Rare postoperative delayed malignant hyperthermia after off-pump coronary bypass surgery and brief review of literature

Abstract

Postoperative malignant hyperthermia (MH) is a very rare phenomena. It is generally observed within less than an hour after discontinuation of the anesthetic trigger. Present case describes rare delayed postoperative presentation of MH after off-pump coronary bypass surgery. Prompt recognition and immediate treatment with dantrolene can effectively treat the fatal syndrome. Family education and genetic counseling should be encouraged.

Malignant Hyperthermia in a Child After Magnetic Resonance Imaging: A Case Report

“…1 MH is known to be an autosomal dominant genetic disease and, in certain situations, may be associated with certain congenital myopathies. [1][2][3] In up to 50% of predisposed patients, the causative mutation of this syndrome occurs in the gene that encodes the ryanodine receptor (RYR1), which is responsible for releasing calcium from the sarcoplasmic reticulum of the muscle fiber. However, it is known that this syndrome has a very varied genotype and is also associated with a mutation in the CACNA1S gene, which is the gene responsible for the skeletal muscle calcium channel.…”

“…This begins after exposure to some of the anesthetic drugs already mentioned. 1,2,4,9 Tachycardia and tachypnea also occur in conjunction with these manifestations. In the absence of an appropriate and prompt medical intervention, the following may occur: rhabdomyolysis -with a risk of myoglobinuria -kidney damage, hyperkalemia, cardiac arrhythmias, and death.…”

“…Despite its severity, delayed MH rarely reaches a fulminant crisis. 2,3,9 It is of utmost importance that patients with MH be monitored in an intensive care setting for a minimum of 48 to 72 hours, as symptoms may recur in up to 25% of cases. Continuing dantrolene treatment has been proposed.…”

“…Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic syndrome triggered by the administration of halogenated anesthetics (ie: halothane, isoflurane, sevoflurane) and neuromuscular blockers such as succinylcholine. 1,2 Following exposure to such drugs, genetically predisposed patients develop contractures and their skeletal muscles become rigid. This results from the sarcoplasmic reticulum-releasing calcium ions.…”

“…[1][2][3] Treatment includes immediate discontinuation of the triggering agent, 100% oxygen delivery, hyperventilation (when on mechanical ventilation), temperature control, and prompt administration of dantrolene intravenously. [1][2][3] Prior to the advent and use of dantrolene, mortality associated with MH was approximately 80%. However, now after it has been used, mortality has been reduced to approximately 5%.…”