Hypertension

   Blood pressure-Blood pressure is the force of blood pushing against the walls of your arteries. It's measured in millimeters of mercury (mm Hg) and is usually written as two numbers, systolic over diastolic.

Hypertension 

  • Hypertension is a disease of vascular regulation in which elevation of arterial pressure above the normal range.
  • Normal blood pressure: 120/80mm of Hg.
  • In Hypertension: 140/90 or above

Causes/ Types 

1. Primary Hypertension/Essential hypertension -

  • It is due to unknown causes or without systemic cause.
  • This type of hypertension is diagnosed after a doctor notices that your blood pressure is high on three or more visits and eliminates all other causes of hypertension.
  • Usually people with essential hypertension have no symptoms, but may experience frequent headaches, tiredness, dizziness or nose bleeds.

Example-

  • Family history
  • Prolonged mental tension
  • Arterial degeneration
  • Hormonal or metabolic disturbance.

2. Secondary Hypertension-

 It is due to pathological conditions.

Example

  • Due to kidney disease, e.g., Pyelonephritis.
  • Due to endocrine disorders, e.g., cushing Syndrome, diabetes mellitus.
  • Congenital deformities, e.g., Renal artery obstruction.
  • Neurological disorders-Brain tumor.Increased intracranial pressure, Sleep apnea
  • Medications-Estrogens,Nonsteroidal anti-inflammatory drugs,Steroids,Antidepressants

Others

  • Enlarged ProstateToxaemia in pregnancy
  • Excessive body weight
  • Nutrients -Excessive sodium intake
  • Age-Hypertension typically appears  Age between 30-50
  • Gender-
  1. Incidence of hypertension is higher in men until about age 55 years.
  2. Between ages of 55 and 74 years, risk in men and women is equal.
  3. After the age of the 74 years, women are at greater risk.
  • Ethnicity (color)- Death rate is highest for black women at 29.3%
  • Obesity
  • Smoking
  • stress
  • Birth control pills 

3.Borderline Hypertension-

  • It is defined as intermittent elevation of B.P. with normal readings.
  • Borderline hypertension is often called high normal pressure or prehypertension. This term refers to pressures in the gray zone between clearly normal and clearly abnormal levels.

4. Malignant Hypertension -

  • It is a Syndrome of markedly elevated blood pressure (above 140 mm of hg).
  • Malignant hypertension is a term that has been used to describe patients with elevated blood pressure (BP) and multiple complications (End organ damage) with a poor prognosis.

5. Benign Hypertension-

  • Also known as uncomplicated hypertension, usually of long duration and mild to moderate severity, may be Primary or Secondary.
  • Malignant hypertension is a complication of hypertension characterized by very elevated blood pressure, and organ damage in the eyes, brain, heart and/or kidneys. Benign hypertension is a condition of mild to moderate hypertension.

6. White Coat Hypertension-

  •  It is due to anxiety only at a time of measuring blood pressure by doctor or nurse in hospital or clinic.

7. Isolated Systolic Hypertension

  • It occurs when the systolic blood pressure is 140 mm Hg or higher but the diastolic blood pressure remains less than 90 mm Hg

8. Gestational hypertension

  • Gestational Hypertension also referred to as Pregnancy-Induced Hypertension (PIH) is a condition characterized by high blood pressure during pregnancy.

Classification

It can be classified on the basis of value of diastolic pressure.

  1. Mild- 90-104 mm Hg
  2. Moderate- 105-114 mm Hg
  3. Severe- 115 mm Hg

Pathophysiology

Primary (Essential) Hypertension

  • Any factor producing an alteration in peripheral vascular resistance, heart rate or stroke volume affects systemic arterial pressure.
  • Four control systems have a major role in maintaining blood pressure-
  1. The arterial baroreceptors and chemoreceptor system
  2. Regulation of body fluid volume
  3. The renin-angiotensin system
  4. Vascular autoregulation

1. Arterial baroreceptors and chemoreceptors controlling the blood pressure 

Baroreceptors (major stretch receptors)➡️Found in(Carotid sinus, aorta, wall of left ventricle)➡️Monitor (Level of arterial pressure)➡️In case of (Increased blood pressure)➡️Counteracts the rise and leads to➡️Vasodilation➡️And cause(Slowing of heart rate through vagus nerve)➡️Chemoreceptors (sensory nerve endings that react to certain chemical stimuli)➡️Located in(Medulla, carotid and aortic bodies)➡️Sensitive to➡️Change in concentration of O2, CO2, and pH of blood➡️Decrease O2, concentration or pH➡️Causes➡️Increase in blood pressure➡️Increase CO2, concentration➡️Causes➡️Decrease in blood pressure

2. Regulation of body fluid volume 

Change in fluid volume➡️Affects(Systemic arterial pressure)➡️When Na and water are in excess➡️Total blood volume increases➡️Thus(Increased blood pressure)➡️Causes(Diuresis)

3. Renin-angiotensin system 

Renin (enzyme produced by kidney))➡️Converts(Angiotensin 1))➡️Angiotensin 2 + 3 (vasoconstrictor) + stimulates aldosterone release)➡️

Increased sympathetic nervous system activity)➡️Causes(Angiotensin 2 and 3))➡️To inhibit)➡️Na excretion)➡️That results in)➡️Increased blood pressure

4. Vascular autoregulation- Hypertension may also develop from deficiencies in vasodilator substances such as prostaglandins, congenital abnormalities in arterioles, etc.

