What Is MH?

The sudden unexpected death of a healthy individual undergoing minor surgery is a tragedy almost beyond comprehension in this day of modern medical miracles. Yet this still happens to patients susceptible to malignant hyperthermia (MH). Even when treated properly, the syndrome known as the MH crisis can cause death. Survivors might be left with brain damage, failed kidneys, muscle damage or impaired function of other major organs.

The MH crisis is a biochemical chain reaction response, “triggered” by commonly used general anesthetics and the paralyzing agent succinylcholine (a neuromuscular blocker), within the skeletal muscles of susceptible individuals. The general signs of the MH crisis include increased heart rate, greatly increased body metabolism, muscle rigidity and/or fever that may exceed 110 degrees F along with muscle breakdown, derangements of body chemicals and increased acid content in the blood. Severe complications include: cardiac arrest, brain damage, internal bleeding or failure of other body systems. Thus, death, primarily due to a secondary cardiovascular collapse, can result.