Stroke precipitated by moderate blood pressure reduction

Augmentation of perfusion with simultaneous vasodilator and inotropic agents in experimental acute middle cerebral artery occlusion: a pilot study

BACKGROUND

This study tests the hypothesis that simultaneous cerebral blood pressure elevation and potent vasodilation augments perfusion to ischemic tissue in acute ischemic stroke and it varies by degree of pial collateral recruitment.

METHODS

Fifteen mongrel canines were included. Subjects underwent permanent middle cerebral artery occlusion; pial collateral recruitment was scored before treatment. Seven treatment subjects received a continuous infusion of norepinephrine (0.1-1.52 µg/kg/min; titrated 25-45 mmHg above baseline mean arterial pressure while keeping systolic blood pressure below 180 mmHg) and hydralazine (20 mg) starting 30 min post-occlusion. Perfusion (cerebral blood flow-CBF) was evaluated with quantitative dynamic susceptibility contrast MRI 2.5 hours post-occlusion to produce images in mL/100 g/min, and relative CBF measured as ratios. Mean region of interest (ROI) values were reported, and compared and subject to regression analysis to elucidate trends.

RESULTS

Differences in quantitative CBF (qCBF) between treatment and control group varied by degree of pial collateral recruitment, based on Wilcoxon rank sum scores and regression model fit. For poorly collateralized subjects, ipsilateral anatomic, core infarct, and penumbra regions showed treatment with higher qCBF, raised above the ischemic threshold, compared with the control, while well collateralized subjects showed a paradoxical decrease maintained above the ischemic threshold for neuronal death. qCBF on the contralateral side increased regardless of collateralization.

CONCLUSION

Results suggest that perfusion can be augmented in ischemic stroke with norepinephrine and hydralazine. Perfusion augmentation depends on degree of collateralization and territory in question, with some evidence of vascular steal.

Poor guideline adherence in a real-world evaluation of hypertensive emergency management

BACKGROUND

The American College of Cardiology and American Heart Association define hypertensive emergency (HTN-E) as a systolic blood pressure greater than 180 mmHg or a diastolic blood pressure greater than 120 mmHg with evidence of end-organ damage (EOD). Based on expert opinion, current guidelines recommend antihypertensive therapy to reduce blood pressure (BP) at specific hourly rates to reduce progression of EOD, outlined by four criteria. Our goal was to describe compliance with guideline recommendations for early management of HTN-E and to analyze safety outcomes related to pharmacologic intervention.

METHODS

This was a retrospective chart review including patients presenting to the emergency department with HTN-E between September 2016 and August 2020. We excluded patients with a compelling indication for altered therapeutic goals (e.g. acute aortic dissection, hemorrhagic or ischemic stroke, and pheochromocytoma). The primary outcome was complete adherence with guideline recommendations in the first 24 h.

RESULTS

Of 758 screened records, 402 were included. Mean age was 54 years and majority Black race (72%). Overall, total adherence was poor (<1%): 30% received intravenous therapy within 1 h, 64% achieved 1-h BP goals, 44% achieved 6-h goals, and 9% had appropriate 24-h maintenance BP. Hypotensive events (N = 67) were common and antihypertensive-associated EOD (N = 21) did occur. Predictors of hypotension include treatment within 1 h and management with continuous infusion medication.

CONCLUSIONS

Current practice is poorly compliant with guideline criteria and there are risks associated with recommended treatments. Our results favor relaxing the expert opinion-based recommendations.

Management of hypertensive emergencies: a practical approach

Background: Acute increases of high blood pressure values, usually described as 'hypertensive crises', 'hypertensive urgencies' or 'hypertensive emergencies', are common causes of patients' presentation to emergency departments. Owing to the lack of ad hoc randomized clinical trials, current recommendations/suggestions for treatment of these patients are not evidenced-based and, therefore, the management of acute increases of blood pressure values represent a clinical challenge. However, an improved understanding of the underlying pathophysiology has changed radically the approach to management of the patients presenting with these conditions in recent years. Accordingly, it has been proposed to abandon the terms 'hypertensive crises' and 'hypertensive urgencies', and restrict the focus to 'hypertensive emergencies'. Aims and Methods: Starting from these premises, we aimed at systematically review all available studies (years 2010-2020) to garner information on the current management of hypertensive emergencies, in order to develop a novel symptoms- and evidence-based streamlined algorithm for the assessment and treatment of these patients.Results and Conclusions: In this educational review we proposed the BARKH-based algorithm for a quick identification of hypertensive emergencies and associated acute organ damage, to allow the patients with hypertensive emergencies to receive immediate treatment in a proper setting.

Influence of simultaneous pressor and vasodilatory agents on the evolution of infarct growth in experimental acute middle cerebral artery occlusion

BACKGROUND

This study sought to test the hypothesis that simultaneous central blood pressure elevation and potent vasodilation can mitigate pial collateral-dependent infarct growth in acute ischemic stroke.

