Medical News USA / Canada: Conscious Sedation Consulting announces the development of a course to educate non-anesthesia physicians and nurses in the administration of propofol. The company announced that a comprehensive didactic course will be provided nationally for physicians, staff and organizations which wish to add propofol administration to their choice of sedatives. The course covers patient selection, a comprehensive detailed explanation of the pharmacology and pharmacokinetics of propofol, BIS monitoring, computer-controlled infusions, airway management, physiological monitoring, as well as the prevention, recognition and management of adverse events. Also covered are documentation, accreditation standards, patient recovery, discharge, follow up and process improvement. The seminar uses as a foundation, an understanding of a culture of safety as described by the Institute of Medicine in its report To Err is Human.

Propofol (2,6-diisopropyl phenol) is classified as an ultra-short-acting hypnotic agent that provides sedative, amnesic, and hypnotic effects. Propofol rapidly crosses the blood-brain barrier and causes a depression in consciousness that is likely related to potentiation of the g-aminobutyric acid A receptor in the brain.1 Propofol is 98% plasma-protein bound, and it is metabolized primarily in the liver by conjugation to its glucuronide and sulfate to produce water-soluble compounds that are excreted by the kidney. Typically, the time from injection to the onset of sedation is 30 to 60 seconds. Its duration of effect is 4 to 8 minutes. The pharmacokinetic properties do not significantly change in patients with renal failure or moderately severe chronic liver disease. Dose reduction is required in patients with cardiac dysfunction and in the elderly as a result of decreased clearance of the drug. Propofol potentiates the central nervous system effects of analgesics and sedatives such as benzodiazepines, barbiturates, narcotics, and other hypnotic/sedative agents. Therefore, the dose requirements of these agents may be reduced. The cardiovascular effects of propofol include decreases in cardiac output, systemic vascular resistance, and arterial pressure.2 Negative cardiac inotropy and respiratory depression can be seen with the use of propofol. These effects reverse rapidly with dose reduction or interruption of drug infusion3 and rarely require temporary ventilator support.

Controversy surrounds the use of Propofol by non-anesthesia providers. This is in part due to the FDA approved package insert which states that propofol should be administered by individuals trained in the administration of general anesthesia. Additionally some independent practitioners are either unwilling or unable to administer propofol due to local institutional policies or in some cases state regulatory restrictions. In spite of such concerns propofol use has seen a dramatic increase over the last decade. A 2006 study published by the American Journal of Gastroenterolgy reported that 68% of US endoscopists using conventional sedation indicate that they would prefer to administer propofol but are reluctant to do so because of widespread perception of increased complication risks.4 Propofol is more widely used in other countries.

Since 2002 more than 500,000 subjects have received propofol for endoscopic sedation.5

From this data, propofol in appropriate patients with trained personnel has demonstrated an excellent safety record. Transient hypoxia occurs in 3% to 7% of cases and transient hypotension in 4% to 7%. Time to recovery ranged between 14 and 18 minutes. In a retrospective review of Nurse Administered Propofol Sedation (NAPS) in several centers and involving greater than 36,000 endoscopies, the rate of clinical adverse events, defined as apnea or airway compromise that required assisted ventilation via bag-mask, ranged from 0.1% to 0.2%. 6 No patients required intubation, and none had permanent injury or death.

1) Trapani G, Altomare C, Liso G, et al. Propofol in anesthesia: mechanism of action, structure-activity relationships, and drug delivery. Curr Med Chem 2007;7:249-71.

2) White PF. Propofol pharmacokinetics and pharmacodynamics. Semin Anesth 1988;7:4-20.

3) Short TG, Plummer JL, Chui PT. Hypnotic and anaesthetic interactions between midazolam, propofol and alfentanil. Br J Anaesth 1992;69: 162-7.

4) Cohen LB, Wecsler JS, Gaetano JN, et al. Endoscopic sedation in the United States: results from a nationwide survey. Am J Gastroenterol 2006;101:967-74.

5)Cohen LB, Hightower CD, Wood DA, et al. Moderate level sedation during endoscopy: a prospective study using low-dose propofol, meperidine/fentanyl, and midazolam. Gastrointest Endosc 2004;59: 795-803.

6) Rex DK, Heuss LT, Walker JA, Qi R. Trained registered nurses/endoscopy teams can administer propofol safely for endoscopy. Gastroenterology 2005;129:1384-91.