Practical management of the patient who has severe, asymptomatic hypertension
The essential questions for primary care providers who take care of the elderly are these: what happens to patients who have untreated, severely elevated blood pressures? What if there pressure remains high for weeks to months? Should an attempt be made to reduce someone’s blood pressure if it is markedly elevated?
In a study conducted in 1967, 143 patients who had diastolic blood pressures ranging from 115 to 129 mm Hg were assigned randomly to antihypertensive treatment or placebo.
During the first 3 months of follow-up there were no adverse events [11]. Another study by Zeller [12] investigated whether acute antihypertensive loading in the emergency department improved short-term control of blood pressure. In this study, 74 asymptomatic patients who had diastolic pressures between 116 and 139 mm Hg who presented to an emergency department were assigned randomly to one of three regimens: hourly doses of clonidine until the diastolic pressure fell by 20 mm Hg, four hourly doses of placebo, or immediate discharge. All patients were prescribed the same antihypertensive regimen on discharge. The results indicated that the mean blood pressure was similar in all three groups at 24 hours and at 1 week after discharge. The conclusion from this study is that acute loading of antihypertensive medications is unlikely to improve short-term control of blood pressure. Although these two studies are small, they highlight the evidence that there is not a benefit in lowering blood pressure acutely.
An important concept in the evaluation of severely elevated blood pressure, whether in the office or emergency department, is regression to the mean. This term refers to a blood pressure that lowers spontaneously after serial measurements without any intervention. This phenomenon is important, because markedly elevated blood pressures tend to prompt many clinicians to initiate acute reduction of blood pressure or immediate referral for definitive treatment of blood pressure [13]. Blood pressure measurement should be repeated in the sitting position at least twice before treatment decisions are made.
Aside from the patient who has an obvious hypertensive emergency or suspicion of such, how should patients who have true, severely elevated but asymptomatic hypertension be evaluated? Should these patients be transported to a higher level of care for definitive reduction of blood pressure? At what blood pressure level does it become advisable to transfer the patient?
There is no evidence to support the notion that acute reduction of blood pressure reduces cardiovascular events in the short or long term. In fact, many cases of harm have been documented. In a commonly cited article published in 1996, the authors note an alarming number of adverse events related to lowering blood pressure rapidly in the acute setting [14]. In addition, multiple case reports published in the emergency medicine literature have documented the same complications. In an article by Fischberg and colleagues [15], the authors report six cases of patients who had initiation or worsening of neurologic deficits induced by administration of oral antihypertensive medications.
In 2006, The American College of Emergency Physicians published a clinical policy on the evaluation and treatment of the asymptomatic patient who has elevated blood pressure. This policy states, “Initiating treatment for asymptomatic hypertension in the emergency department is not necessary when patients have follow-up.” In addition, “Rapidly lowering blood pressure in asymptomatic patients in the emergency department is unnecessary and may be harmful in some patients” [16]. Physicians who provide care for the elderly should realize that asymptomatic patients who do not have end-organ damage or significant comorbid illnesses who are sent to the emergency department to be evaluated probably will not have acute reduction of blood pressure attempted. In addition, asymptomatic patients in stable condition are likely to be discharged from the emergency department with elevated, sometimes markedly elevated, blood pressure.
The recommendations of the seventh Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and antihypertensive medication
There is a plethora of literature on the appropriate antihypertensive agent to prescribe for treatment of patients who have elevated blood pressure. What then, should the practicing geriatrician choose as an initial medical regimen? Data seem to suggest that a low-dose thiazide diuretic is a reasonable first choice as an antihypertensive. Data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial recommend a thiazide diuretic as a first-line antihypertensive agent [17]. A common mistake in clinical practice, however, is assuming that a 25-mg/d dose of hydrochlorothiazide will effectively lower a patient’s blood pressure that is greater than 160/110 mm Hg. Data from the JNC-7 indicate that such patients should be prescribed a minimum of two agents initially [1]. A reasonable second agent is an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker, because activation of the renin-angiotensin-aldosterone system may occur after initiation of a diuretic agent [17].
Evaluation of end-organ damage
End-organ damage secondary to hypertension may be discovered by findings in the history, physical examination, or laboratory analysis. In the office, relatively few laboratory tests are readily available to the primary care physician. Traditional tests ordered for patients who have severely elevated blood pressure include measurement of renal function (serum creatinine level), electrocardiography, urinalysis, and, in some instances, a chest radiograph. The extent of work-up in an outpatient setting obviously is based on the availability of these specific tests. Patient symptoms also should be taken into consideration when the possibility of a hypertensive emergency exists. The presence of chest pain, dyspnea, severe headache, altered mental status, or strokelike symptoms suggests the possibility of a hypertensive emergency even before any testing has been undertaken.
