Blood pressure during the first minutes of focal cerebral ischemia

Blood Pressure Management in Acute Ischemic Stroke

PURPOSE OF REVIEW

Abrupt blood pressure (BP) rise is the most common clinical symptom of acute ischemic stroke (AIS). However, BP alterations during AIS reflect many diverse mechanisms, both stroke-related and nonspecific epiphenomena, which change over time and across patients. While extremes of BP as well as high BP variability have been related with worse outcomes in observational studies, optimal BP management after AIS remains challenging.

RECENT FINDINGS

This review discusses the complexity of the factors linking BP changes to the clinical outcomes of patients with AIS, depending on the treatment strategy and local vessel status and, in particular, the degree of reperfusion achieved. The evidence for possible additional clinical markers, including the presence of arterial hypertension, and comorbid organ dysfunction in individuals with AIS, as informative and helpful factors in therapeutic decision-making concerning BP will be reviewed, as well as recent data on neurovascular monitoring targeting person-specific local cerebral perfusion and metabolic demand, instead of the global traditional parameters (BP among others) alone. The individualization of BP management protocols based on a complex evaluation of the homeostatic response to focal cerebral ischemia, including but not limited to BP changes, may be a valuable novel goal proposed in AIS, but further trials are warranted.

Acute blood pressure levels and long-term outcome in ischemic stroke

OBJECTIVES

Elevated blood pressure (BP) is common in acute ischemic stroke, but its effect on outcome is not fully understood. We aimed to investigate the association of baseline BP and BP change within the first day after stroke with stroke severity, functional outcome, and mortality.

METHODS

Patients admitted to hospital with acute ischemic stroke (IS) from 15 February 2005 through 31 May 2009 were consecutively included. Acute stroke severity and functional outcome at three and twelve months were investigated using multivariate regression analysis; the association between BP and all-cause mortality at one, three, and twelve was investigated by Cox proportional hazard regression and Kaplan-Meier survival curves.

RESULTS

A total of 799 patients (mean age 78.4 ± 8.0, 48% men) were included. Higher decreases in systolic and mean arterial blood pressure (ΔSBP and ΔMAP) were associated with decreased 1-month mortality (ΔSBP: hazard ratio, HR: 0.981; 95% CI: 0.968 - 0.994; p = .005), 3-month mortality (ΔSBP: HR 0.989; 95% CI 0.981 - 0.998; p-value .014), and twelve-month mortality (ΔSBP: HR 0.989; 95% CI 0.982 - 0.996; p-value .003). Stroke severity was associated with ΔMAP (B coefficient -.46, p-value .011). Higher SBP and MAP on admission were associated with better functional outcome at three (SBP: OR 0.987; 95% CI 0.978 - 0.997; p-value .008 - MAP: OR 0.985; 95% CI 0.971 - 1; p-value .046) and twelve (SBP: OR 0.988; 95% CI 0.979 - 0.998; p-value .015 - MAP: OR 0.983; 95% CI 0.968 - 0.997; p-value .02) months.

CONCLUSION

In this elderly population, higher BP on arrival to the emergency room (ER) and decrease in BP after the patients' arrival to the ward were associated with improved functional outcome and reduced mortality, respectively. These results may reflect a regulatory situation in which elevated initial blood pressure indicates adequate response to cerebral tissue ischemia while subsequent blood pressure decrease instead may be a consequence of partial, successful reperfusion.

Acute Ischaemic Stroke: Management, Recent Advances and Controversies

Acute ischaemic stroke is a major cause of death and disability. It may become an enormous burden to the patients themselves, their families as well as the health care systems. Patients at risk of airway, breathing and circulatory compromise should receive prompt resuscitation. Vital parameters and neurological status should be closely monitored. Attentions to blood pressure, temperature and sugar profile are important. The significance of early and correct diagnosis and subsequent treatment cannot be over-emphasised. There have been tremendous recent advances in different treatment modalities in acute stroke management. Various recanalisation modalities include intravenous and/or intra-arterial thrombolysis, acute defibrinogenation, anti-platelet treatment and anticoagulation. Carotid endarterectomy and endovascular strategies are recommended in selected patients. Advanced neuro-imaging techniques and neuroprotectants are being evaluated. Multidisciplinary stroke teams have been shown to improve patient survival and functional outcome. Pre-defined algorithms and protocols should be in place to expedite smooth and effective delivery of stroke service. Future directions should be aimed at exploring safer recanalisation modalities and extending the limit of the current 3-hour treatment window for thrombolysis.

Relationship between Post-Thrombolysis Blood Pressure and Outcome in Acute Ischemic Stroke Patients Undergoing Thrombolysis Therapy

BACKGROUND

The management of blood pressure (BP) for acute ischemic stroke (AIS) patients undergoing thrombolysis is still under debate. The purpose of this study was (1) to explore the association between post-thrombolysis BP and functional outcome and (2) to examine whether post-thrombolysis BP can predict functional outcome in Chinese AIS patients undergoing thrombolysis therapy.

METHODS

From December 2012 to November 2016, AIS patients undergoing thrombolysis were reviewed retrospectively in the Department of Neurology at Xuanwu Hospital. The BP levels were measured before and immediately after thrombolysis. Clinical outcomes, which comprised favorable outcome (modified Rankin Scale score 0-2) and unfavorable outcome (modified Rankin Scale score 3-6) at 3 months, were analyzed by logistic regression model. A receiver operating characteristic curve was used to evaluate the predictive value of post-thrombolysis BP.

