October Case Of The Month

Fever Hours after Administering Succinycholine

 

3 years old boy with respiratory distress was administered succinycholine for tracheal intubation in the ER. Seven hours later, his temperature elevated to 40.4°C while his PCO2 remained at 45.5 mmHg. Rigidity or arrhythmia did not develop. Family history is negative for MH and the child has not been exposed to succinycholine or inhalation agent previously. WBC was 13000.

 

1) What is your diagnosis?

                        A- Definitely MH

                        B- Probably MH

                        C- Pneumonia

                        D- B&C

 

Few hours later, the temperature normalized without the administration of dantrolene. Eighteen hours later, temperature was elevated again without rigidity. The patient’s trachea is still intubated with normal PCO2.

 

2) What action should be taken now?

                      A-  Administer dantrolene 2.5 mg/kg i.v.

                      B-  Actively cool the patient

                      C-  Extubate the trachea

                      D-  Administer antibiotics for pneumonia

 

3) Should this child be referred for MH biopsy testing?

   A-    No

   B-    Yes

   C-    Get more information from the family

 

4) Caffeine halothane contracture testing is indicated in all the following except?
              A- Clinical history suspicions for malignant hyperthermia
              B- A first-degree relative of a patient with documented MH
              C- Unexplained muscular rigidity with MH suspicion
              D- Sudden cardiac arrest on induction of anesthesia

 

Narrative:

 

1)      Although MH can not be ruled out, pneumonia is a diagnosis to consider as the patient presented in respiratory distress. However, normal WBC goes against pneumonia and fever developing few hours after the administration of succinycholine does not rule out MH.

Answer D

 

2)      As most of MH episodes, this patient presented with one of the MH classical findings, elevated temperature. It is recommended to administer dantrolene with probable suspicion of MH. As the presentation of MH varies and all clinical signs (rigidity, arrhythmia, fever, elevated PCO2…etc.) do not often come together. Administering one dose of dantrolene and observing the change in the presenting clinical signs is always safer than delaying MH treatment.

Answer A

 

3)      It is generally a good idea to refer any patient with high probability of MH to a testing center. Ruling out the diagnosis provides peace of mind to the family and the patient. Additionally, confirming the diagnosis provide the medical and counselor help needed for the family and the patient.

Answer B

 

4)      Currently, the in vitro contracture test (IVCT) is the gold standard for diagnosing MH. However, the IVCT is very expensive, requires a surgical procedure that can only be performed on-site in one of approximately 10 specialized testing centers in the US, and has 97% sensitivity and 78% specificity. Consequently, IVCT is only indicated in patients who have had clinical episodes and (possibly) their immediate family members. Sudden cardiac arrest on induction of general anesthesia is most likely an indication for arrhythmias and not MH.

Answer D

 

 

Mohanad Shukry, MD

Assistant Professor, Anesthesiology

Children’s Hospital of Oklahoma

Oklahoma University

750 NE 17th St. Suite 200

Oklahoma City, OK 73104