Symptoms
Symptoms. Signs and symptoms of malignant hyperthermia reaction include a dangerously high body temperature, severe muscle spasms and a fast heart rate. In most cases, the genetic defect that causes malignant hyperthermia is inherited. It is called a pharmacogenetic disorder because the reaction is caused by specific drugs.
Causes
Overview Malignant hyperthermia is a severe reaction to certain drugs used for anesthesia. This severe reaction typically includes a dangerously high body temperature, rigid muscles or spasms, a rapid heart rate, and other symptoms. Without prompt treatment, the complications caused by malignant hyperthermia can be fatal.
Complications
Treatments for malignant hyperthermia include the medication dantrolene (Dantrium, Ryanodex, Revonto), ice packs and other measures to cool body temperature, as well as supportive care.
What are the symptoms of malignant hyperthermia?
Early signs and symptoms of Malignant hyperthermia (MH) Malignant hyperthermia may develop gradually within several hours after exposure to general anesthesia although it is in the majority of cases reported to occur soon after certain drugs are administered, approximately within one hour.
What is malignant hyperthermia in anesthesia?
How is malignant hyperthermia (high body temperature) treated?
How long does it take for malignant hyperthermia to develop?
What is the most common sign of malignant hyperthermia?
Rapid, shallow breathing and problems with low oxygen and high carbon dioxide. Rapid heart rate. Irregular heart rhythm. Dangerously high body temperature.
What is the earliest sign of malignant hyperthermia?
Early signs of malignant hyperthermiaUnexplained increase in heart rate (tachycardia).Unexplained increase in carbon dioxide produced by your body.Rapid breathing (tachypnea).Muscle rigidity.Rapid elevation in temperature.
What are three signs of malignant hyperthermia?
Malignant hyperthermia (MH) is a type of severe reaction that occurs in response to particular medications used during general anesthesia, among those who are susceptible. Symptoms include muscle rigidity, high fever, and a fast heart rate.
How late can malignant hyperthermia occur?
Malignant hyperthermia (MH) may be triggered by exposure to commonly employed anesthetic agents and muscle relaxants, and often manifests itself during the period of anesthesia. Delayedonset MH occurring one to four hours postoperatively has been described in isolated case reports.
How is malignant hyperthermia diagnosed?
A sample of your blood is collected and sent to a lab for analysis. Genetic testing can identify the gene change that shows you have the genetic disorder called malignant hyperthermia susceptibility (MHS).
Who is most at risk for malignant hyperthermia?
Your risk of having the genetic disorder MHS is higher if someone in your family has it. You only need to inherit one changed gene from a parent to be affected by this disorder (autosomal dominant inheritance pattern). If one of your parents has the gene change that causes MHS , you have a 50% chance of having MHS too.
What happens during malignant hyperthermia?
Malignant hyperthermia (MH) is a pharmacogenic disorder of skeletal muscle. It manifests as a life-threatening hypermetabolic crisis associated with a rapid, uncontrolled increase in myoplasmic calcium in skeletal muscles.
Which drug causes malignant hyperthermia?
Malignant hyperthermia (MH) is a pharmacogenetic disorder that manifests as a hypermetabolic response to potent inhalation agents (such as halothane, isoflurane, sevoflurane, desflurane), the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stressors such as vigorous exercise and heat.
What temp is malignant hyperthermia?
Symptoms of Malignant Hyperthermia Often, the first signs are rapid breathing, a fast heart rate, and muscle rigidity, especially in the jaw. Temperature usually becomes extremely high (usually over 104° [40° C] and sometimes higher than 109° F [43° C]). Abnormal heart rhythms, nausea, and vomiting may occur.
What can mimic malignant hyperthermia?
Sepsis is a life-threatening organ dysfunction with non-specific clinical features that can mimic other clinical conditions with hyper metabolic state such as malignant hyperthermia.
Do local anesthetics trigger malignant hyperthermia?
Any potent inhalation agent or neuroleptic agent can trigger MH. Skeletal muscle relaxants, such as succinylcholine chloride, are the most prominent of all triggering agents, causing the most rapid onset of rigidity. Local anesthetics of the amide group also have been implicated in inducing MH.
