Factors influencing changes in surgical intensive care unit utilization.

Abstract

To determine the factors that cause changes in surgical intensive care unit (ICU) utilization. The aim was to uncover the causes of these changes and examine whether any could have been predicted statistically. Retrospective analysis of prospectively collected representative data. University hospital adult surgical ICU. A total of 6,571 consecutive patients admitted over 8 yrs. None. Changes in annual admission rates and lengths of stay were examined to determine their causes, whether they were because of structural changes caused by alterations of physical facilities, functional changes caused by changes in personnel or policies, or clinical changes caused by alterations in clinical practice. The medical literature was examined to determine whether these changes reflected medical trends. During the 8 yrs there was a steady increase in the number of admissions and a steady reduction in the length of stay. These changes in unit utilization were often not predictable statistically and were attributable to a combination of clinical, structural, and functional factors. Surgical ICU utilization was notable for continual, and not predictable, changes. Clinical issues included new surgical techniques and anesthetic practices; structural causes included changes in bed capacity and opening an intermediate care unit; and functional factors involved changes in surgical personnel, policy revisions, and pressures to reduce ICU length of stay. This was further complicated by the observation that changes in the number of admissions were often not paralleled by similar changes in the number of patient days. This complex situation demonstrated the problems of basing predictions of future utilization on previous experiences.