There is little evidence to support most of the screening tests for end-organ damage. Nonetheless, many patients undergo extensive laboratory testing and radiography. In a study examining the clinical utility of obtaining a urinalysis to rule out renal dysfunction in the severely hypertensive patient, a urine dipstick negative for blood and protein was 100% sensitive in detecting elevations in serum creatinine [18]. Although the confidence intervals were wide, the study does indicate that a screening urinalysis may be of some benefit in screening for renal dysfunction. In a study by Bartha and Nugent [19], chest radiographs and electrocardiograms were performed in 116 patients who had severely elevated blood pressures. Therapeutic or diagnostic decisions were changed in only 2 of the 116 patients, and neither influenced management of hypertension. Unless patient symptoms warrant these studies, they will not be particularly helpful in the treatment of the patient. Left ventricular hypertrophy on 12-lead ECG is a common finding and does indicate that an emergency is present. The data on the usefulness of screening patients who have severely elevated but asymptomatic hypertension are limited [16].
Referral to a higher level of care???emergency department and inpatient referral
In some instances it is appropriate to send a patient to a higher level of care for further evaluation and therapy. In most instances the higher level of care is an emergency department or inpatient unit. All patients who have evidence of a hypertensive emergency should be transported to a higher level of care. In addition, patients who have severely elevated blood pressures in the setting of comorbid conditions such as congestive heart failure or recent myocardial infarction should be transferred. Given the lack of evidence of benefit for acute blood pressure reduction, truly asymptomatic patients, despite the degree of blood pressure elevation, do not need to be transferred. Instead, careful titration of antihypertensive medications should be undertaken with plans for close follow-up.
Summary
High blood pressure is indeed one of the most common chronic health problems and is one that primary care providers face on a daily basis. Proper titration of blood pressure medication to achieve a desired blood pressure is a time-consuming but important part of the primary care of the older patient. Because the adage “do no harm” is even more important in the elderly population, primary care physicians who take care of older patients must understand that any attempt to lower an asymptomatic elderly patient’s blood pressure acutely is fraught with complications. Although blood pressure values such as 230/120 mm Hg might prompt the primary care provider to transfer a patient to the emergency department or to “lower the numbers” acutely, no evidence exists to support this treatment strategy. Indeed, some authorities might consider this dangerous and frank malpractice.
References
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[2] D. Cherry and D. Woodwell, National Ambulatory Medical Care Survey: 2000 summary, Adv Data 328 (2002), pp. 1???32.
[3] Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, Arch Intern Med 157 (1997), pp. 2413???2446.
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[7] P. Shayne and S. Pitts, Severely increased blood pressure in the emergency department, Ann Emerg Med 41 (2003), pp. 513???529.
[8] W. Powers, Acute hypertension after stroke: the scientific basis for treatment decisions, Neurology 43 (1993), pp. 461???467.
[9] S. Strandgaard, Autoregulation of cerebral blood flow in hypertensive patients. The modifying influence of prolonged antihypertensive treatment on the tolerance to acute, drug-induced hypotension, Circulation 53 (1976), pp. 720???727.
[10] S. Strandgaard and O. Paulson, Regulation of cerebral blood flow in health and disease, J Cardiovasc Pharmacol 19 (1992) (Suppl 6), pp. s89???s93.
[11] Veterans Administration Cooperative Study Group on Antihypertensive Agents, Effects of treatment on morbidity in hypertension. Results in patients with diastolic blood pressures averaging 115-129 mm Hg, JAMA 202 (1967), pp. 1028???1034.
[12] K. Zeller, Rapid reduction of severe asymptomatic hypertension: a prospective controlled trial, Arch Intern Med 149 (1989), pp. 2186???2189.
[13] S. Pitts and R. Adams, Emergency department hypertension and regression to the mean, Ann Emerg Med 31 (1998) (2), pp. 214???218.
[14] E. Grossman and F. Messerli, Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies?, JAMA 276 (1996), pp. 1328???1331.
[15] G. Fischberg, E. Lozano and K. Rajamani, Stroke precipitated by moderate blood pressure reduction, J Emerg Med 19 (2000) (4), pp. 339???346.
[16] W. Decker, S. Godwin and E. Hess, Clinical policy: critical issues in the evaluation and management of adult patients with asymptomatic hypertension in the emergency department, Ann Emerg Med 47 (2006), pp. 237???249.
[17] H.N. Siragy, Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs. diuretic: the Antihypertesive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), Curr Hypertens Rep 5 (2003) (4), pp. 293???294.
[18] D. Karras, K. Heilpern and L. Riley, Urine dipstick as a screening test for serum creatinine elevation in emergency department patients with severe hypertension, Acad Emerg Med 9 (2002), pp. 27???34.
[19] G. Bartha and C. Nugent, Routine chest roentgenograms and electrocardiograms. Usefulness in the hypertensive workup, Arch Intern Med 138 (1978), pp. 1211???1213.
Robert L. Rogers MD, FAAEM, FACEP, FACP and Robert S. Anderson, Jr. MD
Department of Emergency Medicine, The University of Maryland School of Medicine, 110 South Paca Street, Suite 200, 6th floor, Baltimore, MD 21201, USA
Department of Medicine, The University of Maryland School of Medicine, 22 South Greene Street, Baltimore, MD 21201, USA