Dexmedetomidine Reduces Respiratory Depression in Patients Undergoing Monitored Anaesthesia Care: Presented at ASA

To print: Select File and then Print from your browser's menu
---------------------------------------------------------------------------------------
Title: Dexmedetomidine Reduces Respiratory Depression in Patients Undergoing Monitored Anaesthesia Care: Presented at ASA
URL: http://www.pslgroup.com/dg/2314AE.htm
Doctor's Guide
October 23, 2008

By Deborah Brauser

ORLANDO, Fla -- October 23, 2008 -- Patients who are sedated with dexmedetomidine while undergoing monitored anaesthesia care (MAC) experience reduced respiratory depression and less postoperative anxiety, need less midazolam and fentanyl, and report higher overall satisfaction, according to trial results presented here at the American Society of Anesthesiologists (ASA) 2008 Annual Meeting.

Lead investigator Keith Candiotti, MD, University of Miami Health System and Miller School of Medicine, Miami, Florida, reported the phase 3 trial results here on October 20.

In this multicentre trial, 326 patients requiring MAC for a broad range of elective surgical procedures received 1 of 2 potential doses of dexmedetomidine -- either 0.5 or 1 mcg/kg (n = 134 and 129, respectively) -- or an equal volume of placebo (n = 63). Both dexmedetomidine groups then received a maintenance infusion of 0.6 mcg/kg/h of the study drug, whereas the placebo group received a maintenance infusion of normal saline at the same rate.

Sedation was targeted to an Observer's Assessment of Alertness/Sedation Scale (OAA/S) score of <= 4. If this goal was not achieved, repeated doses of intravenous midazolam 0.5 mg were given. Patients received a local anaesthetic block before their surgical procedure, and fentanyl could be administered as needed for pain in repeated doses of 25 mcg. Patient satisfaction was measured with the Iowa Satisfaction With Anesthesia Scale (ISAS), and patient anxiety was assessed before, during and after infusion of the drug treatments using the Anxiety Assessment Scale.

At the study's end, subjects receiving both doses of dexmedetomidine were significantly better than subjects receiving placebo at maintaining the targeted sedation level of OAA/S <= 4 without additional midazolam (59.7% and 45.7% vs 96.8%, respectively; P < .001). Additionally, both study-drug groups needed a significantly lower mean total dose of rescue midazolam to achieve and/or maintain the targeted sedation level (1.4 +- 1.69 and 0.9 +- 1.51 vs 4.1 +- 3.02, respectively; P < .001). A greater number of patients in the placebo group could not be sedated with midazolam alone, and required additional sedation with either propofol or general anaesthesia to complete their surgical procedures.

Furthermore, the percentage of patients who required fentanyl during the infusion was significantly lower for both study-drug treatment groups (59% and 42.6%) versus the placebo group (88.9%), as was the total dose of fentanyl (84.8 +- 52.94 and 83.6 +- 52.75 vs 144.4 +- 100.15 respectively, P < .001).

In the group receiving the 1-mcg/kg dose of dexmedetomidine, significantly fewer patients required postoperative analgesics versus placebo (P = .025); as well, significantly fewer patients reported less postoperative anxiety versus placebo (P = .007).

The incidence of absolute respiratory depression was significantly lower in both drug treatment groups (3.7% and 2.3%) versus placebo (12.7%) during the infusion period (P <= .018), while the overall ISAS satisfaction scores were significantly higher in both groups versus placebo (P < .001).

Said Dr. Candiotti: "The quick ... takeaway message is that, based on this trial, the [US Food and Drug Administration] has approved dexmedetomidine for the use of sedation in nonintubated patients."

The most significant finding from the trial, Dr. Candiotti stated, is the notable reduction in respiratory depression in the dexmedetomidine treatment groups. "If you consider the ASA Closed Claim database, where respiratory depression was a significant problem in MAC cases, this could substantially affect the outcome of our patients and how we treat [them]."

Dr. Candiotti continued, "I don't think this is going to change clinical practice, because we're all using this drug in this way already. But now that it has an FDA indication behind it, this justifies clinical practice."

Funding for this study was provided by Hospira, Inc.

[Presentation title: Safety and Efficacy of Dexmedetomidine for Sedation During MAC Anesthesia: A Multicenter Trial. Abstract 1202]

http://www.docguide.com

Return to News Story Page

webmaster@pslgroup.com