Transcript MALIGNANT HYPERTHERMIA (Dr. Mary Lehane)

MALIGNANT
HYPERTHERMIA
Dr. Mary Lehane
Malignant Hyperthermia
Investigation Unit
Cork University Hospital
INCIDENCE
• 1:12 000 - 1:40 000
• Male = Female
• No racial difference
MORTALITY
5 % - 80 %
TRIGGERS
• All volatile anaesthetic agents
• Suxamethonium
GENETICS
• Autosomal dominant
• Chromosome 19
• Gene RYR 1
• Mutations
– 78 single point mutations identified to date
PRESENTATION
• 1 A known MH patient
• 2 Unexpected MH crisis
FULMINANT CRISIS
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Tachycardia
Metabolic acidosis,  O2 sat,  pCO2
Muscle rigidity
Electrolyte disturbance
Arrhythmias
Myoglobinuria
Hyperthermia
DIAGNOSIS, consider MH if
• Masseter muscle spasm after sux
• Unexplained, unexpected tachycardia
• Unexplained, unexpected increase in end tidal CO2
EARLY MANAGEMENT 1
• STOP ALL ANAESTHETIC VAPOURS
• CHANGE TO CLEAN ANAESTHETIC
BREATHING SYSTEM
• ABANDON SURGERY IF FEASABLE
EARLY MANAGEMENT 2
• DANTROLENE
• MEASURE ABGs, K+ AND CK
• MEASURE CORE TEMP
• COOL PATIENT
OTHER COMPLICATIONS
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Arrhythmias
Hyperkalaemia
Metabolic Acidosis
Disseminated Intravascular Coagulopathy
Renal Failure
POST CRISIS MANAGEMENT
• WARN PATIENT AND FAMILY
• REFER FOR INVESTIGATION
– ie muscle biopsy
• MEDIC ALERT
INVESTIGATION
• Family history
• Muscle biopsy
• In - vitro contracture tests
• Histology
• Resting CPK etc
• Mutation screening
KNOWN MH PATIENT
• Inform anaesthetist and theatre
• Prepare anaesthetic machine etc
• All hospitals should carry dantrolene
• All staff carry responsibility
The Cork Experience
• 560 Patients biopsied
• MHS
• MHE (h)
• MHE (c)
• MHN
131
100
6
333
The Cork Families
• 98 Pedigrees identified
• 74 Probands
• 24 Deaths
CONCLUSION
• SURVIVAL
• Identification of at-risk patients
• Appropriate management