Does malignant hyperthermia skip generations?
MH is inherited in an autosomal dominant pattern. This means that children, parents and sibs of an MH susceptible have a 50% chance of inheriting MH susceptibility. Aunts and uncles of the MH susceptible and grandchildren have a 25% chance. More distant relatives have a lesser chance.
What can mimic malignant hyperthermia?
Sepsis is a life-threatening organ dysfunction with non-specific clinical features that can mimic other clinical conditions with hyper metabolic state such as malignant hyperthermia.
What is the most common cause of hyperthermia?
The most common causes include heat stroke and adverse reactions to drugs. Heat stroke is an acute temperature elevation caused by exposure to excessive heat, or combination of heat and humidity, that overwhelms the heat-regulating mechanisms of the body.
What happens to blood pressure in malignant hyperthermia?
Common sign and symptoms of malignant hyperthermia are tachycardia, arrhythmia, elevated systolic blood pressure, tachypnoea, muscle rigidity with elevated body temperature.
What is the antidote for malignant hyperthermia?
Dantrolene is the only currently accepted specific treatment for MH. In an episode of MH, muscle metabolism is dramatically increased secondary to an increase in calcium within the muscle. This causes muscles to contract, ATP hydrolysis, and heat production.
What is the prognosis for patients who are at risk for malignant hyperthermia?
What is the prognosis (outlook) for patients who are at risk for malignant hyperthermia? If the patient has an abnormal reaction to anesthesia and the symptoms are treated immediately, the prognosis is good. If malignant hyperthermia is not treated, serious medical complications, up to and include death, can occur.
What is the best treatment for malignant hyperthermia?
The symptoms of malignant hyperthermia must be treated immediately. A drug, usually dantrolene (Dantrium®), is given to relieve symptoms quickly and to stop the excess calcium from getting into the muscles.
How to know if you are under anesthesia?
The patient may not have any health issues until the symptoms actually occur when he or she receives anesthesia. Symptoms come on quickly, and can include: 1 Rapidly increasing body temperature, sometimes to more than 105 degrees F (40.6 degrees C) 2 Muscle stiffness. The muscles react to the anesthesia by releasing calcium that is normally stored within the muscle cells. Excess calcium causes the muscles to shrink and stiffen. 3 Rapid, and possibly irregular, heartbeat
How does hyperthermia affect the body?
If it is not treated, malignant hyperthermia can lead to the failure of several organs, internal bleeding, cardiac arrest and possibly death.
What is the chance of inheriting malignant hyperthermia?
If one parent has the gene for the syndrome, the baby has a 50 percent chance of inheriting it. Most cases occur in people in their early 20s. Some studies show that men are more at risk than women to develop malignant hyperthermia.
What should a patient tell the doctor about his or her family history before surgery?
The patient should tell the doctor and other caregivers about his or her family history before any surgeries or medical procedures. The surgeon and anesthesiologist can then plan to use other anesthesia drugs, and can be on the lookout for signs of malignant hyperthermia once the surgery begins.
What happens if malignant hyperthermia is not treated?
If not treated right away, malignant hyperthermia (MH) can lead to serious and fatal complications such as:
How is malignant hyperthermia caused?
Malignant hyperthermia susceptibility (MHS) is caused because of a genetic mutation (genetic defect). The genetic defect is usually not inherited and usually the result of random gene mutation. Mutations of different genes can cause MHS. The most commonly affected gene in MHS is the RYR1 gene; other genes that may be affected are CACNA1S and STAC3.
How to treat MH?
Treatment of MH involves: 1 Halting the procedure and offending anesthesia agent as soon as possible 2 Medication: A medication called Dantrium ( dantrolene) inhibits the release of calcium into the muscle, which reduces muscle spasms and rigidity. Medications to correct the body's metabolic imbalance are usually administered. 3 Oxygen: Oxygen therapy is required to increase oxygen levels in the body and reduce carbon dioxide levels. 4 Measures to reduce body temperature: Ice packs, cooling blankets, cold air, and a fan with cool mist and administering chilled intravenous (IV) fluids can help reduce body temperature. 5 IV fluids: Extra fluids would usually be administered intravenously. 6 Close monitoring: The patient is usually admitted for around two days in the intensive care unit (ICU) or longer till their condition improves and the vitals and lab tests (to assess muscle and kidney damage) are normal.
