Malignant hyperthermia

Malignant hyperthermia is a syndrome of rapidly rising temperature.

It occurs due to abnormality of Ryanodine receptors which cause release of large amount of calcium from sarcoplasm reticulum leading to sustained muscular contraction.

It is triggered by:
1) Succinylcholine (50%) - most common
2) ether
3) methoxyflurane
4) halothane
5) enflurane
6) isoflurane
7) Desflurane
8) sevoflurane

Clinical features:
1) Masseter muscle spasm - most initial sign
2) Rise in end tidal CO2
3) Tachycardia
4) Respiratory/ metabolic acidosis
5) Hyperkalemia
6) Pulmonary edema
7) Cerebral edema
8) Myoglobinuria
9) Renal failure
10) Rise in temperature - late sign

Treatment:
1) Stop all anesthetic agents (because one of it is a triggering factor).
2) Hyperventilate with 100% O2.
3) Inj.Dantrolene - 2 mg/kg  intravenously every 5 minutes to a maximum dose of 10 mg/kg.
Dantrolene can be continued for next 48 hours.
4) Sodabicarb to correct metabolic acidosis.
5) Cooling of body.
6) Other symptomatic treatment.

To detect malignant hyperthermia:
BEST DIAGNOSTIC TEST -> Halothane Caffeine muscle contraction test.
BEST SCREENING TEST -> Creatinine kinase test.

Thanks for reading.

Madhuri Reddy