METHODS

Twenty mongrel canines (20-30 kg) underwent permanent middle cerebral artery occlusion (MCAO). Eight subjects received continuous infusion of norepinephrine (0.1-1.5200 µg/kg/min; titrated to a median of 34 mmHg above baseline mean arterial pressure) and hydralazine (20 mg) starting 30 min following MCAO. Pial collateral recruitment was scored prior to treatment and used to predict infarct volume based on a previously reported parameterization. Serial diffusion magnetic resonance imaging (MRI) acquisitions tracked infarct volumes over a 4-hour time frame. Infarct volumes and infarct volume growth between treatment and control groups were compared with each other and to predicted values. Fluid-attenuated inversion recovery (FLAIR) MRI, susceptibility weighted imaging (SWI), and necropsy findings were included in the evaluation.

RESULTS

Differences between treatment and control group varied by pial collateral recruitment based on indicator-variable regression effects analysis with interaction confirmed by regression model fit. Benefit in treatment group was only in subjects with poor collaterals which had 35.7% less infarct volume growth (P=0.0008; ANOVA) relative to controls. Measured infarct growth was significantly lower than predicted by the model (linear regression partial F-test, slope P<0.001, intercept=0.003). There was no evidence for cerebral hemorrhage or posterior reversible encephalopathy syndrome.

CONCLUSION

Our results indicate that a combination of norepinephrine and hydralazine administered in the acute phase of ischemic stroke mitigates infarct evolution in subjects with poor but not good collateral recruitment.

Oral short-acting antihypertensive medications and the occurrence of stroke: a nationwide case-crossover study

The purpose of the study was to clarify whether short-acting antihypertensives are associated with the occurrence of ischemic stroke and intracerebral hemorrhage (ICH). This was a retrospective case-crossover study using the Taiwan National Health Insurance Research Database. We identified all adult patients hospitalized with a primary diagnosis of ischemic stroke or ICH between January 2005 and December 2013. For each case, short-term and long-term exposure to short-acting antihypertensives, including nifedipine, labetalol and captopril, during the case vs. control periods were compared, and odd ratios (ORs) and 95% confidence intervals (CIs) for ischemic stroke or ICH were calculated with adjustment for confounders. Among 272785 ischemic stroke and 77798 ICH patients, the mean age was 77.8 ± 14.3 years and 70.8 ± 16.6 years, respectively. The short-term use of the three short-acting antihypertensives were all associated with an increase in the incidence of ischemic stroke (nifedipine: OR 4.51, 95% CIs 3.99-5.11; labetalol: OR 2.07; 95% CIs 1.71-2.51; captopril: OR 1.98, 95% CIs 1.72-2.29) and ICH (nifedipine: OR 2.98, 95% CIs 2.30-3.84; labetalol: OR 2.37; 95% CIs 1.66-3.39; captopril: OR 2.48; 95% CIs 1.69-3.63). The long-term use of short-acting nifedipine for 30 days was associated with a modest increase in the risk for ischemic stroke (OR 1.86; 95% CIs 1.42-2.45). Overall, the short-term use of short-acting antihypertensives is associated with a modest increase in the incidence of stroke, and short-acting nifedipine is linked to a substantial rise in the incidence of ischemic stroke. The long-term use of short-acting nifedipine was also related to an increased incidence of ischemic stroke. Physicians should be cautious of prescribing these short-acting antihypertensives.

Rationale and design of a randomized trial of early intensive blood pressure lowering on cerebral perfusion parameters in thrombolysed acute ischemic stroke patients

BACKGROUND AND RATIONALE

Uncertainty persists over the optimal management of blood pressure (BP) in the early phase of acute ischemic stroke (AIS). This study aims to determine the safety and effects of intensive BP lowering on cerebral blood flow (CBF) and functional in AIS patients treated with intravenous thrombolysis.

METHODS

In a randomized controlled trial, 54 thrombolysed AIS patients with a systolic BP of 160 to 180 mm Hg will be randomized to early intensive BP lowering (systolic target range 140-160 mm Hg) or guideline-based BP management (systolic range 160-180 mm Hg) during first 72-hours using primarily intravenous labetalol. We hypothesize that early intensive BP lowering will not reduce CBF by 20% and/or increase the volume of hypoperfused tissue by >20% on computed tomographic perfusion. Clinical outcome will be assessed using a dichotomized modified Rankin scale (scores 0-1 as excellent outcome vs scores 2-6 as dead or dependent) at 90 days. Other outcome would be symptomatic intracerebral hemorrhage. The trial is registered at ClinicalTrials.gov, NCT03443596.

CONCLUSION

This randomized study will provide important information about the physiological effects of BP reduction on cerebral perfusion after intravenous thrombolysis in AIS.

