RICHMOND AGITATION–SEDATION SCALE (RASS)
A Comprehensive Clinical Guide for Physiotherapists
1. Introduction and Clinical Importance
Level of consciousness, arousal, and agitation profoundly influence the safety, feasibility, and effectiveness of physiotherapy in acute and critical care. In the ICU and high-dependency environments, inappropriate mobilization in a deeply sedated or severely agitated patient increases the risk of adverse events, while delayed mobilization in an appropriately alert patient contributes to ICU-acquired weakness, delirium, and prolonged length of stay.
The Richmond Agitation–Sedation Scale (RASS) is a standardized, validated observational scale used to quantify a patient’s level of alertness and agitation. It is the preferred sedation scale in many international ICU guidelines and is essential for physiotherapists to determine readiness for assessment, exercise, and mobilization.
Within a physiotherapy intranet, RASS should be designated a mandatory pre-mobilization screening tool in ICU, HDU, and acute wards.
2. Purpose of the RASS
The RASS is designed to:
• Quantify level of consciousness and agitation
• Guide sedation management and mobilization readiness
• Facilitate interdisciplinary communication
• Monitor daily changes in arousal
• Reduce complications related to over-sedation or agitation
For physiotherapists, RASS primarily informs when and how to intervene safely.
3. Construct Measured
Primary construct:
• Level of arousal and psychomotor activity
The RASS captures a continuum from deep sedation to severe agitation, integrating:
• Eye opening
• Responsiveness to voice
• Responsiveness to physical stimulation
• Motor activity and agitation
It does not assess:
• Delirium content
• Cognitive function
• Pain severity
These require additional tools (e.g., delirium screening, pain scales).
4. Indications and Clinical Settings
The RASS is appropriate for use in:
• Intensive Care Units (medical, surgical, neuro, cardiac)
• High-dependency units
• Acute wards with altered consciousness
• Postoperative recovery units
• Mechanically ventilated patients
• Patients receiving sedatives or analgesics
Physiotherapists should check RASS before every ICU mobilization session.
5. Description of the Scale
The RASS is a 10-point ordinal scale ranging from –5 to +4, with 0 indicating an alert and calm state.
RASS Levels
Sedation (Negative Scores):
• –5: Unarousable (no response to voice or physical stimulation)
• –4: Deep sedation (no response to voice, movement to physical stimulation)
• –3: Moderate sedation (movement or eye opening to voice, no eye contact)
• –2: Light sedation (briefly awakens to voice, eye contact <10 sec)
• –1: Drowsy (sustained eye contact to voice ≥10 sec)
Alert/Agitated (Zero and Positive Scores):
• 0: Alert and calm
• +1: Restless (anxious, movements not aggressive)
• +2: Agitated (frequent non-purposeful movement)
• +3: Very agitated (pulls lines/tubes, aggressive)
• +4: Combative (overtly violent, immediate danger)
6. Equipment and Environment
Equipment
• None required
• Observation only
Environment
• Bedside assessment
• Minimal stimulation environment preferred
The RASS can be completed in less than 30 seconds.
7. Step-by-Step Administration Procedure
Step 1: Observe Without Stimulation
• Observe the patient quietly
• Assess eye opening, movement, and behavior
If the patient is alert and calm → RASS = 0
Step 2: Verbal Stimulation (If Not Alert)
If not alert:
• Call the patient by name
• Ask them to open their eyes and look at you
Assess:
• Eye opening
• Eye contact duration
Assign RASS –1 to –3 based on response.
Step 3: Physical Stimulation (If No Response to Voice)
If no response to voice:
• Apply gentle physical stimulation (e.g., shoulder shake, sternal rub)
Assign:
• –4 if movement only
• –5 if no response
Step 4: Agitation Assessment (If Overactive)
If the patient is restless or agitated:
• Observe behavior and safety risk
• Assign +1 to +4 based on severity
Step 5: Documentation
Record:
• RASS score
• Time and context (resting, pre-therapy)
Example:
“RASS = –1 prior to physiotherapy session.”
