Use of propofol and other nonbenzodiazepine sedatives in the intensive care unit

Sedative and analgesic medications are the most commonly administered drugs in medical-surgical ICUs in the United States.(22,23,46) A large body of literature discusses the side effects and complications associated with the use and misuse of these drugs. A task force from the Society of Critical Care Medicine and American Society of Health-Systems Pharmacists currently is revising previously published guidelines that review the use of these agents and will propose recommendations for appropriate use of sedatives, analgesics, and neuromuscular-blocking drugs.(28) Sedatives are administered by intermittent injection or by continuous infusions. There are proponents for both methods of administration. Recent data suggest that more careful titration to effect sedatives and analgesics and the use of the lowest allowable dose with periodic down titration or discontinuation may be associated with decreased length of mechanical ventilation, fewer tracheostomies in mechanically ventilated patients, and shortened ICU stay.(33) Sedatives are used to limit stress, to provide comfort, and as pharmacologic aids to maintain a safe environment for critically ill patients. Various activities, including routine nursing and respiratory care, inva sive procedures, maintenance of monitoring equipment, and pathophysiologic changes associated with the patient's disease or injury, can produce pain and discomfort. When addressing the needs of the agitated, anxious, or delirious patient, pain should always be evaluated and treated when present. A host of factors exacerbate patient agitation. Among these factors are the patient's inability to communicate and distressful environmental factors such as excessive auditory, thermal, or visual stimuli. Sleep deprivation is a common cause of agitation (ICU psychosis). In the elderly; this agitation often is referred to as sundowner's syndrome. An altered level of consciousness and lack of comprehension regarding the patient's current state of health frequently lead to anxiety, agitation, and, on occasion, delirium.(23) Agitation related to pain and anxiety can have deleterious effects in critically ill patients. Agitation can lead to the inadvertent disconnection of life-sustaining therapies, increased oxygen consumption, and myocardial ischemia. The impact of ICU psychosis with decreased sleep cannot be ignored.(22) Another less obvious endpoint is the ability to ventilate patients without the use of neuromuscular-blocking agents; this ventilation reduces the potential for paralysis without adequate sedation or analgesia, decreases the loss of respiratory drive, and eliminates the development of postparalysis myopathy. Deep sedation may facilitate synchronization of the mechanically ventilated patient even when alternative modes of ventilation such as permissive hypercapnia, inverse-ratio ventilation, or prone positioning are used.(23,46) Judicious use of sedative drugs in the ICU is important to provide patient comfort without physiologic compromise.(22) An ideal sedative (see box) would produce sedation and amnesia while minimizing cardiovascular lability and respiratory depression. It would have a rapid onset with a short duration of action. It would be readily titratable and would not accumulate. It would undergo predictable metabolism.(11) It would lack active or toxic metabolites, and it would be inexpensive.