Malignant Hyperpyrexia Induced by Nitrous Oxide and Treated With Dexamethasone

Abstract

local barrier to the diffusion of the tumour. As we have shown, however, the presence of metastases in regional nodes is not incompatible with a D + or D + + score and long-term survival. Our results confirm those of other series on all histological types of breast cancer, particularly medullary carcinoma (Hamlin, 1968;Bloom et al., 1970;Wernicke, 1972). Other workers have found no correlation between survival and sinus histiocytosis (Berg, 1956;Moore et al., 1960;Kister et al., 1969), follicular hyperplasia (Moore et al., 1960), and lymphocytic infiltration (Morrison et al., 1973) but we believe that the histology of both tumour and lymph nodes must be studied to obtain an accurate picture of host resistance. There is undoubtedly a close relationship between host immunological response and prognosis in the breast cancer. That this response is cell mediated was confirmed by Fisher et al. (1973), who showed that lymphocytes from lymph nodes draining a breast cancer were stimulated in vitro by phytohaemagglutinin. This transformation was associated with follicular hyperplasia and lymphocytic infiltration, whereas no clear-cut correlation could be shown with the presence or absence of sinus histiocytosis.We believe that further studies of the immunological response of lymph nodes draining a tumour removed at operation would provide more information about prognosis (Lancet, 1973). At present we are correlating tumour lymphocytic infiltration and follicular hyperplasia and sinus histiocytosis in regional lymph nodes with preoperative and postoperative lymphocytic responses to phytohaemagglutinin, aspecific and specific delayed cutaneous hypersensitivity reactions, and distribution patterns of T and B cells at tumour and lymph node levels. journal, 1974, 4, 270-271 Though fever has been recognized as a complication of anaesthesia for over 80 years the specific condition of malignant hyperpyrexia has only comparatively recently been described. It is known that susceptible patients, who have been found to have a subclinical myopathy (Harriman et al., 1973), develop a fulminating and often fatal hyperpyrexia when given certain anaesthetic drugs or depolarizing muscle relaxants (Britt and Kalow, 1970). A working definition of malignant hyperpyrexia is an unexplained fever during anaesthesia in which the body temperature rises at a rate of at least 2°C an hour (Keaney and Ellis, 1971). Most patients develop muscle contracture, acidosis, and hyperkalaemia. The condition is inherited as a Mendelian autosomal dominant.

Xenon: recent developments

“…N 2 O, by comparison, may be a weak triggering agent although it is considered by some to be safe for use in susceptible patients. There has been at least one reported case of nitrous oxide triggering the condition [67].…”

Drug Treatment of Malignant Hyperpyrexia

“…However, large doses of procaine are required to produce the desired effect in vitro, and with the use of equivalent doses in vivo, there is the danger of producing cardiovascular collapse. Other drugs that have been tried in the treatment of malignant hyperpyrexia include pro cain amide (Noble, McKee and Gates 1973), hydrocortisone and dexamethasone (Ellis et al 1974). Unfortunately, the mortality from malignant hyperpyrexia remains high, and at present there is doubt about which drug is the best to use in the clinical emergency of an episode of malignant hyperpyrexia, has prompted us to study the effects of dantrolene sodium on pharmacologically induced contracture in human muscle from normal subjects and from patients who are susceptible to malignant hyperpyrexia, and to compare these with the results of similar experiments using procaine, procainamide, hydrocortisone and dexamethasone.…”

The Prophylaxis of Malignant Hyperthermia by Oral Dantrolene Sodium in Swine

“…formulation of the drug, which is available for clinical use as an oral capsule only. For patients known to be genetically "at risk" from MH (Moulds and Denborough, 1974) there is no completely safe method of general anaesthesia (Ellis et al, 1974;Britt, 1975).…”