Cardioversion
Last modified: 22 September 2022, 12:39:48 PM AEST
Gems1 / 11
- allow enough time for fentanyl to work
- Cardioversion = synchronised delivery of electrical energy
- Defibrillation = asynchronous delivery of electrical energy
- Defibrillator (the machine, which can do both)
- set to "Sync"
- shock is synchronized with the QRS complex (specifically, the R wave)
- PEAK of QRS complex
- prevents shock being delivered during repolarisation (T-wave), thereby precipitating VF
- there will be slight delay in the shock
- Vulnerable period = ventricular repolarisation
- peak of T wave
- R on T phenomenon = PVC / defib during this may precipitate VF
- Must assess RISK of intracardiac THROMBUS
- 3 shocks, and unsuccessful = likely won't work
- Focus is on rate control and anticoagulation
DC2 / 11
- Direct current
- this is used
- Alternating current
- this is NOT used
- ⬆risk myocardial damage
- ⬆energy flux
- ⬆duration
Definition3 / 11
- delivery of shock that depolarises ALL the excitable myocardial tissue
- tissues in re-entrant circuit are depolarised and subsequent refractory
- circuit is unable to propogate
Contraindications4 / 11
- IED (PPM/AICD) must be 8 cm away
Benefits / advantages5 / 11
- termination of abnormal rhythm
- restoration of normal perfusing rhythm
Technique / description6 / 11
- Defib pads on patient
- Monitoring
Dose7 / 11
- biphasic energy
- paediatric
- 0.5 J/kg
- 1 J/kg if necessary
- adult
- Aflutter = 50 J if new onset = least amount of energy required
- AF = 100 J
- SVT = 100 J
- max = 200 J
Drugs8 / 11
- fentanyl 50 mcg
- propofol 0.5-1 mg/kg
Have ready9 / 11
- atropine (bradycardia)
- metaraminol (hypotension)
- emergency trolley
Common questions / related topics10 / 11
- Success factors
- Patient
- Duration of AF
- More likely success in acute > chronic AF
- Cause of AF
- EUC/CMP optimised
- Medications
- Duration of AF
- Anaesthesia
- Adequate dose
- Patient