Effects of a Physician-Staffed Helicopter Emergency Medical Service on Cerebral Infarction Outcomes: A Registry-Based Observational Study

Abstract

Background: The effects of helicopter emergency medical services on the treatment of cerebral infarction remains unclear. We investigated the effects of helicopter transport on outcomes in patients with cerebral infarction. Methods: This study included 1,246 patients with cerebral infarction who were assigned to two groups: patients transported by "Doctor-Heli" (DH group) and patients transported by ground ambulances (GA group). Cerebral performance category (CPC), overall performance category (OPC), and in-hospital mortality were evaluated. Multivariate logistic regression analysis was used to adjust for background factors and evaluate a subgroup of patients with severe cerebral infarction (i.e., a National Institutes of Health Stroke Scale (NIHSS) score >10). Results: The DH group included more patients with severe cerebral infarction. No difference was observed in the interval from illness onset to recombinant tissue plasminogen activator treatment between the groups; however, the interval from illness onset to interventional radiology (IR) was significantly shorter in the DH group. The DH group had a lower CPC than the GA group, but there was no significant difference in OPC. Multivariate logistic regression analysis showed that the odds ratio of DH transport for OPC1-2 was 2.33. Subgroup analysis of severe cases yielded odds ratios of 2.19 and 2.62 for CPC1-2 and OPC1-2 respectively. Conclusion: The DH group included patients with severe cerebral infarction living in remote areas and provided with emergency IR treatment. This analysis suggested that DH transport improves OPC and CPC, particularly in patients with an NIHSS scores of >10.