RASS

Overview

The Richmond Agitation-Sedation Scale (RASS) measures a patient's level of sedation or agitation in the ICU. It is the recommended sedation scale in the PADIS 2018 guidelines and is used as a prerequisite for delirium assessment with CAM-ICU. RASS allows nurses and physicians to rapidly communicate sedation status and titrate sedative medications to a defined target.

Scale

Score	Level	Description
+4	Combative	Overtly combative, violent, immediate danger to staff
+3	Very agitated	Pulls or removes tube(s) or catheter(s); aggressive
+2	Agitated	Frequent non-purposeful movement, fights ventilator
+1	Restless	Anxious, apprehensive, but movements not aggressive
0	Alert and calm	Spontaneously alert and calm
−1	Drowsy	Not fully alert, sustained awakening to voice (> 10 s)
−2	Light sedation	Briefly awakens to voice, eye contact < 10 s
−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
−5	Unarousable	No response to voice or physical stimulation

Assessment Procedure

1. Observe the patient for 30 seconds. If the patient is combative, agitated, or restless, score +1 to +4 accordingly.
2. Call by name / ask to open eyes and look at assessor. If the patient awakens with sustained eye contact (> 10 s), score −1. If eye contact is brief (< 10 s), score −2. If movement only (no eye contact), score −3.
3. Physical stimulation (shoulder shaking or sternal rub). If the patient responds with movement or eye opening, score −4. If there is no response at all, score −5.

Target Sedation

The PADIS 2018 guidelines recommend a target RASS of −1 to 0 for most mechanically ventilated ICU patients (light sedation), unless a clinical indication for deeper sedation exists. Light sedation is associated with shorter ventilator duration and ICU stay.

RASS Range	Clinical Indication
−1 to 0	Recommended target for most ICU patients (PADIS 2018)
−2 to −3	Procedural sedation, transport, refractory agitation
−4 to −5	ARDS (prone positioning), refractory ICP, status epilepticus

ABCDEF Bundle

RASS is the C component ("Choose and taper sedation") of the ICU Liberation ABCDEF Bundle, which is an evidence-based framework for reducing ICU-acquired complications:

• A — Assess, prevent, and manage pain
• B — Both spontaneous awakening and breathing trials
• C — Choose and taper sedation (RASS target)
• D — Delirium assessment and management (CAM-ICU / Nu-DESC)
• E — Early mobility and exercise
• F — Family engagement and empowerment

Literature

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(10):1338–1344.

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 Patients in the ICU. Crit Care Med. 2018;46(9):e825–e873.