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 clinical practice guidelines of the Society of Critical Care Medicine emphasize the need for goal-directed delivery of psychoactive medications to avoid oversedation and to promote earlier extubation (Jacobi, J et al. Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult. Crit Care Med; 30:119-141, 2002.) Most available evidence regarding sedatives and analgesics in ICU patients indicates that it may be less important which drugs are delivered than their proper titration using goal-directed delivery to optimize patient comfort while avoiding complications such as prolonged mechanical ventilation or reintubation.

“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. Few available sedation scales have been appropriately tested for reliability and validity. 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. 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.

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 selected sedation scales. This agitation-sedation scale, which takes less than 20 seconds to perform with minimal training, has been shown 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.

An extensive body of new data on the RASS have been published (Sessler et al, Am J Respir Crit Care Med 2002 and Ely et al JAMA 2003), with a variety of unique approaches to assess an agitation-sedation scale, which support the utility of such instruments for patient care.

In accordance with recent recommendations, healthcare professionals should use valid and reliable instruments such as the RASS to implement sedation protocols for mechanically ventilated patients for goal-directed sedative and analgesic administration throughout patients’ hospital stay. The driving unmet need for goal-directed sedation practice has been met - there is now an instrument that has been shown to detect variations in level of consciousness over time. Taken together, advances in neurologic assessment provided by the RASS and the Confusion Assessment Method (CAM-ICU) 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.