RESULTS

Patients with unfavorable outcome at 3 months had a higher post-thrombolysis systolic BP than those with favorable outcome (P = .015). Multivariate analysis showed that post-thrombolysis systolic BP below 159.5 mm Hg was associated with favorable outcome. According to the receiver operating characteristic curve, post-thrombolysis systolic BP was a predictor of functional outcome with an area under the curve of .573 (95% confidence interval = .504-.642).

CONCLUSIONS

Our study indicated that post-thrombolysis systolic BP is a predictor of functional outcome for Chinese AIS patients undergoing thrombolysis therapy. It is reasonable for AIS patients to keep post-thrombolysis systolic BP below 159.5 mm Hg to obtain a favorable outcome.

Prehospital systolic blood pressure is higher in acute stroke compared with stroke mimics

OBJECTIVE

To assess the natural history of prehospital blood pressure (BP) during emergency medical services (EMS) transport of suspected stroke and determine whether prehospital BP differs among types of patients with suspected stroke (ischemic stroke, TIA, intracerebral hemorrhage [ICH], or stroke mimic).

METHODS

A retrospective, cross-sectional, observational analysis of a centralized EMS database containing electronic records of patients transported by EMS to the emergency department (ED) with suspected stroke during an 18-month period was conducted. Hospital charts and neuroimaging were utilized to determine the final diagnosis (ischemic stroke, TIA, ICH, or stroke mimic).

RESULTS

A total of 960 patients were transported by EMS to ED with suspected stroke. Stroke was diagnosed in 544 patients (56.7%) (38.2% ischemic stroke, 12.2% TIA, 5.3% ICH) and 416 (43.2%) were considered mimics. Age-adjusted mean prehospital systolic BP (SBP) was higher in acute stroke patients (155.6 mm Hg; 95% confidence interval [CI]: 153.4-157.9 mm Hg) compared to mimics (146.1 mm Hg; 95% CI: 142.5-148.6 mm Hg; p < 0.001). Age-adjusted mean prehospital SBP was higher in ICH (172.3 mm Hg; 95% CI: 165.1-179.7 mm Hg) than in either ischemic stroke or TIA (154.7 mm Hg; 95% CI: 152.3-157.0 mm Hg; p < 0.001). Median (interquartile range) SBP drop from initial prehospital SBP to ED SBP was 4 mm Hg (-6 to 17 mm Hg). Mean prehospital SBP was strongly correlated with ED SBP (r = 0.82, p < 0.001).

CONCLUSIONS

Prehospital SBP is higher in acute stroke relative to stroke mimics and highest in ICH. Given the stability of BP between initial EMS and ED measurements, it may be reasonable to test the feasibility and safety of prehospital antihypertensive therapy in patients with suspected acute stroke.

Management of Acute Hypertensive Response in Patients With Ischemic Stroke

High blood pressure (BP) >140/90 mm Hg is seen in 75% of patients with acute ischemic stroke and in 80% of patients with acute intracerebral hemorrhages and is independently associated with poor functional outcome. While BP reduction in patients with chronic hypertension remains one of the most important factors in primary and secondary stroke prevention, the proper management strategy for acute hypertensive response within the first 72 hours of acute ischemic stroke has been a matter of debate. Recent guidelines recommend clinical trials to ascertain whether antihypertensive therapy in the acute phase of stroke is beneficial. This review summarizes the current data on acute hypertensive response or elevated BP management during the first 72 hours after an acute ischemic stroke. Based on the potential deleterious effect of lowering BP observed in some clinical trials in patients with acute ischemic stroke and because of the lack of convincing evidence to support acute BP lowering in those situations, aggressive BP reduction in patients presenting with acute ischemic stroke is currently not recommended. While the early use of angiotensin receptor antagonists may help reduce cardiovascular events, this benefit is not necessarily related to BP reduction.

Predictors of Inhospital Mortality in Geriatric Patients Presenting to the Emergency Department With Ischemic Stroke

AIM

To determine the most important predictors of inhospital mortality that could be assessed in geriatric patients presenting with ischemic stroke at admission to the emergency department(ED).

METHODS

A retrospective cohort study was carried out in geriatric patients with ischemic stroke who were diagnosed in the ED. The primary outcome measure was determined as all-cause inhospital mortality after 30 days of ischemic cerebrovascular event.

RESULTS

During the study period, 247 (35.7%) patients died in the hospital and 445 (64.3%) patients survived the 30-day period. The median age of the patients was 78 (72-83). Higher National Institutes of Health Stroke Scale (NIHSS) scores (odds ratio [OR]: 2.085; 95% confidence interval [CI]: 1.835-2.370), increased creatinine levels (OR: 2.002; 95% CI: 1.235-3.243), increased platelet levels (OR:1.006; 95% CI: 1.002-1.010), and hyperglycemia (OR: 2.610; 95% CI: 1.023-6.660) were found as independent predictors of inhospital mortality.

CONCLUSION

In evaluating geriatric patients with ischemic stroke, laboratory values including platelet count, creatinine levels, hyperglycemia, and NIHSS scores should be considered to predict inhospital mortality in the ED.

Acute post-stroke blood pressure relative to premorbid levels in intracerebral haemorrhage versus major ischaemic stroke: a population-based study

Background

It is often assumed that blood pressure increases acutely after major stroke, resulting in so-called post-stroke hypertension. In view of evidence that the risks and benefits of blood pressure-lowering treatment in acute stroke might differ between patients with major ischaemic stroke and those with primary intracerebral haemorrhage, we compared acute-phase and premorbid blood pressure levels in these two disorders.

