MAGENT

Richmond Agitation-Sedation Scale (RASS): the ten levels from +4 to −5

The Richmond Agitation-Sedation Scale (RASS) describes how alert or agitated a person is with a single number from +4 (combative) to −5 (unarousable). 0 is alert and calm. Positive numbers describe agitation; negative numbers describe sedation.

Not a medical device. Not a diagnosis or dosing recommendation.

Use this calculator via API

What is the RASS?

The RASS comes from Curtis Sessler and colleagues, who described it in the American Journal of Respiratory and Critical Care Medicine in 2002. Their abstract calls it a new 10-level scale, from +4 "combative" to −5 "unarousable", and reports testing it in adult intensive care unit (ICU) patients.

There's no arithmetic in the RASS. The person using it picks the level that matches what they see. Magent's calculator takes that number and returns the matching term and description from the 2002 paper.

This page lists the levels. It doesn't say what a level means for a particular person.

The RASS rule

RASS = one whole number from +4 to −5, chosen by the person using the scale
+4 Combative … 0 Alert and calm … −5 Unarousable

Exact expression the calculator uses:

RASS integer -5 to +4 as assigned by the caller; Sessler 2002 ten levels (Combative through Unarousable)

The ten levels

RASSTermDescription
+4CombativeOvertly combative or violent; immediate danger to staff
+3Very agitatedPulls or removes tube(s) or catheter(s); aggressive
+2AgitatedFrequent nonpurposeful movement, fights ventilator
+1RestlessAnxious but movements not aggressive or vigorous
0Alert and calmAlert and calm
−1DrowsyNot fully alert, sustained awakening with eye contact to voice >10 s
−2Light sedationBriefly awakens with eye contact to voice <10 s
−3Moderate sedationAny movement but no eye contact to voice
−4Deep sedationNo response to voice, any movement to physical stimulation
−5UnarousableNo response to voice or physical stimulation

How the levels are organized

  1. Positive levels (+1 to +4) describe increasing agitation, from restless to combative.
  2. 0 is alert and calm.
  3. −1 to −3 describe how the person responds to voice: eye contact for more than 10 seconds, less than 10 seconds, or movement without eye contact.
  4. −4 and −5 describe response to physical stimulation once there's no response to voice.

Inputs come from the user

The level is set by the person using the calculator. Magent's calculator doesn't observe the patient, speak to them or give physical stimulation, and doesn't adjust sedation. It returns the number, the term, the description and a top value of +4.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: RASS 0

  1. Input: 0.
  2. Term: Alert and calm. Description: "Alert and calm".

Example 2: RASS −1

  1. Input: −1.
  2. Term: Drowsy. Description: "Not fully alert, sustained awakening with eye contact to voice >10 s".

Example 3: RASS −2

  1. Input: −2.
  2. Term: Light sedation. Description: "Briefly awakens with eye contact to voice <10 s".

Example 4: RASS +4

  1. Input: +4, the top of the scale.
  2. Term: Combative. Description: "Overtly combative or violent; immediate danger to staff".

Example 5: RASS −5

  1. Input: −5, the bottom of the scale.
  2. Term: Unarousable. Description: "No response to voice or physical stimulation".

History of the RASS

The scale comes from Sessler CN, Gosnell MS, Grap MJ and colleagues, The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients, American Journal of Respiratory and Critical Care Medicine, 2002 (volume 166, issue 10, pages 1338–1344). The abstract describes two phases: testing agreement between raters in adult ICU patients, then using the scale in a medical ICU with bedside nurses.

When it's used

The 2002 paper studied adult ICU patients, including people with and without mechanical ventilation and with and without sedative medicines.

Where it's used

The 2002 paper was set in ICUs: medical, surgical, cardiac surgery, coronary and neuroscience units.

Who uses it

In the 2002 paper, physicians, nurses and a pharmacist rated patients, and bedside nurses used it in the second phase.

Limits of the calculation

  • You pick the level. The calculator doesn't observe or examine the patient.
  • It returns the 2002 term and description. It doesn't set a sedation goal or change any medicine.
  • It isn't CAM-ICU and doesn't supply any CAM-ICU feature.
  • This page doesn't say what a level means for a particular person.

Clinical decisions belong to a qualified clinician who knows the patient.

  • CAM-ICU is a separate assessment for delirium. It's done separately from the RASS.
  • Glasgow Coma Scale scores eye, verbal and motor responses and adds them.
  • FOUR score is another separate scale of responsiveness.

Glossary

  • ICU: intensive care unit.
  • Agitation: restless or aggressive movement.
  • Sedation: reduced alertness, often from medicine.
  • Physical stimulation: touching or shaking to get a response.
  • Mechanical ventilation: a machine that helps with breathing.

Common mistakes

  • Mixing up the sign. Positive numbers are agitation; negative numbers are sedation.
  • Using −1 for a brief response. Eye contact for less than 10 seconds is −2, not −1.
  • Going past the ends. The scale runs from +4 to −5.
  • Expecting a sum. The RASS is one level, not a total of parts.

Source

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. DOI: 10.1164/rccm.2107138. PMID: 12421743

Frequently asked questions

How is the RASS scored?

Pick the one level from +4 to −5 that matches what you observe. There's nothing to add up.

What does a RASS of -2 mean?

In the 2002 wording, −2 is "Light sedation": briefly awakens with eye contact to voice for less than 10 seconds.

What is RASS 0?

Alert and calm.

What is the lowest RASS?

−5, "Unarousable": no response to voice or physical stimulation.

Is RASS the same as CAM-ICU?

No. They're separate assessments.