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Anaesthesia / Critical Care Emergency Medicine Strong — Am J Respir Crit Care Med 2002

Richmond Agitation-Sedation Scale (RASS)

Standardised sedation and agitation scale for ICU patients. Range −5 (unarousable) to +4 (combative). Used to titrate sedation and assess readiness for awakening trials. Target RASS 0 to −2 for most ventilated patients.

Observe the patient. If awake, score +1 to +4. If not fully awake, call name — if responds, score −1 to −3. If no response to voice, apply physical stimulation — if responds, score −4. If no response at all, score −5.

Score interpretation

Agitated (+1 to +4) 1–4

RASS +1 to +4: Agitation. Risk of self-extubation, line removal, and harm to staff.

→ Assess and treat reversible causes (pain, delirium, hypoxia, urinary retention, constipation). Analgesia-first approach (A1C). Consider titrating sedoanalgesia. Target RASS 0 to −2 for ventilated ICU patients.

Alert and Calm — Target 0

RASS 0: Alert and calm. Optimal state for most non-ventilated ICU patients and spontaneous breathing trials.

→ Maintain current management. Reassess regularly. Ideal for spontaneous awakening trials (SAT) and spontaneous breathing trials (SBT).

Light Sedation — Acceptable -2–-1

RASS −1 to −2: Light sedation. Accepted sedation target for mechanically ventilated ICU patients (PADIS 2018 guidelines).

→ Appropriate level. Continue current regimen. Perform daily SAT. Reassess daily need for sedation. Aim to wean as tolerated.

Deep Sedation -4–-3

RASS −3 to −4: Deep sedation. Associated with prolonged mechanical ventilation, ICU delirium, and increased mortality.

→ Consider reducing sedation unless clinically indicated (raised ICP, prone positioning, status epilepticus, severe dyssynchrony). Reassess sedation protocol. Avoid benzodiazepine infusions where possible.

Unarousable -5

RASS −5: Unarousable. Consider drug-induced coma versus neurological catastrophe.

→ Urgent neurological assessment. Exclude intracerebral event (haemorrhage, oedema). Consider CT head if unexplained. Review all sedating medications. Perform EEG if seizure suspected.

Interpretation bands for the RASS. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.