Methods

In a population-based study in Oxfordshire, UK, we recruited all patients presenting with stroke between April 1, 2002, and March 31, 2012. We compared all acute-phase post-event blood pressure readings with premorbid readings from 10-year primary care records in all patients with acute major ischaemic stroke (National Institutes of Health Stroke Scale >3) versus those with acute intracerebral haemorrhage.

Findings

Of 653 consecutive eligible patients, premorbid and acute-phase blood pressure readings were available for 636 (97%) individuals. Premorbid blood pressure (total readings 13 244) had been measured on a median of 17 separate occasions per patient (IQR 8–31). In patients with ischaemic stroke, the first acute-phase systolic blood pressure was much lower than after intracerebral haemorrhage (158·5 mm Hg [SD 30·1] vs 189·8 mm Hg [38·5], p<0·0001; for patients not on antihypertensive treatment 159·2 mm Hg [27·8] vs 193·4 mm Hg [37·4], p<0·0001), was little higher than premorbid levels (increase of 10·6 mm Hg vs 10-year mean premorbid level), and decreased only slightly during the first 24 h (mean decrease from <90 min to 24 h 13·6 mm Hg). By contrast with findings in ischaemic stroke, the mean first systolic blood pressure after intracerebral haemorrhage was substantially higher than premorbid levels (mean increase of 40·7 mm Hg, p<0·0001) and fell substantially in the first 24 h (mean decrease of 41·1 mm Hg; p=0·0007 for difference from decrease in ischaemic stroke). Mean systolic blood pressure also increased steeply in the days and weeks before intracerebral haemorrhage (regression p<0·0001) but not before ischaemic stroke. Consequently, the first acute-phase blood pressure reading after primary intracerebral haemorrhage was more likely than after ischaemic stroke to be the highest ever recorded (OR 3·4, 95% CI 2·3–5·2, p<0·0001). In patients with intracerebral haemorrhage seen within 90 min, the highest systolic blood pressure within 3 h of onset was 50 mm Hg higher, on average, than the maximum premorbid level whereas that after ischaemic stroke was 5·2 mm Hg lower (p<0·0001).

Interpretation

Our findings suggest that systolic blood pressure is substantially raised compared with usual premorbid levels after intracerebral haemorrhage, whereas acute-phase systolic blood pressure after major ischaemic stroke is much closer to the accustomed long-term premorbid level, providing a potential explanation for why the risks and benefits of lowering blood pressure acutely after stroke might be expected to differ.

Funding

Wellcome Trust, Wolfson Foundation, UK Medical Research Council, Stroke Association, British Heart Foundation, National Institute for Health Research.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Blood pressure lowering and stroke

Hypertension is the most prevalent of the modifiable risk factors for stroke. The benefits of blood pressure (BP) lowering on primary and secondary prevention of stroke are undeniable. Despite this, BP control in hypertensive individuals and patients with prior cerebrovascular events is suboptimal. Noncompliance, inappropriate antihypertensive usage and under-utilization of medications contribute significantly to inadequate BP control. Recently, elegantly designed studies that assessed the preventive role of BP lowering in patients with cerebrovascular disease have helped clarify management issues in terms of BP targets and effective antihypertensive regimens. Current evidence suggests that BP targets for primary and secondary prevention are suboptimal and need reassessment. The effect of BP modulation in acute stroke is still not completely understood. Although the thresholds for BP treatment in acute stroke have been recommended, BP targets are as yet ill-defined. The available evidence supports early lowering of blood pressure following stroke. This review discusses the impact of blood pressure on stroke incidence and outcomes, outlines the recommendations for blood pressure lowering in stroke and delineates questions that still need to be addressed.

Predicting ischaemic stroke subtype from presenting systolic blood pressure: the BASIC Project

OBJECTIVE

We hypothesized that low presenting systolic blood pressure (SBP) predicted cardioembolic stroke aetiology.

DESIGN

Active and passive surveillance were used to identify all ischaemic strokes as part of the Brain Attack Surveillance in Corpus Christi (BASIC) population-based study. Multinomial logistic regression was used to examine the association between stroke subtype and first documented SBP in the medical record.

SETTING

Nueces County, TX, USA (313,645 residents in 2000). The community is urban with the majority of the population residing in the city of Corpus Christi. The area is served by seven adult acute care hospitals.

PATIENTS

Three hundred and eight cases with completed ischaemic stroke and determined subtype aetiology between January 2000 and December 2002.

RESULTS

Lower presenting SBP was associated with stroke subtype (P = 0.001). This association remained significant in the final model adjusted for age and history of coronary artery disease. The odds of cardioembolic versus small vessel occlusion increased by 20% (OR = 1.20, 95% CI: 1.07-1.35) for every 10 mmHg decrease in presenting SBP. Other covariates including race/ethnicity, gender, history of hypertension, and diabetes were neither significant predictors of stroke subtype, nor did they confound the association of SBP and stroke subtype. A 5 year increase in age increased the odds of cardioembolic subtype by 25% (OR = 1.25, 95% CI: 1.07-1.47).

CONCLUSIONS

Lower initial SBP and older age at ischaemic stroke presentation were associated with cardioembolic stroke. Suspicion of cardioembolic stroke should be increased in those presenting with low SBP.

