Seventy-eight percent of patients who had nurse-delivered sedation/analgesia reached levels consistent with general anesthesia, new research has found. The study adds fuel to the controversy surrounding administration of I.V. sedation/analgesia by RNs outside of the OR environment.

The study included 595 patients who received moderate sedation/analgesia (midazolam and fentanyl) for procedures outside of an OR, such as a colonoscopy, upper gastrointestinal endoscopy, or bronchoscopy. Moderate sedation/analgesia is defined by the American Society of Anesthesiologists (ASA) as a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions should be required to maintain a patent airway, spontaneous ventilation, or cardiovascular function.

In the study, nurses were instructed to provide sedation/analgesia according to standard clinical guidelines. Monitoring revealed that 78% of patients had bispectral index (BIS) values less than 60 for more than 5 minutes. Adverse reactions occurring in 6% of patients included episodes of oxygen desaturation, difficulty to arouse, hypertension and hypotension, restlessness, tachycardia, and pain.

Working at Duke University Medical Center in Durham, N.C., the researchers concluded that nurses delivering sedation/analgesia outside the OR frequently administer relatively deep sedation, which could be associated with sedation-related adverse reactions. They call for more studies to determine if the routine use of BIS monitoring could reduce sedation-related adverse reactions and improve patient outcomes.

Researchers announced their findings at the 2008 annual meeting of the ASA. For more information, visit the society's Web site at http://www.asahq.org.