Monitoring sedation, agitation, analgesia, and delirium in critically ill adult patients

Despite the best efforts to provide a humane environment for critically ill adults, as many as 74% become agitated during their ICU stay, and an equal percentage later recall unpleasant memories of their ICU experience including unrelieved pain, sleep deprivation, anxiety, nightmares, and hallucinations.(26,27,64,79,88,92,96) All these experiences are associated with development of posttraumatic stress disorder.(32,46,81,82,84) In addition, agitation commonly is associated with unplanned patient removal of endotracheal tubes or other devices such as vascular catheters and enteral feeding tubes and may be associated with increased morbidity and additional expense.(9,28,50) Delirium, a frequent contributor to ICU agitation, is common and difficult to diagnose in the critically ill. Its incidence varies from 30% in open-heart surgery patients to 87% in medical ICU patients.(24) Whereas inadequate sedation and analgesia are detrimental and carry the risk for the negative outcomes described, excessive sedation is also undesirable because it may lead to prolonged mechanical ventilatory support, increased ICU length of stay, and increased diagnostic testing.(45,47) These factors extend the economic burden of sedating medi- cations beyond the estimated $1 billion spent yearly for the purchase of this group of drugs.(47) Finding a balance between the provision of patient comfort and oversedation has been difficult. Fortunately, recent findings confirm that protocols using validated and reliable scoring systems can enhance the practice of sedation and analgesia, improve patient outcomes, and reduce resource consumption.(8,47,54) This article focuses on the scoring systems that assess sedation, agitation, analgesia, and delirium in adult ICU patients and reviews the data supporting their use and confirming their reliability and validity.