General Stroke Management and Stroke Units

Introduction

While most acute treatments could still be given to a limited number of patients with stroke, stroke unit care has the advantage of being suitable to almost all stroke patients. This chapter characterizes stroke unit care, including all aspects of general stroke management that can optimally be delivered in stroke units. There is strong evidence that treatment of patients with stroke in dedicated stroke units results in significantly lower rates of death, dependency, and the need for institutional care compared to treatment in general medical wards. Stroke units are key elements in the organized stroke care pathway, preceded by prehospital and hyperacute care and followed by rehabilitation. This chapter covers stroke care after a patient has received acute treatment and has been transferred to a stroke unit.

Stroke Unit Care

Organized care in the stroke unit reduces the rates of death or institutional care, and death or dependency. The most recent review of the Stroke Unit Trialists’ Collaboration working group, including 28 randomized controlled trials (RCT) involving 5855 patients from several countries, compared stroke unit care with alternative services. Stroke unit care significantly reduced the risk of death (odds ratio [OR], 0.76; confidence interval [CI], 0.66–0.88), death or dependency (OR, 0.80; CI, 0.67–0.97), and death or institutional care (OR, 0.76; CI, 0.67–0.86) without prolonging the length of stay in a hospital or institution, in up to 1 year of follow-up. These benefits were independent of patients’ age, sex, initial stroke severity, or stroke subtype (ischemic or hemorrhagic), and appeared to be better in stroke units based in a discrete ward. Patients with more severe strokes and those with hemorrhagic stroke seemed to benefit even more. Furthermore, these results were sustained at 5-year follow-up time points when available. The authors concluded that stroke patients who received organized inpatient care in a stroke unit were more likely to be alive, independent, and living at home 1 year after the stroke.

The target population of the stroke unit includes patients with ischemic stroke (IS), intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), transient ischemic attack (TIA), cerebral venous thrombosis (CVT), and subarachnoid hemorrhage (SAH). Some specific patient groups such as those with cerebral vasculitides, moyamoya vasculopathy, reversible cerebral vasoconstriction syndromes, posterior reversible encephalopathy syndrome, and post-carotid endarterectomy hyperperfusion syndrome may also benefit from stroke unit care even in the absence of a fresh stroke. Finally, patients presenting late should not be excluded from stroke unit care unless there are well-organized quick options such as outpatient stroke/TIA clinics performing necessary diagnostics, introducing therapeutics, and starting rehabilitation within 1–2 workdays.

General Stroke Management

The main goals of stroke care in a stroke unit are shown in Box 55.1 . Every patient with acute stroke, even with mild symptoms or with stable vital functions, must be recognized as an urgently ill medical patient. Even transitory, rapidly resolving, or fluctuating symptoms may be associated with a large vessel occlusion in patients with excellent collateral circulation. If the artery is not recanalized, the situation is likely to lead to expansion of the brain infarction and worsening of the patient’s clinical status over several hours. In some cases, hemodynamic ischemia may accentuate the symptoms, if the patient is dehydrated, hypotensive, or immediately mobilized without knowledge of the state of recanalization.

The decision where to treat the patient depends on local resources and the level of care and monitoring at the stroke unit: some stroke units have intensive care facilities, such as continuous arterial blood pressure (BP) monitoring, central venous catheters, mechanical ventilators, and continuous positive airway pressure ventilation. Endotracheal intubation is indicated for patients with reduced consciousness (generally when Glasgow Coma Scale score is ≤8 points), and controlled ventilation is needed for patients with spontaneous hypoventilation.

Reassess the Patient Medically and Neurologically

A quick evaluation of the patient upon arrival to the stroke unit ascertains any deteriorations, as the patients are most vulnerable during the earliest hours and days of their stroke. All stroke patients should undergo a stroke severity measurement (preferably with National Institutes of Health stroke scale [NIHSS]) and Glasgow Coma Scale. At the same time, necessary diagnostic tests, rehabilitation evaluations, and preventative measures can be ordered. Patient and family history may be collected in more detail at this point. Patients and relatives can briefly be informed of the situation and about the next steps. If the patient’s condition worsens, the cause must be quickly detected and corrected.

Ascertain Definite Stroke Diagnosis and Rule Out Stroke Mimics

Stroke mimics ( Box 55.2 ) are conditions where a nonstroke cause of the patient’s symptoms and signs is erroneously interpreted as a stroke. In studies, 5%–31% of emergency stroke presentations were eventually diagnosed as stroke mimics. In a study of 5581 intravenous (IV)-thrombolyzed patients, those presenting with stroke mimics (1.8%) were usually younger, more often females, and had more often vertebrobasilar-territory-like symptoms. Fortunately, serious complications following thrombolysis in stroke mimic patients are rare. Taken together from studies aiming to discriminating mimics from true strokes, two or three focal findings with abrupt onset best suggested a stroke, while the lack of these findings suggested mimic. Most stroke mimics can be diagnosed in the emergency setting with appropriate imaging and laboratory studies combined with clinical skills.

Strokes with atypical presentations that clinically appear to be caused by another disease are called chameleons. Among them are movement disorders (e.g., acute hemiballismus, limb-shaking TIAs), syncope, hypertensive crisis, systemic infections, altered mental status (psychosis, confusional states, and agitation), and suspected acute coronary syndrome. The case with chameleons may potentially be more severe than with mimics if treatable conditions are not correctly identified in established treatment time windows.