8. Correct Use and Common Errors
Correct Practice
• Use standardized assessment sequence
• Score current state, not earlier behavior
• Reassess if patient condition changes
Common Errors
• Estimating RASS without direct observation
• Confusing sleep with deep sedation
• Failing to reassess before mobilization
• Using RASS to diagnose delirium
9. Interpretation for Physiotherapy Practice
Mobilization Readiness (General Guidance)
• RASS –1 to +1: Generally suitable for physiotherapy and mobilization
• RASS –2: Limited participation; consider passive or assisted activity
• RASS ≤ –3: Not suitable for active mobilization
• RASS ≥ +2: Mobilization unsafe until agitation is controlled
Clinical judgment and team communication are essential.
10. Reliability of the RASS
Inter-Rater Reliability
• Weighted kappa / ICC values: 0.85–0.95
• High agreement among trained clinicians
Test–Retest Reliability
• High stability when patient condition is unchanged
Clinical implication:
RASS provides consistent and reproducible arousal assessment.
11. Validity of the RASS
Construct Validity
• Strong correlation with other sedation scales
• Accurately differentiates sedation depth and agitation
Criterion Validity
• Predicts:
– Delirium risk
– Duration of mechanical ventilation
– ICU outcomes
12. Responsiveness and Clinically Meaningful Change
Responsiveness
The RASS is highly responsive to:
• Sedation titration
• Medication changes
• Delirium management
Clinically Meaningful Change
• A change of 1 RASS level is clinically meaningful and may alter mobilization decisions.
13. Clinical Decision-Making Using RASS
RASS scores guide:
• Timing of physiotherapy sessions
• Choice of passive vs active interventions
• Safety planning and staffing requirements
• Communication during ICU rounds
Examples:
• RASS –1 → initiate sitting and assisted mobility
• RASS 0 → progress standing and walking
• RASS +2 → defer mobilization, coordinate with medical team
14. SOAP-Based Documentation Example
S:
Patient appears sleepy but cooperative.
O:
RASS = –1; follows simple commands.
A:
Appropriate arousal level for assisted mobilization.
P:
Proceed with sitting edge of bed and transfer training. Reassess RASS prior to standing.
15. Reassessment and Outcome Tracking
Recommended use:
• Before every ICU physiotherapy session
• After sedation or medication changes
• During episodes of agitation or decreased alertness
RASS trends should be tracked alongside:
• ICU Mobility Scale
• Delirium screening tools
• Ventilator and hemodynamic data
16. Advantages and Limitations
Advantages
• Rapid and simple
• No equipment required
• Excellent reliability and validity
• Direct relevance to mobilization safety
Limitations
• Does not assess delirium content
• Influenced by recent stimulation
• Requires training for consistency
17. Key Clinical Takeaways
• RASS is a mandatory arousal and agitation assessment in ICU physiotherapy
• Guides safe timing and level of mobilization
• Demonstrates strong reliability and validity
• A 1-level change is clinically meaningful
• Essential for interdisciplinary communication
18. Key Literature References
- Sessler CN, Gosnell MS, Grap MJ, et al. The Richmond Agitation–Sedation Scale: Validity and reliability in adult intensive care unit patients. American Journal of Respiratory and Critical Care Medicine. 2002;166(10):1338–1344.
- Ely EW, Truman B, Shintani A, et al. Monitoring sedation status over time in ICU patients: Reliability and validity of the Richmond Agitation–Sedation Scale (RASS). JAMA. 2003;289(22):2983–2991.
- Barr J, Fraser GL, Puntillo K, et al. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the ICU. Critical Care Medicine. 2013;41(1):263–306.
- Devlin JW, Skrobik Y, Gélinas C, et al. Clinical practice guidelines for the prevention and management of pain, agitation/sedation, delirium, immobility, and sleep disruption in adult ICU patients. Critical Care Medicine. 2018;46(9):e825–e873.
- Pandharipande PP, Ely EW. Sedative and analgesic medications: Risk factors for delirium and sleep disturbances in the critically ill. Critical Care Clinics. 2006;22(2):313–327.