The hybrid emergency room (ER) system can provide resuscitation, computed tomography imaging, endovascular treatment, and emergency surgery, without transferring the patient. However, although several reports have demonstrated the effectiveness of the hybrid ER for trauma conditions, only a few case reports have demonstrated its usefulness for non-traumatic critical diseases. In this observational cohort study, we aimed to identify endogenous diseases that may benefit from treatment in the hybrid ER.

We retrospectively reviewed the clinical characteristics of patients with non-traumatic conditions treated in a hybrid ER between August 2017 and July 2022 at our institution. Patients who underwent surgery, endoscopy, or interventional radiology (IR) in the hybrid ER were selected and pathophysiologically divided into a bleeding and non-bleeding group. The rate of shock or cardiac arrest, blood transfusion, and death within 24 h of admission or in-hospital death were compared among the groups using Fisher's exact test. Multivariable logistic regression analysis was performed to confirm the relationships among in-hospital mortality, transfusion, and hemorrhagic conditions in patients who underwent endoscopy and IR.

Among the 726 patients with non-traumatic conditions treated in a hybrid ER system, 50 (6.9%) experienced cardiac arrest at or before admission to the hybrid ER, 301 (41.5%) were in shock, 126 (17.4%) received blood transfusions, 42 (5.8%) died within 24 h of admission to the hybrid ER, and 141 (19.4%) died in the hospital. Emergency surgery was performed in 39 patients (7 in the bleeding group and 32 in the non-bleeding group). Significantly more blood transfusions were administered in the bleeding group (71.4% vs. 18.8%, P = 0.01); there were no significant differences in the rate of shock or cardiac arrest, death within 24 h, or in-hospital death between groups. Endoscopy was performed in 122 patients (80 in the bleeding group and 42 in the non-bleeding group). The bleeding group had a significantly higher rate of shock or cardiac arrest (87.5% vs. 66.7%, P = 0.008) and rate of blood transfusion (62.5% vs. 4.8%, P < 0.0001); there was no significant difference in death within 24 h and in-hospital death between groups. IR was performed in 100 patients (68 in the bleeding group and 32 in the non-bleeding group). Significantly more blood transfusions were administered in the hemorrhage group (67.7% vs. 12.5%, P < 0.0001); there was no difference in the rate of shock or cardiac arrest, death within 24 h, or in-hospital death between groups. Multivariable analysis in patients who underwent endoscopy showed a trend toward more in-hospital deaths in non-hemorrhagic conditions than in hemorrhagic conditions (odds ratio = 3.8, 95% confidence interval: 0.88–17, P = 0.073); however, no significant relationship with in-hospital death was observed for any of the adjusted variables.

Among endogenous diseases treated in the hybrid ER, there is a possible association between in-hospital mortality and hemorrhagic conditions. Future studies are needed to focus on diseases to demonstrate the effectiveness of the hybrid ER.