Rare complication

Question 1

What is malignant hyperpyrexia

Answer 1

Life threatening condition resulting from a genetic sensitivity of skeletal muscles to volatile anaesthetics and depolaring muscle neuromuscular blocking drugs

Question 2

What is the genetics for malignant hyperpyrexia

Answer 2

Autosomal dominant

With variable penetrance

Question 3

Presentation of malignant hyperpyrexia

Answer 3

Muscular rigidity 
Hypermetabolic state
Inc O2 consumption
Inc CO2 production 
hyperthermia 
Rhabdomyolysis

Question 4

Pathophysiology

Answer 4

Mutation in the ryanodine 1 receptor on sarcoplasmic reticulum - stored calcium
Normal muscle - small amount of Ca2+ released when triggered then reabsorbed into the SR for the next cycle
In MH the receptor doesn’t close properly after opening for a stimulus so the there is excess ca2+ release as they are being sequestered but just leak out leading muscle rigidity symptoms
This uses lots of ATP - hypermetabolic
Produced excess heat - hyperaemic
Muscle cells get damaged by depletion of ATP so that the contents leak —> rhabdomyolysis
K+ leak —> hyperkalaemia

Question 5

Triggers for malignant hyperpyrexia

Answer 5

Halothane

Suxamethonium

Question 6

Tx malignant hyperpyrexia

Answer 6

Help
Hyperventilate the patient 100% O2
Finish or abort the procedure 
Cool patient
Clean the breathing system 
Cause diuresis
Treat hyperkalamia, dysrhythmias
Monitor CK
Monitor coagulation
Administer DANTROLENE

Question 7

Test for malignant hyperpyrexia

Answer 7

Muscle biopsy at a special centre

Question 8

What is pseudo cholinesterase deficiency

Answer 8

Inherited enzyme abnormality
There is abnormally slow tabloid degradation of exogenous choilne ester drugs
So you get a pronged duration of sux or LA ester - procaine and Cocaine