Moderate sedation can be achieved for most patients using a standard combination of opioids and benzodiazepines. For some patients, however, conventional regimens are not sufficient. (see Factors Involved in Choice of Sedation Regimen).

Options for difficult-to-sedate patients

Difficult-to-sedate patients may require general anesthesia or deep sedation by an anesthesiologist.  The gastroenterologists may also choose from a variety of alternative agents or the addition of an adjunctive agent to sedate the difficult to sedate patient.

Droperidol
Droperidol is a tranquilizer with antiemetic and antipsychotic properties. Droperidol is not recommended for use as a single agent but can be used in combination with a standard opioid-benzodiazepine regimen for difficult-to-sedate patients or in patients undergoing longer, more complex procedures. Droperidol has the potential to cause serious cardiovascular complications, so should only be used in situations where sedation difficulties are anticipated.

Propofol
Propofol can be an option for patients who are taking high doses of narcotics for treatment of other conditions (such as chronic pain) because it has a different mechanism of action. Although propofol can be used alone, it is more often administered in small bolus doses in combination with an opioid and a benzodiazepine. This minimizes the risks of rapid oversedation inherent when larger doses of propofol are used.

Ketamine
Ketamine is a rapid-acting general anesthetic drug with both analgesic and sedative characteristics. So far, the drug has been used predominately in pediatric patients.  Some recent studies, however, have shown ketamine to be an effective adjunct in patients undergoing advanced endoscopic procedures who were not sufficiently sedated with opioid-benzodiazepine combinations.

Other Adjuncts
The anti-histamine drug, diphenhydramine hydrochloride, can be given as a premedication prior to endoscopic procedures to augment sedation. The drug acts synergistically with opioid-benzodiazepine combinations and may help achieve sedation in patients who are resistant to these agents. It may also allow for the use of lower doses of standard medications.

General anesthesia
In patients who are at high risk for difficult sedation, general anesthesia can be considered as a method of last resort.

American Society for Gastrointestinal Endoscopy. Guidelines for conscious sedation and monitoring during gastrointestinal endoscopy. Gastrointestinal Endoscopy. 2003;58(3): 317-322.

Cohen J, Haber GB, Dorais JA, et al. A randomized, double blind study of the use of droperidol for conscious sedation during therapeutic endoscopy in difficult to sedate patients. Gastrointest Endosc. 2000; 51(5):546-51.

Cohen LB, DeLegge MH, Aisenberg J, Brill JV, Inadomi JM, et al. AGA Institute review of endoscopic sedation. Gastroenterology. 2007 Aug;133(2):675-701.

Ellis, K. Contending with sedation challenges. Endonurse. 04/01/2006. http://www.endonurse.com/articles/sedation_anesthesia/597_641feat2.html

Varadarajulu S, Eloubeidi, MA, Tamhane A, et al. Prospective randomized trial evaluating ketamine for advanced endoscopic procedures in difficult to sedate patients. Alimentary Pharmacology & Therapeutics. 2007;25(8):987-997.

Last Updated September 29, 2008