Monitoring Pressure Augmentation in Patients With Ischemic Penumbra Using Continuous Electroencephalogram: Three Cases and a Review of the Literature

BACKGROUND

Continuous electroencephalography (CEEG) is a sensitive, noninvasive surrogate monitor of cerebral blood flow (CBF). Changes in CBF can be seen as changes in the frequencies on the CEEG. This case series suggests that increase in CEEG frequencies may be used to detect improved CBF following pressure augmentation such as with treatment of vasospasm from subarachnoid hemorrhage (SAH) or acute thrombosis from ischemic stroke. The application of this observation to clinical decision-making has not been clearly defined and requires further study.

METHODS

Case series and imaging.

RESULTS

We present 3 patients with ischemic penumbras either from vasospasm from SAH or thrombosis from acute ischemic stroke. All patients were monitored on CEEG and found to have lateralized slowing. During pressure augmentation, the lateralized slowing improved in frequency, which corresponded with improvement in the patients' neurological examinations.

CONCLUSION

Continuous electroencephalography may be used as a noninvasive monitor to allow for individualization of pressure augmentation in cases of vasospasm from SAH or in cases of acute ischemic strokes. This customized approach may allow for less morbidity associated with pressure augmentation in patients who otherwise may have dysfunction of their intracerebral autoregulation.

As-needed intravenous antihypertensive therapy and blood pressure control

BACKGROUND

Hospitalized patients with elevated blood pressure (BP) in most cases should be treated with intensification of oral regimens, but are often given intravenous (IV) antihypertensives.

OBJECTIVE

To determine frequency of prescribing and administering episodic IV antihypertensives and outcomes.

DESIGN

Retrospective review.

SETTING

Urban academic hospital.

PATIENTS

Non-critically ill, hospitalized patients with an IV antihypertensive order for enalaprilat, labetalol, hydralazine, or metoprolol.

MEASUREMENTS

We analyzed BP thresholds for ordering and administering IV antihypertensives, the types and frequencies of IV antihypertensives administered, and the effect of IV antihypertensive use on short-term BP and adverse outcomes. The BP change during hospitalization was contrasted in those receiving IV antihypertensives between those who did and did not receive subsequent intensification of chronic oral antihypertensive regimens.

RESULTS

Two hundred forty-six patients had an episodic IV antihypertensive order. One hundred seventy-two patients received 458 doses, with 48% receiving a single dose. Over 98% of episodic IV antihypertensive doses were administered for systolic blood pressure (SBP) <200 mm Hg and 84.5% for SBP <180 mm Hg. Within 6 hours of administration, there was a statistically significant decline in average SBP and diastolic BP in patients receiving IV hydralazine and labetolol. After administration of IV antihypertensives, the oral inpatient medication regimen was adjusted in 52% of patients; these patients had a greater reduction in SBP from admission to discharge than patients with no change to their oral regimens. A total of 32.6% of patients receiving treatment experienced a BP reduction of more than 25% within 6 hours.

CONCLUSIONS

IV antihypertensive drugs are ordered and administered in patients with asymptomatic, uncontrolled BP for levels unassociated with substantive immediate cardiovascular risk, which may cause adverse effects.

Risk of ischemic stroke during the initiation period of α-blocker therapy among older men

BACKGROUND

Alpha-blockers are notorious for their first-dose effect of acute hypotension during the early initiation period. Because acute cerebral hypoperfusion may precipitate an episode of ischemic stroke, we aimed to provide a quantitative estimate of the risk of ischemic stroke during the early initiation period of α-blocker therapy, using a self-controlled case series design.

METHODS

We identified all men aged 50 years or more as of 2007 who were incident users of α-blockers and had a diagnosis of ischemic stroke during the 2007-2009 study period using claims data from Taiwan's National Health Insurance claims database. The first day on which the α-blocker was prescribed was the index date. We partitioned different risk periods according to their relationship to the index date (pre-exposure risk periods 1 and 2 = ≤ 21 d and 22-60 d before index date, respectively; post-exposure risk periods 1 and 2 = ≤ 21 d and 22-60 d after index date, respectively); the remainder of the study period was defined as the unexposed period. We estimated the incidence rate ratio (IRR) of ischemic stroke in each risk period relative to the unexposed period using a conditional Poisson regression model.

RESULTS

A total of 7502 men were included. Compared with the risk in the unexposed period, the risk of ischemic stroke was increased in post-exposure risk period 1 among all patients in the study population (adjusted IRR 1.40, 95% confidence interval [CI], 1.22-1.61) and among patients without concomitant prescriptions for other antihypertensive agents (adjusted IRR 2.11, 95% CI 1.73-2.57).

INTERPRETATION

Alpha-blocker therapy was associated with an increased risk of ischemic stroke during the early initiation period, especially among patients who were not taking other antihypertensive agents.

Efficacy of nitric oxide, with or without continuing antihypertensive treatment, for management of high blood pressure in acute stroke (ENOS): a partial-factorial randomised controlled trial

BACKGROUND

High blood pressure is associated with poor outcome after stroke. Whether blood pressure should be lowered early after stroke, and whether to continue or temporarily withdraw existing antihypertensive drugs, is not known. We assessed outcomes after stroke in patients given drugs to lower their blood pressure.

