Surgical Anesthesia | What you need to know

Malignant Hyperthermia is an autosomal dominant disorder wherein a defective gene is inherited, that in turn, affects the metabolism of the affected person in stressful situations or exposure to halogenated anesthetic agents or depolarizing muscle relaxant succinylcholine. Characterized as a metabolic disorder, heat is generated by uncontrolled skeletal muscle contractions. These contractions are caused by the abnormal release of intracellular calcium from the mitochondria and sarcoplasmic reticulum (Porth: Vol 6, 2002 ). The abnormal skeletal muscle contractions result to rapid increase in core body temperature which can go as high as 43 C (109.4 F) at a rate of 1 C q 5 mins. Manifestations that begin with muscle rigidity followed by cardiac arrhythmia and hypermetabolism should be observed during anesthesia. Avoid further damage to the px’s life by discontinuing the triggering agents stat. Other measures include administering dantrolene (blocks Ca release in sarcoplasmic reticulum) and cooling the body. The importance of checking family history for malignant hyperthermia is an important consideration when general anesthesia is needed in an operation.

as i read, vol. 1 (texbook of medical surgical nursing chapt. 19, vol.1) 'bout malignant hyperthermia-it is a rare inherited muscle disorder that is chemically induced by anesthetic agents.Susceptible person include those w/ strong &bulky muscles, a history of muscle cramps or muscle weakness & unexplained temp. elevation & an unexplained death of a family member during surgery that was accompanied by febrile response. But the question is..how can it kill a patient?(pathophysio.) during anesthesia, potent (powerful) agents such as inhalations anesthetics lke(halothane,enflurane)& muscle relaxants ( succinylcholine)may trigger the symptoms of malignant hypethermia w/ c related to cardio & muscular activity.Tachy.(heart rate greater than 150bpm)is often the earliest sign. Also, sympathetic nervous stimulation leads to ventricular dysrhythmia, hypotension, decreased cardiac output, oliguria& lates as cardiac arrest. w/ the abnormal transport of calcium, rigidity or tetanus like movements occur, often in the jaw.the rise in temp. is actually a late sign taht develops rapidly. body temp. increase to 1-2C/5mins. & can exceed to 42C in a very short time. So it must be properly monitored & recorded during surgery.Stress & some medications, such as sympathomimetics(epinephrine), theophylline, aminophylline,anticholinergics(atropine)& cardiac glycosides(digitalis) can induce or intensify such a reaction. It is also related to hypermetabolic condition in a skeletal muscle celss taht involves altered mechanisms of calcium func. at the cellular level. This disruotion of calcium causes clinical symptoms of hypermetabolism.w/c in turn increases muscle contraction & causes hyperthermia & consequent damage to CNS.So as a medical mngt., MHAUS publishes treatment protocol that should be posted in the OR & be readily available on a malignant hyperthermia cart. As soon as diagnosis is made, anesthesia &surgery are halted& the patient is hyperventilated w/ 100% oxygen.Dantrolene sodium(Dantrium), a skeletal muscle relaxant,& sodium bicarbonate are admin. immediately. Continued monitoring of all parameters is necessary to evaluate the patient's status. It usually manifests about 10-20 mins. aft inducion of anesthesia but can also occur the 1st 24 hrs. aft. surgery. To simplified:" HYPOTHALAMUS COULD NOT TOLERATE THE INCREASE TEMP. OF 41C FOR ABOUT 4 HRS.&IT COULD KILL A PERSON DUE TO NEURONS DEATH"

Malignant Hyperthermia is a rare but life-threatening condition that happens to a patient under general anesthesia triggered by exposure to certain drugs. Volatile anesthetics, nearly all gas anesthetics, and neuromuscular blocking agent succinylcholine are anesthetics that may trigger MH. MH can be fatal if left untreated. MH can lead to cardiac arrest, brain damage, internal bleeding or failure of other body systems. Thus, death, primarily due to a secondary cardiovascular collapse, can result. MH-susceptible persons have a mutation that results in the presence of abnormal proteins in the muscle cells of their body. Although normal in everyday life, when these patients are exposed to certain anesthetic agents, it causes an abnormal release of calcium inside the muscle cell, which results in a sustained muscle contraction and the abnormal increase in energy utilization and heat production. The muscle cells eventually run out of energy, and die, and release large amounts of potassium into the bloodstream, which can lead to heart rhythm abnormalities. The muscle pigment myoglobin is also released and may be toxic to the kidney.

Malignant hyperthermia is the result of a chain of reactions triggered in susceptible individuals when they are exposed to certain anesthetic drugs.
This results in greatly increased metabolism, muscle rigidity and a very rapid rise in body temperature - as fast as one to two degrees Fahrenheit every four minutes.
Some drugs can induce a drastic and uncontrolled increase in skeletal muscle oxidative metabolism, that overwhelms the capacity of the body to supply oxygen, remove carbon dioxide, and regulate body temperature, which leads to circulatory collapse and death.

Malignant hyperthermia is an inherited disease that causes a rapid rise in body temperature (fever) and severe muscle contractions when the affected person receives general anesthesia.
There are several risks involved with general anesthesia, including death. This can occur in several ways, one can have a direct reaction to the anesthetic, the mixing with oxygen can be off, cardiorespiratory depression can occur from the anesthesia, and general anesthesia not infrequently results in hypotension. Of the most feared reactions to general anesthesia is malignant hyperthermia, in which the patient's temperature rises - frequently to above 106 degrees Fahrenheit - and carrying a high mortality.


answer by: Del rosario, Jeremay C., Rey, Ruby R, Buenaventura, MAry Grace, Mesa, Remedios

Hi, just a quick guess. Malignant Hyperthermia is a surgical complication characterized by muscular rigidity. The cause could be idiopathic. What triggers Malignant Hyperthermia and who are the people prone to develop this complication is the bigger question. Just my 2 cents. :)