Patients in intensive care units (ICUs) are treated with many interventions (most notably endotracheal intubation and invasive mechanical ventilation) that are observed or perceived to be distressing. Pain is the most common memory patients have of their ICU stay.1 Agitation can precipitate accidental removal of endotracheal tubes or of intravascular catheters used for monitoring or administration of life-sustaining medications. Consequently, sedatives and analgesics are among the most commonly administered drugs in ICUs.
Early intensive care practice evolved from intraoperative anesthetic care at a time when mechanical ventilation was delivered by rudimentary machines that were not capable of synchronizing with patients' respiratory efforts. As a result, deep sedation was commonly used until a patient was able to breathe without assistance. Developments over the past 30 years, including microprocessor-controlled ventilators that synchronize with patients' own respiratory efforts and new, shorter-acting sedative and analgesic medications, have dramatically changed this approach. Equally important has been the recognition that pain, oversedation, and delirium are issues that if undetected and untreated are distressing to patients and associated with increased morbidity and mortality.
