Blood pressure in acute stroke Presented by Ri 李俊豪

Guidelines for Medical Care and Treatment of Blood Pressure in Patients with Acute Stroke Joseph P. Broderick, M.D. University of Cincinnati Medical Center Proceedings of a National Symposium on Rapid Identification and Treatment of Acute Stroke December 12-13, 1996

Overview over 80% have a BP >160/90 during initial post stroke phase and fall spontaneously in the subsequent 10–14 days. Because cerebral autoregulation is impaired after the acute event, cerebral blood flow is very sensitive to changes in systemic BP levels. Ischemic: increasing blood flow to the ischaemic penumbra. : increasing the risk of cerebral oedema haemorrhagic transformation of the infarct. ICH: lowering blood pressure is to decrease the risk of ongoing bleeding from ruptured small arteries and arterioles. decrease CPP and theoretically worsen brain injury

The mechanisms underlying the rise in BP post stroke impairment of baroreceptor sensitivity increased sympathetic nervous system activity activation of the renin aldosterone mechanisms the Cushing reflex

Intracranial hemorrhage Control of elevated blood pressure has never been shown to decrease the risk of ongoing or recurrent bleeding in patients with intracerebral hemorrhage. treatment of moderate and severe elevations of blood pressure ( systolic BP> 180 mm Hg or MAP> 130 mm Hg). The goal of treatment : MAP of mm Hg or to the low hypertensive range (e.g., systolic pressure of mm Hg ). If systolic arterial blood pressure falls below 90 mm Hg, pressors should be given.

guidelines for antihypertensive therapy in acute stroke 1. If systolic BP is >230 mm Hg or diastolic BP >140 mm Hg on 2 readings 5 minutes apart, institute nitroprusside. 2. If systolic BP is 180 to 230 mm Hg, diastolic BP 105 to 140 mm Hg, or mean arterial BP 130 mm Hg on 2 readings 20 minutes apart, institute intravenous labetalol, esmolol or enalapril, 3. If systolic BP is <180 mm Hg and diastolic BP <105 mm Hg, defer antihypertensive therapy. Choice of medication depends on other medical contraindications (eg, avoid labetalol in patients with asthma). 4. If ICP monitoring is available, cerebral perfusion pressure should be kept at >70 mm Hg.

The antihypertensive medication quick in onset and easily titratable. Intravenous labetalol is an excellent choice because it is fast- acting, titratable, and has no known adverse effect on either ICP or autoregulation of local cerebral flow. (Intravenous enalapril ) For more severe elevations (e.g., diastolic pressures > 130 mm Hg) nitroprusside is recommended. Theoretically, nitroprusside can increase ICP because it is a cerebral arterial vasodilator. ( clinical use:-, easiest medication to titrate.) Calcium channel blockers, such as sublingual nifedipine, are less predictable, slower in onset, and can dilate cerebral arteries. ( as a second-line medication when the other medications cannot be used.)

Blood Pressure Management in ICH Elevated blood pressure Labetalol5–100 mg/h by intermittent bolus doses of 10–40 mg or continuous drip (2–8 mg/min) Esmolol500 µg/kg as a load; maintenance use, 50–200 µg/kg/min Nitroprusside0.5–10 µg /kg/min Hydralazine10–20 mg Q 4–6 h Enalapril0.625–1.2 mg Q 6 h as needed

Low blood pressure Volume replenishment is the first line of approach. Isotonic saline or colloids can be used and monitored with CVP If hypotension persists after correction of volume deficit, continuous infusions of pressors should be considered, particularly for low systolic blood pressure such as <90 mm Hg. Phenylephrine2–10 µg · kg-1 · min-1 Dopamine2–20 µg · kg-1 · min-1 NorepinephrineTitrate from 0.05–0.2 µg · kg-1 · min-1

Ischemic stroke Unless systolic BP> 220 mm Hg or diastolic BP> 120 mm Hg (sustained on repeated measurement), elevated blood pressure should not be treated within the first day after ischemic stroke. The ischemic penumbra loses autoregulation, and perfusion is directly linked to mean arterial pressure. Acute elevations in blood pressure are often transient, and spontaneous declines are common. Overzealous treatment of hypertension following acute ischemic stroke can convert the ischemic penumbra into an infarct.

studied blood pressure (BP) changes in 115 patients who had recently suffered a stroke. The average BP on admittance to hospital was 160/94mmHg. All patients experienced a drop in BP in the acute phase of disease (24 hours after the stroke) spontaneously or with medication. Forty-four of the patients had a poor outcome three months later, requiring assistance to complete everyday activities such as eating and dressing. Each 10 % decrease in systolic BP during the first 24 hours after stroke nearly doubled the likelihood of poor outcome three months later. Brazilian researchers.Dr Jamary Oliveira-Filho and Colleagues from the Hospital Sao Rafael and the Federal University of Bahia in Salvador

The two exceptions (1) after use of tissue plasminogen activator (t-PA), blood pressure should be maintained below 185/110 mm Hg (2) in the presence of myocardial infarction, heart failure or aortic dissection, elevated blood pressure should be treated aggressively.

Algorithm for Ischemic Stroke If diastolic BP > 140 mm Hg occurs on 2 readings 5 minutes apart, then start a continuous IV infusion of an antihypertensive agent such as sodium nitroprusside If systolic BP is > 220 mm Hg or diastolic BP is mm Hg or mean arterial blood pressure is > 130 mm Hg on two readings 20 minutes apart, then give an easily titratable antihypertensive medication such as labetalol at 10 mg IV over 1-2 minutes. If systolic BP is mm Hg or diastolic BP is mm Hg, emergency therapy should be deferred in the absence of left ventricular failure, aortic dissection, or acute myocardial ischemia.

