Hypertension

Management Cont.

- In the practice guidelines, the determination of risk includes the evaluation of three factors: (1) the risk imposed by the patient's cardiovascular disease, (2) the risk imposed by the surgery or procedure, and (3) the risk imposed by the functional reserve or capacity of the patient. -Perioperative cardiac risk is increased in patients who are unable to meet a 4-MET demand during most normal daily activities, which is equivalent to climbing a flight of stairs. Thus, a patient who reports inability to climb a flight of stairs without chest pain, shortness of breath, or fatigue would be at increased risk during a procedure. -long stressful appointments to be avoided -short morning appointments are best -If the patient becomes anxious or apprehensive during the visit, the appointment may be terminated and rescheduled for another day. Anxiety can be reduced for many patients by oral premedication with a short-acting benzodiazepine such as triazolam -Nitrous oxide plus oxygen for inhalation sedation is an excellent intraoperative anxiolytic for use in patients with hypertension. Care is indicated to ensure adequate oxygenation at all times, avoiding postdiffusion hypoxia at the termination of administration. If the blood pressure rises above 179/109 mm Hg, the procedure should be terminated, the patient referred to his or her physician, and the appointment rescheduled. -Ambulatory (outpatient) general anesthesia in the dental office generally is recommended only for patients whose status on the American Society of Anesthesiologists (ASA) classification is ASA I (status of a healthy, normal patient) or ASA II (presence of mild to moderate systemic disease)

Epi

-A metaanalysis of several clinical studies determined that the mean resting venous plasma epinephrine concentration is 39 pg/mL; this is approximately doubled by the intraoral injection of a single cartridge of 2% lidocaine with 1 : 100,000 epinephrine. 20 This resulting elevation in plasma epinephrine is linear and dose-dependent. Although large doses of epinephrine may cause a significant rise in blood pressure and heart rate, small doses such as those contained in one or two cartridges of lidocaine with 1 : 100,000 epinephrine cause minimal physiologic changes -After injection of 1.8 mL (one cartridge), plasma levels increased two- to three-fold, but no significant changes were observed in heart rate or blood pressure. -With 5.4 mL of solution (three cartridges), however, plasma levels increased five- to six-fold; these changes were accompanied by significant increases in heart rate and systolic blood pressure, but with no adverse symptoms or sequelae -the increased risk of adverse events among patients with uncontrolled hypertension was low, and the reported occurrence of adverse events associated with the use of epinephrine in local anesthetic agents was minimal. -Thus, the existing evidence indicates that use of modest doses (one or two cartridges of 2% lidocaine with 1 : 100,000 epinephrine) carries little clinical risk in patients with hypertension, the benefits of its use far outweighing any potential problems. - Levonordefrin should be avoided in patients with hypertension, however, because of its comparative excessive α 1 stimulation. -A reasonable conclusion from all of the available evidence is that the benefits of use of epinephrine outweigh the increased risks, so long as modest doses (e.g., one or two carpules) are used at one time, and care is taken to avoid inadvertent intravascular injection. -Topical vasoconstrictors generally should not be used for local hemostasis in patients with hypertension. As an alternative, one study reported that tetrahydrozoline (Visine; Pfizer Inc, New York, New York), oxymetazoline (Afrin; Schering-Plough, Summit, New Jersey), and phenylephrine (Neo-Synephrine; Bayer, Morristown, New Jersey) may be used to soak the cord, providing hemostatic effects similar to those obtained with epinephrine but with minimal cardiovascular effects.

Etiology

-About 90% of patients have no readily identifiable cause for their disease, which is referred to as primary (essential) hypertension. In the remaining 10% of patients, an underlying cause or condition may be identified; for these patients, the term secondary hypertension is applied. -A linear relationship exists between blood pressures at any level above normal and an increase in morbidity and mortality rates from stroke and coronary heart disease. Blood pressures above 115 mm Hg systolic and 75 mm Hg diastolic are associated with increased risk of cardiovascular disease. -For every increase in blood pressure of 20 mm Hg systolic and 10 mm Hg diastolic, a doubling of mortality related to ischemic heart disease and stroke occurs.