METHODS

In our multicentre, partial-factorial trial, we randomly assigned patients admitted to hospital with an acute ischaemic or haemorrhagic stroke and raised systolic blood pressure (systolic 140-220 mm Hg) to 7 days of transdermal glyceryl trinitrate (5 mg per day), started within 48 h of stroke onset, or to no glyceryl trinitrate (control group). A subset of patients who were taking antihypertensive drugs before their stroke were also randomly assigned to continue or stop taking these drugs. The primary outcome was function, assessed with the modified Rankin Scale at 90 days by observers masked to treatment assignment. This study is registered, number ISRCTN99414122.

FINDINGS

Between July 20, 2001, and Oct 14, 2013, we enrolled 4011 patients. Mean blood pressure was 167 (SD 19) mm Hg/90 (13) mm Hg at baseline (median 26 h [16-37] after stroke onset), and was significantly reduced on day 1 in 2000 patients allocated to glyceryl trinitrate compared with 2011 controls (difference -7·0 [95% CI -8·5 to -5·6] mm Hg/-3·5 [-4·4 to -2·6] mm Hg; both p<0·0001), and on day 7 in 1053 patients allocated to continue antihypertensive drugs compared with 1044 patients randomised to stop them (difference -9·5 [95% CI -11·8 to -7·2] mm Hg/-5·0 [-6·4 to -3·7] mm Hg; both p<0·0001). Functional outcome at day 90 did not differ in either treatment comparison-the adjusted common odds ratio (OR) for worse outcome with glyceryl trinitrate versus no glyceryl trinitrate was 1·01 (95% CI 0·91-1·13; p=0·83), and with continue versus stop antihypertensive drugs OR was 1·05 (0·90-1·22; p=0·55).

INTERPRETATION

In patients with acute stroke and high blood pressure, transdermal glyceryl trinitrate lowered blood pressure and had acceptable safety but did not improve functional outcome. We show no evidence to support continuing prestroke antihypertensive drugs in patients in the first few days after acute stroke.

FUNDING

UK Medical Research Council.

Interventions for deliberately altering blood pressure in acute stroke

BACKGROUND

It is unclear whether blood pressure should be altered actively during the acute phase of stroke. This is an update of a Cochrane review first published in 1997, and previously updated in 2001 and 2008.

OBJECTIVES

To assess the clinical effectiveness of altering blood pressure in people with acute stroke, and the effect of different vasoactive drugs on blood pressure in acute stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched in February 2014), the Cochrane Database of Systematic reviews (CDSR) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 2), MEDLINE (Ovid) (1966 to May 2014), EMBASE (Ovid) (1974 to May 2014), Science Citation Index (ISI, Web of Science, 1981 to May 2014) and the Stroke Trials Registry (searched May 2014).

SELECTION CRITERIA

Randomised controlled trials of interventions that aimed to alter blood pressure compared with control in participants within one week of acute ischaemic or haemorrhagic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and extracted data. The review authors cross-checked data and resolved discrepancies by discussion to reach consensus. We obtained published and unpublished data where available.

MAIN RESULTS

We included 26 trials involving 17,011 participants (8497 participants were assigned active therapy and 8514 participants received placebo/control). Not all trials contributed to each outcome. Most data came from trials that had a wide time window for recruitment; four trials gave treatment within six hours and one trial within eight hours. The trials tested alpha-2 adrenergic agonists (A2AA), angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor antagonists (ARA), calcium channel blockers (CCBs), nitric oxide (NO) donors, thiazide-like diuretics, and target-driven blood pressure lowering. One trial tested phenylephrine.At 24 hours after randomisation oral ACEIs reduced systolic blood pressure (SBP, mean difference (MD) -8 mmHg, 95% confidence interval (CI) -17 to 1) and diastolic blood pressure (DBP, MD -3 mmHg, 95% CI -9 to 2), sublingual ACEIs reduced SBP (MD -12.00 mm Hg, 95% CI -26 to 2) and DBP (MD -2, 95%CI -10 to 6), oral ARA reduced SBP (MD -1 mm Hg, 95% CI -3 to 2) and DBP (MD -1 mm Hg, 95% CI -3 to 1), oral beta blockers reduced SBP (MD -14 mm Hg; 95% CI -27 to -1) and DBP (MD -1 mm Hg, 95% CI -9 to 7), intravenous (iv) beta blockers reduced SBP (MD -5 mm Hg, 95% CI -18 to 8) and DBP (-5 mm Hg, 95% CI -13 to 3), oral CCBs reduced SBP (MD -13 mmHg, 95% CI -43 to 17) and DBP (MD -6 mmHg, 95% CI -14 to 2), iv CCBs reduced SBP (MD -32 mmHg, 95% CI -65 to 1) and DBP (MD -13, 95% CI -31 to 6), NO donors reduced SBP (MD -12 mmHg, 95% CI -19 to -5) and DBP (MD -3, 95% CI -4 to -2) while phenylephrine, non-significantly increased SBP (MD 21 mmHg, 95% CI -13 to 55) and DBP (MD 1 mmHg, 95% CI -15 to 16).Blood pressure lowering did not reduce death or dependency either by drug class (OR 0.98, 95% CI 0.92 to 1.05), stroke type (OR 0.98, 95% CI 0.92 to 1.05) or time to treatment (OR 0.98, 95% CI 0.92 to 1.05). Treatment within six hours of stroke appeared effective in reducing death or dependency (OR 0.86, 95% CI 0.76 to 0.99) but not death (OR 0.70, 95% CI 0.38 to 1.26) at the end of the trial. Although death or dependency did not differ between people who continued pre-stroke antihypertensive treatment versus those who stopped it temporarily (worse outcome with continuing treatment, OR 1.06, 95% CI 0.91 to 1.24), disability scores at the end of the trial were worse in participants randomised to continue treatment (Barthel Index, MD -3.2, 95% CI -5.8, -0.6).

