Descriptive analysis of critical care units in the United States: patient characteristics and intensive care unit utilization.

OBJECTIVE: To gather data about occupancy, admission characteristics, patients' ages, and types of therapy utilized in ICUs in the United States.

DESIGN AND SETTING: Survey instruments were mailed to the administrators of 4,233 hospitals to gather information from the medical director of the institutions' respective ICUs for the purpose of developing a database on ICUs in the United States. The sampling frame for this study was based on all American Hospital Association (AHA) hospitals stating they had ICUs.

MEASUREMENTS: Census questionnaires solicited information on occupancy, where the patients were admitted from, length of stay, therapies rendered, intensive care diagnoses, and resuscitation status, as well as other information.

MAIN RESULTS: Data were obtained regarding 32,850 ICU beds, with 25,871 patients from 2,876 separate ICUs in 1,706 hospitals in the United States. The census response rate was 40% of the AHA hospitals that stated they had ICUs, with specific ICU data on 38.7% of the nation's ICUs. Overall, the responding units reported a mean occupancy rate of 84% of total bed capacity and 87% of available beds. As hospital size increased, so did ICU occupancy. Nearly 17% of all of the critical care patients had been in the units for > 14 days. More precisely, 49% of all responding units indicated that they had one or more "chronic" (> 14-day length of stay) patients. Most patients were admitted to the units from the emergency room (38%), operating room/postanesthesia care unit (22%), and the general hospital floor (16%). Neonatal units were exceptions to this observation, where most patients came from the delivery room (60%). Admission from other hospitals represented a significantly larger group of patients in the cardiac care, pediatric, and neonatal units. Respondents indicated that many of their current patients were elderly, with 43% of these patients aged 65 to 84 yrs and with 4% being > or = 85 yrs of age. The 47% of patients > or = 65 yrs of age increased to 58% when the neonatal and pediatric units were eliminated from the analyses. For all units responding to the survey, the leading primary admitting intensive care diagnoses were postoperative management, ischemic heart disorder, respiratory insufficiency/failure, and prematurity. Elimination of units predominantly treating children (pediatric and neonatal) from the analysis left "adult" units with three primary admitting diagnoses: ischemic heart disease, postoperative management, and respiratory insufficiency/failure with variation according to specific unit type. The leading diagnoses in pediatric units were respiratory insufficiency/failure, postoperative management, and congenital abnormalities. For neonatal units, prematurity was the primary admitting diagnosis, accounting for 59% of these units' patients. Respondents reported 5.3 +/- 10.9% of patients had received cardiopulmonary resuscitation (CPR) before admission into the critical care unit. Only 6.0 +/- 11.9% of patients in these critical care units had instructions that CPR not be performed while in the unit.

CONCLUSIONS: This report should be viewed as the beginning step of an effort to improve both the information base available on critical care medicine and the performance of ICUs. Our survey findings provide an introduction into the everyday workings of critical care units throughout the United States. Research is required to determine which patients will benefit from intensive care and how to efficiently utilize the vast technology we have available for them in a world with limited financial resources, an aging population, and a multiplicity of societal and ethical concerns.