We present a review of the impact of intensivists and ICU teams on patient
outcomes, with specific emphasis on varying hospital environments and study
designs. While the demand for critical care services is likely to increase
, 50% of ICU patients still receive care from nonintensivists in conjunctio
n with consultants. While no "standard" of critical care practice exists, c
osts are substantial: there are about 55,000 ICU patients/day in the United
States, and organizational structures vary substantially. ICU outcome stud
ies can be divided into three groups: multi-institutional comparisons, befo
re-and-after studies, and side-by-side comparisons. Multi-institutional com
parisons have tended to show improved outcomes in well-organized ICUs, with
strong medical direction and on-site intensivists. The change from an "ope
n" to a "closed" format for ICU care is associated with decreased low-acuit
y admissions, resource utilization and mortality rates, and improved effici
ency. Side-by-side com parisons have demonstrated improved efficiency decre
ased complications, and decreased resource use on ICU services directed by
an intensivist.