Sedation and Analgesia

Andrew Stephen, MD

Key concepts

The goal of analgesia and sedation regimens is to maintain patients in a comfortable and calm state while they recover from injuries or operations.  Care has modernized quite a bit over the last two decades and it is no longer acceptable to have patients deeply sedated(RASS -4, -5) unless for very particular reasons.  There are some unique challenges at Rhode Island Hospital with our large population of elderly patients.  Inadequate treatment of pain in the elderly has been shown to result in increased rates of delirium, depression, sleep disturbance, and lack of mobility and participation in care. (Hip fracture and cancer studies from the 1990’s) Yet overuse of opioids and any use of benzodiazepines in the elderly is also associated with increased rates of delirium.  The elderly also have a very narrow “therapeutic window”where analgesia and sedation agents provide comfort without affecting mental status.

Critical care pain observation tool(CPOT)

Pain is often reported by ICU survivors as the worst part of their experience.  These strong memories of pain during the ICU stay have been shown to persist up to 5 years after discharge.  Tools such as the Visual Analog Scale are not useful in many intubated or sedated ICU patients however CPOT has been validated in both conscious and unconscious patients and has a high sensitivity to diagnose pain.  CPOT elements:

  •             -facial expression
  •             -body movement
  •             -muscle tension

CPOT vs behavioral pain scale(BPS) in the critically ill

Issue with infusions

We have adopted an analgesia and sedation protocol at RIH that is available in the SICU and TICU.  The major theme is to wean patients off opioid and sedation infusions and to use intermittent agents IV or enterally.  This results in reduced time on the ventilator and in the ICU and likely positively affects rates of a series of other downstream complications. 

A key issue with infusions is bioaccumulation.  Fentanyl is highly lipophilic so it accumulates in adipose tissue.  Fentanyl infusions can also cause opioid withdrawal later on.  For a review of some of the issues with fentanyl infusions Pulmcrit has a succinct blog entry from 2016:

Midazolam also can bioaccumulate, especially in patients with renal dysfunction as it has an active metabolite, hydroxymidazolam that is entirely renally cleared.

Sedative Infusions are acceptable to use in ARDS patients receiving neuromuscular blocking agent infusions and in young patients with open abdomens.   

ABCDE approach

The ABCDE approach to adult ICU patients was created to improve outcomes in ventilated patients.  The key to success of the ABCDE approach is that they are nursing driven but SICU residents should know the elements well. 

  1. awakening trial daily

Landmark trial: Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation. Kress JP, Pohlman AS, O’Connor MF, Hall JB. N Engl J Med. 2000 May 18;342(20):1471-7

  • spontaneous breathing trial daily

Put patient on pressure support ventilation early in the day if respiratory and HD status stable. 

  • coordinating the awakening and breathing trials
  • delirium assessment
  • early mobilization

What should I use?

Generally pain should be addressed first as it is one of the most common causes of discomfort and agitation in ICU patients.  Using sedatives when pain is the primary issue is ineffective and increases risk of developing delirium. 

Every 5 years or so the American College of Critical Care Medicine (ACCM) in conjunction with Society of Critical Care Medicine (SCCM) and American Society of Health-System Pharmacists (ASHP) release updated guidelines on management of pain, agitation, and delirium. 

Here is the 2018 paper: Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Devlin JW et al. Crit Care Med. 2018 Sep;46(9):e825-e873.

SCCM website presentation by Devlin(PharmD): https://www.sccm.org/Research/Guidelines/Guidelines/Guidelines-for-the-Prevention-and-Management-of-Pa

RASS

Sedation scores should be presented on ventilated patients in the SICU so that they are not undersedated or oversedated.  The Richmond Agitation and Sedation Score is simple and objective.  The scale ranges from -5 to +4.

  • +4 – combative (violent, dangerous to self and staff)
  • +3 – very agitated (pulling on tubes and lines, aggressive to staff)
  • +2 – agitated (nonpurposeful movement, some thrashing around)
  • +1 – restless
  •  0 – alert and calm
  • -1 – drowsy (can awaken > 10 seconds to voice)
  • -2 – lightly sedated (awakens < 10 seconds to voice)
  • -3 – moderately sedated (some movement to voice)
  • -4 – deeply sedated (movement only to physical stimuli)
  • -5 – unarousable

Procedural sedation 

There are numerous combinations of agents that can be used for procedures such as intubations and dressing changes.  Ketamine has really emerged recently as a useful agent due to its ability to provide analgesia and sedation simultaneously while minimizing respiratory and cardiovascular depression.

Pharmacy Joe provides a nice 17 minute audio review of ketamine’s usefulness in the ICU