超急性期脳梗塞におけるｒｔ‐ＰＡ静注療法適応について―後ろ向き検討によるシミュレーション―

Abstract

Background and Purpose:Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) within 3 hours after onset of cerebral ischemia was approved in Japan in October 2005. Preceding using rt-PA for acute cerebral infarction, we built a simulation model of patient flow using inpatient data and clarified issues of in-hospital systems.Methods:We retrospectively analyzed consecutive 485 patients with acute ischemic stroke admitted in our center from May 2002 to October 2005. We analyzed the patients who arrived at our center within 120 minutes after the onset, because at least 60 minutes by the admission will be required for evaluating of patient status and informed consent. We estimate the ratio of patients who fulfilled inclusion criteria for intravenous administration of rt-PA in the patients with acute ischemic stroke. We also assessed interval from the arrival to the admission in these patients and factors related to the interval.Results:There were 148 patients (30.5%) who arrived at our center within 120 minutes after the onset of symptoms. There were 94 men and 54 women. Age was 73.9±10.0 years-old (Mean±SD). The time from the onset to the arrival was 78.8±39.8 minutes. Baseline National Institutes of Health Stroke Scale (NIHSS) was 12.4±9.6. In these patients, only 32 patients (21.6%) fulfilled criteria for the inclusion prior to the admission. The remaining patients were excluded due to the following reasons:unknown onset time, 55; regression of symptoms, 11; mild symptom (NIHSS54), 47; history of intracranial hemorrhage, 3;convulsion, 3; extensive early CT sign, 35 and other reasons, 8. In the included 32 patients, five patients needed more than 180 minutes from the onset to the admission. Finally, 27 patients (5.6% in the all patients) admitted within 180 minutes after the onset and fulfilled the inclusion criteria. In 148 patients, 81 patients were not admitted within 60 minutes after the arrival. Sixty-seven patients were admitted within 60 minutes after the arrival and had significant higher NIHSS than those admitted more than 60 minutes. Age, referral hospital, ambulance or arrival time was not significant factor for the interval from the arrival to the admission.Conclusion: We estimated the candidate for acute thrombolysis using intravenous rt-PA to be 5.6% of total patients with acute ischemic stroke. Patient evaluation frequently required more than 60 minutes prior to the admission, even if the patients arrived at our center within 120 minutes after the onset. We should establish the in-hospital system to reduce the time for patient evaluation.