Effect of Emergency Department and ICU Occupancy on Admission Decisions and Outcomes for Critically Ill Patients :

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e163">Objectives</h5> <p id="P1">Intensive Care Unit (ICU) admission delays can negatively affect patient outcomes, but Emergency Department (ED) volume and boarding times may also affect these decisions and associated patient outcomes. We sought to investigate the effect of ED and ICU capacity strain on ICU admission decisions, and to examine the effect of ED boarding time of critically ill patients on in-hospital mortality. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e168">Design</h5> <p id="P2">Retrospective cohort study</p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e173">Setting</h5> <p id="P3">Single academic tertiary care hospital.</p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e178">Patients</h5> <p id="P4">Adult critically ill ED patients for whom a consult for Medical ICU admission was requested, over a 21-month period. </p> </div><div class="section"> <a class="named-anchor" id="S5"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e183">Interventions</h5> <p id="P5">None.</p> </div><div class="section"> <a class="named-anchor" id="S6"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e188">Measurements and Main Results</h5> <p id="P6">Patient data, including severity of illness (Mortality Probability Model on admission (MPM ₀-III)) and outcomes of mortality and persistent organ dysfunction (POD+D), as well as hourly census reports for the ED, for all ICUs and all adult wards were compiled. A total of 854 ED requests for ICU admission were logged, with 455 (53.3%) as “Accept” and 399 (46.7%) as “Deny” cases, with median ED boarding times 4.2 (IQR=2.8, 6.3) and 11.7 (3.2, 20.3) hours and similar rates of POD+D 41.5% and 44.6%, respectively. Those accepted were younger (mean±SD: 61±17 vs. 65±18 years) and more severely ill (median MPM ₀-III score= 15.3% (7.0, 29.5) vs. 13.4 (6.3, 25.2)) than those denied admission. In the multivariable model, a full Medical ICU was the only hospital-level factor significantly associated with a lower probability of ICU acceptance (OR 0.55 (95%CI: 0.37, 0.81). Using propensity score analysis to account for imbalances in baseline characteristics between those accepted or denied for ICU admission, longer ED boarding time post consult was associated with higher odds of POD+D (OR 1.77 (1.07, 2.95) per log10 hour increase). </p> </div><div class="section"> <a class="named-anchor" id="S7"> <!-- named anchor --> </a> <h5 class="section-title" id="d3182484e199">Conclusions</h5> <p id="P7">ICU admission decisions for critically ill ED patients are affected by Medical ICU bed availability, though higher ED volume and other ICU occupancy did not play a role. Prolonged ED boarding times were associated worse patient outcomes, suggesting a need for improved throughput and targeted care for patients awaiting ICU admission. </p> </div>