Safety of intravenous thrombolytic use in four emergency departments without acute stroke teams

Abstract

Objectives: The objective was to evaluate safety of intravenous (IV) tissue plasminogen activator (tPA) delivered without dedicated thrombolytic stroke teams.

Methods: This was a retrospective, observational study of patients treated between 1996 and 2005 at four southeastern Michigan hospital emergency departments (EDs) with a prospectively defined comparison to the National Institute of Neurological Disorders and Stroke (NINDS) tPA stroke study cohort. Main outcome measures were mortality, intracerebral hemorrhage (ICH), systemic hemorrhage, neurologic recovery, and guideline violations.

Results: A total of 273 consecutive stroke patients were treated by 95 emergency physicians (EPs) using guidelines and local neurology resources. One-year mortality was 27.8%. Unadjusted Cox model relative risk (RR) of mortality compared to the NINDS tPA treatment and placebo groups was 1.20 (95% confidence interval [CI] = 0.87 to 1.64) and 1.04 (95% CI = 0.76 to 1.41), respectively. The rate of significant ICH by computed tomography (CT) criteria was 6.6% (odds ratio [OR] = 1.03, 95% CI = 0.56 to 1.90 compared to the NINDS tPA treatment group). The proportions of symptomatic ICH by two other prespecified sets of clinical criteria were 4.8 and 7.0%. The rate of any ICH within 36 hours of treatment was 9.9% (RR = 0.94, 95% CI = 0.58 to 1.51 compared to the NINDS tPA group). The occurrence of major systemic hemorrhage (requiring transfusion) was 1.1%. Functional recovery by the modified Rankin Scale score (mRS = 0 to 2) at discharge occurred in 38% of patients with a premorbid disability mRS < 2. Guideline deviations occurred in the ED in 26% of patients and in 25% of patients following admission.

Conclusions: In these EDs there was no evidence of increased risk with respect to mortality, ICH, systemic hemorrhage, or worsened functional outcome when tPA was administered without dedicated thrombolytic stroke teams. Additional effort is needed to improve guideline compliance.

© 2010 by the Society for Academic Emergency Medicine.

Figures

Figure 1. Patient Characteristics

1A. Distribution of the National Institutes of Health Stroke Scale (NIHSS) scores 1B. Distribution of time from stroke onset to treatment

Figure 2. Patient Outcomes

2A. Survival curves for study and National Institute of Neurological Disorders and Stroke (NINDS) cohorts 2B. Functional outcomes for study and NINDS cohorts* * Distribution of discharge (mean 8 days) modified Rankin scores in the study cohort compared to those measured at 7–10 days in the NINDS trial. Excludes subjects in all cohorts with pre-stroke mRS > 1. Includes all NINDS subjects treated at 91 – 180 minutes (one tPA and three placebo treated patients excluded from NINDS groups due to missing data).