracheal tube.

The patient was extubated following surgery. On POD one, he was doing well but dark urine was noted and a CK 21,000 IU was recorded.  On POD 2, the CK rose to 80,000 and, because of hypoxemia, the patient was reintubated. The MH hotline was called to discuss the relation of rhabdomyolysis to MH susceptibility.

1. Was this a manifestation of MH?

a. No
b. Unlikely
c. Likely
d. Yes

2. Should patient be treated with dantrolene?

a. Yes, 2.5mg/kg followed by 1mg/kg every 6 hours
b. Yes but only if there is fever, acidosis
c. No, too late for MH

3. What are the complications of CK to 80,000?

a. DIC
b. Renal failure
c. Hepatic failure
d. Cardiac failure
e. All of the above

4. What are the possible causes of postop rhabdomyolysis?

a. Name three drugs associated with rhabdomyolysis:

b. Name three diseases/syndromes associated with rhabdomyolysis:

c. Name other “environmental” stressors that can lead to rhabdomyolysis:

5. Would you recommend testing for MH susceptibility?

a. Yes, contracture test
b. No contracture test
c. Yes, genetic test
d. No test needed 

Answers:

1.  B

Postoperative rhabdomyolysis has a large differential diagnosis.  Among the causes are enzyme deficiency, such as CPT-2 deficiency, myopathies, drug-related reactions, sepsis and seizures.  A few cases in the literature have documented MH susceptibility in patients whose only perioperative problem was postoperative rhabdomyolysis.

2.  B

Dantrolene’s utility relates to treatment of acute MH or NMS and as an adjunct to treatment of marked hyperthermia.  In this case, I would recommend only dantrolene if there were signs of MH or high fever.

3.  B

Elevation of CK above 10,000IU is associated with myoglobinuria. Renal failure is a problem with massive myoglobinuria, which in turn is usually associated with CK values above 20,000IU.

4.  a. Succ, haloperidol, amphetamines, MDMA agonists, statins
     b. MH, NMS, CPT -2 def, sepsis
     c. Exercise, heat stress, prolonged position

5.  A

I would recommend contracture testing along with muscle histology, since the implications are significant if the patient is MH susceptible.

Muscle biopsy should not be done until three or more months have elapsed since the resolution of episode of myoglobinuria and renal failure.

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Henry Rosenberg, MD, CPE
MH Hotline Consultant
Saint Barnabas Medical Center
Livingston NJ 07039