|Year : 2007 | Volume
| Issue : 6 | Page : 534-535
Malignant hyperthermia -a case report
Kirti N Saxena1, CK Dua2
1 Professor, Department of Anaesthesiology and Intensive Care, MaulanaAzad Medical College and associated LN Hospital, New Delhi, India
2 Ex- Professor and Head, Department of Anaesthesiology and Intensive Care, MaulanaAzad Medical College and associated LN Hospital, New Delhi, India
|Date of Acceptance||25-Sep-2007|
|Date of Web Publication||20-Mar-2010|
Kirti N Saxena
B-302, Geetanjali Apartments, Vikas Marg Extension, New Delhi-110092
Source of Support: None, Conflict of Interest: None
A twenty-eight year old female was scheduled to undergo excisional reconstruction and plating of the mandible following a diagnosis of ameloblastoma on incisional biopsy under local anaesthesia. On preanaesthetic evaluation, there was no significant finding except restricted mouth opening and a swelling over the mandible. On attempting laryngoscopy the patient was found to have masseteric spasm following administration of succinylcholine. After one hour it was noted that the EtCO2 was being maintained at 47 -48 mmHg inspite of slight hyperventilation. Within half an hour EtCO2 rose gradually to 60 mm Hg and then suddenly to 80 mm Hg .The patient's pulse rate rose gradually to 130 beats per minutes and then suddenly to 160 beats per minutes .At this time the patient was found to have nasopharyngeal temperature of 106.50 F. Aprovisional diagnosis of malignant hyperthermia was made and the patient was treated accordingly. Further the patient was investigated to rule out other conditions and clinch the diagnosis of MH. This is probably the first case report of this disease from India.
Keywords: Hyperthermia, Malignant Hyperthermia, End tidal CO2
|How to cite this article:|
Saxena KN, Dua C K. Malignant hyperthermia -a case report. Indian J Anaesth 2007;51:534-5
| Introduction|| |
Malignant hyperthermia(MH) is a myopathy associated with abnormal skeletal muscle calcium homeostasis in response to triggering agents. The pathophysiology  of malignant hyperthermia involves altered sarcoplasmic reticulum Ca 2+ channel gating kinetics. The stimulus may be provided by triggering agents such as succinylcholine and halothane which have been strongly implicated. Sustained high levels of calcium in sarcoplasmic reticulum lead to increased aerobic and glycolytic metabolism leading to acidosis, rigidity, altered permeability and hyperkalaemia. Increased metabolismleads to hyperthermia. A rise in endtidal CO 2 (EtCO 2 ) out of proportion to the clinical setting is the first sign of the condition under anaesthesia. Ahereditary pattern of the disease has been found. Mutations associated with MHS have been reported in two genes  : RYR1and CACNA1S. Mutations in RYR1(Ryanodine receptor) are also responsible for central core disease (CCD), a myopathy that can be associated with a positive response to the in vitro caffeine halothane contracture test.Association has been found with King's syndrome , Duchenne muscular dystrophy, myotonia congenita and other muscle disorders 
We present here a case showing all the clinical signs and symptoms of malignant hyperthermia.To the best of our knowledge no case of MH has been reported from India.
| Case report|| |
A twenty-eight year old female was scheduled to undergo excisional reconstruction and plating of the mandible .She had been diagnosed to have ameloblastoma following incisional biopsy of the mandible under local anaesthsia. On preanaesthetic evaluation, there was no significant finding except restricted mouth opening and a swelling over the mandible. The interincisor gap was 3 centimetres and Mallampatti grade was 3.
On the day of the surgery the patient had received diazepam 5 mg orally two hours earlier .Her pulse rate was 88 beats per minutes and blood pressure was 110/ 80 mm Hg on the O.T. table. After attaching the pulse oximeter and cardiac monitor morphine and glycopyrrolate were given intravenously. The patient was preoxygenated for two minutes and induced with thiopentone and succinylcholine and ventilated with oxygen ,nitrous oxide and halothane. On attempting laryngoscopy the patient was found to have masseteric spasm therefore she was ventilated for some more time and then laryngoscopy was tried again however the jaw spasm did not resolve. The laryngoscope blade could just be inserted into the mouth and laryngoscopy was performed with difficulty and only the posterior half of the laryngeal inlet could be seen after application of a BURP maneuver. Nasotracheal intubation was done. After return of spontaneous respiration vecuronium was given and IPPV was maintained with oxygen, nitrous oxide and halothane.
