Presentations Sux Apnoea

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 ++ 

Anaesthetic drugs       

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 

Recovery Drowsy  Co-operative and talking  No recollection  Required narcotic analgesia  Very dry mouth  Puffy eyes  Husband to visit 

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 

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 

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 

The end!!

Thankyou very much for your attention.