European Malignant Hyperthermia Group guidelines for investigation of malignant hyperthermia susceptibility.

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.

Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group.

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.

Studies of vegans: the fatty acid composition of plasma choline phosphoglycerides, erythrocytes, adipose tissue, and breast milk, and some indicators of susceptibility to ischemic heart disease in vegans and omnivore controls.

The fatty acid composition of erythrocytes, of plasma choline phosphoglycerides, and of adipose tissue, serum cholesterol, triglyceride and vitamin B12 concentrations, weights, heights and skinfold thickness were determined on 22 vegans and 22 age and sex matched omnivore controls. The fatty acid composition of breast milk from four vegan and four omnivore control mothers, and of erythrocytes from three infants breast fed by vegan mothers and six infants breast fed by omnivore control mothers was determined. The proportions of linoleic acid and its long-chain derivatives were higher, the proportion of the long-chain derivatives of alpha-linolenic acid was lower, and the ratio of 22:5omega3/22:6omega3 was greater in the tissues of the vegans and infants breast-fed by vegans than in controls; the most marked differences were in the proportions of linoleic (18:2omega6) and docosahexenoic (22:6omega3) acids. Weights, skinfold thickness, serum vitamin B12, cholesterol and triglyceride concentrations were less in vegans than in controls. The difference in serum cholesterol concentration was most marked. It is concluded that a vegan-type diet may be the one of choice in the treatment of ischemic heart disease, angina pectoris, and certain hyperlipidemias.

Some effects of PCO2 and pH on nerve tissue.

1. Rat phrenic nerve preparations were used in vitro to study action potential amplitude and nerve conduction time under varying conditions of Pco(2) and sodium bicarbonate concentration in the surrounding Krebs solution.2. A correlation was found between action potential amplitude and pH but not between action potential amplitude and Pco(2).3. A better correlation was found between conduction time and pH than between conduction time and Pco(2).

Plasma and erythrocyte membrane long chain polyunsaturated fatty acids in endogenous depression.

Patients suffering from endogenous depression had significantly greater proportions of long chain polyunsaturated fatty acids (LCP), docosahexaenoic acid (22:6?3) and eicosapentaenoic acid (20:5?3), and a reduced proportion of linoleic acid (18:2?6) in their plasma choline phosphoglycerides (CPG) compared with age-sex-matched healthy controls. Patients suffering from reactive depression or from other psychiatric disorders did not differ significantly from matched controls. Changes in the fatty acid composition of the major erythrocyte membrane phospholipids were in the same direction but were less marked. The importance and possible reasons for the elevated LCP in endogenous depression are discussed.

Plasma and erythrocyte membrane fatty acids in oral contraceptive users.

The fatty acid composition of the plasma choline phosphoglycerides (CPG) and erythrocyte phospholipids were determined in women using oral contraceptive agents and age-matched female controls. Those using oestrogen and progestogen combined preparations had higher concentrations of palmitic acid (16:0) and linoleic acid (18:2 omega 6) and lower concentrations of stearic acid (18:0) and long chain polyunsaturated fatty acids (LCP), in particular arachidonic acid (20:4 omega 6) and eicosapentaenoic acid (20:5 omega 3), in their plasma CPG than controls. These differences were reflected in the erythrocyte phospholipids. The progestogen-only group had similar concentrations to matched controls. It is suggested that the lower concentrations of LCP in combined pill users may affect membrane function and prostaglandin synthesis and may relate to their increased risk of thrombosis.

Malignant hyperthermia: how important after 30 years.

Malignant hyperthermia has been recognised for over 30 years. In this time its apparent incidence and importance have changed. The developments and the likely role of MH in the future are discussed, as is the impact and importance of genetic screening to anesthetic practice.