Imaging is the cornerstone of stroke diagnostics. Early imaging with computed tomography (CT) upon arrival will help in establishing a definite diagnosis in majority of IS patients and almost all hemorrhagic stroke patients. Structural abnormalities mimicking a stroke, such as tumors, can be grossly diagnosed by CT, especially if combined with contrast imaging. When magnetic resonance imaging (MRI) is used at the emergency room, only few IS patients will not demonstrate an acute ischemic diffusion-weighted imaging (DWI) lesion. MRI is superior to CT in diagnosing stroke mimics. Metabolic disorders mimicking stroke can usually be diagnosed with simple and quick blood tests. Patients who are considered candidates for recanalization therapies should follow the institutional shortcut imaging guidelines. In other cases, a comprehensive diagnostic imaging protocol with “one-stop” principle with a versatile sequence package of MRI and magnetic resonance angiography (MRA) is preferable.

Establish Stroke Etiology

Brain imaging reliably distinguishes between ischemic and hemorrhagic strokes and gives hints on their mechanisms. Ancillary tests and clinical data help in identifying stroke mechanisms in IS, e.g., artery-to-artery embolism from atherosclerotic plaques, cardiac embolism, paradoxical embolism, small-vessel occlusion, hypoperfusion, dissections, and other rare causes. Ancillary or repeat parenchymal imaging and vascular imaging aid in diagnosing underlying structural causes in ICH patients, such as arteriovenous malformation, cavernoma, moyamoya, reversible cerebral vasoconstriction syndrome, and CVT, or presence of aneurysm(s) in SAH.

Etiologic stroke classification is an integral part of individual patient care and stroke research. The benefits of precise etiologic classification are manifold: (1) it necessitates a systematic comprehensive search for pathologies, mechanisms, and risk factors underlying stroke, (2) guides treatment choices and risk factor management, (3) helps in estimating outcomes and recurrence rates, (4) allows for correct statistics and epidemiologic studies, (5) helps in recording correct diagnosis in discharge notes (using ICD-codes where possible), (6) sometimes leads to extending diagnostic studies to family members (e.g., in monogenic disorders), (7) detects correct patients for ongoing or future studies, (8) serves for developing new diagnostic tests and biomarkers, and (9) allows clear-cut phenotype descriptions that may help in phenotype–genotype analyses for detecting potentially underlying genetic factors.

There are several classification systems for IS, such as Trial of ORG 10172 in Acute Stroke Treatment (TOAST), Causative Classification System (CCS), and ASCOD (A for Atherosclerosis; S for Small-vessel disease, C for Cardiac pathology, O for Other causes, and D for Dissection), with TOAST being the most commonly used. SAH is usually classified simply into aneurysmal and non-aneurysmal, which determines interventive treatments and informs on recurrence risks. Instead, there is a shortage of classification systems in ICH, reflecting the difficulty of developing one. The SMASH-U (S for Structural, M for Medication-related, A for Amyloid angiopathy-caused, S for Systemic disease-related, H for Hypertensive, U for Undetermined) may be a useful tool, as it is also a prognostic classification system, but has still-limited validation in external cohorts. ^, Another recently introduced ICH classification, the H-ATOMIC (H for hypertension, A for cerebral Amyloid angiopathy, T for Tumor, O for Oral anticoagulants, M for vascular Malformation, I for Infrequent causes, and C for Cryptogenic) was compared with SMASH-U, both showing high intra-rater and inter-rater reliability, albeit discrepancies were frequent between the two systems.

Achieve and Maintain Vital Functions Within or Close to Physiologic Ranges (Homeostasis)

Vital functions of a patient with acute stroke should be stabilized in the emergency department. For a patient with decreased consciousness or in whom airway (e.g., due to bulbar dysfunction), breathing, or cardiovascular function (the ABCs) is compromised, intensive care facilities are used until the clinical situation is stable. Supplemental oxygen should be delivered to keep oxygen saturation ≥95%.

Automated monitoring of physiologic parameters (a minimum of ECG, pulse, respiratory rate, arterial BP, oxygen saturation, and body temperature, intermittent monitoring of blood glucose and NIHSS score) in the acute phase improves the outcome of stroke patients and is strongly recommended, especially during the first days. The length of monitoring should be adapted according to individual needs.

One monitored stroke unit bed is recommended for each 100 stroke admissions, as the average stay on monitoring is approximately 72 hours. Although size of units and patient volumes differ greatly depending on many factors, a minimum of four monitored beds is suitable and cost-effective, with a minimum of 200 patient admissions annually allowing for accumulation of knowledge and development of effective patient pathways.

Close monitoring of acute stroke patients is essential for detecting any deteriorations and for timely diagnosis of a number of life-threatening conditions. Furthermore, one or several days of cardiac monitoring may disclose acute myocardial infarction as well as previously undiagnosed atrial fibrillation. Close monitoring in a stroke unit includes 24/7 presence of a nurse in the same observation room with direct visual contact, frequent automated measurements of BP (continuous online measurement with intra-arterial line in selected patients), continuous ECG, pulse, respiratory rate, and oxygen saturation monitoring on a large and visible monitor, and blood sugar measurements a few times a day. If a temperature-probe urinary catheter is inserted, core temperature can be monitored online; otherwise it can be frequently measured by various methods. All monitored parameters should preferably be saved continuously into electronic medical records systems.