Address for Correspondence: Dr Priyanka Pavithran, MBBS,
MD, DNB Anaesthesiology, Consultant, Department of
Anaesthesiology, Aster MIMS, Calicut, Kerala, India. Email:
priyanka.pavithran@gmail.com
Malignant hyperthermia is a hypermetabolic crisis caused by
disordered calcium metabolism when the susceptible individual
is exposed to the triggering agent. It is caused by a
pathogenic mutation of the RYR1 gene. Here we report our
experience with a suscpected case of malignant hyperthermia
which was confirmed posthumously with a genetic diagnosis.
Case report
A teenage boy who had sustained a subdural hematoma and facial
trauma was posted for suturing of the facial lacerations.
Under standard monitoring, general anaesthesia was
administered with Inj. Fentanyl 100 microgram, Inj.
Propofol 100 mg and intubated under Inj. Succinylcholine 100
mg. He was maintained on oxygen, nitrous oxide and isoflurane.
Post intubation patient remained stable for half an hour, when
his end tidal carbon dioxide (ETCO2) started
increasing gradually reaching a value of 45 mmHg. Minute
ventilation was increased, but ETCO2 kept
rising. As we made attempts to take blood sample for
performing acid blood gas (ABG) analysis it was noticed that
the patient was febrile. A provisional diagnosis of malignant
hyperthermia was made and management measures were initiated.
Surgeon was informed and surgery was abandoned. Inhalational
agent was discontinued and soda lime canister was changed. A
new flushed anaesthesia workstation was made available.
Femoral artery was cannulated for blood pressure monitoring
and internal jugular vein was catheterized. Ice packs were
applied. Sodium bicarbonate, insulin dextrose and propofol
infusions were started. Dantrolene was not available at our
institution or any other hospital in our city. By one hour
post induction, his ETCO2 was 135 mmHg, heart rate
140/min, blood pressure was 136/74 mm Hg and temperature was
40 degrees Centigrade. ABG analysis showed a pH 6.3, PaCO2
150 mm Hg and potassium to be 8.1 mEq/l. Two hours after
induction he developed asystole which was revived with one
cycle of cardiopulmonary resuscitation and he was shifted to
intensive care unit. He continued to have multiple episodes of
cardiac arrests and succumbed soon after. His blood sample was
sent for genetic analysis and he had a heterozygous pathogenic
mutation, c.1024G>C (p.Glu342Gln) in Exon 11 in the RYR1
gene.
His family was counseled to undergo genetic testing which has
not been done yet.
Discussion
Malignant hyperthermia (MH) is a rare pharmacogenetic disorder
which causes a hyper metabolic reaction due to disordered
skeletal muscle contraction on exposure to triggering agents.
The most consistent clinical features of an MH reaction
include a rise in ETCO2, unexplained tachycardia,
muscle rigidity, hyperthermia and acidosis.[1] Larach et
al.[2] developed a scoring system to help diagnose MH and our
patient had a score of 111 which gives an almost certain
diagnosis of MH.
The ryanodine receptor 1 (RYR1) gene is the main gene
implicated in MH. Molecular testing alone cannot be used to
identify at risk individuals and In Vitro Contracture test
(IVCT) is the gold standard for detecting MH susceptible
individuals. Genetic screening can only be considered as an
adjunct to IVCT in patients with a family history of MH.[3]
There are reports of MH susceptible patients being
anaesthetized uneventfully by avoiding the known triggering
agents.[4]
Thought to be non-existent in our population till 2007, few
cases have been reported till date.[5,6] MH can have varying
presentations from florid to more subtle presentations which
are not investigated adequately and are left unreported. There
is an ethical question that remains when we take up patients
for anaesthesia without keeping dantrolene available knowing
MH can happen any time. Increased awareness and vigilance
leading to early detection and treatment are the best options
available presently. Since we do not have registries for
reporting these incidents, case reports can serve as reminders
and improve awareness on the incidence of MH in Indian
population.
Conclusion
The emerging case reports of malignant hyperthermia in our
population contradict the prior belief that malignant
hyperthermia is non-existent in our patients. This fact
underlines the importance of stocking dantrolene. High
vigilance in detecting and removing triggering agents can help
prevent the progression of MH.
References
1. Gupta PK, Hopkins PM. Diagnosis and management of malignant
hyperthermia. BJA Educ 2017;17: 249-54.
2. Larach MG, Localio AR, Allen GC, Denborough MA, Ellis FR,
Gronert GA, et al. A clinical grading scale to predict
malignant hyperthermia susceptibility. Anesthesiology
1994;80:771-9.
3. Beebe D, Puram VV, Gajic S, Thyagarajan B, Belani KG.
Genetics of malignant hyperthermia: A brief update. J
Anaesthesiol Clin Pharmacol 2020;36:552-5.
4. Joshi M, Reddy BA, Bollampally B, Joshi SD. Successful
anaesthetic management of a patient with prior history of
malignant hyperthermia for corrective scoliosis surgery.
Indian J Anaesth 2014;58:78-80.
5. Kirti N, Saxena CKD. Malignant hyperthermia ‑A case report.
Indian J Anaesth 2007;51:534.
6. Sharma A, Karnik H, Kukreja S, Jagger K. Malignant
hyperthermia: Dantrolene sodium - A must have. Indian J
Anaesth 2012;56:212-3.
The consent for publication was obtained from the family of
the deceased patient with the guarantee that their anonymity
will be maintained.