Comparison of propofol and etomidate anaesthesia for elective electrical cardioversion

Background: Propofol has been previously shown to be superior to etomidate during electrical cardioversion (EC) of atrial tachyarrhythmias. However, literature on this topic is scarce and the optimal anaesthetic technique for EC has not yet been firmly established. Aim: To compare anaesthetic management with propofol against a mixture of etomidate and low-dose fentanyl for EC. Methods: One hundred patients, aged 32 to 87, underwent elective EC for various atrial arrhythmias. All patients were haemodynamically stable before the procedure and were randomly allocated into one of two groups. Group I (n = 50) was given propofol (bolus 1 mg/kg, followed by increments containing 20% of the initial close). Group II (n = 50) received 1 mu g/kg of fentanyl i.v. (single dose) and etomidate (bolus 0.15 mg/kg, followed by increments containing 20% of the initial dose). Heart rate and non-invasive blood pressure values were taken before induction of anaesthesia (T1), before EC (T2), after EC (T3) and when awake (T4). The number of shocks, the total amount of energy, the number of patients in whom EC failed to restore sinus rhythm, and the time taken to achieve maximal Aldrette score, as well as side effects, were all noted. Results: Heart rate values were similar in both groups. Blood pressure was significantly lower at T2, 13 and T4 in patients who received propofol. Anaesthesia time was similar; however, maximal Aldrette score was achieved quicker in group I than in group II (4.7 +/- 2.2 vs 6.7 +/- 4.9 min, p < 0.01). Overall, the efficacy of EC was similar in both groups: 41 (82%) patients from group 1 and 46 (92%) patients from group II regained sinus rhythm (NS). Significantly more side effects, such as pain at the time of injection, muscle tremor, nausea and vomiting, were noted in group II. Conclusions: In terms of side effects, propofol is superior to etomidate with fentanyl for elective EC of atrial tachyarrhythmias.