Dexmedetomidine Good for Conscious Sedation During Colorectal Procedure

Authors: Caroline Helwick

Anesthesiology News

Dexmedetomidine is effective for conscious sedation during dissection of colorectal lesions and is associated with greater patient satisfaction with the procedure, researchers have found.

The randomized study found that dexmedetomidine (Precedex, Hospira) may be an appealing substitute for propofol, which has a relatively smaller margin of safety, or for deeper sedation with other agents.

“We believe that dexmedetomidine is an ideal sedation method for colorectal endoscopic submucosal dissection [ESD],” said Hideaki Kinugasa, MD, of Hiroshima City Hiroshima Citizens Hospital in Japan, who presented the findings at the 2018 Digestive Disease Week (abstract 921).

Often used in the intensive care setting, dexmedetomidine is a centrally acting, highly selective alpha2-adrenoceptor agonist. The study evaluated the utility of dexmedetomidine for conscious sedation during ESD of colorectal lesions in a prospective randomized, double-blind trial conducted in Japan.

“Deep sedation is often desirable for ESD of lesions in the esophagus and stomach. However, the suitable sedation level in colorectal ESD is different,” Dr. Kinugasa said.

Sedation can have variable effects on respiration, he explained, which can be an issue during colorectal ESD, as patients often must hold their breath or change position during the procedure. Dexmedetomidine is notable for its ability to provide sedation without the risk for respiratory depression associated with propofol.

The study enrolled 80 patients undergoing ESD of colorectal lesions. Patients were assigned to receive placebo or dexmedetomidine (induction dose, 6 mcg/kg per hour; maintenance dose, 0.4 mcg/kg per hour), with pethidine as an analgesic in both groups. Demographics and disease characteristics were similar in both groups.

The primary outcome was patient satisfaction, based on a 10-point visual analog scale (VAS). Among 13 secondary outcomes were patient pain level (VAS), endoscopist satisfaction, patient movement during ESD, resection time and frequency of side effects.

Dexmedetomidine outperformed placebo across multiple outcomes, Dr. Kinugasa reported (Table). Patient satisfaction was scored at 9.1, versus 8.4 for placebo (P=0.018). Regarding the secondary outcomes, patient pain level, endoscopist satisfaction, patient pain as judged by the endoscopist, and incidence of side effects all were significantly better for dexmedetomidine than placebo.

“All of these were significantly better results—patients were more comfortable and had less dexmedetomidine pain—in the group,” he said. “No additional medication was needed.”

Significantly more patients receiving dexmedetomidine slept through the procedure (33% vs. 6%; P<0.001). No patient in either group was deeply sedated, and none in either arm was restless, according to the researchers.

John Lieb II, MD, an associate professor of gastroenterology at Drexel University College of Medicine, in Philadelphia, said dexmedetomidine has not shown much efficacy as sedation in upper endoscopy. “Compared to propofol, patient satisfaction scores have been less and there’s been more bradycardia,” he said. “What’s unique here is they are studying it in colonoscopy, where the idea is to give moderate sedation so that the patient is aware of what’s going on, but is not bothered much by it.”

Dr. Lieb added that the study would have been stronger if the control arm had received another form of sedation instead of placebo.

Jonathan Cohen, MD, a clinical professor of medicine at NYU Langone Health in New York City, agreed that a comparison between dexmedetomidine and deep sedation with propofol would be useful. “Basically, the patients were still conscious, but they were more sedated than usual and they felt better than the controls,” he said. “From our long-standing experience with combinations of opiates and benzodiazepines, we are accustomed to the observation that combinations of medications can produce a little better sedation. The bottom line is [that] a little more sedation helps.”