Hypertension Overview and Complications

Hypertension

• Hypertension is referred to as a "silent killer"
• Patients are often asymptomatic until target organ disease occurs
• Usually no symptoms other than elevated blood pressure
• Symptoms related to organ damage appear late and are serious, including retinal and other eye changes, renal damage, myocardial infarction (MI), angina, and cardiac hypertrophy.

Hypertension Symptoms

• Symptoms often secondary to target organ disease, including fatigue and reduced activity tolerance, dizziness, palpitations, angina, and dyspnea

Hypertension Complications

• Prolonged high blood pressure damages blood vessels throughout the body
• Target organ diseases occur most frequently in the heart (coronary artery disease (CAD), myocardial infarction (MI), heart failure (HF), left ventricular hypertrophy), brain (stroke), peripheral vascular systems, kidneys (renal failure), and eyes (impaired vision)

Etiology of Hypertension

• Primary (Essential or Idiopathic): Elevated blood pressure without a specific cause. Accounts for 90-95% of cases
• Secondary: Elevated blood pressure with a specific cause. Accounts for 5-10% of cases in adults. Often occurs in children greater than 80%

Risk Factors for Primary Hypertension

• Diabetes Mellitus (DM): Elevated serum lipids
• Dyslipidemia: Elevated serum lipids
• Obesity
• Family history/heredity
• Ethnicity
• Sedentary lifestyle
• Socioeconomic status
• Stress

Risk Factors for Hypertension in Cardiovascular Patients

• Smoking
• Obesity
• Physical inactivity
• Dyslipidemia
• Diabetes mellitus (DM)
• Microalbuminuria (MA): A value above 30 mg/day can indicate high albumin excretion
• Older age
• Family history

Risk Factors for Secondary Hypertension

• Congenital narrowing of the aorta
• Renal disease
• Endocrine disorders (e.g., pheochromocytoma)
• Neurological disorders
• Cirrhosis
• Medications (e.g., NSAIDs)
• Pregnancy-induced hypertension

Blood Pressure

• Blood Pressure (BP) is the force exerted against artery walls
• BP = Cardiac Output x Peripheral Resistance
• High BP results from changes in either cardiac output (CO) or peripheral resistance (PR), or both
• CO = Heart Rate (HR) x Stroke Volume (SV)
• Cardiac output is usually expressed in liters/minute
• BP is a significant sign used to monitor patient clinical status, risk factor for atherosclerotic cardiovascular disease, and a sign of high disease

Blood Pressure Classification for Adults 18 Years and Older

• Based on average of two or more, properly measured, seated readings taken on two or more office visits
• Table 32-1 outlines the classifications of normal, prehypertension, stage 1 hypertension, and stage 2 hypertension.
• Data are values in millimeters of mercury (mmHg) for systolic and diastolic blood pressure

Pathophysiology of Hypertension

• A multifactorial condition caused by several factors interacting within the body
• Factors that influence the development of hypertension involve sympathetic nervous system activity, reabsorption of sodium chloride and water by kidneys, activity of the rennin-angiotensin system, vasodilation of arterioles, insulin resistance, and more.

Medical Management of Hypertension

• Goals: Control blood pressure, reduce cardiovascular risk, prevent complications and/or death.

• Treatment Goals:

  • Most adults: Maintain blood pressure at or below 140/90 mm Hg.
  • Adults with DM or chronic kidney disease: Maintain blood pressure at or below 130/80 mm Hg

• Management Options: Treatment algorithm from the Joint National Committee (JNC 7).

• Treatment Plan: Lifestyle modifications (e.g., weight reduction, alcohol intake, sodium intake) and medication

Lifestyle Modifications

• Weight reduction
• Reduce alcohol intake
• Reduce sodium intake (less than 2.4 g of sodium/day or 6 g sodium chloride)
• Diet high in fruits, vegetables, and low-fat dairy foods
• Avoid tobacco products
• Regular physical activity; at least 30 minutes most days of the week

Pharmacologic Therapy

• Drug therapy to treat hypertension uses various mechanisms including:
  • Reduction of systemic vascular resistance (SVR)
  • Reduction of circulating blood volume
  • Various classifications of drugs; commonly used drugs may include diuretics, adrenergic inhibitors, vasodilators, ACE inhibitors, calcium channel blockers and others

Medication Treatment

• Initial treatment starts with low doses, titrating gradually
• Additional medications may be necessary
• Lifestyle changes initiated to control BP must be maintained
• When BP is regularly below 140/90 mmHg for at least one year, medication types and dosage may be reduced gradually

Medication Therapy Classifications

• Diuretics
• Loop diuretics
• Potassium-sparing diuretics
• Aldosterone receptor blockers
• Beta-blockers
• Central alpha2-agonists
• Alpha1-blockers

Patient Assessment

• History and physical examination
• Laboratory tests: urinalysis, blood chemistry, cholesterol levels
• ECG
• Echocardiogram

Nursing Process Considerations for Hypertension

• Assessment: Obtain detailed history, identify risk factors, and assess for potential target organ damage symptoms (headaches, shortness of breath, etc.), and perform cardiovascular assessments
• Goals: Patient understanding of disease process, treatment regimen, self-care, and absence of complications.
• Nursing Diagnoses: Knowledge deficit related to the treatment regimen and control of disease process; noncompliance with therapeutic regimen related to side effects
• Interventions: Patient education, support of adherence, emphasize control, and long-term support.
• Nursing Alert: Cautions for use of antihypertensive medications, including reporting low BP, postural hypotension, teaching slow position changes, and use of supportive measures.

Hypertensive Crises

• Hypertensive Emergency: BP above 180/120 mmHg with acute, life-threatening blood pressure elevations. Immediate blood pressure lowering is needed to prevent damage to target organs.
  • Conditions associated with hypertensive emergency: Pregnancy-induced hypertension, acute myocardial infarction (MI), intracranial hemorrhage
• Hypertensive Urgency: Elevated BP without acute symptomatic target organ damage.
• Assessment and Monitoring: Continued monitoring of blood pressure closely and assess for potential organ damage is necessary for both emergency and urgency

Therapeutic Goals

• Hypertensive Emergency: Reduce blood pressure 25% in the first hour and 160/100 mmHg in 6 hours. Gradual reduction to normal levels over several days. IV vasodilators (e.g., sodium nitroprusside, nicardipine) and other medications such as ACE inhibitors, may be utilized.
• Hypertensive Urgency: Close monitoring of blood pressure, assess for organ damage. Oral medications such as beta-blockers, ACE inhibitors, or alpha2-agonists are used.