What are the major risk factors of increased perioperative cardiovascular risk

-Acute or recent MI -Unstable or severe angina -decompensated heart failure -significant arrythmias -severe valvular disease

Potential issues

-Antibiotics: avoid erythromycin and clarithromycin with Ca2+ channel blockers because the combo can increase hypotension -Analgesics: avoid for long term (.>2weeks) these meds can interfere with some antihypertensives -Anesthesia: levonordefrin should be avoided. Use of epi may be tolerated but should be discussed with physician if >180/110. -Anxiety: pts. with hypertension and anxiety are good candidates for preoperative oral and intraoperative oral sedation -Chair position: avoid rapid changes which could cause orthostatic hypertension secondary to anit-hypertensives -Drugs: epi can react with Beta blockers but is dose dependent and very unlikely -Devices: patients with BP greater than 160/100 periodic monitoring

Signs and symptoms

-Before the age of 50, hypertension typically is characterized by an elevation in both diastolic and systolic pressures. Isolated diastolic hypertension, defined as a systolic pressure of 140 or less and a diastolic pressure of 90 or greater, is uncommon and most often is found in younger adults -Isolated systolic hypertension is defined as a systolic pressure of 140 or higher and a diastolic blood pressure of 90 or less; it generally is found in older patients and constitutes an important risk factor for cardiovascular disease. -Occasionally, isolated systolic blood pressure elevation is found in older children and young adults, often male. In these age groups, this form of hypertension is due to the combination of rapid growth in height and very elastic arteries, which accentuate the normal amplification of the pressure wave between the aorta and the brachial artery, resulting in high systolic pressure in the brachial artery but normal systolic pressure in the aorta. -The earliest sign of hypertension is an elevated blood pressure reading; however, funduscopic examination of the retina may show early changes of hypertension consisting of narrowed arterioles with sclerosis. -but when symptoms do occur, they include headache, tinnitus, and dizziness. These symptoms are not specific for hypertension, however, and may be experienced just as commonly by normotensive persons. -Persons with hypertension may report fatigue and coldness in the legs, resulting from the peripheral arterial changes that may occur in advanced hypertension. Patients with hypertension often demonstrate an accelerated cognitive decline with aging.

Management

-For hypertensive patients with diabetes or kidney disease, however, the goal is less than 130/80 mm Hg. For regular goal is <140/90 -Those most commonly used include thiazide diuretics, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), beta blockers (BBs), and calcium channel blockers (CCBs). -If lifestyle modification is ineffective at lowering blood pressure adequately, then thiazide diuretics are most often the first drugs of choice, given either alone or in combination with ACEIs, ARBs, BBs, or CCBs, depending on the degree of elevation of blood pressure. -Patients with severe, uncontrolled hypertension, defined as blood pressure of 180/110 or higher, may require urgent or immediate treatment, including hospitalization. -Hypertensive emergencies are characterized by a severe elevation in blood pressure with evidence of impending or progressive target organ dysfunction such as hypertensive encephalopathy, intracerebral hemorrhage, acute MI, left ventricular failure with pulmonary edema, or unstable angina pectoris. -Patients with severe hypertension but with less ominous clinical signs and symptoms such as headache, shortness of breath, nosebleeds, or severe anxiety require urgent treatment, but this level of hypertension does not constitute an emergency. The underlying problem in these patients most often is found to be noncompliance or an inadequate medication regimen. They should receive timely treatment to reduce blood pressure but without the immediacy of concern associated with evidence of progressive target organ damage.

Guidelines

-In summary, patients with blood pressures less than 180/110 mm Hg can undergo any necessary dental treatment, both surgical and nonsurgical, with very little risk of an adverse outcome. -For patients found to have asymptomatic blood pressure of 180/110 mm Hg or greater (uncontrolled hypertension), elective dental care should be deferred, and a physician referral for evaluation and treatment within 1 week is indicated. - Patients with uncontrolled blood pressure associated with symptoms such as headache, shortness of breath, or chest pain should be referred to a physician for immediate evaluation. In patients with uncontrolled hypertension, certain problems such as pain, infection, or bleeding may necessitate urgent dental treatment.

Prehypertension

-Prehypertension is not a disease but rather a designation that reflects the fact that these patients are at increased risk for the development of hypertension. Lifestyle modifications include losing weight; adopting a diet rich in vegetables, fruits, and low-fat dairy products; reducing intake of foods high in cholesterol and saturated fats; decreasing sodium intake; limiting alcohol intake; and engaging in daily aerobic physical activity -DASH (dietary approaches to stop hypertension) - It is considered essential that patients with prehypertension, as well as those with diagnosed hypertension, follow these recommendations, because lifestyle modifications have been shown to effectively reduce blood pressure, prevent or delay the incidence of hypertension, enhance antihypertensive drug therapy, and decrease cardiovascular risk.

