Malignant hyperthermia and ECT.

The malignant hyperthermia syndrome is a rare hypermetabolic state that occurs in patients after the administration of certain drugs, most frequently anesthetics and/or succinylcholine. In view of the widespread use of succinylcholine to induce muscle relaxation prior to ECT, it is important that the individual who administers succinylcholine in this setting be familiar with the syndrome and its treatment. This report reviews what is known about malignant hyperthermia and proposes a course of action when the syndrome occurs in a patient undergoing ECT or a patient with known susceptibility to malignant hyperthermia needs ECT.

Psychotropic drugs, summer heat and humidity, and hyperpyrexia: a danger restated.

The authors note an apparent unawareness of, as well as a paucity of recent literature pertaining to, hyperpyrexia as a complication of psychotropic drug treatment. They report a case of hyperpyrexia in a patient receiving psychotropic agents during a summer heat wave; massive muscle destruction (rhabdomyolysis) with myoglobinuria and acute renal failure make this case of particular interest. Causative mechanisms, preventive measures, and the benefits of prompt recognition and treatment of this condition are discussed.

Suspected malignant hyperthermia in a strabismus patient. A case report.

Malignant hyperthermia is an autosomal dominant disorder with variable expressivity that is caused by a membrane defect in the sarcolemma of myofibrils. A patient with strabismus (esotropia) had tachycardia and masseter muscle rigidity on exposure to succinylcholine chloride and halothane, but because of rapid recognition of the condition and discontinuation of the procedure, the potentially lethal complications of malignant hyperthermia did not develop. A serum creatine phosphokinase level showed a substantial increase above normal. Two weeks later, the patient underwent successful correction of the strabismus under general anesthesia, using morphine sulfate and thiopental sodium without complication. This condition is of interest to ophthalmologists because it occurs with increasing frequency in patients with strabismus and ptosis, and it may be triggered by certain local anesthetic agents often used by ophthalmologists.

Malignant hyperthermia associated with enflurane anesthesia.

Malignant hyperthermia is induced by potent inhalation anesthetics. Enflurane must be added to the list of those anesthetic agents (such as halothane and succinylcholine) that are associated with this condition. The patient in our study was a young woman with no history of prior exposure to general anesthetics, and no family history of complications following administration of anesthetics. The other possible causes of hyperthermia in the patient were investigated and eliminated, and the condition was finally associated with enflurane. Enflurane should not be used in patients with a family history of this rare but often lethal disorder.

Effect of halothane on adenylate kinase in porcine malignant hyperpyrexia.

The effects of halothane on adenylate kinase activity in porcine muscle have been examined. No abnormality in malignant hyperpyrexia susceptible muscle was found. At clinical concentrations of halothane only slight inhibition of adenylate kinase activity was observed. The inhibition increased with increasing concentrations of halothane and with decreasing concentrations of the substrates AMP or ADP. The inhibition was similar in both malignant hyperpyrexia susceptible and control muscle. It seems unlikely that adenylate kinase is involved directly in triggering malignant hyperpyrexia.

Malignant hyperpyrexia: an update for the otolaryngologist.

Malignant hyperpyrexia (MH) is a syndrome with a mortality of 60%, triggered by a broad variety of anesthetic agents. The most significant recent advance influencing the clinician's ability to safely manage MH individuals is the emergence of dantrolene sodium as both a prophylactic and a therapeutic agent. The purpose of this presentation is to review recent clinical and laboratory studies and advances which are the basis for establishing the pathophysiology of this syndrome and pharmacology of treatment. The FDA has recently approve intravenous Dantrium for treatment of malignant hyperpyrexia. Intravenous and oral Dantrium has much theoretical support and experimental evidence which suggests it will significantly reduce the mortality previously associated with this syndrome.

Environmental and drug-induced hyperthermia. Pathophysiology, recognition, and management.

Environmental heat illness may affect the aged and infirm as well as the athletic. In addition, intoxication with a variety of drugs and toxins can produce hyperthermia, which may be indistinguishable from environmental heat illness. This article reviews current concepts of the pathophysiology, recognition, and management of environmental and drug-induced hyperthermia.

Relationships between the H and A-O blood types, phosphohexose isomerase and 6-phosphogluconate dehydrogenase red cell enzyme systems and halothane sensitivity, and economic traits in a superior and an inferior selection line of swiss landrace pigs.

Associations between production traits and the genes for halothane sensitivity (HAL), S, A and H blood group systems and phosphohexose isomerase (PHI) and 6-phosphogluconate dehydrogenase (6-PGD) enzyme systems were investigated in two lines of pigs selected for an index. The phenotypic variance-covariance matrix of the index included backfat thickness and daily gain, whereas the genetic variance-covariance matrix included daily gain, feed conversion and percentage of lean meat. The experiment was conducted at the experimental station of the Institute of Animal Production and has been underway since 1973. The same index was applied but in two opposite directions to give a superior and inferior line in relation to the production traits. One hundred twenty-nine animals of the superior line in the seventh generation and 88 animals of the inferior line in the sixth generation were studied. Forty-two percent (54/129) of the animals of the superior line were halothane-positive. No animals in the inferior line were halothane reactors. Of the halothane-positive pigs, 70.4% (38/54) in the superior line had the HaHa and 94.4% (51/54) had the SsSs genotype, whereas only 4% (3/75) of the HaHa and 12% (9/75) of the SsSs pigs were halothane-negative. By practicing selection at the H and S loci, it seems possible to efficiently reduce halothane sensitivity in Swiss Landrace pigs. In pigs of the superior line, there were significant differences in percentage of lean meat, carcass length, pH1 (pH value at 45 min to 1 h postmortem, M. longissimus) and reflectance values among genotypes of the HAL, S and H systems and among some genotypes of the 6-PGD system. Poorest meat quality, highest percentage of lean meat and shortest carcass length were observed in pigs homozygous for the alleles HALn, Ss, Ha, PHIB and 6-PGDA. In the inferior line, these associations were absent. As the HAL locus is associated with the above mentioned production traits, linkage disequilibria may explain the observed associations among the H, S, PHI and 6-PGD types and production traits.