Analgesia, sedation and delirium

Sedation targets, RASS and sedative choice

Reviewed Nov 2026·7 references
New· views rounded down, updated weekly

Target light sedation (RASS -1 to 0) with daily awakening, prefer propofol or dexmedetomidine over benzodiazepines, and reserve deep sedation for specific indications.

Definition
RASS ranges from +4 (combative) to -5 (unrousable). Light sedation (RASS -2 to 0) is the default; deep sedation (RASS -4 to -5) only for specific indications (severe ARDS with NMB, raised ICP, status epilepticus, TTM shivering).

At the bedside

  1. 1

    Set a target

    Document a RASS target every shift (usually -1 to 0); assess RASS every 2-4 h.

  2. 2

    Choose agent

    Propofol or dexmedetomidine rather than benzodiazepines; PADIS 2025 suggests dexmedetomidine over propofol for light sedation (less delirium, more time at target, more bradycardia).

  3. 3

    Daily SAT paired with SBT

    Stop or reduce sedation daily (if no contraindication) and pair with a spontaneous breathing trial (ABC trial).

  4. 4

    Benzodiazepines only when needed

    Alcohol/benzodiazepine withdrawal, seizures, deep sedation when propofol limited, palliative sedation.

  5. 5

    Deep sedation indications

    Use with NMB, refractory ICP, status epilepticus; monitor with BIS/EEG where available; reassess daily.

  6. 6

    Weaning

    Taper long infusions (> 5-7 days) to avoid iatrogenic withdrawal; consider enteral clonidine or dexmedetomidine to transition.

Sedation

Propofol

IV
Dose
0.3-3 mg/kg/h (max 4 mg/kg/h)
Preparation
1% neat = 10 mg/mL
Worked example
70 kg at 1.5 mg/kg/h = 105 mg/h = 10.5 mL/h (count 1.1 kcal/mL as fat calories)
Open infusion calculator

Light sedation / delirium

Dexmedetomidine

IV
Dose
0.2-1.4 mcg/kg/h, no loading
Preparation
200 mcg in 50 mL NS = 4 mcg/mL
Worked example
70 kg at 0.5 mcg/kg/h = 35 mcg/h = 8.75 mL/h
Open infusion calculator

Deep sedation when needed

Midazolam

IV
Dose
0.02-0.1 mg/kg/h
Preparation
50 mg in 50 mL = 1 mg/mL
Worked example
70 kg at 0.05 mg/kg/h = 3.5 mg/h = 3.5 mL/h

Richmond Agitation-Sedation Scale

ScoreDescription
+4Combative, violent, danger to staff
+3Very agitated, pulls tubes, aggressive
+2Agitated, frequent non-purposeful movement, fights ventilator
+1Restless, anxious, movements not aggressive
0Alert and calm
-1Drowsy, sustained awakening to voice (eye contact > 10 s)
-2Light sedation, briefly awakens to voice (< 10 s)
-3Moderate sedation, movement or eye opening to voice, no eye contact
-4Deep sedation, no response to voice, movement to physical stimulation
-5Unrousable, no response to voice or physical stimulation
Red flag · call your senior now
Propofol > 4 mg/kg/h or long infusions with unexplained metabolic acidosis, rising CK, lipaemia or arrhythmia: propofol infusion syndrome - stop propofol.
Pitfall
Benzodiazepine infusions as routine sedation: more delirium and longer ventilation.
Pitfall
Early dexmedetomidine as sole sedative in older patients (SPICE III signal of increased mortality in > 65 years).
Pearl
Agitation on waking during SAT often signals pain or delirium - treat the cause, then restart at half the previous dose if needed.

Calculators for this topic

Richmond Agitation-Sedation Scale

Single-item sedation/agitation score from +4 to −5.

Infusion rate from per-kg-per-hour dose

Pump rate for drugs dosed per kg per hour (insulin U/kg/h, midazolam mg/kg/h, propofol mg/kg/h, fentanyl mcg/kg/h, dexmedetomidine mcg/kg/h).

References

  1. 1

    Devlin JW, Skrobik Y, Gelinas C, et al. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS). Crit Care Med 2018;46:e825-73.

  2. 2

    Lewis K, Balas MC, Stollings JL, et al. A focused update to the clinical practice guidelines for the prevention and management of pain, anxiety, agitation/sedation, delirium, immobility, and sleep disruption in adult patients in the ICU. Crit Care Med 2025;53:e711-27.

  3. 3

    Sessler CN, Gosnell MS, Grap MJ, et al. The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients. Am J Respir Crit Care Med 2002;166:1338-44.

  4. 4

    Girard TD, Kress JP, Fuchs BD, et al. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (ABC trial). Lancet 2008;371:126-34.

  5. 5

    Shehabi Y, Howe BD, Bellomo R, et al. Early sedation with dexmedetomidine in critically ill patients (SPICE III). N Engl J Med 2019;380:2506-17.

  6. 6

    Hughes CG, Mailloux PT, Devlin JW, et al. Dexmedetomidine or propofol for sedation in mechanically ventilated adults with sepsis (MENDS2). N Engl J Med 2021;384:1424-36.

  7. 7

    Murray MJ, DeBlock H, Erstad B, et al. Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient. Crit Care Med 2016;44:2079-103.

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