What is the recommended sedation regimen for cardioversion?

Appropriate Sedation for Cardioversion

For cardioversion, use propofol as the first-line sedative agent in hemodynamically stable adults, administered by slow infusion (0.5 mg/kg over 3-5 minutes) with continuous cardiorespiratory monitoring, as it provides rapid onset, excellent amnesia, and faster recovery compared to alternatives. 1, 2, 3, 4

Sedation Protocol for Cardioversion

First-Line Agent: Propofol

Propofol is the preferred sedative for cardioversion based on superior recovery profiles and minimal adverse effects. 4

• Dosing: Administer 0.5 mg/kg IV over 3-5 minutes, titrated to clinical effect 3
• Administration technique: Use slow infusion or slow injection techniques rather than rapid bolus to minimize cardiorespiratory depression 3
• Monitoring: Continuous pulse oximetry, blood pressure, and ECG monitoring are mandatory 3
• Recovery time: Median awakening time of 8 minutes (range 3-15 minutes) 4

Alternative Agents

Etomidate can be used when hemodynamic stability is a concern, though myoclonus occurs in approximately 44% of patients 4

• Provides rapid induction with minimal hemodynamic effects 4
• Median awakening time of 9.5 minutes (range 5-11 minutes) 4
• Major caveat: Do not use in patients with septic shock due to adrenal suppression 1

Midazolam is effective but results in significantly prolonged recovery times 5, 4, 6, 7

• Dosing: 0.05-0.1 mg/kg IV or 3 mg bolus followed by 2 mg increments 6, 7
• Median awakening time of 21 minutes (range 1-42 minutes) without reversal 4
• Provides excellent amnesia in 99-100% of patients 5, 6, 7
• With flumazenil reversal: Awakening time reduced to 3 minutes, but 83% of patients experience resedation after flumazenil discontinuation 4, 8

Critical Safety Considerations

Pre-Cardioversion Requirements

Adequate sedation or anesthesia must be provided before cardioversion in conscious, hemodynamically stable patients. 1, 2

• In extremely unstable patients, do not delay cardioversion to establish IV access or provide sedation—proceed immediately 2
• Establish IV access before cardioversion whenever possible 2
• Have resuscitation equipment immediately available, as patients may deteriorate to pulseless VT or VF 2, 9

High-Risk Populations

In elderly, debilitated, or ASA-PS III/IV patients, reduce propofol dosage to 80% of usual adult dose and avoid rapid bolus administration. 3

• Rapid bolus can cause undesirable cardiorespiratory depression including hypotension, apnea, airway obstruction, and oxygen desaturation 3
• Use slow infusion over 3-5 minutes in these populations 3

Respiratory Monitoring

Serious respiratory failure may occur with midazolam in patients with COPD, debilitated patients, or when injected rapidly. 5

• Confine midazolam use to areas equipped to manage cardiorespiratory complications 5
• Mean oxygen saturation reduction of 5.4% occurs with midazolam administration 7

Pediatric Cardioversion Sedation

For pediatric patients requiring cardioversion, use sedation if possible before delivering synchronized shocks. 1

• Start with 0.5-1 J/kg energy dose 1
• If unsuccessful, increase to 2 J/kg 1
• Propofol can be used in children ≥2 months for procedural sedation, with higher weight-based dosing requirements than adults 3

Common Pitfalls to Avoid

Never use digoxin or sotalol for pharmacological cardioversion—they may be harmful. 1

Avoid rapid bolus administration in elderly or hemodynamically compromised patients, as this significantly increases risk of hypotension and respiratory depression 3

Do not rely on midazolam alone if rapid patient turnover is needed, as recovery times are 2-3 times longer than propofol 4

If using midazolam with flumazenil reversal, plan for extended monitoring, as 83% of patients experience resedation requiring continued observation 4

When propofol sedation is supplemented with opioids or benzodiazepines, expect increased sedative and respiratory effects with slower recovery. 3