Problems with non selective Beta blockers

-The basis for concern with use of nonselective β-adrenergic blocking agents (e.g., propranolol) is that the normal compensatory vasodilatation of skeletal muscle vasculature mediated by β 2 receptors is inhibited by these drugs, and injection of epinephrine, levonordefrin, or any other pressor agent may result in uncompensated peripheral vasoconstriction because of unopposed stimulation of α 1 receptors. This vasoconstrictive effect could potentially cause a significant elevation in blood pressure and a compensatory bradycardia.

Dental Management

-When a patient with upper-level stage 2 blood pressure is receiving dental treatment, consideration should be given to leaving the blood pressure cuff on the patient's arm and periodically checking the pressure during the appointment. The dentist should not make a diagnosis of hypertension but rather should inform the patient that the blood pressure reading is elevated, and that a physician should evaluate the condition. -The primary concern in dental management of a patient with hypertension is that during the course of treatment, a sudden, acute elevation in blood pressure might occur, potentially leading to a serious outcome such as stroke or MI. -Other concerns include potential drug interactions between the patient's antihypertensive medications and the drugs used in dental practice, and oral adverse effects that may be caused by antihypertensive medications. -What are the associated risks of treatment in this patient? -At what level of blood pressure is treatment unsafe for the patient?

Prevalence

-With 35 million office visits annually, hypertension is the most common primary diagnosis in America. -Isolated systolic hypertension gradually increases with age such that among patients older than 50 years of age, it is the most prevalent form of hypertension. -The prevalence of high blood pressure increases with aging, such that more than half of all Americans aged 65 and older have hypertension. 6 If people live long enough, more than 90% will develop hypertension. -Isolated diastolic hypertension most commonly is seen before age 50. Diastolic blood pressure is a more potent cardiovascular risk factor than is systolic blood pressure until age 50; thereafter, systolic blood pressure is more important. -Prevalence varies with race as well and is highest among African Americans.

What are the minor risk factors of increased perioperative cardiovascular risk

-advanced age (>70) -Abnormal ECG -Rhythm other than sinus rhythm -Uncontrolled systemic hypertension (greater than 180/110) -head and neck surgery carries an intermediate cardiac risk of less than 5%

Calcium channel blockers

-can cause gingival overgrowth

What are the intermediate risk factors of increased perioperative cardiovascular risk

-history of ischemic disease -history of compensated or previous heart failure -history of cerebrovascular disease -diabetes mellitus -Renal insufficiency

Lab findings

-including 12-lead electrocardiogram, urinalysis, blood glucose, hematocrit, and a serum potassium, creatinine, calcium, and lipid profile.

What are the most common causes of secondary hypertension

-sleep apnea -drug induced or drug related -chronic kidney disease -primary aldosteronism -renovascular disease -Chronic steroid therapy and cushings syndrome -Pheochromocytoma -coarctation of the aorta -thyroid or parathyroid disease

White Coat Syndrome

About 15% to 20% of patients with untreated stage 1 hypertension have what is called white coat hypertension, which is defined as persistently elevated blood pressure only in the presence of a health care worker but not elsewhere.

What are the early and late signs of hypertension

Early -Elevated BP readings -Narrowing and sclerosis of retinal arterioles -Headache -dizziness -tinnitus Late -Rupture and hemorrhage of retinal arterioles -papilledema (swelling that

High BP number

In adults, a sustained systolic blood pressure of 140 mm Hg or greater and/or a sustained diastolic blood pressure of 90 mm Hg or greater is defined as hypertension.

Definition

In children and adolescents, hypertension is defined as elevated blood pressure that persists on repeated measurement at the 95th percentile or greater for age, height, and gender

Measurement

Measurement of blood pressure most commonly is achieved using the auscultatory method with a mercury, aneroid, or hybrid sphygmomanometer

Pulse pressure MAP

The difference between diastolic and systolic pressures is called pulse pressure. Mean arterial pressure is roughly defined as the sum of the diastolic pressure plus one-third the pulse pressure.