Malignant hyperpyrexia. Further muscle studies in asymptomatic carriers identified by creatinine phosphokinase screening.

The history, clinical presentation, and management of malignant hyperpyrexia are presented. The aetiology seems to be associated with some inherited abnormality which affects the movement and binding of calcium ions in the sarcoplasmic reticulum, sarcoplasm, and mitochondria. Whether this is a primary muscular defect or secondary to some trophic neural influence is yet to be established. The subjects carrying the abnormal trait show evidence of a myopathy which is subclinical in most instances and revealed only by estimation of serum CPK or biopsy. In some families where the myopathy is clinically obvious there may be, in addition, a variety of musculoskeletal abnormalities. A plea is made for routine monitoring of temperature during anaesthesia and for procainamide or procaine to be readily available in all operating theatres. A history of anaesthetic deaths in a family calls for special care, and, if the serum CPK is elevated, suxamethonium and halothane are to be avoided. Families with orthopaedic and muscular abnormalities are at increased risk and should have estimation of serum CPK before surgery. As a bonus of this study it is suggested that serum CPK estimations be used to screen pigs for selective breeding and so eliminate the disease, which causes soft exudative pork.