"Mobile Stroke-Unit" for Reduction of the Response Time in Ischemic Stroke
Condition: Stroke
MeSH terms: Stroke; Ischemic Stroke
Study type: Interventional

Summary: 
      Stroke, the most common cause of permanent disability, the second most common cause of
      dementia and third most common cause of death, has tremendous socio-economic consequences.

      Currently, systemic thrombolysis with the tissue plasminogen activator represents the only
      causal and approved treatment for acute ischemic stroke. However, the chances to save the
      brain tissue by a thrombolytic therapy exponentially decrease with proceeding time after
      onset of symptoms.

      In most cases, the beginning of the thrombolysis therapy is delayed by a variety of factors,
      like delivery to the hospital, re-examinations and delay of blood analysis or of CT scans.
      Due to this, a thrombolytic therapy is possible only in a minority of the stroke patients
      (2-5 %). The aim of this study is to investigate whether a "Mobile Stroke Unit", a rescue car
      with an integrated CT scanner, necessary for essential diagnostics, contributes to a better
      stroke management by saving precious time until a therapeutic decision is made. The trial is
      planned as a monocentric, randomised prospective trial.
    

Detailed description: 
      Stroke is the most common cause of permanent disability, the second most common cause of
      dementia and the third most common cause of death in elderly in industrialized countries.
      Approximately 85 % of all strokes are due to cerebral ischemia, whereas 15% are due to
      cerebral hemorrhage. In 1998, over 600.000 new strokes occurred within the European Union.
      Since the incidence of stroke is strongly age-related, the number of stroke victims is
      expected to increase substantially over the next decades as the proportion of the subjects
      older than 70 is estimated to grow from about 13 % to 20 % (Wahlgren 2001; The European
      stroke initiative, 2000). Within the next 8 years the yearly direct costs for stroke can be
      estimated to about 27 billion € only in Germany (Kolominsky-Rabas et al., 2006). Due to the
      increased incidence in the future, these costs are expected to increase by about 10 - 15 %
      within the next 10 years.

      The main causes of ischemic stroke are thromboembolic occlusion of cerebral vessels by
      embolism of the heart or of the brain feeding arteries. This occlusion of a cerebral artery
      leads to an immediate drop of the blood flow in the corresponding arterial territory. This
      reduced blood flow leads to the known neurological symptoms of the affected brain area.

      Animal experiments show that a massive cellular death occurs within minutes after the
      occlusion of an intracerebral artery in the centre of the ischemic lesion (infarction core).
      The region surrounding this area (penumbra) is at high risk by a functionally reduced blood
      flow. By improving the blood flow, this area could potentially be rescued and therefore
      represents the focus of every stroke therapy. Aggravatingly, the first irreversible cellular
      death in the penumbra starts as early as 30 minutes to 1 hour after stroke onset (Astrup et
      al., 1981; Heiss et al., 1983; Garcia et al., 1995; Watanabe et al., 1977; Siesjo et al.,
      1992; Hossmann 1994; Hu et al., 2001). Based on these data, a causal therapy of ischemic
      stroke appears only possible, if the cerebral blood flow is re-established within the very
      first hours after symptom onset (Dyker et al., 1998; Kasner et al., 1997; Adams et al., 1996;
      Brott et al., 1992; Del Zoppo et al., 1996; Zivin, 1998).

      Currently, systemic thrombolysis with the recombinant tissue plasminogen activator (rt-PA),
      which is approved in Germany since 2000, represents the first evidence-based and the only
      causal treatment for acute ischemic stroke. The therapy should be performed as early as
      possible to minimize the cerebral injury and to avoid complications (i.e., hemorrhagie).
      Treatment with rt-PA has been studied in 6 large randomized placebo-controlled multi-centre
      studies (The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study
      Group, 1995; Hacke et al. 1995; Hacke et al., 1998; Clark et al., 2000). Meta-analysis of
      these studies showed that a thrombolytic therapy within the first 3 hours results in a
      significant reduction of disability or death (Hacke et al., 1998; 2004).

      The chances to save the brain tissue by a thrombolytic therapy exponentially decrease with
      passing time. In most cases, the patient is examined by an emergency physician, but the
      beginning of the final thrombolysis therapy is delayed by a variety of factors, like delivery
      to the hospital, neurologist re-examinations, and delay in blood analysis or CT scan.

      Due to this, a therapy decision is possible within the first 3 hours only in a minority of
      the stroke patients. This contributes to the low lysis rate of only 4-7 % of all stroke
      patients.

      The odds ratio (OR) of a favourable 3-month outcome of stroke therapy converges against 1 in
      the first 4 hours in favour of the rt-PA group (Hacke et al., 2004). Meta-analyses
      demonstrate that a reduction of time until the beginning of the thrombolytic therapy has the
      best potential to reduce the disabling effects of a stroke.

      The rational of this study is to investigate whether a "Mobile Stroke Unit" contributes to a
      better stroke management by saving precious time until a therapeutic decision is made,
      according to the concept "time is brain".
    

Intervention name(s): MSU; OCCM
Intervention type(s): Procedure; Procedure
Intervention description(s): In the "Mobile Stroke Unit" procedure: Conventional Emergency Medical Service together with the MSU will meet at the side, where the patient is found. The MSU is an ambulance, equipped with a neurologist and neuroradiologist and includes CT scanner and point of care laboratory unit. The patient's medical history and the physical examination will be directly performed by the neurologist. CT scan analysis will be performed by the neuroradiologist, while the neurologist will analyze the blood samples with the point of care laboratory unit. If the inclusion and exclusion criteria are fulfilled, the thrombolytic therapy will directly be started by the neurologist. A possible thrombolytic therapy will be performed under the current inclusion and exclusion criteria that are associated with the rt-PA drug approval in Europe. After performance of the acute therapy, the patient will be transported to the University Hospital of the Saarland.; In the optimized conventional clinical management: After patient's medical history, physical examination and emergency treatment by the emergency physician, the patient will be transported to the University Hospital of the Saarland. The delivery of the patient will directly take place at the CT scanner. The neurologist will perform a second medical history, physical examination, while the blood will be drawn by the assisting nurse. CT scan will be performed, while the blood will be analyzed by point of care technique, placed close to the CT scanner. Additionally the blood will be sent in parallel to the hospital central laboratory for conventional laboratory analysis. Depending on the results, a thrombolytic therapy will be initiated directly at the CT. Thereafter, the patient will be transported to the hospital Stroke Unit.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Health Services Research
Keywords: stroke; mobile stroke unit; thrombolysis; stroke management; computerized tomography