[Telephone enquiries on the topic of malignant hyperthermia: Evaluation of the content and subsequent diagnostic results at the MH Center Leipzig]

Abstract

Background: Malignant hyperthermia (MH) is an autosomal dominant metabolic myopathy. The in vitro contracture test (IVCT) is still considered to be the gold standard for diagnosing a disposition for MH. However, advances in genetic testing for MH disposition have supplemented or even replaced the invasive procedure of the IVCT. Information about MH can be obtained by either contacting the hotline for MH as a nationwide 24 h/7 days a week service or one of the regional MH centers.

Methods: The protocols of telephone conversations concerning MH at the MH Center University Leipzig were retrospectively analyzed. Data were collected from January 2011 to March 2015. Additionally, the results of the IVCT and genetic testing evolving from the counseling interviews were examined.

Results: A total of 205 telephone calls were documented during the period in question and an IVCT was performed as a consequence of 112 of the telephone calls. The IVCT resulted in 27 individuals being identified as MH susceptible which was subsequently diagnosed in 15 individuals with known familial MH disposition and 12 individuals were identified as new index patients. In 24 individuals a total of 13 different mutations were detected and of these 4 mutations were causative concerning MH. Of the 205 telephone calls 131 were private and 74 of medical professional origin. Among the private enquiries MH disposition within the family was a frequent reason for contacting the MH Center (61.8%). Conversations relating to MH-like symptoms during general anesthesia were carried out with 35.1% of medical doctors and with 22.9% of private callers. Advice about neuromuscular symptoms of unknown genesis was given to 15.3% of private individuals and to 24.3% of medical doctors. Overall MH topics were discussed with 23% (N = 17) of the medical profession and approximately half of these were anesthesiologists (N = 8). Not a single call was documented for the treatment of a suspected MH crisis.

Conclusion: Private individuals and families affected by a MH disposition often showed good compliance with respect to counseling and diagnostics for MH and contacted the MH center more often than medical doctors. A more comprehensive cooperation with the medical profession is preferable and necessary to obtain a systematic and broad synopsis of characteristic and uncharacteristic signs and symptoms of MH. The telephone conversations analyzed as well as the diagnostic results (IVCT and genetic testing) underline that MH disposition is still a current and relevant topic.

Keywords: Anesthesia related incident; Genetic testing; In vitro contracture test; Malignant hyperthermia; Telephone hotline.