Background: Mobile stroke units (MSU) can speed treatment with intravenous tissue plasminogen activator (tPA) for stroke patients. MSUs may use either an on-board (OB) or telemedicine (TM) based vascular neurologist (VN) for deciding tPA treatment. In the first phase of this study, we showed that agreement on giving tPA between a TM and OB-VN on a MSU is the same as between two VNs evaluating the same patient on site in the emergency department. In that phase, the actual treatment was determined by the OB-VN so that the TM-VN decision was delayed. In this phase, we determined the time from MSU arrival to tPA treatment decision and treatment when the TM-VN was the primary decision-maker and compared these to the same metrics for the OB-VN in the first phase.
Methods: After MSU arrival on-scene, with the assistance of the OB nurse and paramedic, the TM-VN directed the evaluation of the patient, the CT scan was directly pushed to the TM-VN via a cloud-based picture archiving and communication system, and the TM-VN made the decision whether or not to treat. Times from MSU arrival to tPA decision and tPA bolus were compared to the same metrics for the OB-VN during the first phase of the study using a 2-sample t-test with log-transformation to satisfy t-test assumptions. Median times and interquartile range (IQR) were calculated for each group (Table 1).
Results: The TM-VN was, on average, 3 minutes slower in making the tPA decision compared with the OB-VN (OB: 18 minutes [IQR 14-23] versus TM: 21 minutes [IQR 16-26], p=0.05). There was no difference however, in the time to tPA bolus between the two groups [OB: 23 minutes (IQR 19-30) versus TM: 24 minutes (IQR 19-28), p=0.70, with 95% confidence interval [-2.18-3.24].
Conclusion: A telemedicine based VN can treat a patient with tPA on a MSU as quickly as an on-board VN.