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Most patients in intensive care units (ICUs) experience pain, agitation, or delirium at some point during their critical illness. During the last two decades, tremendous growth in knowledge regarding the assessment and management of these syndromes in the ICU has prompted important changes in the practice of intensive care medicine. Validated tools now allow clinicians to quickly and reliably evaluate patients for pain, assess their level of consciousness, and detect delirium. These assessments, in turn, guide clinicians as they choose and titrate therapies targeted to best manage a patient’s symptoms. Novel strategies to address pain, agitation, and delirium have recently been investigated. The use of validated tools to diagnose these important clinical syndromes and the use of evidence-based management strategies improve both short- and long-term outcomes. This chapter reviews these assessment tools and describes best practices for management of pain, agitation, and delirium in patients with critical illness.


Patients with critical illness frequently suffer from pain.1,2 Because pain is nearly ubiquitous in the ICU and is a common source of agitation in patients with critical illness, clinicians should seek to treat pain first as a means by which to ensure patients are able to maintain an alert and calm state.3–5 Nevertheless, although effective treatments for pain are widely available, detecting pain in those critically ill patients who are unable to report it is challenging. Prolonged pain in the critically ill is associated with adverse physiologic effects.6 Because analgesia is most effective when pain is identified and treated early, clinicians should frequently assess patients for pain and treat it when identified.7

Assessing Pain in the Critically Ill

Pain is subjective by nature; therefore, a patient’s self-report (using a numeric scale or a visual analog scale) is an easy and reliable method to determine its presence. In fact, the Society of Critical Care Medicine (SCCM) recommends that the numeric rating scale be used to assess pain when patients can self-report.4 Among the critically ill, however, self-reporting is not always possible due to sedation or delirium. In cases where patients cannot self-report their pain, clinicians may view vital signs as indicators of pain, but multiple studies show that vital signs are poor correlates of pain in patients with critical illness.8–10 Therefore, several instruments have been developed and validated to help clinicians identify and quantify pain in critically ill patients.

The two most widely studied pain assessment tools for use with ICU patients who are unable to report pain are the Behavioral Pain Scale (BPS) and the Critical Care Pain Observation Tool (CPOT).11,12 Both the BPS and CPOT use nonverbal cues and patient behaviors to establish the presence of pain; these include facial expressions, body movements, and compliance with mechanical ventilation (Table 151-1A,B). Alternatively, a patient’s ...

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