Blood pressure management in acute stroke

The optimal management of arterial blood pressure in the setting of an acute stroke has not been defined. Many articles have been published on this topic in the past few years, but definitive evidence from clinical trials continues to be lacking. This situation is complicated further because stroke is a heterogeneous disease. The best management of arterial blood pressure may differ, depending on the type of stroke (ischemic or hemorrhagic) and the subtype of ischemic or hemorrhagic stroke. This article reviews the relationship between arterial blood pressure and the pathophysiology specific to ischemic stroke, primary intracerebral hemorrhage, and aneurysmal subarachnoid hemorrhage, elaborating on the concept of ischemic penumbra and the role of cerebral autoregulation. The article also examines the impact of blood pressure and its management on outcome. Finally, an agenda for research in this field is outlined.

EMS management of acute stroke--out-of-hospital treatment and stroke system development (resource document to NAEMSP position statement)

The American Heart Association estimates an annual incidence of stroke in the United States at 700,000, leading to over 150,000 deaths. Of all strokes, approximately 88% are ischemic and 12% are hemorrhagic. Almost half of all stroke deaths occur in the out-of-hospital environment. Within a given region, the emergency medical services (EMS) system has an important role in the management of the acute stroke patient. Decisions made by EMS personnel can affect treatment and contribute to the immediate, short-term, and long-term outcomes of the patient. Because the patient may require emergent treatment regardless if the stroke is ischemic or hemorrhagic, EMS personnel should manage all potential stroke patients in a time-dependent nature. Proper treatment and disposition of the stroke patient begins in the out-of-hospital environment, continues in the emergency department, and then extends to the inpatient admission. This article reviews the literature on the out-of-hospital treatment of stroke patients and the role of EMS in the development of stroke systems of care.

Blood pressure augmentation in acute ischemic stroke

Although control of hypertension is established as an important factor in the primary and secondary prevention of stroke, management of blood pressure in the setting of acute ischemic stroke remains controversial. Given limited data, the general consensus is that there is no proven benefit to lowering blood pressure in the first hours to days after acute ischemic stroke. Instead, there is concern that relative hypotension may lead to worsening of cerebral ischemia. For many years, the use of blood pressure augmentation ("induced hypertension") has been studied in animal models and in humans as a means of maintaining or improving perfusion to ischemic brain tissue. This approach is now widely used in neurocritical care units to treat delayed neurological deficits after subarachnoid hemorrhage, but its use in ischemic stroke patients remains anecdotal. This article reviews the cerebral physiology, animal models and human studies of induced hypertension as a treatment for acute ischemic stroke. Although there has not been a large, randomized clinical trial of this treatment, the available clinical data suggests that induced hypertension can result in at least short-term neurological improvement, with an acceptable degree of safety.

Comparison of noninvasive oscillometric and intra-arterial blood pressure measurements in hyperacute stroke

OBJECTIVES

This study aims to compare automatic oscillometric blood pressure recordings with simultaneous direct intra-arterial blood pressure measurements in hyperacute stroke patients to test the accuracy of oscillometric readings.

METHODS

A total of 51 first-ever stroke patients underwent simultaneous noninvasive automatic oscillometric and intra-arterial blood pressure monitoring within 3 h of ictus. Casual blood pressure was measured in both arms using a standard mercury sphygmomanometer on hospital admission. Patients who received antihypertensive medication during the blood pressure monitoring were excluded.

RESULTS

The estimation of systolic blood pressure (SBP) using oscillometric recordings underestimated direct radial artery SBP by 9.7 mmHg (95% confidence interval: 6.5-13.0, P<0.001). In contrast, an upward bias of 5.6 mmHg (95% confidence interval: 3.5-7.7, P<0.001) was documented when noninvasive diastolic blood pressure (DBP) recordings were compared with intra-arterial DBP recordings. For SBP and DBP, the Pearson correlation coefficients between noninvasive and intra-arterial recordings were 0.854 and 0.832, respectively. When the study population was stratified according to SBP bands (group A: SBP<or=160 mmHg; group B: SBP>160 mmHg and SBP<or=180 mmHg, group C: SBP>180 mmHg), higher mean DeltaSBP (intra-arterial SBP-oscillometric SBP) levels were documented in group C (+19.8 mmHg, 95% confidence intervals: 12.2-27.4) when compared with groups B (+8.5 mmHg, 95% confidence intervals: 2.7-14.5; P=0.025) and A (+5.9 mmHg, 95% confidence intervals: 1.8-9.9; P=0.002).

CONCLUSION

Noninvasive automatic oscillometric BP measurements underestimate direct SBP recordings and overestimate direct DBP readings in acute stroke. The magnitude of the discrepancy between intra-arterial and oscillometric SBP recordings is even more prominent in patients with critically elevated SBP levels.

Management of blood pressure after acute ischemic stroke: An evidence-based guide for the hospitalist

Hospitalists are frequently called upon to manage blood pressure after acute ischemic stroke. A review of both post infarction cerebral perfusion physiology and the data from randomized trials of antihypertensive therapy is necessary to explain why consensus guidelines for blood pressure management after stroke differ from those of other hypertensive emergencies. The peri-infarct penumbra is the central concept in understanding post ischemic cerebral perfusion. This area of impaired cerebral blood flow is dependent on mean arterial blood pressure and acute reduction of blood pressure may expand the area of infarction. Review of clinical trials fails to show benefit from reduction of blood pressure after ischemic stroke and current guidelines suggest antihypertensive therapy be employed if the systemic blood pressure is greater than 180/105 mmHg after tPA is employed, or 220/120 mmHg when tPA is not used. Induced hypertension remains a promising but unproven therapy in the acute setting, but the evidence for long term control of blood pressure to less than 140/80 mmHG for secondary prevention of stroke is strong. Adherence to guidelines is poor but it is recognized that current evidence is limited by a lack of trials in which blood pressure is titrated to a pre-specified goal, as is common in clinical practice.

