Do ED-ICU’s Do…Anything?

Critically-ill patients are typically admitted through the Emergency Department (ED). In a perfect world, these patients would be admitted directly to the ICU where their hypotension would be immediately addressed, sepsis immediately treated with antibiotics, their GI bleed rapidly managed with transfusion and emergent endoscopy. The world, however, is far from perfect and critically-ill patients  admitted to the ICU will typically wait in the ED due to a lack of space in the ICU. These patients may wait hours and studies have shown that boarding in the ED for more than 6 hours has been associated with worse outcomes. There are also increased costs and resource utilization while patients are boarding in the ED.

Several EDs have attempted to address these issues by creating ICU’s within the ED. These models staff physicians with additional training in critical care or resuscitation, have 1:2 nurse to patient ratios, and less volume than the main ED for a more focused approach to care. While these ED-ICU models make logistical sense, there is little patient-centered data supporting their use. The authors of this study wanted to change that.

What did they do?

Gunnerson, et al. conducted a before and after study at a large (75,000 visits/year) academic center. They retrospectively analyzed prospectively collected data before the institution of an ED-ICU. This unit consisted of 5 resuscitation / trauma bays and 9 patient rooms located adjacent to the main ED. The ED-ICU team consisted of a multi-disciplinary team consisting of physicians, residents and fellows, critical care physician assistants, ED nurses, respiratory therapists, and pharmacists. The nurse to patient ratio was 1:2 consistent with current standards in ICU level care. 

All patients in the study were initially evaluated and treated by the main ED team and were subsequently transferred to the ED-ICU for continued patient care and monitoring. The most common diagnoses for admission to the ED-ICU were severe sepsis and shock, severe electrolyte disturbances, altered mental status, diabetic ketoacidosis, undifferentiated hypotension, congestive heart failure, respiratory failure and GI bleeding. 

What did they find?

The primary outcome was 30-day mortality and there was a statistically significant reduction in mortality by 15.4%. The odds of mortality were also reduced when analyzed for patients with an emergency severity index (ESI) score of 1 and 2 (i.e., more severe illness). Further statistical analysis revealed that the implementation of the ED-ICU resulted in 220 lives saved per year, this is a number needed to treat of 333 patient encounters (or approximately 3 lives saved per 1000 ED visits. It was also observed that after implementation of the ED-ICU there was a reduction of 24-hour and overall hospital mortality. ED admissions to the ICU were also reduced by 12.9% after the implementation of the ED-ICU. Finally, it was noted that admissions to the ICU from non-ICU floors were reduced after the introduction of the ED-ICU, a statistically significant reduction. 

What should we take away from this?

This single-center before and after trial of an ED-ICU model demonstrated reductions in both mortality and ICU admissions for patients presenting to this Emergency Department. This lead to better ICU utilization and less admissions to the ICU from non-ICU wards in the hospital. These observations were observed during a period where ED volumes were actually increasing. This study has many important implications for US health-care as ED acuity is increasing with a simultaneous reduction in ICU resources. ED-ICUs have the potential to reduce ICU boarding times in the ED (i.e., ≥6hours) which, have been associated with an increased morbidity and mortality.  Although this ED-ICU model is not a new one, this is the first known study to demonstrate these patient-centered outcomes. This study also revealed that critically ill patients could be stabilized and downgraded to the medical floor without an increase in admission to the ICU; this could reduce utilization of ICU resources. This ED-ICU model is unique as it utilized multi-disciplinary specialists including Emergency Medicine providers as part of their ICU staff. Despite the many positive effects demonstrated, a few limitations of this study should be pointed out. First, this was a before and after study at a single-center, so generalizability to other types of hospitals should be limited until there is further study. A second limitation was that the statistical analysis of their 30-day mortality may have been limited because patients whose mortality was unknown to the investigators were assumed to be alive when analyzing the data; this may have skewed their results.  A third limitation was the introduction of a new electronic medical record during their study period. This may have affected risk-adjusted mortality rates before the ED-ICU period was started. Finally, the authors attempted to control for all variables during the pre- and post-ED-ICU period but there may have been other variables that were not considered. Despite these limitations, this study provides novel evidence that an ED-ICU may help with many problems when critically-ill patients are admitted and board in the Emergency Department.