8: 54-year-old man with elevated blood pressure Flashcards
When to Screen for High Blood Pressure
The United States Preventive Service Task Force (USPSTF) makes evidence-based recommendations about screening for diseases with poor outcomes that could be prevented through early detection and treatment.
The USPSTF recommends screening for high blood pressure in adults aged 18 years or older. The USPSTF recommends obtaining measurements outside of the clinical setting for diagnostic confirmation before starting treatment.
Evaluation of a patient with a possible new diagnosis of hypertension has three goals:
- Assess for the presence or absence of target end organ disease.
- Assess cardiovascular risk factors or concomitant disorders that may affect prognosis and guide treatment.
- Reveal identifiable causes of hypertension.
- Assess for the presence or absence of target end organ disease. Untreated or poorly treated hypertension can lead to serious complications in several organs, including the:
Heart - Left ventricular hypertrophy, angina or myocardial infarction, heart failure.
Brain - Cerebrovascular accident or transient ischemic attack.
Kidneys - Chronic renal failure.
Blood vessels - Peripheral vascular disease. Eyes - Retinopathy.
Thus, it is important to ask about signs or symptoms of end organ disease in these areas, such as any history of congestive heart failure, cardiovascular disease (CVD) or symptoms, renal disease, peripheral vascular disease, or retinopathy. It is also appropriate to ask about history of known hypertension and duration. A patient with more than 10 years of hypertension may already have end-stage organ disease.
- Assess lifestyle and identify other cardiovascular risk factors or concomitant disorders that may affect prognosis and guide treatment.
Diabetes Hypercholesterolemia Obesity Smoking Increased age Family history of premature CVD (men under age 55, women under age 65) Physical inactivity Chronic kidney disease (estimated GFR less than 60 mL/minute) Unhealthy diet
- Reveal identifiable causes of high blood pressure:
Obstructive sleep apnea Primary aldosteronism Renovascular disease Renal parenchymal disease Drug or alcohol induced (including NSAIDS, sympathomimetics, cocaine, etc.) Pheochromocytoma Coarctation of the aorta Thyroid or parathyroid disease Cushing's syndrome Primary hyperparathyroidism
- Other appropriate questions include:
Family history of diabetes and/or hypercholesterolemia
Diet history
A review of psychosocial stressors: Stress leads to the release of cortisol and norepinephrine (flight or fight syndrome) which can elevate blood pressure; stressors can also make prioritizing adherence to blood pressure medicines difficult.
Causes of Hypertension
95% to 98% of the hypertension diagnosed in the United States is essential hypertension - chronically higher blood pressure readings than normal with no underlying identifiable cause.
Htn with an identifiable cause is far less common and is known as secondary hypertension. Testing for secondary causes of htn is appropriate if htn increases in severity, has a poor response to treatment, or if a patient has history or physical exam findings that point to a secondary cause.
Criteria for Diagnosing Hypertension
In order to accurately diagnose a patient with hypertension, at least two elevated measurements - five minutes apart, one in each arm - should be made on two or more visits. This is often difficult to achieve in a busy medical practice, so it is important to double check before definitive diagnosis or making a recommendation for treatment. As noted previously, the USPSTF also recommends obtaining measurements outside of the clinical setting for diagnostic confirmation before starting treatment.
A patient cannot be diagnosed with hypertension if the patient is acutely ill or in acute pain at the time of the measurement.
The measurements are required in each arm because on rare occasions, you may encounter an adult with an aortic anomaly - such as coarctation of the aorta - and blood pressure will be high in the right arm but low on the left.
Important Elements of the Physical Exam in Patients with Hypertension
Body mass index (BMI) Funduscopic eye examination Auscultate for carotid, abdominal, and femoral bruits Palpation of the thyroid gland Lung examination Heart examination Abdominal examination Lower extremity examination Conduct a neurologic assessment
Hypertension Managment: Thiazide Diuretics
Thiazides may affect electrolyte levels and cause hyponatremia or hypokalemia, and thus require periodic monitoring of blood electrolytes.
Thiazide diuretics should be used with caution in patients with a history of gout as they may precipitate flares. Patients on uric acid lowering therapy are less likely to experience a flare.
Thiazide diuretics may cause elderly patients to become incontinent of urine. Aging decreases bladder capacity, decreases time of awareness of need to void, increased detrusor instability decreased pelvic floor muscles, incomplete emptying, and atrophic urethral changes. Thiazide diuretics may exacerbate problems for those on the threshold or already incontinent of urine.