The Management of Blood Pressure After Stroke

BACKGROUND

Control of hypertension is a well-established goal of primary prevention of stroke, but management of blood pressure in patients with a previous stroke or in the setting of acute stroke is complicated by the effect blood pressure changes may have on cerebral perfusion.

REVIEW SUMMARY

For patients with previous transient ischemic attack or chronic stroke, blood pressure reduction appears to be a safe and important facet of the secondary prevention of recurrent stroke. Less information is available concerning blood pressure management in acute stroke. Current protocols require strict blood pressure control in patients who are treated with thrombolytic therapy, to reduce the risk of hemorrhagic complications. In patients presenting with acute intracerebral hemorrhage, blood pressure reduction does not appear to cause significant reduction of cerebral blood flow, but at this time there are no studies to determine if there is a clinical benefit of acute blood pressure reduction in these patients. Finally, blood pressure reduction is not routinely recommended in patients with acute ischemic stroke, as it may precipitate further cerebral ischemia. Preliminary studies suggest, in fact, that there may be a role in the future for blood pressure elevation in the treatment of patients with acute ischemic stroke.

CONCLUSIONS

Current data support the use of blood pressure reduction in the secondary prevention of stroke in patients with cerebrovascular disease. In the setting of acute stroke, however, data are limited and blood pressure management must be tailored to the specific clinical situation.

Induced hypertension for the treatment of acute MCA occlusion beyond the thrombolysis window: case report

BACKGROUND

A minority of stroke patients is eligible for thrombolytic therapy. Small pilot case series have hinted that elevation of incident arterial blood pressure might be associated with a favorable prognosis either in acute or subacute stroke. However, these patients were not considered for thrombolytic therapy and were not followed - up systematically. We used pharmacologically induced hypertension in a stroke patient with middle cerebral artery (MCA) occlusion ineligible for thrombolysis that was followed-up by radiological, clinical and functional outcome assessment.

CASE PRESENTATION

A patient with acute embolic MCA occlusion producing a large, ischemic penumbra confirmed by perfusion CT was treated by induced hypertension with phenylephrine started within 4 h of admission. Increase in the mean arterial pressure by 20% led to a reduction of neurological deficit by 3 points on the National Institute of Stroke Scale. MRI and CT scans performed during phenylephrine infusion showed the presence of limited subcortical and cortical infarct changes that were clearly less extensive than the perfusion deficit in the brain perfusion CT at baseline, found in the absence of MCA patency. No complications due to induced hypertension therapy occurred. Moderate functional improvement up to modified Rankin scale 2 at follow up took place.

CONCLUSION

Induced hypertension in acute ischemic stroke seems clinically feasible and may be beneficial in selected normo- or hypotensive stroke patients not eligible for thrombolytic recanalization therapy.

Primary intracerebral hemorrhage

This article reviews the epidemiology, pathophysiology and management of primary intracerebral hemorrhage. In North American and European populations, 15% of strokes are due to intracerebral hemorrhage. Pathologically in hypertension, early arteriolar proliferation of smooth muscle is followed later by smooth muscle cell death and collagen deposition. This eventually leads to occlusion or ectasia of arterioles. The latter leads to Charcôt-Bouchard aneurysm formation and possible intracerebral hemorrhage. Amyloid deposition in the tunica media causes similar brittle arterioles. Fibrin globes in concentric spheres attempt to seal off the site of bleeding. But vasculopathy (either amyloid or hypertensive) inhibits the contractile capability of arterioles. The size of the final sphere of blood at cessation of bleeding determines the clinical spectrum, from asymptomatic to fatal. Since arteriolar bleeding is slower than arterial bleeding, several hours exist where intervention may be useful. While medical intervention is controversial, guidelines for blood pressure, intracranial pressure, glucose and seizure management exist. Surgical trials have tended to show no benefit. Recombinant factor VIIa is undergoing investigation as hemostatic therapy for intracerebral hemorrhage, to limit clot expansion and possibly also as a hemostatic adjunct to surgery.

Blood Pressure Management in Acute Stroke

The optimal management of arterial blood pressure in the setting of acute stroke has not been firmly defined. The different types of stroke--ischemic, intracerebral hemorrhage, and subarachnoid hemorrhage--have different pathophysiologies and require different approaches in terms of blood pressure management in the acute setting. This article reviews the current literature and experience at the authors' institution.

Blood pressure in acute ischemic stroke and mortality: a study with noninvasive blood pressure monitoring

BACKGROUND

In acute ischemic stroke, a transient elevation of blood pressure is common; its significance and its relationship with the neurological outcome are still unclear.

