Malignant hyperthermia

an emergency situation in surgical patient

1. Malignant hyperthermia Dr jameel kifayatullah [email protected]

2. Malignant hyperthermia Serious life threatening condition characterised by a state of hypermetabolism leading to hyperthermia and massive rhabdomyolysis

3. RHABDOMYOLYSIS

4. Causes Autosomal dominant genetic defect of one of several receptors within sarcoplasmic reticulum i.e Mutation in the ryonodine receptor, CACNA 1S calcium receptor involvement Volatile anaesthetic agents e.g halothane,sevofluorane and skeletal muscle relaxant S uccinylcholine

5. Ryanodine receptor

6. Volatile anaesthetic agents

7. Pathophysiology Triggering agents such as Succinylcholine and volatile anaesthetic agents in a genetically predisposed patient release calcium from sarcoplasmic reticulum leading to elevated concentrations of calcium in the muscle cells This increase metabolism is responsible for the symptoms of Malignant hyperthermia

8. P athophysiology

9. Definitive Diagnosis History suspicious of Malignant hyperthermia should undergo the following tests before anaesthesia skeletal muscle biopsy caffeine halothane testing Genetic susceptibility testing for ryanodine and CACNA 1S receptor mutations

10. Early signs of Malignant Hyperthermia Hypercapnia Tachycardia Muscle rigidity Tachypnea Hypoxia Arrhythmias Unstable Blood pressure Flushed cyanotic or ruddy skin

11. Late signs of Malignant Hyperthermia Fever/diaphoresis Respiratory and metabolic acidosis High : Potassium,calcium,magnesium,glucose,creatin kinse (CK), LDH,SGOT Low Clotting factors Myoglobinemia

12. Malignant hytperthermia

13. Steps for treating Malignant Hyperthermia Emergency page to staff anaesthesiologist Discontinue the triggering agents Discontinue the surgical procedure as quickly as possible Start TIVA(Total Intravenous anaesthetic agents) Hyperventilate with 100% Oxygen at high flow rate

14. Steps for treating Malignant Hyperthermia Give D antrolene sodium 2.5 mg/Kg I.V Obtain Labs( ABGs,Electrolytes,CK,serum /urine myoglobin,Coagulation parameters) Treat Hyperkalemia :Calcium chloride,Glucose,Insulin Treat Metabolic Acidosis: Bicarbonate:1-2 mEq / kgs

15. Steps for treating Malignant Hyperthermia Incase of hyperthermia: cool patient cold IV fluids(normal saline),Apply ice packs to groin , axilla , nasogastric lavage with cold solution Foley catheter for urine output ICU admission

16. Cooling Techniques for Hyperthermia