AUTHORS' CONCLUSIONS

There is insufficient evidence that lowering blood pressure during the acute phase of stroke improves functional outcome. It is reasonable to withhold blood pressure-lowering drugs until patients are medically and neurologically stable, and have suitable oral or enteral access, after which drugs can than be reintroduced. In people with acute stroke, CCBs, ACEI, ARA, beta blockers and NO donors each lower blood pressure while phenylephrine probably increases blood pressure. Further trials are needed to identify which people are most likely to benefit from early treatment, in particular whether treatment started very early is beneficial.

Severely elevated blood pressure: when is it an emergency?

High blood pressure is one of the most common chronic medical conditions in this country, occurring in about 1 of every 3 adults. It is not uncommon for nurses to see individuals in the emergency room, hospital, home, or other settings who have severely elevated blood pressure readings. Extremely elevated readings generally evoke considerable concern among healthcare staff. They are faced with deciding whether the individual requires immediate treatment and a higher level of care, such as transport to an emergency department. Severely elevated blood pressure can be a true medical emergency, may require urgent care, or may in fact be a nonemergency. The purpose of this article is to assist nurses in recognizing those situations in which severely elevated blood pressure requires immediate intervention. Current research and best evidence regarding severely elevated blood pressure are presented.

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.

A sartan derivative with a very low angiotensin II receptor affinity ameliorates ischemic cerebral damage

Angiotensin II receptor blockers (ARBs) have a potent ability to inhibit oxidative stress and advanced glycation, in addition to their protective effects originated from blood pressure lowering and angiotensin II type 1 receptor (AT(1))-blockade. To obtain a pharmacological tool to dissect the mechanisms of ARBs' protective benefits in experimental stroke, we synthesized a novel ARB-derivative, R-147176, which is 6,700 times less potent than olmesartan in AT(1)-binding inhibition and therefore has a minimal antihypertensive effect, but retains marked inhibitory effects on oxidative stress and advanced glycation. We evaluated the effect of R-147176 (10-30 mg/kg per day), administered orally or intravenously, on brain infarct volume in transient thread occlusion and photothrombotic models in rats. The antioxidative and antiinflammatory properties were also investigated. R-147176 significantly reduced infarct volume, without influence on blood pressure, in both models. R-147176 significantly reduced the numbers of ED-1-positive cells and of TUNEL-positive cells, and protein carbonyl formation in the damaged brain. This ARB derivative, despite its significantly lower AT1 affinity and virtually no antihypertensive effect, ameliorated ischemic cerebral damage through antioxidative and antiinflammatory properties. These findings suggest potential usefulness of R-147176 as a pharmacological tool to investigate the ARBs' protective effect in experimental stroke and open new therapeutic avenues.

Management of hypertension in acute stroke

Hypertension is commonly seen in the setting of an acute stroke. Although hypertension is the most important modifiable risk factor for both ischemic and hemorrhagic stroke, the immediate management of elevated blood pressure in this setting is controversial. Questions remain to be definitively answered, such as when to start lowering blood pressure, by how much to lower pressure, which pharmaceutical agents to use and whether to continue or stop previous antihypertensive medications. Recently, pilot studies have been initiated in an attempt to answer these questions and will hopefully lay the foundation for larger definitive studies.

Problems Related to Short-Term Antihypertensive Therapy in Acute Ischemic Stroke

Hypertension is a common early finding after an acute ischemic stroke, even in previously normotensive patients. But its significance and proper management are a matter of debate, because of the lack of adequately powered randomized clinical trials. A close analysis of observational and interventional trials, published so far, fails to convince that an early antihypertensive therapy is needed and beneficial. During the first 24-48 hr after ischemic stroke, only blood pressure values repeatedly higher than 220/120 mmHg require antihypertensive treatment to keep blood pressure levels in the range of 180-220 mmHg systolic and 100-120 diastolic. Blood pressure reduction should be cautious with the aim of keeping the pressure at relatively high values (180/100-105 in previously hypertensive patients and 160-180/90-100 in previously normotensive patients). The usefulness of increasing blood pressure with vasopressive agents in selected patients with ischemic stroke deserves adequate testing with randomized clinical trials.

