Systemic Hypertension

Systemic blood pressure measures 140/90 mm Hg or higher on at least two occasions a minimum of 1 to 2 weeks apart

Systemic hypertension is the most common circulatory derangement in the United States, affecting about 30% of adults

Hypertension is a significant risk factor for the development of ischemic heart disease and a major cause of congestive heart failure, cerebrovascular accident (stroke), arterialaneurysm, and end- stage renal disease

The pulse pressure—that is, the difference between the systolic blood pressure and diastolic blood pressure—is emerging as a new marker of the degree of vascular stiffness.Increased pulse pressure is a cardiovascular risk factor, and some studies have linked an increased pulse pressure with intraoperative hemodynamic instability and adverse postoperative outcomes.

Pathophysiology Systemic hypertension is characterized as essential or primary hypertension when a cause for the increased blood pressure cannot be identified. It is termed secondary hypertension when an identifiable cause is present.

Hypertension, insulin resistance, dyslipidemia, and obesity often occur concomitantly, and an estimated 40% of patients with hypertension also have hypercholesterolemia Alcohol and tobacco use are associated with an increased incidence of essential hypertension 30% of hypertensive patients manifest obstructive sleep apnea

The standard goal of therapy for essential hypertension is to decrease systemic blood pressure to less than 140/90 mm Hg. In the presence of concurrent diabetes mellitus or renal disease, current guidelines (JNC 7) recommend lowering the blood pressure to less than 130/80 mm Hg, but this is somewhat controversial

Treatment of Essential Hypertension LIFESTYLE MODIFICATION PHARMACOLOGIC THERAPY

1.include weight reduction or prevention of weight gain, 2.moderation of alcohol intake, 3. increase in physical activity, 4.adherence to recommendations for dietary calcium and potassium intake 5. moderation in dietary salt intake

Smoking cessation is critical, because smoking is an independent risk factor for cardiovascular disease. Weight loss may be the most efficacious of all nonpharmacologic interventions in the treatment of hypertension.

Patients with concomitant risk factors 1.hypercholesterolemia 2.diabetes mellitus 3.tobacco use 4.family history of hypertension 5.age >60 years 6. evidence of target organ damage 7. angina pectoris 8. prior myocardial infarction 9.left ventricular hypertrophy 10. cerebrovascular disease 11.nephropathy 12. retinopathy 13.peripheral vascular disease

Treatment of Secondary Hypertension SURGICAL THERAPY PHARMACOLOGIC THERAPY

Hypertensive Crises Hypertensive crises typically present with a blood pressure of more than 180/120 mm Hg and can be categorized as either a hypertensive urgency or a hypertensive emergency, based on the presence or absence of impending or progressive targetorgan damage.

HYPERTENSIVE EMERGENCY

Patients with evidence of acute or ongoing target organ damage 1. encephalopathy 2. intracerebral hemorrhage 3.acute left ventricular failure with pulmonary edema 4. unstable angina 5.dissecting aortic aneurysm 6.acute myocardial infarction 7.eclampsia 8. microangiopathic hemolytic anemia 9. renal insufficiency

HYPERTENSIVE URGENCY

Hypertensive urgencies are situations in which the blood pressure is severely elevated, but the patient is not exhibiting evidence of target organ damage

the subset of patients who manifest anxiety-related hypertension are likely to have exaggerated pressor responses to direct laryngoscopy and are more likely than others to develop perioperative myocardial ischemia or to require antihypertensive therapy during the perioperative period.

End-organ damage (angina pectoris, left ventricular hypertrophy,congestive heart failure, cerebrovascular disease,stroke, peripheral vascular disease, renal insufficiency) should be evaluated preoperatively.

Patients with essential hypertension should be presumed to have ischemic heart disease until proven otherwise. Renal insufficiency secondary to chronic hypertension is a marker of a widespread hypertensive disease process

It is useful to review the pharmacology and potential side effects of the drugs being used for antihypertensive therapy.

INDUCTION OF ANESTHESIA

MAINTENANCE OF ANESTHESIA Intraoperative Hypertension Intraoperative Hypotension

Monitoring

POSTOPERATIVE MANAGEMENT