Rapid Sedation Non-Intubated ICU Patient

Guiding principles before you reach for a drug

• Rule-out and treat correctable drivers (pain, hypoxia, hypoglycaemia, urinary retention, withdrawal, severe delirium, etc.).
• Use the Richmond Agitation–Sedation Scale (RASS) or CAM-ICU to titrate to light, cooperative sedation (target RASS 0 to −2).
• Start with the lowest effective dose, give it IV whenever rapid control is essential, and re-assess every 5–10 min; repeat or escalate only as needed.
• Continuously monitor SpO₂, end-tidal CO₂ (if available), ECG (QTc) and haemodynamics.

Rapid-acting agents that keep the airway reflexes intact

Class / agent (typical ICU dose)	Onset (min)	Key advantages	Main cautions
Ketamine 0.5–1 mg kg-1 IV push (or 3–5 mg kg-1 IM)	1–2 IV; 3–5 IM	Very fast tranquilisation, preserves airway tone & respiratory drive, bronchodilator	Emergence reaction, ↑BP/HR, laryngospasm (rare)
Dexmedetomidine 0.5 µg kg-1 over 10 min (optional) → infusion 0.2–0.7 µg kg-1 h-1	5–10	“Co-operative” sedation, minimal resp. depression, useful to bridge into the night	Bradycardia / hypotension (avoid rapid bolus in unstable patients)
Droperidol 2.5–5 mg IV/IM (may repeat q15 min to 10 mg total)	5–10	Faster than haloperidol, short half-life, good for delirium	QTc prolongation → baseline ECG & Mg/K repletion
Haloperidol 2.5–5 mg IV/IM (q15–30 min up to 10–20 mg)	10–20	Familiar, little resp. depression, can combine with 0.5 mg benztropine to ↓EPS	QTc ↑ (less than droperidol), dystonia, akathisia
Second-generation antipsychotics • Olanzapine 10 mg IM • Ziprasidone 10–20 mg IM	15–30	Similar efficacy, less EPS than haloperidol	Post-injection somnolence, QTc ↑, avoid with IM benzodiazepines within 1 h
Small-dose benzodiazepine (e.g., Midazolam 1 mg IV every 2–3 min only if withdrawal or stimulant-driven agitation)	2–3	Synergistic with antipsychotics when a single agent fails	Respiratory depression—titrate in tiny aliquots, avoid large bolus

Practical bedside algorithm

1. First 2 minutes – verbal & environmental measures
   Family presence, low lighting, correct sensory deficits, treat pain.
2. If immediate chemical control is required
   • Choose ketamine for violent or stimulant-intoxicated patients where seconds matter.
   • Choose droperidol or haloperidol when delirium is the likely driver and you can wait 10 min.
   • Start a dexmedetomidine infusion early if agitation is expected to persist overnight or if the patient is at high risk for delirium.
3. Re-check RASS at 5 min
   • If still ≥ +2, repeat previous dose or add a different class (e.g., haloperidol + low-dose midazolam).
   • Stop escalating once RASS ≤ 0.
4. Ongoing care
   • Daily ECG if antipsychotics > 24 h or combined QT-prolonging drugs.
   • Maintain daytime wakefulness / night-time light to reduce delirium.
   • De-escalate and discontinue agents as soon as agitation resolves.

Pearls & pitfalls

• Avoid propofol or large benzodiazepine doses in the unconstrained airway—both cause dose-dependent apnoea.
• Correct electrolytes (K⁺, Mg²⁺) before or during antipsychotic therapy to minimise torsades risk.
• Consider low-dose clonidine (0.1–0.2 mg PO/NG) for milder agitation or sympathetic over-activity, but onset is ≥30 min.
• Always search for unmet physiologic needs—sedation should never replace treating hypoxia, sepsis, or painful invasive devices.