After one hour it was noted that the EtCO 2 was being maintained at 47 -48 mmHg inspite of slight hyperventilation. Suspecting some problem to have developed in the breathing circuit, it was changed, but the EtCO 2 continued to be maintained at this level .The patient was having normal temperature at this time .Also, it was noticed that the vecuronium was being needed more frequently .Within half an hour EtCO 2 rose gradually to 60 mm Hg and then suddenly to 80 mm Hg .The patient's pulse rate rose gradually to 130 beats per minutes and then suddenly to 160 beats per minutes .At this time the patient was found to have nasopharyngeal temperature of 106.5° F. A provisional diagnosis of malignant hyperthermia was made and the halothane vaporizer was disconnected from the circuit. The patient was ventilated with O 2 :N 2 O,50:50 until the completion of the surgery which was half way through and was completed quickly.
Meanwhile, intravenous cold saline drip and cold sponge hydrotherapy were started. Gradually the temperature decreased to 99.2 o F and pulse rate to 104 beats per minute. Hydrocortisone i.v was given. An arterial blood sample analysis at FiO 2 0.5 showed the following result : pH-7.1, pCO 2 -78 mmHg ,pO 2 -224 mm Hg ,base excess -9.5, HCO 3 -21mEq.L -1 , Na-142mEq.L1 and K-7.0mEq.L -1 . Sodiumbicarbonate i.v was given to correct the metabolic acidosis and patient was hyperventilated for correction of respiratory acidosis. The patient was shifted to the ICU, where she was electively ventilated for the next 24 hours. Sedation was given with morphine and muscle relaxant was changed to pancuronium which has been found to be the relaxant of choice for these patients 1 .AnABG done after 4 hours showed : pH- 7.5, pCO 2 -25.3 mmHg, pO 2 -218.4 mmHg at FiO2 0.5, Na-148.7mEq.L-1 , K-3.1mEq.L -1 and Ca0.75mEq.L -1 . Blood investigations done at this time showed creatinine kinase -1635 I.U.,LDH-170 I.U.,blood urea-14.8mg%, s.creatinine-0.9mg%,blood sugar 167.9 mg %. Urine for myoglobin was negative.
Subsequently, the only abnormal finding was a decrease in serum potassium for which correction was given and creatinine kinase which rose to 1890 I.U. on the second day and showed a falling trend thereafter. The patient was reversed and extubated the next day and was kept under observation for the next five days during which she remained normal and was discharged on the eighth day. CPK at this time was normal.
Since malignant hyperthermia has not been reported in India it was decided to further investigate this patient. To eliminate causes such as thyrotoxicosis and phaeochromocytoma, thyroid function tests and urinary VMA were done. These were found to be within normal limits.
As per the protocol suggested by Larach et.al  ,3months later a muscle biopsy from the patient's rectus femoris muscle was planned to clinch the diagnosis of MH.
On the morning of surgery, the anaesthesia machine was prepared as per the protocol suggested by Beebe et al  . The halothane vaporiser was removed from the machine and the machine was flushed with 100% oxygen for 10 minutes following which the DatexOhmeda monitor showed no trace of halothane.A fresh Bains circuit was used. The patient was premedicated with oral diazepam on the morning of surgery and anaesthesia was given with pethidine and propofol infusion given intravenously.The patient kept breathing oxygen and nitrous oxide spontaneously with mask. No volatile inhalational agent was given. The patient underwent the biopsy uneventfully.
