Sedation in PACU: the role of propofol

In critically ill patients, adequate sedation increases comfort, minimizes stress response and facilitates diagnostic and therapeutic procedures. Propofol (2-, 6-diisopropylphenol) is an intravenous sedative-hypnotic agent popular for sedation in the Intensive Care Unit. The favorable propofol pharmacokinetic, characterized by a three compartment linear model, allows rapid onset and short duration of action. The emergence time from sedation with propofol varies with the depth and the duration of sedation and the patient's bodyweight. Propofol causes hypotension, particularly in volume depleted patients, decreases cerebral oxygen consumption, reduces intracranial pressure and has potent anti-convulsant properties. It is a potent antioxidant, has anti-inflammatory properties and is a bronchodilator. As a consequence of these properties, propofol is being increasingly used in the management of traumatic head injury, status epilepticus, delirium tremens, status asthmaticus and in septic patients. Prolonged use (>48 h) of high doses of propofol (>66 mcg/Kg/min) has been associated with lactic acidosis, bradycardia, and lipidemia in pediatric patients. A rare complication firstly reported in pediatrics patients and also observed in adults is known as "propofol syndrome" characterized by myocardial failure, metabolic acidosis and rhabdomiolysis. Hyperkalemia and renal failure have also been associated with this syndrome. Hypertriglyceridemia and pancreatitis are uncommon complications. A large number of trials have compared the use of propofol with midazolam. Sedation with propofol is associated with adequate sedation in ICU patients, shorter weaning time and earlier tracheal extubation compared to midazolam, but not before ICU discharge.