Interventions for deliberately altering blood pressure in acute stroke

BACKGROUND

It is unclear whether blood pressure should be altered actively during the acute phase of stroke. This is an update of a Cochrane review first published in 1997, and previously updated in 2001.

OBJECTIVES

To assess the effect of altering blood pressure in people with acute stroke, and the effect of different vasoactive drugs on blood pressure in acute stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched July 2007), the Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2 2008), MEDLINE, EMBASE and other databases, reference lists of relevant publications and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials of interventions that aimed to alter blood pressure in patients within one week of acute ischaemic or haemorrhagic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and extracted data.

MAIN RESULTS

Twelve trials involving 1153 participants were included (603 participants were assigned active therapy and 550 participants received placebo/control). The trials tested angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor antagonists (ARA), calcium channel blockers (CCBs), clonidine, glyceryl trinitrate (GTN), thiazide diuretic and mixed antihypertensive therapy. One trial tested phenylephrine. At 24 hours after randomisation ACEIs reduced systolic blood pressure (SBP, mean difference, MD -6 mmHg, 95% confidence interval, CI -22 to 10) and diastolic blood pressure (DBP, MD -5 mmHg, 95% CI -18 to 7), ARA reduced SBP (MD -3, 95% CI -7 to 2) and DBP (MD -3, 95% CI -6 to 0.4), iv CCBs reduced SBP (MD -32 mmHg, 95% CI -65 to 1) and DBP (MD -13 mmHg, 95% CI -31 to 6), oral CCBs reduced SBP (MD -13 mmHg, 95% , CI -43 to 17) and DBP (MD -6 mmHg, 95% CI -14 to 2), GTN reduced SBP (MD -10 mmHg, 95% CI -18 to -3) and DBP (MD -1 mmHg, 95% CI -5 to 3) while phenylephrine, non-significantly increased SBP (MD 21 mmHg, 95% CI -13 to 55) and DBP (MD 1 mmHg, 95% CI -15 to 16). Functional outcome and death were not altered by any of the drugs.

AUTHORS' CONCLUSIONS

There is insufficient evidence to evaluate the effect of altering blood pressure on outcome during the acute phase of stroke. In patients with acute stroke, CCBs, ACEI, ARA and GTN each lower blood pressure while phenylephrine probably increases blood pressure.

A Novel Sartan Derivative With Very Low Angiotensin II Type 1 Receptor Affinity Protects the Kidney in Type 2 Diabetic Rats

Background— Antihypertensive angiotensin II receptor blockers (ARBs) protect the kidney, at least in part, independently of blood pressure lowering. Still, the extent to which blood pressure lowering is related to renoprotection remains unclear.

Methods and Results— 139 newly synthesized ARB-derivatives were assayed for inhibition of advanced glycation (AGEs). The 9 most powerful compounds were then tested for transition metal chelation, angiotensin II type 1 receptor (AT1R) affinity, and pharmacokinetic parameters. R-147176 was eventually selected as it strongly inhibits advanced glycation but is 6700 times less effective than olmesartan in AT1R binding. It is orally bioavailable and toxicologically safe. Despite a minimal blood pressure lowering effect, it provides significant renoprotection in 3 experimental rat models with renal injury, ie, obese, hypertensive, type 2 diabetic rats (SHR/NDmcr-cp), normotensive type 2 diabetic rats (Zucker diabetic fatty), and remnant kidney rats.

Conclusion— R-147176 retains renal protective properties despite a minimal blood pressure–lowering effect. Clearly, the renal benefits of ARBs do not necessarily depend on blood pressure lowering and AT1R affinity, but rather on the inhibition of AGEs and oxidative stress inherent to their chemical structure. R-147176 opens new avenues in the treatment of cardiovascular and kidney diseases.

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.

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.

A novel inhibitor of advanced glycation and endoplasmic reticulum stress reduces infarct volume in rat focal cerebral ischemia

We have developed a novel, non-toxic inhibitor of advanced glycation and oxidative stress, TM2002, devoid of effect on blood pressure. In transient focal ischemia, TM2002 significantly decreased infarct volume compared with vehicle (79.5+/-18.7 vs. 183.3+/-22.9 mm3, p<0.01). In permanent focal ischemia, TM2002 (2.79, 5.58, and 11.16 mg/kg twice a day) dose-dependently reduced infarct volume (242.1+/-32.3, 201.3+/-15.1, and 171.3+/-15.2 mm3, respectively), and improved neurological deficits. Reduction of infarct volume is demonstrable, provided that TM2002 was administered within 1.5 h after the occlusion. To unravel TM2002's mechanism of action, we examined its in vitro effect on endoplasmic reticulum (ER) stress, using aortic smooth muscle cells isolated from ORP 150(+/-) mice and F9 Herp null mutated cells. Cell death induced by ER stress (tunicamycin or hypoxia) was dose-dependently prevented by TM2002. In vivo immunohistochemical study demonstrated a significant reduction of ORP- and TUNEL-positive apoptotic cells, especially in the penumbra. Inhibition of advanced glycation and oxidative stress was confirmed by a significantly reduced number of cells positive for advanced glycation end products and heme oxygenase-1. TM2002 reduced the levels of protein carbonyl formation in ischemic caudate. The efficacy of TM2002 is equivalent to that of a known neuroprotective agent, NXY-059. In conclusion, TM2002 significantly ameliorates ischemic cerebral damage through reduction of ER stress, advanced glycation, and oxidative stress, independently of blood pressure lowering.

