title: Minimally invasive metabolic testing for malignant hyperthermia susceptibility: a systematic review of the methodology and results.
abstract: BACKGROUND
  Malignant hyperthermia (MH) is a potentially lethal hypermetabolic syndrome that develops in susceptible individuals exposed to volatile anesthetics or depolarizing neuromuscular blocking agents. Because genetic screening is successful only in 30 - 50% of all suspected cases, contracture testing following an open muscle biopsy is performed to diagnose MH susceptibility. Two different protocols exist, the in vitro contracture test (IVCT) for Europe and the caffine halothane contracture test for the US. As replacement for the IVCT, an in vivo metabolic test might allow an equal discrimination of MH susceptible individuals. In this systematic review, all available metabolic testing methods are analyzed.
  
  
  RESULTS
  The reader will gain insight in methods and results of alternative approaches to diagnose MH.
  
  
  METHODS
  Relevant studies involving in vivo metabolic testing were systematically searched (Medline) and reviewed. Their ability to discriminate MH susceptible individuals was analyzed and compared. Any systemic or local side effects were documented and evaluated in order to allow more robust conclusions based on larger sample sizes than the single trials.
  
  
  CONCLUSIONS
  All discussed study protocols allowed an adequate discrimination of MH susceptible individuals. The latest study protocol reaches a specificity of 79% with a sensitivity of 100%. No severe systemic or local adverse effects could be seen in the pooled analysis. Minimally invasive metabolic testing is a promising novel approach to diagnose MH. Further multi-center studies have to be conducted to optimize the results in order to replace the IVCT.
authors.affiliation: University of Regensburg, Department of Anaesthesiology, Regensburg, Germany +49 941 944 9055 ; +49 (0) 941 944 9054 ; tom.metterlein@gmx.net.
authors.forename: Thomas
authors.initials: T
authors.lastname: Metterlein
authors.forename: Frank
authors.initials: F
authors.lastname: Schuster
authors.forename: Peter
authors.initials: P
authors.lastname: Kranke
authors.forename: Norbert
authors.initials: N
authors.lastname: Roewer
authors.forename: Martin
authors.initials: M
authors.lastname: Anetseder