Sux Apnoea
- A Case Study
Karenne Nielsen
Clinical Nurse Specialist
West Gippsland Healthcare Group
Suxamethonium Chloride
“Sux” “Scoline”
Short acting muscle relaxant
 Allows rapid intubation of trachea &
provides short periods of neuromuscular
blockade
 Main uses - difficult intubation
- emergency conditions
- brief procedures

Suxamethonium “Sux”
Dose = 1-2 mgs/kg IVI or IMI
 Rapid onset of muscle relaxation
- fasciculation 30-60 seconds
 Short duration of 5-10 minutes
- apnoea lasts ≈ 5 mins
- paralysis recovery another 5 mins

Suxamethonium – “Sux”
Metabolised by plasma cholinesterase
- an enzyme produced in the liver &
present in the blood
 Plasma cholinesterase is usually
present in sufficient concentration to
give a half-life of approx. 4 mins
 No reversal agent

Side effects
Cardiovascular – bradycardia
 Hyperkalaemia
 Raised intraocular/pressure
 Allergic reaction → Anaphylaxis
 Malignant hyperthermia
 Muscle pains- calf & chest
 Prolonged muscle paralysis

“Sux apnoea”
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Rare condition in 4-6% population
Patients with abnormal plasma
cholinesterase are incapable of
metabolising suxamethonium resulting in
prolonged muscle paralysis and apnoea.
Inherited - often normal levels but abnormal
plasma cholinesterase (up to 8hrs or more)
Acquired – lower levels of normal plasma
cholinesterase
Case study
55 year old Female
 No significant medical/family history
 Nil current medications
 Non smoker
 Surgical & Anaesthetic history
- Varicose Vein Ligation 2002
- GA no muscle relaxants

Pre-Anaesthetic Assessment
Weight: 77.5 kgs / Height: 156cm
 Reflux lying flat in bed
“High risk of gastric reflux”
 Undershot jaw – Airway Grade III
“? Difficult intubation”
 ASA score 2
 Anxious patient ++
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Anaesthetic drugs
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Midazolam 2mgs IVI
Fentanyl 100µgs IVI
Propofol 200mgs IVI
Suxamethonium 100mgs IVI @ 1355
Nitrous/Oxygen 2:2
Sevoflurane 2%
Cephazolin 1gm IVI
Anaesthetic/Operation
Ventral Hernia Repair with Mesh
- surgery straightforward = 1hr
 No muscle movement noted
throughout the operation – end
time 1hr & 10 mins after “sux”given
 Sux apnoea or another diagnosis ?
 Assumption of Sux apnoea confirmed
by nerve stimulation

Management
Anaesthesia maintained
- important to be patient
- keep asleep and unaware
 Continuous monitoring
 Entropy monitoring
 Fluid and electrolyte balance
 Temperature
 BSL

Management
Urinary catheter
 Pressure area care
 Calf stimulation
 Eye care
 Wound/drain care
 Nerve stimulator
Plan for emergency surgery

Management
Relatives kept informed & to visit
- truthful explanation of condition
- reassure safe & waiting to wake
- ? Fresh Frozen Plasma
 Started to swallow @ 6½hrs
 Extubated 30 mins later
 Total time = 7 hours
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Recovery
Drowsy
 Co-operative and talking
 No recollection
 Required narcotic analgesia
 Very dry mouth
 Puffy eyes
 Husband to visit
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Post-op period
Hypokalaemia post op day 1& 2
- Potassium replaced IVI & orally
 Febrile post op day 2
- CXR ? pneumonia
- oral antibiotics
 Erythema of wound day 3
 Discharged post op day 5
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Follow up for Sux Apnoea
Review 1 month post-op
 Debriefing with family present
- Sux Apnoea episode
- Importance of alerting staff with
future anaesthetics  Pseudocholinesterase typing &
Phenotype differentiation
 Patient and family tested
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Follow up testing
Normal Dibucaine = over 70%
 Homozygous normal = (6.0-15.6)
 “K” – Dibucaine Inhibition = 15%
confirming susceptibility to “Sux”
 Genotype testing unavailable but
length of apnoea suggests rare
clinical variant
 Children 4/6 tested – all normal levels
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The end!!
Thankyou very much
for your attention.