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.

Severe Hypertension in the Geriatric Patient—Is it an Emergency or Not?

Hypertension is a medical condition commonly seen in the outpatient setting. Primary care providers should be aware that asymptomatic hypertension, despite the degree of elevation, is rarely an emergency. Based on consensus guidelines from the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and the lack of any evidence showing harm, extreme blood pressure elevations do not need acute treatment. This article provides evidence for the argument that hypertension is rarely an emergency at all; even patients who have exceedingly high blood pressure can be treated as outpatients.

Overuse of antihypertensives in patients with acute ischemic stroke

BACKGROUND

The Stroke Council of the American Heart Association/American Stroke Association (AHA/ASA) recommends conservative management of hypertension (HTN) during acute ischemic stroke (AIS), although clinicians often manage blood pressure more aggressively. Our hypothesis was that aggressive management of HTN in patients with AIS is associated with hypotensive events and worsened neurologic outcomes.

METHODS

The study was a retrospective, observational cohort of patients who were admitted to the hospital with AIS. Classification of neurologic outcomes was based on nurses' neurologic assessments and were categorized as "worsened," "stayed the same," or "improved." The accuracy of these assessments was verified by review of physician's progress notes. Management of arterial HTN was recorded in all patients.

RESULTS

Fifty medical records of patients with AIS who met inclusion criteria were reviewed. While only 22% of patients met the AHA/ASA criteria for hypertension treatment, 98% of the cohort were given antihypertensive therapy. Relative hypotension occurred in 64% of treated patients. Absolute hypotension associated with antihypertensive medications was uncommon but did occur in 2 of 15 patients who experienced neurologic worsening (13%), in 1 of 28 (3%) of patients who stayed the same, and in none of those who improved. Blood pressure was reduced excessively in all 11 of the patients who met AHA/ASA guidelines for treatment.

CONCLUSIONS

Adherence to AHA/ASA guidelines for HTN management during AIS was poor. Initiation or intensification of antihypertensive drugs was not associated with worsened neurologic outcomes. Furthermore, relative hypotension, absolute hypotension and excessive reductions in blood pressure were not associated with worsened neurologic outcomes.

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 variability in acute ischemic stroke depends on hemispheric stroke location

The relationship between blood pressure (BP) variability and stroke location was examined in 85 patients admitted with acute ischemic stroke. The patients were divided into three groups according to stroke location: right hemisphere (32 patients), left hemisphere (30 patients) and non-localized (23 patients). BP upon admission was 147.94/76.53 +/- 20.72/13.70 mmHg in the right hemisphere group, 151.81/76.10 +/- 25.69/16.23 mmHg in the left hemisphere and 155.23/83.41 +/- 30.45/15.74 in the non-localized group. The left hemisphere group had significantly (p < 0.01) greater variations in systolic and diastolic BP between days 2 and 3 and in systolic BP between days 3 and 4 after stroke compared with the other groups. BP in the left hemisphere group was less stable than in the other two groups. Non-localized patients without pre-existing hypertension had a significantly lower and more stable BP during the week following stroke than non-localized patients with pre-existing hypertension. Non-localized patients with pre-existing hypertension had the highest BP and showed no improvement during the week. Systolic BP tended to be higher and less stable in left hemisphere patients than in right hemisphere, whereas among non-localized ischemic stroke patients BP was higher in those who had a prior diagnosis of hypertension.

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.

Hypertensive emergency and severe hypertension: what to treat, who to treat, and how to treat

Remember to treat patients, not numbers. Use fast acting shortterm medicines only when convincing evidence of rapidly evolving end-organ damage is present. For all patients, emergent or asymptomatic, the treatment goal is long-term control of hypertension. Potent IV agents for the im-mediate control of elevated blood pressure need to be used cautiously,bearing in mind both the side effects and the hazards of overly rapid control of hypertension. Conventional oral medication regimens demonstrated to modify the risks of chronic hypertension should be used whenever possible and as early as is practical to promote gradual control of hypertension. Whenever a patient presents for the evaluation of severe hypertension in an emergent setting, take the opportunity to encourage appropriate ongoing follow-up; after all, hypertension is not a single episode, it is an ongoing threat to good health.

