• Chance Reaves

Understanding Sedation Scales

I remember going through nursing school and being told repeatedly...

"You have 5 vital signs: Pulse, respiratory rate, blood pressure, temperature, and pain!"

And then I was told...

"Pain is what the patient says it is!"

Enough with the yelling already!

Ok, so I know a couple of things from these repeated badgerings.

First off, I have to include pain assessments every time I do a set of vitals (I would come to find out later, especially in the surgical trauma ICU that it was a much more frequent assessment). Secondly, I have to take what a patient says their pain is, at face value (even if they are outwardly exhibiting something that I would interpret differently).

But before we get into sedation scales, let's look at two key factors to pain control: opioid tolerance and opioid dependence.

Simply put, opioid tolerance is a repeated use of opioids, but the effectiveness of pain control goes down. It just doesn't work as well as it used to because of that repeated exposure. This is really common in patients with chronic pain, such as a slipped disc or osteoarthritis. Over time, the drugs just don't work as well. And the problem is that they require higher doses of pain medication to control breakthrough pain.

Opioid dependence is the physical manifestation of symptoms of withdrawal as a result of stopping the opioid. This is different than opioid addiction - this part focuses on the body's physical need/requirement to get the drug.

Herein lies the problem with pain medications...

So I have to treat my patient's pain level, because they told me that it was a 7/10, and they want their Dilaudid, especially since they have breakthrough pain and a history of chronic pain.

Evaluating a Patient's Pain Level with Sedation Scales

So how exactly can I assess my patient's level of sedation so that I can give them pain medication safely?

Well, I present to you Richmond Agitation Sedation Scale & Pasero Opioid-induced Sedation Scale!

As nurses, we need some sort of evaluation to determine how safe it is to give pain medication. We need some sort of barometer...and unfortunately, if a patient can't tell us how bad their pain is, we have to use some sort of manifestation of pain like tachycardia or hypertension.

But any experienced nurse will tell you, we've all had patients who said their pain was 10/10, but they couldn't keep their eyes open long enough to hold a conversation. But they were just pleading for more Dilaudid.

The beauty of both Richmond (RASS) and Pasero (POSS), is that they give us some consistent standard to figure out if we should give pain medication. And honestly, you should be using these sedation scales with combinations of Pain Assessments (such as Verbal, Non-Verbal/Alverno, FACES, etc). These will help you to make the best decisions, and how you can document pain consistently.

Richmond Agitation Sedation Scale (RASS)

Now, I've used RASS plenty in the ICU. It's a great tool, and it can really help

you understand the needs of your patients, especially given that many of them are ventilated and sedated, and some are even agitated as a complication of being in the ICU (known as ICU delirium).

Click the Link Below to Download this Infographic PDF

RASS was originally developed as a means of finding out how well a patient was tolerating the ventilator but became an effective tool in seeing how well a patient would tolerate sedation, were agitated, or could tolerate further opiates for breakthrough pain.

Many facilities use RASS given a patient's location, such as being ventilated in the Emergency Department or in the ICU.

A word of caution - pay attention to your facility's pain/sedation policy. Many policies are prescriptive in that only certain scales can be used in certain areas. When in doubt, speak with your manager, or refer to your policy.

Download PDF • 98KB

The way that RASS works is that when you go to assess your patient's sedation, you assess their level of "agitation." While I'm not married to the semantics, it's still a good frame of reference. "Agitation" can have a negative connotation, so think of agitation as "tolerance." In other words, how well are they tolerating the ventilator or sedation.

If a patient is aggressively pulling at the tubes and presents a danger to staff, their RASS is +4. The closer they come to being calm, the closer they are to ZERO. As they swing the other way with excessive sedation or opioids, they'll become more drowsy. For patients who are sedated deeply, their score will rate at a -3 or lower.

I do get it though - if a patient is sedated on the ventilator because they have ARDS or some other respiratory disease where we want the lungs to rest, then zero may not be realistic. Pay attention to your sedation/pain orders to find out what goal should be used (most sedation should have some sort of "goal" level).

Pasero Opioid-induced Sedation Scale

Like RASS, I've used POSS, but much less. The biggest difference between the two is that Pasero is really used in lower acuity settings, versus RASS, which is used in locations such as the ICU or the Emergency Department.

Click the Link Below to Download this Infographic PDF

Unlike RASS, we aren't really evaluating for a level of tolerance or sedation. We are looking mainly at making sure that the patient isn't oversedated. While RASS is much more complex, POSS is pretty easy to remember. Basically, if your patient is asleep, but can wake up easily, and is only slightly drowsy, then they'll score anywhere from S (sleeping) to 2. If my patient can't hold a conversation and drifts off to sleep, that's a 3. If your patient won't wake up to any verbal or physical stimuli, that's a 4.

Download PDF • 66KB

Both 3 and 4 require constant monitoring, stopping the use of opioids, and in the case of some emergencies, the use of Naloxone. In my opinion, if your patient is at 3 or 4, you'd better be doing something about it, and quickly.

Just like with RASS, please pay attention to your unit/facility policy on the safe use of pain medications and Naloxone. I can't state this enough - you'll be most protected and safest when you default to your hospital's policy regarding sedation/pain medication and assessments.


Both RASS and POSS are excellent tools - so excellent that The Joint Commission explicitly recommends them here. However, remember, just like with monitors, they are tools. They are designed to help you critically think and make a determination about your patient and their safety. You'll have to use your nursing brain and experience (and sometimes intuition) to do what's safest for your patient.

The biggest takeaway is that you really should only use one or the other. Only in extremely rare circumstances, and at the direction of your facility, should you use both.

Richmond Agitation Sedation Scale

  • Used in higher acuity areas (ICU/ED/PCU)

  • Used to determine the level of tolerance to sedation/agitation

  • Is a 10 point scale

  • The top portion of the scale is focused on escalating aggression

  • The lower portion of the scale is focused on increasing oversedation

Pasero Opioid-induced Sedation Scale

  • Used in lower acuity areas (Med-Surg/OB/Outpatient)

  • Used to determine the level of sedation (particularly oversedation)

  • Is a 5 point scale

  • Levels S-2 are acceptable

  • Level 3 is unacceptable and is concerning for oversedation

  • Level 4 is unacceptable, is concerning for oversedation, and should be considered urgent/emergent

Remember to follow your unit and facility policy regarding safe pain management, medication, sedation, and documentation standards when reporting/recording sedation and pain medication administration. When in doubt, refer to the policy, or seek out management clarity for any concerning circumstances.


The goal of this website is to give you the ultimate resources to improving your practice of documentation. Please remember to always practice an abundance of caution and seek answers regarding your documentation's legality with your organization or through your state board of nursing.

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