How long does it take for malignant hyperthermia to resolve?
Malignant hyperthermia (MH) is required to be treated right away to avoid life-threatening complications. With appropriate treatment, MH resolves in a few days.
How to reduce body temperature?
Measures to reduce body temperature: Ice packs, cooling blankets, cold air, and a fan with cool mist and administering chilled intravenous (IV) fluids can help reduce body temperature. IV fluids: Extra fluids would usually be administered intravenously.
What does too much heat do to your body?
Too much heat can make you tired, sick, and woozy. WebMD guides you through these and other things heat can do to your body and what to do about it.
What are the symptoms of MH?
The signs and symptoms of MH can vary in patients; they include: Extremely high body temperature, which can be dangerous. Severe muscle rigidity. Muscle spasms. Rapid and shallow breathing leading to an increase in carbon dioxide levels and a decrease in oxygen levels in the body. Tachycardia (increased heart rate)
What is malignant hyperthermia?
Malignant hyperthermia (MH) is a hereditary disorder of skeletal muscle that classically presents as a hypermetabolic response to halogenated anesthetic gasses and/or the depolarizing muscle relaxant succinylcholine.
How many people have malignant hyperthermia?
Studies demonstrate that malignant hyperthermia occurs in about 1 in 100,000 adults and 1 in 30,000 in children. The incidence of malignant hyperthermia varies based upon geographic region. There are concentrations of malignant hyperthermia susceptible families present in Wisconsin and the upper Midwest. The mortality rate is 3% to 5%, even when properly treated.
What is the gold standard for malignant hyperthermia?
The gold standard in the laboratory diagnosis of malignant hyperthermia is the caffeine halothane contracture test (CHCT), although genetic testing is rapidly advancing and may one day replace the muscle biopsy. The CHCT involves exposing a sample of live muscle fibers to halothane and caffeine to determine the muscle response to halogenated anesthetics. Genetic testing for mutations of the RYR1 or other associated genetic variants associated with malignant hyperthermia is becoming increasingly more valuable as the testing improves. Testing can be expensive and is only available in certain centers. Therefore, when presented with a patient for urgent or emergent surgery who has a history suggestive of a close relative who has had a malignant hyperthermia episode, anesthesiologists will usually provide a "non-triggering anesthetic," which is typically a variety of combinations of intravenous anesthetic agents. The differential diagnosis for malignant hyperthermia can include many other, unrelated disorders such as neuroleptic malignant syndrome, pheochromocytoma, sepsis, thyroid storm, serotonin syndrome, or iatrogenic overheating. [5][6][7]
Is malignant hyperthermia a swine disease?
Malignant hyperthermia susceptibility has also been described in other species, particularly in swine, where much of the early research into the disease and its treatment originated.
Can Xenon cause hyperthermia?
Genetically susceptible patients can have a malignant hyperthermia reaction in response to triggering agents such as halogenated anesthetic gasses and/or succinylcholine and more rarely to stressors such as vigorous exercise and heat exposure. Nitrous Oxide and Xenon, although they are inhaled anesthetics, are not halogenated and have not been implicated in malignant hyperthermia.
Is exercise induced hyperthermia fatal?
Early researchers described rare episodes of stress-induced "awake malignant hyperthermia." Later, Tobin described one of the most convincing cases of fatal, exercise-induced malign ant hyperthermia in a 13-year-old boy in whom the causative RYR1 mutation was present and was later found to be present in his family members. [2]
Can you treat hyperthermia with dantrolene?
Despite having been performed frequently in the past, pretreating malignant hyperthermia-susceptible patients with dantrolene does not play a role in their care and should not be done. Instead, these patients should receive a non-triggering anesthetic.
How Late Can Malignant Hyperthermia Occur?
With respect to sevoflurane, desflurane, and isoflurane, the onset of malignant hyperthermia with sevoflurane is shorter compared to the period it will take for the condition to prevail in the presence of isoflurane and desflurane. In the presence of succinylcholine, which is a muscle relaxer, the time period for onset of malignant hyperthermia is shorter, regardless of the anesthetic used.