Advances in stroke neuroprotection: hyperoxia and beyond

Refinements in patient selection, improved methods of drug delivery, use of more clinically relevant animal stroke models, and the use of combination therapies that target the entire neurovascular unit make stroke neuroprotection an achievable goal. This article provides an overview of the major mechanisms of neuronal injury and the status of neuroprotective drug trials and reviews emerging strategies for treatment of acute ischemic stroke. Advances in the fields of stem cell transplantation, stroke recovery, molecular neuroimaging, genomics, and proteomics will provide new therapeutic avenues in the near future. These and other developments over the past decade raise expectations that successful stroke neuroprotection is imminent.

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.

Risk-benefit effects of tocolytic therapy

Tocolytics are potent drugs that are used to interdict preterm labour. Although all of these agents have some side effects, if not frankly adverse effects under certain clinical situations, two of these drugs, the beta-mimetics and magnesium sulphate (MgSO(4)), have been found to have considerable potential for adverse maternal cardiovascular and respiratory effects. Furthermore, magnesium sulphate has been shown to have harmful, indeed, sometimes lethal, effects in some babies. Although less well established, NSAIDs, the most common example of which is indomethacin, also have some important adverse effects in fetuses. Within the limits of contemporary scientific knowledge, calcium channel blockers, such as nifedipine, appear to be among the more efficacious and safer drugs that are currently being used for tocolysis.

Adverse events associated with aggressive treatment of increased blood pressure

Patients with severely increased blood pressure often present to the emergency department. Rapid lowering of blood pressure can precipitate or worsen end organ damage. We report two cases that developed cerebrovascular and cardiovascular adverse events associated with aggressive treatment of increased blood pressure by the use of sublingual nifedipine capsule. The first patient had developed ischaemic stroke; the second patient actually had acute left ventricular failure causing deteriorated, and required positive inotropic treatment for persistent hypotension. These cases emphasise that the pseudoemergency may rapidly progress into a real emergency when blood pressure is rapidly and aggressively reduced.

Factors influencing acute blood pressure values in stroke subtypes

The aim of this prospective observational study was to determine the association of acute blood pressure values with independent factors (demographic, clinical characteristics, early complications) in stroke subgroups of different aetiology. We evaluated data of 346 first-ever acute (<24 h) stroke patients treated in our stroke unit. Casual and 24-h blood pressure (BP) values were measured. Stroke risk factors and stroke severity on admission were documented. Strokes were divided into subgroups of different aetiopathogenic mechanism. Patients were imaged with CT-scan on admission and 5 days later to determine the presence of brain oedema and haemorrhagic transformation. The relationship of different factors to 24-h BP values (24-h BP) was evaluated separately in each stroke subgroup. In large artery atherosclerotic stroke (n=59), history of hypertension and stroke severity correlated with higher 24-h BP respectively. In cardioembolic stroke (n=87), history of hypertension, stroke severity, haemorrhagic transformation and brain oedema were associated with higher 24-h BP, while heart failure with lower 24-h BP. History of hypertension and coronary artery disease was related to higher and lower 24-h BP, respectively, in lacunar stroke (n=75). In patients with infarct of undetermined (n=57) cause 24-h BP were mainly influenced by stroke severity and history of hypertension. An independent association between higher 24-h BP and history of hypertension and cerebral oedema was documented in intracerebral haemorrhage (n=68). In conclusion, different factors influence acute BP values in stroke subtypes of different aetiology. If the clinical significance of these observations is verified, a differentiated approach in acute BP management based on stroke aetiology may be considered.

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.

The 5 Ps of acute ischemic stroke treatment: parenchyma, pipes, perfusion, penumbra, and prevention of complications

Stroke is a treatable disease. Despite the therapeutic nihilism of the past, the advent of thrombolysis has changed the way stroke is approached. Acute ischemic stroke is a challenging and heterogeneous disease. Treatment needs to be based on an understanding of the underlying pathophysiology of ischemia. Interventions are designed to improve neuronal salvage and outcome. The underlying tenets of stroke therapy focus on the brain parenchyma, arterial flow (pipes), perfusion, the ischemic milieu or penumbra, and prevention of complications. This article focuses on the practical issues of ischemic stroke care, with a brief review of supporting literature.

Adverse and beneficial effects of tocolytic therapy

In addition to questions raised about the efficacy of many tocolytics, appropriate concern has been voiced about the safety of these potent drugs. Although some degree of risk for adverse effects with drugs promising a strong therapeutic effect can be accepted, caution needs to be exercised when benefits are marginal or unproven. Unfortunately, some of the tocolytics, most notably the betamimetics and magnesium sulfate, have been found to have considerable potential for adverse maternal cardiovascular and respiratory effects. Although less clearly established, the use of indomethacin appears to be associated with increased fetal and neonatal risks. Concerning magnesium sulfate, in addition to the well-known maternal effects, the accumulating evidence showing an increased frequency of adverse outcomes in the fetus and neonate has led to the recommendations to abandon its use entirely as a tocolytic. Given the limitations of our current state of knowledge, nifedipine would appear to be among the more efficacious and safer tocolytics available to use when properly indicated.