Clinical Manifestations

  • People with hypertension remain asymptomatic for a long period of time.
  • Physical examination may reveal-
  1. Retinal changes, e.g., hemorrhage, exudate, papillary edema, arteriolar narrowing
  2. Headache
  3. Dizziness
  4. Fatigue
  5. Palpitations
  6. Flushing
  7. Epistaxis
  8. Alteration in speech
  9. Alteration in vision
  10. Paralysis.
  • Pathologic changes in kidney (increased blood urea nitrogen and creatinine) cause nocturia.
  • Cerebrovascular involvement may lead to stroke or transient ischemic attack (TIA).

Diagnostic Evaluation

  • Health history and physical examination
  • ECG- Presence of underlying heart disease
  • Chest X-ray may show cardiomegaly
  • Routine laboratory tests include urinalysis, blood chemistry (analysis of Na, K, creatinine, fasting blood glucose, high density lipoprotein, cholesterol levels)
  • Proteinuria, elevated serum blood urea nitrogen (BUN) and creatinine levels, indicate kidney disease as a cause or effect of hypertension.
  • Renal function test- Blood urea, serum creatinine.
  • Liver function test-
  1. Serum glutamate oxaloacetate transaminase (SGOT)
  2. Serum glutamate pyruvate transaminase (SGPT) Bilirubin level
  • Other tests- Creatinine clearance, renin level, 24-hour urinary protein.

Complications 

  • Heart attack or Heart Failure 
  • Stroke 
  • Kidney Failure 
  • Retinopathy 
  • Outpouching of aorta
  • Left ventricle  Hypertrophy 
  • Temporary  Hemiplagia

Management

The goal is to count the arterial blood pressure below 140/90 or nearby and includes normalizing arterial pressure by

  1. Lifestyle modification.
  2. Drug therapy.

1. Lifestyle Modification

  • Weight reduction- Excess body fat accumulated in the torso with a waist circumference of 34 inches or greater for women and 39 inches or greater for men has been associated with increased risk for hypertension.Therefore, assess the client blood pressure during weight reduction.
  • Sodium restriction- A moderate restriction of Na intake to 2.3 g of Na or 6 g of salt can be used to lower blood pressure.
  • Dietary fat modification- Fruits, vegetables, nuts and low fat dairy foods with reduced saturated and total fats should be recommended.
  • Exercise- A regular program of aerobic exercise is adequate to achieve at least a moderate level of physical fitness.
  • Alcohol restriction- Gradually decreasing the intake of alcohol will help to reduce blood pressure.
  • Caffeine restriction- Acute intake of caffeine may increase blood pressure.
  • Relaxation technique- Meditation, yoga, biofeedback, Progressive muscle relaxation, psychotherapy reduces blood pressure.
  • Smoking cessation- Nicotine increases heart rate and produces peripheral vasoconstriction which increases arterial blood pressure. Therefore, smoking should be gradually stopped.
  • Potassium supplementation- An increase in consumption of low sodium and high potassium food is needed for maximum benefits.

2.Drug therapy

Various groups of drugs are used for the treatment of hypertension, collectively these drugs are called as antihypertensive drugs, which includes,

  • Diuretics- it helps the kidneys to inhibit the sodium reabsorption in the distal convoluted tubules, ascending limb and loop of henle. Eg: chlorothiazide, furosemide
  • Beta blockers- These medications reduces the workload of the heart and blood vessal and causing the heart to beat slowly and with less force. Eg: Atenolol, propanolol
  • Alpha blockers- These medications causes the peripheral vasodilation of blood vessals. Eg: Prazosin
  •  Vasodilators- These medications acting directly on the muscles in the wall of arteries and preventing the muscles from tightening and arteries from narrowing. Eg: Nitroglycerin, Sodium nitro prusside
  • ACE(Angiotenis-Converting Enzyme) Inhibitors-This group of medication will reduce the conversion of A-I to A-II and prevents vasoconstriction. Eg: Captopril, Ramipril
  • Calcium channel blockers-These medicines will block the movement of extra cellular calcium into the cells and causing vasodilation and decreased heart rate. Eg: Amlodipine, Verapamil
  • Alternative therapies which are helpful to regulate blood pressure includes acupuncture, relaxation techniques and diversional therapies.

Nursing Management

  • Frequently monitor blood pressure.
  • Administer antihypertensive medications as prescribed
  • Have two large-bore IVs
  • Provide oxygen If the saturations are low (less than 94%)
  • Limit fluid intake if the patient is in heart failure
  • Assess ECG to ensure the patient is not having a heart attack
  • Check report of the chest X-ray to ensure the patient is not in heart failure
  • Listen to the heart for murmurs and lungs for rales and crackles
  • Provide comfortable Position as well as provide rest to patient with raised head of bed or use pillow.
  • Check if the patient has edema
  • Check renal function and electrolyte levels
  • Encourage rest and provide a quiet room
  • Educate the patient on how to lower stress
  • Educate patient on a low salt diet, exercise, and healthy eating
  • Educate the patient on the importance of taking antihypertensive medications

 

 

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