Drug | Uses | Suggested induction dose* | Advantages | Potential adverse effects |
Propofol | Induction agent of choice for most patients | - 1 to 2.5 mg/kg
- Older age: 1 to 1.5 mg/kg
- Hypovolemia or hemodynamic compromise: ≤1 mg/kg
| - Rapid onset and offset
- Antiemetic properties
- Antipruritic properties
- Bronchodilation
- Anticonvulsant properties
- Decreases CMRO2, CBF, and ICP
| - Dose-dependent hypotension
- Dose-dependent respiratory depression
- Pain during injection
- Microbial contamination risk
- Rare anaphylaxis in patients with allergy to its soybean oil emulsion with egg phosphatide
|
Etomidate | May be selected in patients with hemodynamic instability due to any cause | - 0.15 to 0.3 mg/kg
- Presence of profound hypotension: 0.1 to 0.15 mg/kg
| - Rapid onset and offset
- Hemodynamic stability with no changes in BP, HR, or CO
- Anticonvulsant properties
- Decreases CMRO2, CBF, and ICP
| - High incidence of PONV
- Pain during injection
- Involuntary myoclonic movements
- Absence of analgesic effects
- Transient acute adrenocortical suppression
|
Ketamine | May be selected in hypotensive patients or those likely to develop hypotension (eg, hypovolemia, hemorrhage, sepsis, severe cardiovascular compromise) | - 1 to 2 mg/kg
- Chronic use of tricyclic antidepressants: 1 mg/kg
- Presence of profound hypotension: 0.5 to 1 mg/kg
- Intramuscular dose: 4 to 6 mg/kg
| - Rapid onset
- Increases BP, HR, and CO in most patients
- Profound analgesic properties
- Bronchodilation
- Maintains airway reflexes and respiratory drive
- Intramuscular route available if IV access lost
| Cardiovascular effects - Increases myocardial oxygen demand due to increases in HR, BP, and CO
- Increases pulmonary arterial pressure (PAP)
- Potentiates cardiovascular toxicity of cocaine or tricyclic antidepressants
- Exacerbates hypertension, tachycardia, and arrhythmias in pheochromocytoma
- Direct mild myocardial depressant effects
- Psychotomimetic effects (hallucinations, nightmares, vivid dreams)
- Increases CBF and ICP; may increase CMRO2
- Unique EEG effects may result in misinterpretation of BIS and other processed EEG values
|
Methohexital | Induction for electroconvulsive therapy (ECT) because it activates seizure foci | | - Lowers seizure threshold, facilitating ECT
- Decreases CMRO2, CBF, and ICP
| - Limited availability
- Dose-dependent hypotension
- Dose-dependent respiratory depression
- Involuntary myoclonic movements
- Pain during injection
- Contraindicated in patients with porphyria
|