Ketamine (Ketalar)
- Used in moderate sedation at low, sub-dissociative doses as an adjunct alongside a primary sedation medication — not as a stand-alone sedative.
- Not a primary use drug.
- Administer drug only with previous experience or under the direction of a provider familiar with its use.
Mechanism of Action
Selectively interrupts cerebral pathways, causing dissociative anesthesia.
Dosage and Administration
|
Route |
Onset of Action |
Peak Effect |
Duration |
|---|---|---|---|
|
IV |
Less than 60 seconds |
5 – 10 minutes |
5 – 15 minutes |
- Usually 0.25 to 1.0 mg/kg.
- Dose is based on patient response to medication.
- Rate of infusion should not exceed 50 mcg/kg/min.
Adverse Reactions
- Respiratory effects – bradypnea, dyspnea, respiratory depression, apnea, bronchial smooth muscle relaxation, increased tracheo-bronchial tree secretions
- Cardiovascular effects – bradycardia, tachycardia, hypertension, hypotension, arrhythmias
- Musculoskeletal – enhanced skeletal tone
- CNS – uncontrolled muscle movements, visual illusions
- GI – vomiting, increased salivary secretions
- Special considerations – monitor patient for emergent reactions including vivid dreams, or hallucinations. Consider premedication (midazolam) to reduce potential for symptoms.
Ketamine in Moderate Sedation
Ketamine for moderate sedation is nearly always an adjunct rather than the primary agent — a small, sub-dissociative dose added to reduce the amount of the primary sedative and opioid needed, or to blunt a painful step of a procedure. At the low end of its range it preserves airway reflexes and spontaneous breathing better than many alternatives, which is part of why it is reached for in patients where hemodynamic stability matters. Recovery monitoring watches for the emergence reactions on the adverse-reactions list above — vivid dreams, hallucinations, agitation — which are dose-related and more likely as the dose climbs toward its dissociative range; keeping the room quiet and low-stimulus during recovery, and premedicating with midazolam as listed above, are both standard ways to reduce them. Administration follows the facility’s sedation policy and the credential and experience requirements set by the provider’s scope of practice.
Educational reference for sedation providers, relocated from the previous version of this site — not a substitute for the current package insert, your facility protocols, or clinical judgment. Verify all doses against current references before clinical use.