How it's calculated
Procedural sedation dosing is 1-2 mg/kg IV or 4-5 mg/kg IM. Sub-dissociative analgesic dosing is a much lower 0.1-0.3 mg/kg, typically given IV over about 10 minutes to reduce dysphoria and other side effects.
Dosing summary
| Indication | Route | Dose |
|---|---|---|
| Procedural sedation | IV | 1-2 mg/kg |
| Procedural sedation | IM | 4-5 mg/kg |
| Sub-dissociative analgesia | IV | 0.1-0.3 mg/kg over 10 min |
Clinical use
- Widely used for short, painful procedures (e.g. fracture/dislocation reduction, wound care, paediatric procedures) where dissociative sedation with preserved airway reflexes and cardiovascular stability is desirable.
- Sub-dissociative ('low-dose') ketamine is increasingly used as an opioid-sparing analgesic in the emergency department for acute pain.
- Emergence reactions (vivid dreams, dysphoria, agitation on recovery) are more common in adults; a calm, low-stimulation recovery environment reduces their incidence and severity.
Frequently asked questions
Why does ketamine dosing differ so much between indications?
Procedural sedation aims for a dissociative state, needing a substantially higher dose than sub-dissociative analgesia, which targets pain relief at NMDA-receptor-modulating doses well below what causes dissociation.
Is ketamine safe in patients with raised intracranial pressure?
This was traditionally considered a contraindication, but more recent evidence suggests ketamine doesn't significantly worsen intracranial pressure when ventilation is adequately controlled — practice varies, so follow local/current protocol and specialist input in this population.
What monitoring is needed during ketamine procedural sedation?
Continuous pulse oximetry, cardiac monitoring, and regular clinical reassessment per your institution's procedural sedation protocol — requirements for fasting, staffing, and recovery vary locally.
References
- Green SM, et al. Clinical Practice Guideline for Emergency Department Ketamine Dissociative Sedation. Ann Emerg Med. 2011.
- Motov S, et al. Intravenous Subdissociative-Dose Ketamine Versus Morphine for Analgesia in the Emergency Department. Ann Emerg Med. 2015.