The muscle biopsy was subjected to microscopic examination by the pathologist and a contracture test in response to caffeine and halothane were done as per the protocol of European malignant hyperthermia group  . These tests were done for the first time in our institution and there was no control. The results of the contracture test were negative. Microscopic examination of the frozen section revealed non-specific features like mild variation in size of muscle fibres. On succinicdehydrogenase enzyme staining, there was exaggerated reactivity in 6 per section of muscle fibres (More than 2 per section is in favour of malignant hyperthermia but is not diagnostic of it)  .
| Discussion|| |
There are innumerable case reports of malignant hyperthermia in the western journals since Denborough reported the first case in 1960. The incidence of malignant hyperthermia is 1 in 2,50,000 of all anaesthetics  in Denmark. When only potent anaesthetics and succinylcholine were used then it was 1 in 62,000 and a suspicion of MH was seen in 1 in 16,000 anaesthetic administrations. A high incidence of mortality was associated with the condition. With better understanding and treatment strategies , mortality can be prevented. No case has been reported in India and there is widely held belief in India that this is a disease of the western world.
The diagnosis of malignant hyperthermia is based on:
The clinical presentation in this case conformed to a typical episode of malignant hyperthermia .Masseter spasm was seen following administration of succinylcholine and halothane. However since this is not diagnostic but predictive of MH halothane was continued. There is a problem in defining the point where a normal response of depolarization following succinylcholine becomes pathognomic of malignant hyperthermia  . This was followed by increase in EtCO 2 and hyperthermia. Rigidity was absent in this case but it has been seen that mild hypothermia, depressants such as barbiturates, tranquilizers and nondepolarising muscle relaxants(specially the steroid group) delay the onset of MH  .
- Clinical presentation
- Contracture test
- Genetic studies
Larach et al  gave a clinical grading scale using clinical indicators for determining the Malignant Hyperthermia Raw Score. This score has been considered to be a definitive diagnostic indicator of MH based on clinical findings and biochemical tests. The parameters used were rigidity, muscle breakdown, respiratory acidosis, hyperthermia, cardiac involvement, family history of MH and some biochemical parameters. The clinical indicators and the points assigned to them as per the score are given in [Table 1]. These parameters were given points according to the MH rank and these were added up to get the MH Raw Score which were interpreted as shown in [Table 2]. The total score in our patient was 71 which puts the patient in MH rank 6 making the diagnosis of malignant hyperthermia almost certain.
Since the contracture studies are not being done in India it was not possible to do a standardized caffeinehalothane contracture test in this patient. Larach et al 4 recommended that diagnostic muscle biopsies should not be performed until a minimum of 10 normal control patients have been tested and found to be normal by the new labroratory. This was not possible in our setup hence the validity of the test done by us is doubtful since it was done for the first time by us and there was no control. Also, the muscle must be subjected to the test within an hour of harvesting it, hence it was not possible to send it to any of the centres abroad where this test is being done. There are only 30 such centres worldwide. However, cases have been reported  with negative caffeinehalothane contracture test who had full blown clinical episode of malignant hyperthermia under anaesthesia hence the importance of the MH Raw Score. Recently it has been suggested that intramuscular injection of caffeine can be given and the local CO 2 concentrations be measured  .However there is a likelihood of this precipitating an acute MH attack. Microscopic examination of the biopsy was suggestive of MH.
Several genes have been implicated rather than MH being a single gene defect  . Genetic testing for malignant hyperthermia is not available in India presently and could not be done in this patient.
The diagnosis in this case was made by calculating the MH Raw Score  which has been described above.This score was created for reaching a clinical diagnosis in case confirmation cannot be made by laboratory tests as in our case where the control tests were not available.The high MH Raw Score (71) of our patient placed her in the almost certain group. The other probable diseases such as phaeochromocytoma and thyrotoxicosis were ruled out by appropriate investigations. Neuroleptic malignant syndrome was ruled out as the patient was not on any of the implicated drugs for this syndrome .
The treatment of choice for malignant hyperthermia is dantrolene sodium(calciumchannel blocker) given intravenously. We could not obtain this drug anywhere in New Delhi. It is currently not manufactured in India.
To conclude, we have presented a patient with full blown signs and symptoms of malignant hyperthermia whose diagnosis could not be supported by diagnostic tests as these are unavailable in India. To the best of our knowledge, this is the first such report from India. It is perhaps time that centers for testing for MH were setup and also dantrolene sodium the specific antagonist be made available.
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[Table 1], [Table 2]