Abstract 355: Performance of Inclusion and Exclusion Criteria Based on Prognosis in an Interventional Out-of-Hospital Cardiac Arrest Study

Abstract

Introduction: Selection of out-of-hospital cardiac arrest (OHCA) patients for inclusion in randomized control trials (RCT) presents a challenge. The goal is to enroll patients with severe injury warranting intervention yet exclude those with extreme irreversible disease. Selection early after return of spontaneous circulation (ROSC) is complicated by a relative paucity of prognostic variables. We examined the accuracy of enrollment criteria in the iNO OHCA study (NCT03079102) in excluding patients likely to have good or poor outcomes within three hours (3h) of ROSC. Methods: OHCA patients arriving to two tertiary care centers in Pittsburgh were screened within 3h of ROSC. We excluded subjects that followed commands (good prognosis expected) and subjects expected to have poor prognosis based on: Full Outline of UnResponsiveness Brainstem (FOUR B) score <2; CPR time >40 min; investigator estimate of >95% mortality; CT evidence of cerebral edema or intracranial hemorrhage; clinical evidence of myoclonic status epilepticus; or traumatic OHCA etiology. We also excluded subjects not within 3h of ROSC. We compared discharge survival and good neurologic outcome based on disposition (location). Results: Over a nine-month period we screened 155 patients with ROSC following OHCA, 20 subjects (13%) were included in the study and 135 (87%) were excluded ( Table ). The odds ratio (OR) of survival if excluded for poor prognosis was 0.03 (95% CI: 0.01 - 0.08) and worsened when >1 criteria were met. Exclusion for good prognosis was associated with improved survival (OR = 67.2 [95% CI: 14.3 - 316.3]). Conclusions: Our criteria reliably exclude OHCA subjects with good or poor prognosis within 3h of ROSC, yielding a study population with intermediate survival which can be applicable to future OHCA trials. Our criteria selected a minority (13%) of OHCA patients likely to benefit from intervention while reserving resources.