Thiazides have demonstrated marked reduction in morbidity and mortality from hypertension in comparison to newer, more expensive antihypertensive medications. Studies have also demonstrated that despite the availability of 50 mg hydrochlorothiazide tablets, doses of hydrochlorothiazide above 25 mg do not decrease blood pressure further or further reduce morbidity and mortality rates. A 2004 JAMA meta-analysis of clinical studies indicated that low-dose (12.5 to 25 mg/d chlorthalidone or hydrochlorothiazide) and high-dose (50 mg/d or more of both drugs) diuretic therapy lowered blood pressure to a similar degree and exerted a similar benefit in reducing stroke, congestive heart failure, cardiovascular and total mortality, but only low-dose diuretic therapy significantly reduced coronary heart disease incidence. A 2009 Cochrane review reinforced that no other drug class improved health outcomes better than low-dose thiazides, and beta-blockers and high-dose thiazides were found to be inferior.
Thiazide diuretics should be started at lower doses such as 6.25mg or 12.5mg/d in elderly patients, because this population may be more sensitive to this drug class and may experience hypotensive episodes or electrolyte abnormalities. Most other adults can start at 25mg/d.
Lifestyle Modifications to Decrease Blood Pressure
Weight loss
1 mmHg/kilogram weight loss
DASH eating plan
~11 mmHg
Dietary sodium reduction
4-6 mmHg
Physical activity
5-8 mmHg
Moderation of alcohol consumption
~6 mmHg
Dietary potassium
4-5 mmHg
Lifestyle Modifications to Decrease Blood Pressure
Weight reduction: Achieved through a combination of reduced calorie intake and exercise, or with pharmacotherapy or bariatric surgical procedures if needed.
Adopt DASH eating plan: Consume a diet rich in fruits, vegetables, and low-fat dairy products with a reduced content of saturated and total fat.
Dietary sodium reduction: Reduce dietary sodium intake by about 25% (usually about 1,000 mg per day) by eating fresh foods, checking labels to ensure that there is “no added sodium,” minimizing the addition of salt to food at the table, and other measures.
Physical activity: Engage in regular aerobic physical activity (at least 30 minutes per day, most days of the week).
Moderation of alcohol consumption: Limit consumption to no more than 2 drinks (e.g., 24 oz beer, 10 oz wine, or 3 oz 80-proof whiskey) per day in most men, and to no more than 1 drink per day in women and lighter weight persons.
Dietary potassium: Good sources of potassium include fresh fruits and vegetables, low-fat dairy products, some fish and meats, nuts, and soy products. The DASH eating plan is high in potassium content.
When to Initiate Aspirin in Patients with Hypertension
The USPSTF recommends initiating low-dose aspirin use for the primary prevention of cardiovascular disease (CVD) and colorectal cancer (CRC) in adults aged 50 to 59 years who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years.
For older patients (ages 60-69) who have a 10% or greater 10-year CVD risk, the decision to initiate low-dose aspirin use for the primary prevention of CVD and CRC should be an individual one. Persons who are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years are more likely to benefit. Persons who place a higher value on the potential benefits than the potential harms may choose to initiate low-dose aspirin.
There is insufficient evidence to assess the benefits and harms of aspirin prophylaxis in patients younger than 50 and older than 69.
Approach to the Treatment of Hypertension
Goal blood pressure for patients with hypertension is <130/80 mmHg. If a diuretic has been started and this goal is not met at follow-up visits, sequential addition of medications from the other preferred classes (calcium channel blockers, ACE-Inhibitors, Angiotensin Receptor Blockers) should be added.
IMPORTANT: Always avoid combined use of an ACE-I and an ARB to avoid the risk of hyperkalemia and worsening kidney function.
Throughout treatment, lifestyle modifications should be continually discussed and encouraged.
There are other medications (for example: loop diuretics, beta blockers, alpha blockers) that may be used if patients are unable to tolerate medications from the preferred classes, or if goal blood pressure has not been reached despite their use (in this case, a search for causes of secondary hypertension may also be warranted).
Thiazides
Chlorthalidone is preferred on the basis of prolonged half-life and proven trial reduction of CVD.
Monitor for hyponatremia and hypokalemia, monitor uric acid and calcium levels.
Use with caution in patients with history of acute gout unless patient is on uric acid– lowering therapy.
