Anestesia

Anesthesia for patients with a history of malignant hyperthermia
Frank Wappler
University Witten/Herdecke, Department of Anaesthesiology and Intensive Care Medicine, Department of Paediatric Anaesthesia, Clinics of Cologne, Cologne, Germany Correspondence to Frank Wappler, MD, University Witten/Herdecke, Department of Anaesthesiology and Intensive Care Medicine, Department of PaediatricAnaesthesia, Clinics of Cologne, Ostmerheimer Straße 200, 51109 Cologne, Germany Tel: +49 221 8907 3863; fax: +49 221 8907 3868; e-mail: wapplerf@kliniken-koeln.de Current Opinion in Anaesthesiology 2010, 23:417–422

Purpose of review Malignant hyperthermia-susceptible patients have an increased risk during anaesthesia. The aim of this review is to present current knowledge about pathophysiology andtriggers of malignant hyperthermia as well as concepts for safe anaesthesiological management of these patients. Recent findings Trigger substances and mechanisms have been well defined to date. Anaesthesia can be safely performed with i.v. anaesthetics, nitrous oxide, nondepolarizing muscle relaxants, local anaesthetics as well as xenon. Attention must be directed to the preparation of theanaesthetic machine because modern workstations need longer cleansing times than their predecessors. Alternatively, activated charcoal might be beneficial for elimination of volatile anaesthetics. Day case surgery can be performed in malignant hyperthermia-susceptible patients, if all safety aspects are regarded. Whether there is an association between malignant hyperthermia susceptibility and otherdisorders is still a matter of debate. Summary The incidence of malignant hyperthermia is low, but the prevalence can be estimated as up to 1 : 3000. Because malignant hyperthermia is potentially lethal, it is relevant to establish management concepts for perioperative care in susceptible patients. This includes preoperative genetic and in-vitro contracture testing, preparation of the anaestheticworkstation, use of nontriggering anaesthetics, adequate monitoring, availability of sufficient quantities of dantrolene and appropriate postoperative care. Taking these items into account, anaesthesia can be safely performed in susceptible patients. Keywords anaesthesia, dantrolene, malignant hyperthermia, propofol, trigger
Curr Opin Anaesthesiol 23:417–422 ß 2010 Wolters Kluwer Health | LippincottWilliams & Wilkins 0952-7907

Introduction
Malignant hyperthermia is an inherited, pharmacogenetic disorder of the skeletal muscle, which is triggered by halogenated volatile anaesthetics, depolarizing muscle relaxants, and in rare cases by strenuous exercise and/or heat exposure [1]. Susceptibility to malignant hyperthermia is based on an altered regulation of calcium within the skeletal musclefibre caused by a defective calcium release channel at the sarcoplasmic reticulum, for example the ryanodine receptor [2]. Once malignant hyperthermia is triggered an abnormally high release of calcium from the sarcoplasmic reticulum is initiated resulting in a hypermetabolic state, leading to typical clinical signs, such as tachycardia, muscle rigidity, hypercapnia as well as hyperthermia. Theincidence of malignant hyperthermia episodes has been calculated to be between 1 : 5000 and 1 : 100 000 [3]; however, the frequency has increased in recent years [4]. Furthermore, owing to the autosomal dominant
0952-7907 ß 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins

inheritance in humans, the prevalence of malignant hyperthermia can be estimated as up to 1 : 3000. Thus,anaesthesiologists must be prepared to deliver well tolerated anaesthesia to patients with history of malignant hyperthermia as well as to those with increased risk, for example relatives of malignant hyperthermia patients. In this review, the anaesthetic management of patients predisposed to malignant hyperthermia will be presented.

Patients at risk for malignant hyperthermia
Only a minority of...