Malignant hyperthermia: Periop mgmt
Advanced, Basic Sciences, Pharmacology
1. Immediately discontinue anesthetics, including succinylcholine. Life-threatening surgery will be continued, but with the use of a non-triggering anesthetic agent and machine to prevent residual inhalation agent from triggering a second episode.
2. Hyperventilate 100% oxygen at a high flow rate of 10L/min to treat effects of hypercapnia, metabolic acidosis, and increased oxygen consumption
3. Dantrolene 2.5mg/kg IV as soon as possible; given every five minutes until symptoms subside.
4. Change ventilator tubing and soda lime canister. Some anesthesia providers may still perform this action, but research has shown that it is not necessary to change the breathing circuit and anesthesia machine since the oxygen delivery rapidly clears the machine of the anesthetic gases.
5. Sodium bicarbonate 1-2 mEq/kg IV to combat metabolic acidosis due to increase of lactate in the circulatory system
6. Ice packs Apply to groin area, axillary regions, and sides of neck – where major arteries are located.
7. Iced lavage lavage the stomach and rectum with cold fluids to lower temperature. It is recommended not to lavage the bladder since the fluids can alter the true amount of urine being excreted by the patient and alter measurement of output. Avoid causing hypothermia; cooling should be discontinued when the core body temperature reaches 38º C.
8. Mannitol or furosemide. Muscle cells are destroyed during an MH crisis and the myoglobin that is released accumulates in the kidneys, obstructing urinary flow, referred to as myoglobinuria. Diuretics are given IV to promote and maintain urinary flow in order prevent renal damage. Mannitol 0.25g/kg IV; furosemide 1mg/kg IV; up to four doses each. Urinary output of 2ml/kg/hr or higher must be maintained to prevent renal failure.
9. Procainamide 200 mg IV to treat arrhythmias secondary to electrolyte imbalances.
10. Dextrose and insulin. Treat hyperkalemia due to the release of potassium into the circulatory system as muscle cells are destroyed. Dextrose 25-50g IV; regular insulin 10 units in 50ml of 50% dextrose in water given IV.
11. Monitor urine output Insert Foley catheter if one is not in place
12. Monitor electrolyte levels Blood samples taken every 10 minutes to measure sodium, potassium, chlorides, calcium, phosphate, and magnesium levels.
13. Perform clotting studies
14. ABG Every five to 10 minutes
15. Arterial blood pressure Insert line if one is not in place
16. Central venous pressure Insert line if one is not in place
17. Capnograph Instrument used to produce a capnogram, a tracing that measures the proportion of carbon dioxide in exhaled air.