TUESDAY, Dec. 11 (HealthDay News) -- Doctors routinely use sedatives on patients who are hooked up to mechanical ventilators in intensive care units, but some experts worry that too much sedation might slow down recovery and leave patients in an unnecessary fog.

Now, researchers report that by substituting a newer medication, dexmedetomidine (Precedex), for the more commonly used lorazepam (Ativan), doctors could reduce the amount of time patients experience delirium and coma. They also found a reduction in the length of time on mechanical ventilation and an improvement in survival, though these differences didn't reach the level of statistical significance.

"By changing the way we give medications, we may be able to improve outcomes," said study author Dr. Pratik Pandharipande, from the anesthesiology and critical care department at Vanderbilt University Medical Center in Nashville, Tenn. His report is published in the Dec. 12 issue of the Journal of the American Medical Association.

"By incorporating this sedative, patients had four more days alive without delirium or coma. They also had greater time off the mechanical ventilator and had shorter ICU stays. And, there was an important trend toward decreased mortality, about a 10 percent reduction in mortality," he said.

However, not everyone is convinced that the newer sedative is a significant improvement.

"This study reminds me of the importance in minimizing sedation. The principles of this study make sense to me, but the study is flawed. They started using 10 milligrams per hour of lorazepam, and it's a dose we don't use. It's a rarity to use a dose that high," said Dr. Kevin Grady, interim chief medical officer for St. John's Health System and director of pulmonary and critical care at St. John Hospital and Medical Center in Detroit. Grady said a more standard dose of lorazepam is 2 to 4 milligrams per hour.

"This just doesn't prove to me that dexmedetomidine is better than lorazepam," added Grady.

The current study included 106 people hospitalized in the ICU and on mechanical ventilators. They were randomly assigned to receive sedation either with dexmedetomidine or with lorazepam. The sedation period varied but lasted as long as 120 hours.

While the manufacturer of dexmedetomidine, Hospira, provided an unrestricted grant and the study medication to the researchers, the company had no input in the study's design, conduct or analysis, according to the authors.

The researchers found that sedation with dexmedetomidine reduced the number of days that patients experienced delirium or coma by an average of four days. The prevalence of coma was 92 percent for those on lorazepam and 63 percent for those on dexmedetomidine.

The 28-day mortality rate was 27 percent for the lorazepam group versus 17 percent for those on dexmedetomidine.

According to Pandharipande, although the initial cost of dexmedetomidine might be higher than that of lorazepam, the improved outcomes offset that cost.

Because the study size was small, Pandharipande said more research needs to be done to confirm these findings, but that this study offered "proof of concept."

"We do have an alternate sedation strategy to reduce the burden of brain dysfunction," said Pandharipande.

Grady said there are certain patients who may benefit more from the use of dexmedetomidine, such as those going through alcohol withdrawal. But, until further studies are done, Grady added, "I'm hard-pressed to think it's worth the expense. This drug costs twice as much as lorazepam."

More information

Read more about lorazepam and its potential side effects at the U.S. National Library of Medicine.

SOURCES: Pratik Pandharipande, M.D., department of anesthesiology and critical care, Vanderbilt University Medical Center, Nashville, Tenn.; Kevin Grady, M.D., director, pulmonary and critical care, St. John Hospital and Medical Center, and interim chief medical officer, St. John's Health System; Dec. 12, 2007, Journal of the American Medical Association

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