What is the impact of prolonged emergency department (ED) length of stay (LOS), particularly ED-to-ICU time (from ED admission to ICU admission) and ED-boarding time (time between ICU admission decision and transfer), on hospital outcomes? Studies suggest prolonged ED-to-ICU times may increase ICU and hospital mortality, though findings are mixed.
Some EDs have reduced mortality by integrating ICU beds. However, an Australasian study found no significant link between ED-to-ICU time and mortality, possibly due to methodological limitations. A 2019 study showed prolonged ED-to-ICU times increased mortality, especially for patients with high APACHE-IV probability scores. Critiques questioned the use of APACHE-IV scores, which might reflect treatment effects during ED stays or act as mediators rather than confounders. The study revealed a shift from a favourable to an unfavourable association between ED-to-ICU time and mortality after adjusting for APACHE-IV probability, supporting its use as an early indicator of clinical condition.
To address these concerns, a larger retrospective study was conducted, stratifying by hospital type (academic vs. nonacademic) and using the ED-triage score as a potentially earlier and more relevant measure of illness severity compared to the APACHE-IV probability.
The study analysed data from the Dutch National Intensive Care Evaluation registry (2009–2020), focusing on patients directly admitted from the ED to the ICU across four academic and eight non-academic teaching hospitals. Using multivariable regression, the researchers estimated odds ratios (ORs) for mortality associated with ED-to-ICU time. The study included 28,455 patients with a median ED-to-ICU time of 1.9 hours.
No significant association was found between ED-to-ICU time and hospital mortality after adjusting for APACHE-IV probability. Among patients with an APACHE-IV probability >55.4% and ED-to-ICU times >3.4 hours, the adjusted odds ratio for mortality was 1.24 compared to those with ED-to-ICU times <1.1 hours. Adjusted ORs for increasing ED-to-ICU times were significantly higher for ED-to-ICU times of 1.6–2.3 hours, 2.3–3.4 hours and >3.4 hours using APACHE-IV adjustments. After adjusting for ED-triage scores, the OR for times >3.4 hours was 0.98. No significant associations were observed with APACHE-IV adjustments. After adjusting for ED-triage scores, all ORs were <1.0 for increasing ED-to-ICU times.
Overall, prolonged ED-to-ICU times had different impacts on mortality across hospital types and patient severity, highlighting the complexity of these associations. In academic hospitals, prolonged ED-to-ICU time was linked to increased hospital mortality in patients with the highest APACHE-IV probability. No significant or consistent unfavourable associations were observed in lower-risk groups or in nonacademic teaching hospitals. After adjusting and stratifying by ED-triage scores, the association between longer ED-to-ICU times and higher mortality was no longer evident.
Source: Critical Care Medicine
Image Credit: iStock