How does malignant hyperthermia progress?
Anesthetics are usually used during surgery or intensive care to induce temporary loss of consciousness and unresponsiveness. The manifestation of malignant hyperthermia starts with an increase in calcium levels in the muscles. This is because of abnormality in the ryanodine receptor, which is responsible for controlling calcium levels in the muscles. The high calcium levels cause hypermetabolism, which in turn, leads to high levels of carbon dioxide, acidity, heat production, and fast oxygen consumption.
How long does hyperthermia last?
For fast progressive malignant hyperthermia, symptoms may start within the first hour of exposure. It could also last up to twelve hours for the condition to manifest and the first symptoms to be noted.
What happens if you have high calcium levels?
The high calcium levels cause hypermetabolism, which in turn, leads to high levels of carbon dioxide, acidity, heat production, and fast oxygen consumption. If intervention is not done early enough, the condition can lead to multiple organ dysfunction and failure, and in worst case scenario, death. The early symptoms of malignant hyperthermia ...
Can malignant hyperthermia cause death?
The condition involves the skeletal muscle which in turn results in a series of potentially life-threatening symptoms which can cause death if treatment is not given in good time. Patients susceptible to malignant hyperthermia can be children, younger adults, the elderly, males or females.
Can you get malignant hyperthermia?
In terms of age, there is no barrier to who or who can’t get malignant hyperthermia. But, most cases of malignant hyperthermia occur in children and young adults. When it comes to gender, the male counterpart is more susceptible to the condition than females.
Can succinylcholine cause malignant hyperthermia?
Malignant hyperthermia cases are more frequent when anesthetics and succinylcholine are used together. Malignant hyperthermia cases are common among patients who are in surgery or intensive care unit. Depending on how long the patient takes to react to the anesthesia used or succinylcholine, malignant hyperthermia can also develop after surgery.
What is malignant hyperthermia?
Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:5,000 to 1:50,000–100,000 anesthesias. However, the prevalence of the genetic abnormalities may be as great as one in 3,000 individuals. MH affects humans, certain pig breeds, dogs, horses, and probably other animals. The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis, all related to a hypermetabolic response. The syndrome is likely to be fatal if untreated. Early recognition of the signs of MH, specifically elevation of end-expired carbon dioxide, provides the clinical diagnostic clues. In humans the syndrome is inherited in autosomal dominant pattern, while in pigs in autosomal recessive. The pathophysiologic changes of MH are due to uncontrolled rise of myoplasmic calcium, which activates biochemical processes related to muscle activation. Due to ATP depletion, the muscle membrane integrity is compromised leading to hyperkalemia and rhabdomyolysis. In most cases, the syndrome is caused by a defect in the ryanodine receptor. Over 90 mutations have been identified in the RYR-1 gene located on chromosome 19q13.1, and at least 25 are causal for MH. Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs. Elucidation of the genetic changes has led to the introduction, on a limited basis so far, of genetic testing for susceptibility to MH. As the sensitivity of genetic testing increases, molecular genetics will be used for identifying those at risk with greater frequency. Dantrolene sodium is a specific antagonist of the pathophysiologic changes of MH and should be available wherever general anesthesia is administered. Thanks to the dramatic progress in understanding the clinical manifestation and pathophysiology of the syndrome, the mortality from MH has dropped from over 80% thirty years ago to less than 5%.
How fast does hyperthermia increase?
Hyperthermia, when it occurs, is marked by increase in core temperature at a rate of 1–2°C every five minutes. Severe hyperthermia (core temperature greater than 44°C) may occur, and lead to a marked increase in oxygen consumption, carbon dioxide production, widespread vital organ dysfunction, and disseminated intravascular coagulation (DIC) [11].
What is MH in medical terms?
Malignant hyperthermia (MH) is a hypermetabolic response to potent inhalation agents (such as halothane, sevoflurane, desflurane), the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The majority of patients with Central Core Disease (CCD), an inherited myopathy characterized by muscle weakness, are susceptible to MH. Multi-Minicore Disease (MmCD) also predisposes to episodes of MH.
What causes MH mutations?
