An intensive care unit (ICU) stay is often a stressful and painful experience. Recent surveys indicate that 50–80% of patients experience pain during their ICU stay [1]. Critically ill patients experience pain more readily than healthy subjects; a phenomenon known as hypernociception. The most painful experiences for ICU patients are endotracheal suctioning and being turned in bed. In addition, many patients have pain at rest without a noxious stimulus [1]. This decreased threshold of pain in the ICU has been attributed to immobility and systemic inflammation. In addition to pain, ICU patients often suffer from stress, which has been frequently attributed to painful procedures. Other factors that may play a role in ICU stress include inability to communicate due to endotracheal intubation, interruption of sleep, hallucinations, and nightmares. This stressful experience is not without complications, as one retrospective study found that 25% of ICU patients with self-reported stressful experiences during their ICU stay, such as nightmares, anxiety, respiratory distress, or pain, showed symptoms of post-traumatic stress disorder four years later [2], thus, the importance of adequate analgesia and sedation to achieve patient comfort.

The recent evolution of critical care management has emphasized the need to minimize continuous deep sedation and paralysis to improve outcome and decrease length of stay in the intensive care unit (ICU). This recommendation is especially important in patients with neurologic dysfunction.

In this sense, sedative regimens in the neurologic ICU have been well ahead of general ICU doctrine. One of the primary tenets of care of these patients is the capacity to perform repeated neurologic exams as the optimal means of assessing the patients’ condition. With respect to bedside evaluation and titration of sedation, the neurologically injured patient may indeed be the most difficult ICU population to manage. Cognitive dysfunction leads to increased fear, restlessness, and agitation from the inability to understand one's predicament. Yet even modest sedation may mask subtle neurologic deterioration, hence the need for close nursing and physician support and observation, and titrating medications as needed without impairing neurologic evaluation.

Patients with traumatic brain injury (TBI) constitute the hallmark brain disorder when discussing difficult sedation paradigms. They are often agitated and at risk of injury to self or the medical staff caring for them. Many TBI patients are also withdrawing from chronic alcohol and drug use, and this must be factored into the choice and duration of sedation.

SEDATION

Indications for Sedation

Before initiation of sedation in any ICU patient, it is imperative to exclude all alternative explanations for agitation, confusion, or sympathetic hyperactivity.