| Medication | Initial dose | Onset (minutes) | Duration (minutes) | Repeat dose (as necessary) | Comments |
| Propofol | 0.5 to 1 mg/kg | 0.5 | 5 | 0.25 to 0.5 mg/kg every 1 to 3 minutes | - Sedative and amnestic. No analgesia.
- Rapid onset and neurological recovery.
- Useful in older adults without major comorbidities; reduce dose by ≥20% (maximum initial bolus: 0.5 mg/kg) and administer slowly (eg, over 3 to 5 minutes).
- Respiratory depression, hypotension, and injection site pain may occur.
- Contains egg lecithin, soybean oil (potential allergens; refer to UpToDate discussion of perioperative anaphylaxis).
|
| Etomidate | 0.1 to 0.15 mg/kg | 5 to 15 seconds | 5 to 15 | 0.05 mg/kg every 3 to 5 minutes | - Sedative. No analgesia.
- Generally maintains hemodynamic stability. Useful for patients at risk of hypotension.
- In older adults or patients with impaired kidney or liver function, use doses at lower end of range.
- Myoclonus, respiratory depression, injection site pain, and nausea/vomiting may occur.
|
| Midazolam | 0.02 to 0.03 mg/kg over 2 to 3 minutes Usual individual dose: 0.5 or 1 mg and titrated to effect Maximum single dose: 2.5 mg (1.5 mg in older adults) | 2 to 5 | 30 to 60 | May repeat after 2 to 5 minutes | - Sedative and anxiolytic. No analgesia. Often combined with fentanyl for PSA.
- Useful as a single agent when minimal sedation (anxiolysis) is required.
- Relatively slow onset; requires more gradual initiation.
- Prolonged effect or delayed recovery in older adults and patients with impaired liver or kidney function. Use lower doses and longer dosing intervals.
- Use reduced dose in combination with other agents.
|
| Fentanyl | 0.5 to 1 mcg/kg | 2 to 3 | 30 to 60 | 0.5 mcg/kg every 2 minutes (usual maximum cumulative dose: 5 mcg/kg or approximately 250 mcg) | - Analgesic. No amnesia. Often combined with midazolam for PSA.
- Minimal hypotension and histamine release.
- Use reduced dose in combination with other agents (eg, maximum single dose: 0.5 mcg/kg).
- May cause prolonged sedation in older adults or patients with impaired kidney or liver function; use lower doses (single and cumulative) and longer dosing intervals.
- Respiratory depression may occur.
|
| Ketamine | 1 to 2 mg/kg over 1 to 2 minutes | 0.5 | 10 to 20 | 0.25 to 1 mg/kg every 5 to 10 minutes (0.25 to 0.5 mg/kg if in combination with other sedatives) | - Dissociative sedative, analgesic, and amnestic.
- Minimal cardiorespiratory depression; does not inhibit protective reflexes. Useful for patients at risk of hypotension or with potentially difficult airway.
- May be given intramuscularly; however, onset of sedation will be delayed by approximately 5 minutes.
- Emergence reactions common in adults. Nausea and vomiting may occur.
- Sympathetic stimulation, tachycardia, and hypertension may also occur (rare).
|
| Dexmedetomidine | Bolus: 0.5 to 1 mcg/kg over 10 minutes Infusion: 0.2 to 1 mcg/kg/hour | 5 to 10 | Post-continuous infusion: 60 to 240 minutes (dose dependent) | Not applicable | - Sedative. Some analgesia. Not amnestic.
- Useful in patients with potentially difficult airway or when tachycardia or hypertension would be particularly dangerous.
- May also be administered intranasally (2 to 3 mcg/kg) for anxiolysis and sedation when other routes are not optimal; however, onset of action is delayed.
- Impaired liver function: use lower starting doses.
- Decreased respiratory drive and airway obstruction can occur (rare).
- Bradycardia and hypotension can occur with loading doses and during rapid dose titration (dose dependent); however, hypertension with loading doses and high-dose infusion has also been observed.
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| Methohexital | 0.75 to 1 mg/kg | 1 | 10 | 0.5 mg/kg every 2 to 5 minutes | - Sedative and amnestic. No analgesia.
- May cause prolonged sedation in older adults or patients with impaired kidney or liver function; use lower doses (single and cumulative) and longer dosing intervals.
- Cardiorespiratory depression, hypotension, and tachycardia can occur.
- Can precipitate or worsen seizures.
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