No abstract

It is 30 yr since the British Journal of Anaesthesia published the first consensus protocol for the laboratory diagnosis of malignant hyperthermia susceptibility from the European Malignant Hyperthermia Group. This has subsequently been used in more than 10 000 individuals worldwide to inform use of anaesthetic drugs in these patients with increased risk of developing malignant hyperthermia during general anaesthesia, representing an early and successful example of stratified medicine. In 2001, our group also published a guideline for the use of DNA-based screening of malignant hyperthermia susceptibility. We now present an updated and complete guideline for the diagnostic pathway for patients potentially at increased risk of developing malignant hyperthermia. We introduce the new guideline with a narrative commentary that describes its development, the changes to previously published protocols and guidelines, and new sections, including recommendations for patient referral criteria and clinical interpretation of laboratory findings.

The IVCT for diagnosis of MH susceptibility in Europe has a high sensitivity and a satisfactory specificity.

Key points † MH is rare, but its incidence may be increasing. † Prompt recognition is the key to a safe outcome. † These guidelines provide a template for diagnosis and treatment. † Suspected cases and their relatives should be followed up and investigated for MH.Survival from a malignant hyperthermia (MH) crisis is highly dependent on early recognition and prompt action. MH crises are very rare and an increasing use of total i.v. anaesthesia is likely to make it even rarer, leading to the potential risk of reduced awareness of MH. In addition, dantrolene, the cornerstone of successful MH treatment, is unavailable in large areas around the world thereby increasing the risk of MH fatalities in these areas. The European Malignant Hyperthermia Group collected and reviewed all guidelines available from the various MH centres in order to provide a consensus document. The guidelines consist of two textboxes: Box 1 on recognizing MH and Box 2 on the treatment of an MH crisis.

SummaryConditions for insertion of the laryngeal mask were assessed following induction of anaesthesia with either propofo12.5 rnglkg or thiopentone 4.0 mglkg in 80 patients premedicated with diazepam 10 mg. Insertion following induction with thiopentone resulted in a greater incidence of gagging ( p < 0.01). The use of additional induction agent, where necessary, resulted in no ultimate signgcant dixerence between the groups for the provision of satisfactory conditions. Key wordsAnaesthetics, intravenous; propofol, thiopentone. Equipment; laryngeal mask.The laryngeal mask is a new form of airway (LMA),' which is introduced blindly into the hypopharynx to form a seal around the larynx.2 It has been shown to provide a clear airway and leaves the anaesthetists' hands free.3 In our department the preferred induction agent for insertion of the LMA for general anaesthesia with spontaneous ventilation is propofol. In view of the relative expense of propofol and pain on injection it would be of value to confirm or disprove the advantage of this agent in this respect. MethodsThe study was approved by the District Ethics Committee. Eighty ASA 1 or 2 patients aged 18 to 70 years undergoing surgery for which the LMA was appropriate were studied. Exclusion criteria consisted of a history of asthma and any potential risk of gastric regurgitation.All patients were premedicated with diazepam 10 mg orally 2 hours before operation. Induction was with fentanyl 1 pg/kg followed by a randomly allocated equipotent dose of either propofol 2.5 mg/kg or thiopentone 4.0mg/kg, given over 30 seconds. LMA insertion, as previously described,* was by another anaesthetist who was unaware which induction agent had been given. Anaesthesia was then maintained with a volatile agent and 66% nitrous oxide in oxygen, with the patient breathing spontaneously through a Bain system. Successful atraumatic insertion requires the abolition of the gag and cough reflexes.* The anaesthetist inserting the LMA scored both reflexes using a -, + and + + system, together with any comments. The necessary use of additional induction agent was also recorded. The anaesthetists varied in experience from SHO to consultant, but all were experienced in the use of the LMA.Patients' demographic data were also noted and compared between the propofol and thiopentone groups using unpaired t-tests and a Chi-squared test. The gagging and coughing scores were compared using Mann-Whitney U tests, and the quantity of additional induction agent using a Chi-squared test and a Fisher exact probability test. Yates' correction was applied to the Chi-squared tests. A p value of < 0.05 was accepted as indicative of a significant difference.