A Review of the Factors Affecting the Incidence of Malignant Hyperthermia in the Greater Kansas City Area

Abstract

Malignant Hyperthermia (MH) is a rare genetic disease. However, it is devastating when it occurs in a patient. MH is usually triggered by inhalational anesthetics and/or depolarizing muscle relaxants. Public awareness of MH has increased with the presentation of an episode on the television program, “House”, and the availability of web-based information. For over 20 years, the MH susceptible pig has been used in experiments by our group as an animal model for MH in humans. The incidence of Malignant Hyperthermia in the Greater Kansas City Area has declined dramatically since the introduction of Sevoflurane in 1992 as the anesthetic of choice (over 60% usage rate) in most surgical procedures. Historically, Malignant Hyperthermia was reported to occur at a rate of 1:50,000 during surgical procedures [1] . In the Greater Kansas City Area, Malignant Hyperthermia (MH) occurred at a rate of 1:53,636 during the 1965-1985 time period, as there were 38 MH cases in 35 patients [2] . During the past ten years (1996-2006), there were only 2 cases of MH, representing an incidence rate of 1:597,240. That decrease is an 11.13 fold (or 89%) decrease which is very significant. Despite the reduced incidence of Malignant Hyperthermia, two recent cases of MH that result in deaths in Wisconsin and Florida make it imperative that MH is recognized early and appropriate treatment initiated without delay. We have expanded our analysis of the futile cycle mechanism that underlies the MH syndrome. MH is equivalent to the rapid discharge of a battery by a short circuit.