Reference — Critical Care
Sedation Scales Reference
Standardized sedation assessment ensures ICU patients receive the lightest level of sedation that maintains comfort and safety. RASS and SAS are the two most widely validated and used sedation scales in critical care practice.
Educational use only. Sedation targets are individualized by the care team based on patient condition, ventilator status, and clinical goals. Always follow provider orders and institutional protocols for sedation management. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Purpose of Sedation Assessment
Standardized sedation assessment serves critical clinical functions in the ICU:
- Prevents over-sedation — deep sedation is associated with prolonged mechanical ventilation, ICU delirium, neuromuscular weakness, and increased mortality
- Prevents under-sedation — inadequate sedation causes patient distress, self-extubation, and ventilator dyssynchrony
- Guides sedation titration — provides objective language for nursing-to-nursing and nursing-to-provider communication
- Supports ABCDEF bundle implementation — sedation assessment is core to spontaneous awakening trials (SATs) and delirium screening
PADIS guidelines (Pain, Agitation/Sedation, Delirium, Immobility, Sleep) recommend targeting the lightest sedation level that achieves clinical goals — typically RASS 0 to −2.
Richmond Agitation-Sedation Scale (RASS)
| Score | Label | Description |
|---|---|---|
| +4 | Combative | Overtly combative, violent, immediate danger to staff |
| +3 | Very Agitated | Pulls or removes tubes/catheters; aggressive |
| +2 | Agitated | Frequent non-purposeful movement, fights ventilator |
| +1 | Restless | Anxious, apprehensive, but movements not aggressive |
| 0 | Alert and Calm | Spontaneously awake, calm, attentive |
| −1 | Drowsy | Not fully alert; sustained awakening to voice (> 10 sec) |
| −2 | Light Sedation | Brief awakening to voice (eye opening/contact < 10 sec) |
| −3 | Moderate Sedation | Movement or eye opening to voice — no eye contact |
| −4 | Deep Sedation | No response to voice; movement or eye opening to physical stimulation only |
| −5 | Unarousable | No response to voice or physical stimulation |
Nursing use: Assess every 2–4 hours or per protocol. Document score and titrate sedation infusions per orders to reach target. Typical target for mechanically ventilated patients: RASS −1 to −2.
SAT criteria: Spontaneous awakening trials are generally indicated when RASS is −3 or better (patient responds to voice stimulation). Check facility protocol for specific SAT criteria.
Sedation-Agitation Scale (SAS)
| Score | Label | Description |
|---|---|---|
| 7 | Dangerous Agitation | Pulling at ET tube, trying to remove catheters, thrashing, climbing over bed rail |
| 6 | Very Agitated | Does not calm despite frequent verbal reminding; requires physical restraint |
| 5 | Agitated | Anxious or mildly agitated; calms with verbal instructions |
| 4 | Calm and Cooperative | Calm, arousable, follows commands |
| 3 | Sedated | Difficult to arouse; awakens to verbal stimuli or gentle shaking; follows simple commands |
| 2 | Very Sedated | Arouses to physical stimuli; does not communicate or follow commands; may move spontaneously |
| 1 | Unarousable | Minimal or no response to noxious stimuli; does not communicate or follow commands |
Nursing use: SAS 3–4 represents the typical target range — sedated but arousable, or calm and cooperative. SAS provides a 1–7 scale where higher scores indicate more agitation. Note that SAS and RASS number directions are inverse — RASS uses negative numbers for deeper sedation; SAS uses lower numbers.
RASS vs SAS — Key Comparison
- Both are validated for ICU sedation assessment in mechanically ventilated and non-ventilated patients.
- RASS (−5 to +4) has a 10-point scale with distinct positive and negative ranges; more granular in sedated states. Widely adopted as standard.
- SAS (1–7) has a 7-point scale with higher numbers representing agitation; simpler scoring direction.
- Use whichever is specified by your institution's protocol — consistency within a unit is more important than which scale is chosen.
- Both integrate with delirium screening (CAM-ICU) — delirium assessment requires RASS ≥ −3 or SAS ≥ 3.
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Society of Critical Care Medicine (SCCM) · Surviving Sepsis Campaign · American Association of Critical-Care Nurses (AACN). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →