Availability of ICU Beds and Outcomes

The demand for beds in intensive care units (ICUs) may at times exceed supply, necessitating prioritization of admissions. As the population ages, demands for critical care services are expected to increase, raising concerns about plans for allocation of resources such as ICU beds when demand exceeds supply.

According to researchers, formal triage protocols are not a routine part of rapid response systems or decision making vis-à-vis ICU admissions. The researchers recently designed a study to assess the association between the availability of ICU beds (0, 1, 2, or >2 beds) and the process and outcomes of care for a population-based cohort of hospitalized patients with sudden clinical deterioration. Results of the study were reported online in Archives of Internal Medicine [2012;172(6):467-474. doi:10.1001/archinternmed.2011.2315].

The researchers identified consecutive hospitalized adults (excluding those in cardiac surgery and coronary care units) in Calgary, Alberta, Canada, with sudden clinical deterioration that was identified by the rapid response system and triggered medical emergency team (MET) activation between January 1, 2007, and December 31, 2009. The Alberta Health System manages all METS in Calgary. The decision to admit patients to the ICU is made by the attending physician on a case-by-case basis, without a triage protocol or decision-making support. Hospital wards activating the MET are not generally aware of ICU bed availability.

The primary outcome measure of the study was ICU admission within 2 hours of MET activation. The secondary outcomes were (1) change in patient goals of care (resuscitative, medical, or comfort), (2) hospital mortality, (3) healthcare resource use, determined according to the investigations and interventions performed during the initial MET activation or a new MET activation, and (4) ICU admission during the remainder of the hospitalization (>2 hours following the initial MET activation).

There were 3494 patients in the study cohort. The median age was 72 years; 46.8% of the patients were female, 46.2% had ≥1 comorbidity, and 10.3% had a previous ICU admission during their hospital stay.

When ICU beds were available, MET activations occurring at night and for respiratory reasons were more common. Reduced ICU bed availability was associated with a decreased likelihood of patient admission within 2 hours of MET activation (P=.03) and with an increased likelihood of changes in patient goals of care (from resuscitative care to medical or comfort care) P2 ICU beds were available, when 0 beds were available, patients were 33.0% less likely to be admitted to the ICU and 89.6% more likely to have their goals of care changed.

There was no significant association between ICU bed availability and hospital mortality.

Study limitations cited by the researchers include the subjective definition of the primary outcome (admission to the ICU within 2 hours of MET activation), possible residual confounding, an inherent risk in all observational studies (factors other than ICU bed availability might explain the differences in ICU admission rates), an inability to exclude all but clinically important differences in patient outcomes, and conducting the study in a single publicly funded health region.

In summary, the researchers said, “For hospitalized patients, the number of ICU beds available at the time of sudden clinical deterioration affects processes of care. As the number of available ICU beds decreases, patients are less likely to be admitted to the ICU and more likely to have their goals of care changed, although this does not seem to be associated with hospital mortality. This suggests that the development of validated ICU admission and discharge guidelines might improve hospital efficiency, without affecting outcomes.”