Which are the symptoms of Malignant hyperthermia?

Symptoms of Malignant Hyperthermia

Malignant hyperthermia (MH) is a rare but potentially life-threatening condition that can occur during or after general anesthesia. It is characterized by a severe reaction to certain medications used during surgery, particularly volatile anesthetics and the muscle relaxant succinylcholine. MH is considered a pharmacogenetic disorder, meaning it is caused by a genetic predisposition.

When an individual with a susceptibility to MH is exposed to triggering agents, a cascade of biochemical events occurs within the muscle cells. This leads to a rapid and uncontrolled increase in calcium levels, resulting in muscle rigidity, hypermetabolism, and a dangerous rise in body temperature. The symptoms of MH can vary in severity and may include:

• Unexplained high body temperature: One of the hallmark signs of MH is a sudden and significant increase in body temperature, often exceeding 104°F (40°C). This hyperthermia is not responsive to typical cooling measures.


• Muscle rigidity: MH causes generalized muscle rigidity, particularly in the jaw, neck, and extremities. This rigidity can be so severe that it impairs ventilation and leads to difficulty breathing.


• Rapid heart rate: Tachycardia, or a fast heart rate, is commonly observed in individuals experiencing an MH episode. The heart may beat irregularly or arrhythmias may occur.


• Increased breathing: MH triggers rapid and shallow breathing, which can progress to respiratory distress if not promptly addressed.


• Metabolic acidosis: As a result of increased metabolism, MH leads to an accumulation of lactic acid in the blood, causing metabolic acidosis. This can result in symptoms such as confusion, dizziness, and fatigue.


• Dark, cola-colored urine: Rhabdomyolysis, the breakdown of muscle tissue, can occur during an MH crisis. This can lead to the release of myoglobin, a protein that can cause kidney damage and result in dark, cola-colored urine.


• Excessive sweating: Profuse sweating is a common symptom of MH. However, in some cases, individuals may experience a lack of sweating due to dehydration.


• Changes in blood pressure: MH can cause blood pressure to become unstable, leading to hypertension or hypotension.


• Altered consciousness: In severe cases, MH can result in confusion, agitation, or even loss of consciousness.

If any of these symptoms are observed during or after anesthesia, it is crucial to recognize the possibility of MH and take immediate action. Prompt treatment is essential to prevent complications and potential fatalities. Suspected MH cases should be reported to the medical team, who will initiate specific interventions, such as administering the antidote dantrolene and providing supportive care.

Note: This information is provided for educational purposes only and should not be used as a substitute for professional medical advice. If you suspect you or someone else may be experiencing MH, please seek immediate medical attention.