METHODS

In 71 consecutive patients with acute ischemic stroke, aged 25-94 years, admitted to our unit, we investigated the relationships between the blood pressure variation during the first 24 h and mortality at 3 months (study endpoint). Neurological status was assessed with the National Institutes of Health Stroke Scale. Blood pressure was measured with bedside noninvasive blood pressure monitoring every 15 min. The mean of four measurements at the emergency department and the mean of 12 measures (during a 3-h interval) at 12 and at 24 h after stroke onset were considered for analysis. Antihypertensive treatment was given in accordance with the Recommendations for Stroke Management of European Stroke Initiative.

RESULTS

In the whole series, 21% were atherothrombotic, 32% cardioembolic, 34% lacunar, and 13% of unknown or other cause. Blood pressure was 160+ or -3/86+ or -2 mmHg at the emergency department, 148+ or -3/82+ or -2 mmHg at 12 h, and 147+ or -3/81+ or -2 mmHg at 24 h (P<0.05). Four patients (11%) of those in whom mean blood pressure decreased >5 mmHg, and 12 (33%) of the others, in whom mean blood pressure decreased < or =5 mmHg or did not decrease, reached the endpoint (P<0.05). According to the multivariate Cox model, NIHSS score at the emergency department (95% confidence interval: 1.025-1.238, P=0.013) and age (95% confidence interval: 1.007-1.259, P=0.038) were predictors of reaching the endpoint, whereas mean blood pressure reduction 24 h after stroke onset had a protective effect (95% confidence interval: 0.845-0.995, P=0.038). Diabetes, mean blood pressure at the emergency department and the need for antihypertensive therapy did not correlate with the outcome.

CONCLUSIONS

Noninvasive blood pressure monitoring during the first 24 h of acute ischemic stroke may be useful in the prognostic stratification by showing moderate blood pressure decrease, either spontaneous or drug induced, which is associated with a favorable prognosis at 3 months.

Blood pressure management in acute stroke: a long-standing debate

Although elevated blood pressure (BP) levels are a common complication of acute stroke, whether of ischaemic or haemorrhagic type, a long-standing debate exists regarding the management of post-stroke hypertension. In the absence of solid, randomised data from controlled trials, the current observational evidence allows different approaches, since theoretical arguments exist for both lowering BP in the setting of acute stroke (reduce the risk of stroke recurrence, of subsequent oedema formation, of rebleeding and haematoma expansion in patients with cerebral bleeding) as well as leaving raised BP levels untreated (avoid reduction in cerebral perfusion pressure and blood flow to viable ischaemic tissue in the absence of normal autoregulation). The present review will summarize the evidence for and against the therapeutic manipulation of BP in acute stroke provided by the currently available observational studies and randomised trials, consider the ongoing clinical trials in this area and address the present recommendations regarding this conflicting issue.

Non-Pharmacological Neuroprotection: Role of Emergency Stroke Management

Acute stroke should be considered a medical emergency, where actions taken in the first hours are fundamental for achieving recovery of the damaged cerebral tissue and a better prognosis for the patient. Recanalization and neuroprotective treatment has been used with mixed results. The effectiveness observed in the first hours with thrombolytic drug treatment is only applicable to a small percentage of patients, and attempts to widen this treatment window have not yet proved fruitful. Pharmacological neuroprotective treatment has not yet demonstrated the clinical effectiveness observed in experimental models. The concept of neuroprotection in cerebral ischemia also involves a series of mechanisms that take place at the cerebral level following vascular occlusion. In this context, it should be borne in mind that a series of physiological functions usually involved in the cerebral metabolism (control of blood pressure, of temperature, of glycemia and of arterial oxygen saturation) play a key role in modulation of the ischemic process. Changes in the control of these mechanisms may aggravate the process of cerebral damage in the first hours of ischemic stroke. In this work we review the prognostic importance of the main mechanisms that may influence the acute phase of cerebral ischemic stroke, as well as their therapeutic management and control in the clinical situation.

Blood pressure management during acute ischaemic stroke

Control of hypertension is a well-established goal of primary stroke prevention. Management of blood pressure in patients during acute ischaemic stroke, however, is complicated by the need to maintain brain perfusion. Lowering blood pressure in the acute setting may avoid the deleterious effects of high blood pressure but may also lead to cerebral hypoperfusion and worsening of the ischaemic stroke. Little information is available from clinical trials concerning optimal blood pressure management in acute stroke. Current protocols of thrombolytic therapy require strict blood pressure control below certain prescribed limits; however, in most acute stroke patients not treated with thrombolysis, blood pressure reduction is not routinely recommended and guidelines for target blood pressures are difficult to justify. Preliminary studies, in fact, suggest that there may be a role for blood pressure elevation in the treatment of some patients with acute ischaemic stroke.

Severe Hypertension in the Emergency Department Patient

Severely elevated blood pressure is a common clinical problem en-countered in the Emergency Department. It is often difficult for physicians to differentiate between patients who need emergent blood pressure reduction, requiring the use of intravenous agents and in-tensive monitoring, and those for whom careful, slow reduction in BP is more appropriate. The optimal assessment and management of these patients is reviewed here, with an emphasis on clinical strategies that will most efficiently identify those at greatest risk.

