Choice of powerful sedatives and analgesic medications is clearly of importance to our patients’ clinical outcomes. In addition to choice, how we dose and titrate, and when we choose to discontinue these medications is of paramount importance. Much of our group's recent and ongoing research centers around improving these issues in critical care practice. For example, we first showed an association between commonly prescribed sedative medications and delirium in 2006 and then our MENDS study, published in JAMA in 2007 (see history and timeline of this field) investigated two different sedative paradigms to see which was safer and more effective. Currently we are conducting two other NIH sponsored investigations in medical and surgical ICU patients called MIND-USA (antipsychotics for delirium and sedation sparing effect) and MENDS II (studying sedative choices in severe sepsis patients) to determine best management practices for critically ill patients.
Patient-Oriented Goal-Directed Sedation Delivery
Increased scrutiny has recently been placed on appropriate titration of sedative and analgesic medications in critically ill patients, especially those being treated with mechanical ventilation. Patient comfort should be a primary goal in the intensive care unit (ICU), including adequate pain control, anxiolysis, and prevention and treatment of delirium. However, achieving the appropriate balance of sedation and analgesia is challenging. Without rational and agreed upon target levels of sedation, it is likely that different members of the healthcare team will have disparate treatment goals, increasing the chance for iatrogenic complications and potentially impeding recovery.
The Pain, Agitation and Delirium (PAD) clinical practice guidelines of the Society of Critical Care Medicine (2013 PAD SCCM/ACCP Guidelines) emphasize management of pain first, followed by goal-directed delivery of psychoactive medications to avoid oversedation and to promote earlier extubation.
Improving ICU Sedation and Delirium
Goal-directed delivery of sedatives is best accomplished by the use of sedation scales to help the medical team agree on a target sedation level for each individual patient. Sedation scales with broad acceptance include (among others) the Ramsay scale, the Sedation Agitation Scale (SAS), the Motor Activity Assessment Scale (MAAS), the COMFORT scale for pediatric patients, and the Richmond Agitation-Sedation Scale (RASS). These are all discussed to some degree in the references for the sedation clinical practice guidelines and the RASS. Of the available scales the PAD guidelines recommend the use of the RASS and the SAS based on published literature and the psychometric properties of the scale.
The Richmond Agitation-Sedation Scale (RASS) was developed by a multidisciplinary team at Virginia Commonwealth University in Richmond, Virginia. A unique feature of RASS is that it uses the duration of eye contact following verbal stimulation as the principal means of titrating sedation.
The RASS has been demonstrated to have excellent interrater reliability in a broad range of adult medical and surgical ICU patients and to have excellent validity when compared to a visual analogue scale and other sedation scales. This RASS takes less than 20 seconds to perform with minimal training, and has been shown to be highly reliable among multiple types of healthcare providers. The RASS has an expanded set of scores (10-point scale) at pivotal levels of sedation that are determined by patients' response to verbal versus physical stimulation, which will help the clinician in titrating medications.
The Richmond Agitation-Sedation Scale (RASS)
The Riker Sedation-Agitation Scale (SAS)
RASS and SAS Sedation Scale Conversions
Management of pain and agitation
In accordance with the recent PAD recommendations, healthcare professionals should use valid and reliable pain monitoring instruments and treat pain first. An analgesia based approach may be adequate for a majority of critically ill patients without the need for additional sedative medications. Level of agitation and sedation should be monitored frequently with agitation-sedation scales such as the RASS or SAS. When additional sedation is required due to agitation or anxiety, then sedation strategies using non-benzodiazepine sedatives (either propofol or dexmedetomidine) may be preferred over sedation with benzodiazepines (either midazolam or lorazepam) to improve clinical outcomes, in mechanically ventilated adult ICU patients. Light levels of sedation should be maintained either via goal-directed therapy, or via incorporation of daily awakening trials coordinated with daily wake up trials More information can be found on the Awakening and Breathing page.
Protocol for Management of Pain, Agitation, and Delirium in Mechanically Ventilated Patients
Analgesia/Sedation Protocol for Mechanically Ventilated Patients
An important third element in the PAD guidelines is monitoring and management of delirium. This is discussed in detail in the page on delirium monitoring. Taken together, advances in neurologic assessment provided by the RASS or SAS and the delirium monitoring instrument used (either the Confusion Assessment Method for the ICU [CAM-ICU) or the Intensive Care Delirium Screening Checklist [ICDSC]), should lead to earlier identification and characterization of acute brain dysfunction as an organ failure, reductions in the random variation with which patients' sedatives are currently managed, and appropriate interventions aimed at prevention or reversal of acute brain dysfunction.