- Guidelines - MH
Link:www.aagbi.org/sites/default/files/MH%20guideline%20for%20web%20v2.pdf
- Diagnosis
- Unexplained increase in EtCO₂ with
- Unexplained tachycardia with
- Unexplained increase in O₂ consumption
- Masseter spasm after suxamethonium indicates high risk of MH susceptibility but is usually self limiting
- ITU management
- Monitor for compartment syndrome
- Assess renal failure
- Give further dantrolene as necessary
- Consider other diagnosis (eg sepsis, phaeo, myopathy)
- Late management
- Council family regarding implications of MH
- Refer to MH unit
- Pathophysiology
- Genetic, chromosome 19 long arm
- Mutation in RYR1
- RYR1 has an A site and an I site
- Trigger increases affinity of A site for Ca²⁺
- Causes massive Ca²⁺ release
- Reabsorbing this Ca²⁺ uses up ATP & generates heat
- Treatment
- Remove triggers
- Call for help
- 100% O₂
- Use new circuit and high flows
- Maintain anaesthesia with IV agents
- Dantrolene 2.5mg/kg IV then 1mg/kg prn
- Active cooling
- Monitoring
- ECG, EtCO₂, SpO₂, IABP, CVP, core and peripheral temperature, urine output, CK, K⁺, Hct, platelets, clotting
- Effects of MH
- Hypoxia and acidosis
- 100% O₂ and hyperventilate
- Hyperkalaemia
- Sodium bicarbonate, glucose/insulin, IV calcium chloride
- Myoglobinaemia
- Forced alkaline diuresis (aim for >3ml/kg; pH >7)
- DIC
- Cardiac arrhthmias
- Metoprolol, Mg²⁺, amiodarone (avoid CCBs)
- CEACCP
Link:ceaccp.oxfordjournals.org/content/3/1/5.full.pdf