A "substantial portion" of the patients in costly hospital intensive care units may not need to be there, a new George Washington University study suggests.

An eight-month survey of 624 patients in the general surgical-medical intensive care unit (ICU) at the GW medical center found that nearly half of those admitted were in stable condition and "received only observation or minimal amounts of active treatment."

This finding contrasts sharply with the traditional image of the ICU as a "treatment area for critically ill patients" who "require a costly level of therapeutic intervention and have a high in-hospital mortality," noted the report, published in the latest edition of the Journal of the American Medical Association.

Instead, concluded study director Dr. William A. Knaus and his colleagues, "it is appropriate to ask whether some of these patients needed to be admitted to a special care unit," particularly in light of current concerns about the costs of medical care and the continued demand for more ICU beds.

Although 49 percent of the patients in GW's unit were not found to need intensive treatment, Knaus said in an interview last week that "this does not mean they all don't need intensive care." Because many were surgical patients at added risk, they would still need close nursing attention not available in the rest of the hospital, he said.

However, since the JAMA study was completed, Knaus said, his ICU research has better defined those patients at "low risk of needing treatment" who are "too healthy" to be admitted to intensive care units. The new, as yet unpublished, criteria suggest that perhaps 5 to 10 percent of those now admitted to ICUs could instead be admitted to regular hospital units.

"The effects of this nationwide are potentially large," said Knaus, who serves as co-director of GW's intensive care unit. He said that preliminary evidence from a study of about 10 hospitals around the country suggests that GW is fairly representative of teaching hospitals. He said that it is also likely that smaller, community hospitals, which generally have fewer critically ill patients, could safely move more of them out of ICUs.

Although the GW study is considered the first of its kind involving general surgical ICUs, it confirms an earlier study of a coronary care intensive unit that found that more than 75 percent of the patients were admitted for monitoring only and only 10 percent of them later needed additional treatment.

While the growth in the number of hospitals has slowed, the number of ICU beds continues to increase at 4 percent per year. Only 10 percent of U.S. hospitals with more than 200 beds had these units in 1960, but 99 percent do today, the authors noted.

Knaus said that an ICU bed costs three times as much as a regular hospital bed and that 20 percent of total hospital costs are estimated to be from intensive care units. In addition, many hospitals have recently experienced problems in intensive care units because of the shortage of nurses to staff them.

Beyond the economic costs of extensive ICU care, Knaus is also concerned about the "psychological" problems for patients in the tense environment. There is also a slightly increased risk of infection in such units.

He agreed that it may be difficult to discourage use of ICUs since they have become a "security blanket" for both patients and doctors. He said he hopes to implement a patient selection system for the ICU unit at GW.