Experimental evidence from a variety of sources, in vitro, in vivo, isolated cells, transfected cells and mice who's DNA has been altered to express one of the MH causative mutations clearly indicates that the signs and symptoms of MH are related to an uncontrolled release of intracellular calcium from skeletal muscle sarcoplasmic reticulum (SR). In MH susceptible swine and in "knock-in" mice, a variety of environmental conditions can trigger the accelerated calcium release such as environmental heat, exercise and stress. In humans, however, MH results most often from exposure to potent inhalation anesthetics +/- succinylcholine. The enhanced intracellular calcium results in activation of muscle contraction, oxygen consumption, carbon dioxide production, ATP breakdown and heat. The normal sequestration of released calcium is inadequate and energy is expended in a futile manner, in an attempt to lower intracellular calcium. Presumably, the declining levels of ATP lead to failure of membrane integrity and release of potassium and creatine kinase, although the exact steps in the process have not been definitively demonstrated.
What happens if you have uncontrolled hypermetabolism?
Uncontrolled hypermetabolism leads to cellular hypoxia that is manifested by a progressive and worsening metabolic acidosis. If untreated, continuing myocyte death and rhabdomyolysis result in life-threatening hyperkalemia; myoglobinuria may lead to acute renal failure. Additional life-threatening complications include DIC, congestive heart failure, bowel ischemia, and compartment syndrome of the limbs secondary to profound muscle swelling, and renal failure from rhabdomyolysis. Indeed, when body temperature exceeds approximately 41°C, DIC is the usual cause of death.
What are the main diagnostic features of MH?
The principal diagnostic features of MH are unexplained elevation of end-tidal carbon dioxide (ETCO2) concentration, muscle rigidity, tachycardia, acidosis, hyperthermia, and hyperkalemia. The variability in the order and time of onset of signs often makes the clinical diagnosis rather difficult.
Can you diagnose MH without anesthesia?
As almost all patients who are MH susceptible have no phenotypic changes without anesthesia, it is impossible to diagnose susceptibility without either the exposure to the "trigger" anesthetics or by specific diagnostic testing. The key diagnostic features include an unexplained elevation of expired carbon dioxide, muscle rigidity and rhabdomyolysis, hyperthermia, acidosis and hyperkalemia.
What is the temperature of a person with malignant hyperthermia?
There is an increase in body temperature (extremely high body temperature to 105 degrees F or higher), increased heart rate and palpitations as well as increased breathing rate. Carbon dioxide is produced in large amounts, cannot be eliminated properly, while on the other hand, the body uses too much oxygen. As a result, the amount of oxygen becomes insufficient.
When was malignant hyperthermia first identified?
As far as history is concerned, the condition was first identified in one family from Australia in 1962.
How long does it take for hyperthermia to develop?
Malignant hyperthermia may develop gradually within several hours after exposure to general anesthesia although it is in the majority of cases reported to occur soon after certain drugs are administered, approximately within one hour.
What is the term for a severe metabolic imbalance?
The above mentioned is closely related to a severe metabolic imbalance known as acidosis. The muscles become rigid. One may even develop rhabdomyolysis. Rhabdomyolysis is a serious condition characterized by the breakdown of muscle fibers. Damaged muscle cells release huge amount of myoglobin into the blood. The excess of this protein can cause damage to the kidneys and even make matters worse. The urine containing blood is dark brown while damage to muscles always triggers muscle ache similar to one we experience while exercising or when muscles are somehow injured.
Is malignant hyperthermia the same as malignant hyperthermia?
Classification. There is no special classification, since malignant hyperthermia is always associated with the same symptoms and signs. However, there are different names which describe the same condition. So, malignant hyperthermia is also referred to as malignant hyperthermia syndrome or malignant hyperpyrexia.
Can sevoflurane cause hyperthermia?
Since in the majority of cases malignant hyperthermia is practically triggered by volatile anesthetic gases like halot hane, sevoflurane etc. or certain muscle relaxants , these medications are best to avoid. It is also essential to be fully prepared for potential attack and react promptly.
Can you prevent malignant hyperthermia?
So, only once the person develops the condition, doctors can be sure that he/she is suffering from malignant hyperthermia and may prevent any repeated attack.