[Acute cerebral circulation problems]

Acute stroke is the third most common cause of death and also the most common cause of permanent disability in industrialized countries. Ischemic stroke is caused by occlusion of a cerebral artery leading to a critical reduction in brain perfusion in the respective brain area (penumbra). Most acute stroke treatment strategies are based on the penumbra concept: attaining rapid and persistent reperfusion is followed by the protection of critically ischemic and not yet infarcted (penumbral) tissue by, e.g., neuroprotection. Examination of the acute stroke patient includes a brief history, neurostatus and imaging (CT or MRI) for the exclusion of intracerebral hemorrhage. The diagnostic standard is CT; modern stroke MRI protocols provide an improved selection in later time windows. Intravenous thrombolysis with rt-PA within 3 h of symptom onset is the only approved therapy with a proven significant benefit for the patient. The effect is smaller but still significant if treatment occurs up to 4.5 h, and may still be present in MRI selected patients up to 9 h. More aggressive forms of therapy include interventional reperfusion techniques and therapy of malignant MCA infarction such as hemicraniectomy and hypothermia, which at present, however, are not routine and are only performed in specialized centers.

Blood pressure course in acute ischaemic stroke in relation to stroke subtype

OBJECTIVES

Blood pressure (BP) management in acute stroke remains a matter of little consensus. Data on BP changes during the first hours of ictus are lacking. We aimed to evaluate the early spontaneous time course of BP in different ischaemic stroke (IS) subtypes.

METHODS

Twenty-four h BP monitoring was performed in 200 first-ever hyper-acute IS patients. The recording was initiated and terminated at 3 h and 27 h of ictus respectively. All IS patients were classified on admission into the following subgroups of different etiology: large artery atherosclerotic stroke (LAA), cardio-embolic stroke (CE), lacunar stroke (LAC) and infarct of undetermined cause (IUC). Statistical comparisons between stroke subgroups were performed using one-way ANOVA and linear regression analyses were used to evaluate the influence of different factors in BP course.

RESULTS

Although there were no significant differences in 24 h systolic (SBP) and diastolic (DBP) BP values between IS subgroups, a distinctly different SBP course was observed. The SBP dropped sharply in the LAA and LAC subgroups, while a more gradual decrease was monitored in the CE subgroup. Throughout the BP-recording, a SBP decrease of 10.1% (95% CI: 8.6-11.5) and 10.4% (95% CI: 9.0-11.8) was documented in patients with LAA and LAC respectively, while a milder drop was recorded in CE (3.7%, 95% CI: 2.4-5.0) and IUC (5.5%, 95% CI: 4.1-6.8). Increasing stroke severity (p<0.001) and brain oedema (p=0.013) was independently associated with a milder spontaneous SBP reduction.

CONCLUSIONS

Spontaneous SBP course varies in acute ischaemic stroke subtypes of different etiology. This may have implications in the optimal management of post-stroke hypertension.

Hourly Blood Pressure Monitoring After Intravenous Tissue Plasminogen Activator for Ischemic Stroke

BACKGROUND AND PURPOSE

Blood pressure (BP) control is considered essential in patients treated with tissue plasminogen activator (tPA) for ischemic stroke, and it is recommended that BP be monitored every 15 minutes to 1 hour for 24 hours in these patients. We postulated that patients whose BP is not initially elevated are unlikely to have elevated BP later and, therefore, may not need prolonged BP monitoring.

METHODS

We performed a retrospective chart review of patients treated with intravenous tPA for ischemic stroke over a 3-year period. Patients with incomplete records were excluded.

RESULTS

Seventy-nine patients (35 male, age 68.8+/-14.3 years) were studied. Before tPA treatment, 16 patients (20%) had hypertension (systolic BP > or =185 or diastolic BP > or =110 mm Hg). All 16 patients had subsequent hypertension over the next 24 hours. Of the remaining 63, 27 patients (43%) had hypertension (systolic BP > or =180 or diastolic BP > or =105 mm Hg) within the first 6 hours. An additional 4 had minor transient systolic elevations (< or =182 mm Hg) after 6 hours that normalized without treatment. Neurological worsening, seen in 13 patients (17%), was not associated with the presence of hypertension (initial or subsequent).

CONCLUSIONS

In patients receiving tPA for stroke, absence of hypertension at presentation does not preclude subsequent increase in blood pressure. However, if blood pressure is not elevated during the first 6 hours, subsequent hypertension over the next 18 hours is unlikely. This study is small and retrospective, and needs to be repeated in a larger prospective cohort. However, our results provide preliminary evidence to suggest that where resources are scarce, these patients may be discharged from the intensive care unit earlier than the recommended 24 hours, provided that they are not at high risk for neurological deterioration.

[Sequelae of hypertension on end-organs of the brain]

Hypertension is the most important risk factor for stroke and vascular dementia. Antihypertensive treatment reduces stroke risk by 40%. Most probably all antihypertensive drugs are equally effective with the exception of alpha-blockers. Blood pressure is increased in many patients with acute stroke. In this phase sudden drops in blood pressure should be avoided. The combination of an ACE-inhibitor and a diuretic reduced strokes by 28% after TIA or a first stroke. Whether this is a drug specific effect or due to lowering blood pressure per se is investigated at the moment.

Hypoperfusion and Its Augmentation in Patients with Brain Ischemia

Control of hypertension is a well-established goal of the primary and secondary prevention of stroke. However, management of blood pressure in the setting of acute brain ischemia is complicated by the possible effect of blood pressure changes on cerebral perfusion. In acute stroke, patients may have an ischemic penumbra of brain tissue, which has impaired perfusion but which is not irreversibly damaged. The ischemic penumbra may be salvaged with reperfusion. Lowering of blood pressure in this setting, however, would hasten the progression of the penumbra to infarction. With the exception of patients treated with thrombolytic agents, blood pressure reduction is not recommended in acute ischemic stroke for this reason. Preliminary studies suggest that there may be a role for interventions to elevate blood pressure as a treatment for acute stroke patients. Despite interest in induced hypertension as a treatment of stroke dating back to the 1950s, this practice has not achieved widespread use owing to concerns about potential adverse effects such as intracerebral hemorrhage, cerebral edema, and myocardial ischemia. It is commonly used, however, to treat patients with threatened cerebral ischemia due to vasospasm after subarachnoid hemorrhage. Until future studies clarify the effectiveness of induced hypertension in stroke treatment, maintaining adequate blood pressure and fluid volume is recommended for patients with acute ischemic stroke, particularly if the neurologic deficits are fluctuating or the patient has persistent large-vessel occlusive disease.

