Abstract Sat506: The efficacy of New Protocol for Out-of-hospital Cardiac Arrest Patients with “do not attempt resuscitation” orders in Japan

Background: In Japan, emergency medical technicians (EMTs) are not permitted to terminate resuscitation for patients with out-of-hospital cardiac arrest (OHCA), even if the patient has a do-not-attempt-resuscitation (DNAR) order. To address this issue, a new protocol allowing EMTs to terminate resuscitation for OHCA patients with DNAR orders has been implemented. However, the effectiveness of this DNAR protocol remains unclear. Methods: We conducted a population-based analysis in Kobe, Japan, to investigate the current situation about DNAR and assess whether the newly introduced DNAR protocol reduces EMS activity time and the use of medical resources, based on emergency medical system records. The primary outcome was the duration of various EMT activities, including the time from call to dispatch, dispatch to departure from the scene, and call to return to the local department. Secondary outcomes included the proportion of medical interventions such as advanced airway placement, intravenous access, adrenaline administration, and defibrillation. Results: Of 2,023 OHCA cases, 1,686 cases were included in the analysis (93 in the DNAR group and 1,593 in the non-DNAR group). EMT activity time was not shorter in the DNAR group [96 minutes (IQR: 78–117) vs. 83.5 minutes (IQR: 69–98); p <0.01]. However, when termination of resuscitation was successfully completed, the time from dispatch to return to the local department was reduced [87 minutes (IQR: 68.5–107) vs. 79 minutes (63–97); p=0.04]. The proportion of defibrillation did not significantly differ between the groups [13.3% (211/1,593) vs. 11.7% (11/93); p =0.67]. In contrast, the use of advanced airway devices [66.3% (1,056/1,593) vs. 13.8% (13/93); p <0.01], intravenous access [54.1% (861/1,593) vs. 5.3% (5/93); p <0.01], and adrenaline administration [24.4% (388/1,593) vs. 2.1% (2/93); p <0.01] was significantly higher in the non-DNAR group. Conclusions: The DNAR protocol is effective in reducing EMS activity time when termination of resuscitation is successfully carried out. Otherwise, EMS activity duration is not shortened. The use of medical resources for prehospital care differ significantly between the two groups except for defibrillation.