In acute stroke patients with systolic blood pressure < 185 mm Hg or diastolic blood pressure < 105 mm Hg, antihypertensive therapy is usually not indicated. Although there are no data to support a threshold for treatment of hypotension in stroke patients we recommend treatment for signs of dehydration, blood pressure that is substantially below the expected level for a given patient (consider past history of hypertension, treated or untreated), or both.

Chronic Management of Blood Pressure After Stroke Pedelty, Laura; Gorelick, Philip B. From the Department of Neurology and Rehabilitation, University of Illinois at Chicago.

When Is it Safe to Administer Blood Pressure Lowering Therapy After Stroke? There remain no definitive data to guide decisions regarding this issue discussion with experts suggests that the optimum time period for starting antihypertensive therapy after acute stroke may be as early as 7 days and as long as a month or more.

What Is the Target BP Goal, and How Soon Should This Goal Be Reached? A precise target blood pressure goal for prevention of recurrent stroke has not been established according to clinical trial data. HOPE, blood pressure was lowered by [almost equal to]3/2 mm Hg in the ramipril treatment group compared with placebo : ramipril 10 mg PO daily provided no statistically significant benefit in patients with previous stroke/TIA The Captopril Prevention Project trial demonstrated that captopril lead to an increased risk for stroke compared to diuretics, b-blockers, or both

What Is the Target BP Goal, and How Soon Should This Goal Be Reached? PROGRESS: Perindopril Protection Against Recurrent Stroke Study was a randomized, double-blind, placebo- controlled trial conducted at 172 centers in Asia, Australasia, and Europe. Perindopril-based therapy reduced the overall risk of major vascular events

Perindopril (1) it has a long duration of action, providing smooth 24-hour blood pressure control from a once-daily dose; (2) it has a minimal first-dose effect; (3) it does not compromise cerebral blood flow.

PROGRESS In conclusion, blood pressure –lowering therapy is now established as the most important measure for primary and secondary stroke prevention. Results of PROGRESS suggest that antihypertensive treatment with a combination of perindopril plus indapamide should now be routinely considered for all patients with previous stroke or TIA. The PROGRESS results support blood pressure – lowering therapy for secondary stroke prevention, not only for patients with hypertension, but also for nonhypertensive individuals

PATS PATS Post-stroke Antihypertensive Treatment Study 5665 patients in China Previous stroke or TIA Average BP 154/93 mmHg Mean age 60 years FU 2 years BP reduction 5/2 reduction 1st fatal/nonfatal stroke by 29%

What Is the Target BP Goal, and How Soon Should This Goal Be Reached? In the absence of large-scale clinical trial data needed to help establish blood pressure lowering targets for prevention of recurrent stroke, utilization of the 7th report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) targets seems reasonable. This translates to a target blood pressure of <140/90 mm Hg for most stroke patients and <130/80 mm Hg for patients with diabetes mellitus or chronic kidney disease.

COSSACS Continue Or Stop post-Stroke Antihypertensives Collaborative Study Robinson TG, Potter JF 18 October

Membership Professor Christopher BULPITT Professor of Geriatric Medicine, Imperial College School of Medicine Professor Gary FORD Professor of Pharmacology of Old Age, University of Newcastle-Upon-Tyne Dr Joanne KNIGHT Associate Director of Research and Development, Stroke Association Professor John POTTER (Co-Principal Investigator) Professor Of Medicine for the Elderly, Leicester Warwick Medical School Professor Neil POULTER (Chairman) Professor of Preventative Cardiovascular Medicine, Imperial College School of Medicine Dr Thompson ROBINSON (Co-Principal Investigator) Senior Lecturer in Medicine for the Elderly, Leicester Warwick Medical School Professor Carol JAGGER (Trial Statistician) Professor of Epidemiology, University of Leicester 2005/9/30

COSSACS Study Design and Objectives Up to 40% of acute stroke patients on hospital admission are already taking antihypertensive therapy However, no guidelines exist as to whether antihypertensive therapy should be continued or discontinued following acute stroke. United Kingdom based Multi-centre, prospective, randomised, open, blinded-endpoint trial. Antihypertensive therapy should be continued or discontinued within 24 hours of stroke onset and for the subsequent two weeks. The trial will assess the short- (2 weeks) and long-term (6 months) rates of death and disability in the continued versus discontinued groups, and provide information to support the future evidence-based management of acute post-stroke hypertension.

COSSACS Early Endpoints Neurological deterioration (NIHSS). Functional status (Barthel Index). BP changes (admission to 2 weeks). Serious Adverse Events.

COSSACS Late Endpoints Death. Dependency (Modified Rankin Score). Fatal and non-fatal stroke recurrence. Health-related quality of life –IST questionnaire –EuroQOL Place of Residence.

References otherapy.com/Issue11/EBP/Mysak%2520T%2520EBP% % htm+ Post-stroke+antihypertensive&hl=zh-TW htm#table% /N/ ?ja=358038&PAGE=1.html&sid= &source=MI Proceedings of a National Symposium on Rapid Identification and Treatment of Acute Stroke December 12-13, 1996 Trials on blood pressure-lowering and secondary stroke prevention.

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