Critical care issues in stroke and subarachnoid hemorrhage

The outcomes of devastating neurological emergencies such as stroke and subarachnoid hemorrhage may be measurably improved by timely treatment in a neurointensive care unit (NICU). Optimal care requires a multidisciplinary approach, with attention to a wide range of treatment issues. This review examines the key therapeutic concerns in the NICU management of acute ischemic and hemorrhagic stroke and subarachnoid hemorrhage, including mechanical ventilation, blood pressure management, cardiac monitoring, intracranial pressure assessment, vasospasm, seizures, sedation, fluids, electrolytes, and nutrition. The discussion of mechanical ventilation includes rapid sequence induction and intubation, indication for intubation and extubation, and prognostic factors in mechanical ventilation. Differing blood pressure management concerns in hemorrhagic and ischemic events are discussed, and specific target blood pressures and pharmacologic interventions are reviewed. The discussion of cardiac monitoring includes concurrent stroke and cardiac ischemia and arrhythmias, cardiac imaging, anticoagulation, and vasopressor therapy. The importance, monitoring and management of cerebral blood flow and intracranial pressure (ICP) are discussed, and strategies for treatment of elevated ICP are outlined in detail. The discussion of vasospasm includes evaluation, prophylaxis, and treatment with medications, hypervolemic hemodilution, and angioplasty. Management of seizure and status epilepticus in stroke and subarachnoid hemorrhage are reviewed and current algorithms are presented. The management of fluids, electrolytes and enteral nutrition are also reviewed.

Damage control: past, present, and future of prehospital stroke management

Early identification of stroke patients by emergency medical services is a valuable part of optimal care. Accurate identification of the stroke victim by EMS has been shown to expedite treatment. Care is enhanced when the EMS professional ascertains when the patient was last at baseline state, performs an expeditious assessment and transport, checks the patient's blood glucose level, and avoids lowering the blood pressure. The death and disability toll of acute stroke can be lowered. There is a long way to go, however. EMS professionals can help make progress on that journey.

The course of blood pressure in acute stroke is related to the severity of the neurological deficits

OBJECTIVES

To evaluate how soon after stroke the diagnosis of hypertension could be established.

METHODS

In a prospective study including 1192 patients with acute stroke within 6 h, blood pressure was measured serially at 2-h intervals during the first 24 h. Results are presented as mean arterial blood pressure (MAP). The Scandinavian Stroke Scale (SSS) assessed the neurological deficit.

RESULTS

In 779 patients with mild to moderate ischaemic stroke or transient ischaemic attack (TIA) and SSS > 25, MAP was 118 mmHg (CI 95%: 116-119 mmHg) on admission and 109 mmHg (CI 95%: 108-110 mmHg) 4 h later (paired t-test, P < 0.001). No such early decrease was observed in 228 patients with severe cerebral infarction (CI). In mild to moderate ischaemic stroke or TIA, MAP at 24 h was not different from MAP at 3 months in paired t-test.

CONCLUSIONS

Blood pressure 24 h after admission in patients with mild to moderate CI or TIA was representative of the patient's blood pressure 3 months after stroke. A diagnosis of arterial hypertension can be established a few days after stroke.

Prehospital care of the stroke patient

Acute stroke care is a multidisciplinary effort. It crosses the boundaries of traditional hospital-based medicine, relying heavily on prehospital providers to obtain a significant amount of clinical information. Currently, modifications of existing EMS systems are underway to support the idea that "time is brain." Dispatchers and EMS providers are vital players in the Chain of Recovery, and are challenged to perform within this new paradigm for acute stroke care. In the near future, optimal management of the acute stroke patient may include the administration of neuroprotective medications in the prehospital setting. Educational efforts targeting high risk and elderly populations also continue to be a priority for healthcare providers and public interest groups such as the NSA. Stroke victims, family members, and caregivers must all be aware of the warning signs and symptoms of stroke. The importance of using EMS during the initial phase of acute stroke cannot be overstated. Emergency physicians must lead in coordinating the resources, placing greater emphasis on educating and assessing the performance of prehospital providers [50]. These leaders must ensure that prehospital providers understand they are integral members of the stroke team, vital to improving stroke care in the community.

Acute ischemic stroke: emergent evaluation and management

This article discusses stroke, the third leading cause of death and number one cause of adult disability in the United States, inflicting a devastating physical, emotional, and financial toll on its victims and their families. The last decade has seen the emergence of new treatments for acute stroke, energizing stroke care providers and spreading a sense of optimism among them. Because effective stroke treatment is extremely time-dependent, it is paramount that emergency physicians understand and excel in their critical role at the forefront of stroke management. This article outlines the emergent evaluation and management of acute ischemic stroke, emphasizing the importance of the emergency physician in acute stroke treatment.