Indications and Dosing Ketamine

Ketamine in the ICU – quick reference

Adult dosing, scoped for your blog’s dark theme. Aim for analgesia first, sleep with dexmedetomidine if desired, and avoid large rapid boluses when hypertension is a concern.

Indications (ICU and ED)

• Analgesia Sub-dissociative opioid-sparing pain control in trauma, burns, post-op abdominal pain, opioid tolerance or hyperalgesia, neuropathic pain.
• Sickle crisis Vaso-occlusive crisis pain when opioid-sparing is needed or allodynia limits opioid escalation.
• Procedural sedation Short painful procedures, dressing changes, reductions.
• RSI/induction Especially in hypotensive trauma or when bronchospasm is present.
• ICU sedation Analgosedation adjunct or alternative to propofol/benzodiazepines.
• Status asthmaticus Bronchodilation and improved ventilation.
• Refractory status epilepticus NMDA antagonism for seizure control.
• Severe agitation Excited delirium rescue with airway-ready monitoring.
• Status migrainosus Rescue in selected protocols.
• Alcohol withdrawal Refractory cases as adjunct to standard care.
• Psychiatry Treatment-resistant depression (protocolized settings).

Dosing cheat sheet

• Analgesia (sub-dissociative): bolus 0.1 to 0.3 mg/kg IV given slowly; infusion 0.1 to 0.3 mg/kg/hr (about 1.7 to 5 mcg/kg/min). Titrate by 0.05 to 0.1 mg/kg/hr every 15 to 30 min.
• Sickle cell VOC pain: same sub-dissociative dosing as above; consider avoiding large boluses to limit blood pressure and heart rate rise.
• Procedural sedation: 0.5 to 1 mg/kg IV over 1 to 2 min, then 0.25 to 0.5 mg/kg IV every 5 to 10 min as needed. IM 3 to 5 mg/kg when no IV.
• RSI/induction: 1 to 2 mg/kg IV once (use lower end if in shock or on vasopressors).
• ICU maintenance sedation: 0.3 to 1 mg/kg/hr; short-term up to 2 mg/kg/hr with EEG or close monitoring when needed.
• Status asthmaticus: 0.5 to 1 mg/kg IV once, then 0.5 to 1 mg/kg/hr.
• Refractory status epilepticus: load 1 to 2 mg/kg IV, then 1 to 5 mg/kg/hr (some protocols allow up to 10 mg/kg/hr) to EEG target.
• Severe agitation/excited delirium: 4 to 5 mg/kg IM or 1 to 2 mg/kg IV with airway-ready monitoring.
• Status migrainosus: 0.2 to 0.3 mg/kg IV once or infusion 0.1 to 0.3 mg/kg/hr for 3 to 6 hr.
• Refractory alcohol withdrawal: 0.3 mg/kg IV then 0.3 to 0.5 mg/kg/hr as adjunct to standard therapy.

Units crosswalk: 0.1 mg/kg/hr equals about 1.7 mcg/kg/min. Use weight in kilograms and round to practical infusion rates.

Practical pearls and safety

• Hemodynamics: expect mild to moderate rise in blood pressure and heart rate, most noticeable after bolus. Prefer slow small boluses or start a low infusion if hypertension is a concern.
• Catecholamine depletion: in late sepsis or prolonged critical illness, direct myocardial depression can dominate and blood pressure may fall. Start low and be ready to support.
• Airway and secretions: hypersalivation is common. Glycopyrrolate 0.2 mg IV can be used if needed. Laryngospasm is rare and usually linked to large rapid pushes.
• CNS effects: dysphoria or emergence reactions are dose and rate related. Reduce risk by avoiding rapid pushes; a small dose of a GABAergic agent can help if required.
• Gut: generally neutral for motility and a useful adjunct when ileus risk makes anticholinergic sedatives undesirable.
• Combinations: pairs well with opioids for analgesia. Dexmedetomidine can offset tachycardia and hypertension and improve sleep continuity.
• Titration: adjust every 15 to 30 min based on pain scores, RASS, blood pressure, and heart rate. Use continuous cardiac and pulse oximetry monitoring. Capnography is preferred when also using opioids.
• Renal and hepatic: no renal adjustment; in hepatic impairment or cirrhosis use lower doses and slower titration.

Contraindications and cautions

• Absolute: known ketamine or formulation allergy.
• Strong cautions: uncontrolled hypertension; acute aortic dissection; severe coronary disease with active ischemia; tachyarrhythmias; severe pulmonary hypertension; intracranial hemorrhage or subarachnoid hemorrhage where blood pressure surges are hazardous.
• Neuropsychiatric: history of severe psychosis or mania may worsen; use only if benefits outweigh risks with close monitoring.
• Endocrine: pheochromocytoma or untreated thyrotoxicosis can have exaggerated sympathetic responses.
• Pregnancy: use only when benefits outweigh risks and after obstetric consultation.
• Peri-MI and HOCM: avoid large boluses; prefer slow titration to limit demand ischemia or dynamic obstruction.

If severe hypertension, chest pain, ischemic ECG changes, or distressing dysphoria occurs, pause titration and treat the cause. Resume at a lower rate or consider an alternative.

Monitoring and hold parameters

• Continuous ECG and pulse oximetry. Use capnography when combined with opioids.
• Blood pressure and heart rate at least every 5 min during bolus and every 15 min during titration.
• Hold or reduce for: new chest pain or ischemic ECG changes; severe uncontrolled hypertension; sustained heart rate above target; intolerable dysphoria; oxygen saturation under 92 percent despite support.