HYPERTENSION(HIGH BLOOD PRESSURE)
A condition in which the force of the blood against the artery walls is too high.Usually hypertension is defined as blood pressure above 140/90, and is considered severe if the pressure is above 180/120.
High blood pressure (hypertension) is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease.
Blood pressure is determined both by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. A blood pressure reading is given in millimeters of mercury (mm Hg). It has two numbers.
There are two types of high blood pressure.
Primary (essential) hypertension
For most adults, there’s no identifiable cause of high blood pressure. This type of high blood pressure, called primary (essential) hypertension, tends to develop gradually over many years.
Some people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:
- Obstructive sleep apnea
- Kidney disease
- Adrenal gland tumors
- Thyroid problems
- Certain defects you’re born with (congenital) in blood vessels
- Certain medications, such as birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs
- Illegal drugs, such as cocaine and amphetamines
High blood pressure has many risk factors, including:
- Age. The risk of high blood pressure increases as you age. Until about age 64, high blood pressure is more common in men. Women are more likely to develop high blood pressure after age 65.
- Race. High blood pressure is particularly common among people of African heritage, often developing at an earlier age than it does in whites. Serious complications, such as stroke, heart attack and kidney failure, also are more common in people of African heritage.
- Family history. High blood pressure tends to run in families.
- Being overweight or obese. The more you weigh, the more blood you need to supply oxygen and nutrients to your tissues. As the amount of blood blow through your blood vessels increases, so does the pressure on your artery walls.
- Not being physically active. People who are inactive tend to have higher heart rates. The higher your heart rate, the harder your heart must work with each contraction and the stronger the force on your arteries. Lack of physical activity also increases the risk of being overweight.
- Using tobacco. Not only does smoking or chewing tobacco immediately raise your blood pressure temporarily, but the chemicals in tobacco can damage the lining of your artery walls. This can cause your arteries to narrow and increase your risk of heart disease. Secondhand smoke also can increase your heart disease risk.
- Too much salt (sodium) in your diet. Too much sodium in your diet can cause your body to retain fluid, which increases blood pressure.
- Too little potassium in your diet.Potassium helps balance the amount of sodium in your cells. A proper balance of potassium is critical for good heart health. If you don’t get enough potassium in your diet, or you lose too much potassium due to dehydration or other health conditions, sodium can build up in your blood.
- Drinking too much alcohol. Over time, heavy drinking can damage your heart. Having more than one drink a day for women and more than two drinks a day for men may affect your blood pressure.If you drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and two drinks a day for men. One drink equals 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof liquor.
- Stress. High levels of stress can lead to a temporary increase in blood pressure. Stress-related habits such as eating more, using tobacco or drinking alcohol can lead to further increases in blood pressure.
- Certain chronic conditions. Certain chronic conditions also may increase your risk of high blood pressure, including kidney disease, diabetes and sleep apnea.
The excessive pressure on your artery walls caused by high blood pressure can damage your blood vessels as well as your organs. The higher your blood pressure and the longer it goes uncontrolled, the greater the damage.
Uncontrolled high blood pressure can lead to complications including:
- Heart attack or stroke. High blood pressure can cause hardening and thickening of the arteries (atherosclerosis), which can lead to a heart attack, stroke or other complications.
- Aneurysm. Increased blood pressure can cause your blood vessels to weaken and bulge, forming an aneurysm. If an aneurysm ruptures, it can be life-threatening.
- Heart failure. To pump blood against the higher pressure in your vessels, the heart has to work harder. This causes the walls of the heart’s pumping chamber to thicken (left ventricular hypertrophy). Eventually, the thickened muscle may have a hard time pumping enough blood to meet your body’s needs, which can lead to heart failure.
- Weakened and narrowed blood vessels in your kidneys. This can prevent these organs from functioning normally.
- Thickened, narrowed or torn blood vessels in the eyes. This can result in vision loss.
- Metabolic syndrome. This syndrome is a group of disorders of your body’s metabolism, including increased waist size, high triglycerides, decreased high-density lipoprotein (HDL) cholesterol (the “good” cholesterol), high blood pressure and high insulin levels. These conditions make you more likely to develop diabetes, heart disease and stroke.
- Trouble with memory or understanding.Uncontrolled high blood pressure may also affect your ability to think, remember and learn. Trouble with memory or understanding concepts is more common in people with high blood pressure.
- Dementia. Narrowed or blocked arteries can limit blood flow to the brain, leading to a certain type of dementia (vascular dementia). A stroke that interrupts blood flow to the brain also can cause vascular dementia.
The principle is to initiate treatment with a single drug and then to add agents with a different mode of action till BP is controlled.
First line drugs:-
Diuretics-Thiazides or Lasix (Frusemide) or combi- nation of Lasix with Spironolactone or β-blockers cardioselective (Atenolol, Metaprolol, Acetabutolol) or noncardioselective (Propranolol). They are prefer- red in patients with concomitant ischaemic heart disease.
Calcium antagonist: Nifedipine 10-20 mg
ACE inhibitors: Captopril, Enalapril Lirinopril or Amlodipine can be used the above three drugs cannot be used.
Second line drugs
Combination of drugs to be used if single drug does not reduce BP to within a target range.
-Calcium antagonist plus β blockers.
-ACE inhibitor plus Thiazide diuretic.
-β-blocker plus Thiazide diuretic.
-Nifedipine 5 mg sublingually every 10 minutes till diastolic BP < 110 mmHg. Then 5-10 mg 6 hourly up to total dose of 60 mg in 24 hours.
-If response inadequate—Injection Lasix 80 mg IV.
-If still response inadequate—Injection Diazoxide
150 mg IV rapidly. Repeat as needed at 5 mm
interval till total of 600 mg.
-If response inadequate—Injection Nitroprusside-
dissolve 50 mg vial in 2 ml glucose water and further
diluted in 500 ml 5 per cent Glucose.
-Start with 0.5 mcg/kg/minute and adjust dose till BP reaches at desired level.
or Hydralazine 5 to 20 mg IM 2-4 hourly.
Mild Hypertension (Diastolic 90-110):-
• Thiazides (e.g. Esidrex) or Lasix for one week, if not controlled add Reserpin, Hydralazine, Methyldopa, Clonidine or Propranolol.
Moderate Hypertension (Diastolic 110-130):-
Treat with a diuretic (Thiazide) + any of the second line drugs from beginning. Combination of Hydralazine + Propranolol (Corbetazine) is best as betablocker Propra- nolol counteracts the sympathetic stimulation caused by Hydralazine and consequently the combination has fewer side effects.
If there is associated renal failure then Hydralazine, Methyldopa, Clonidine are preferred. Guanethidine should replace rather than be added to other agents.
MAO inhibitors if combined with antihypertensive drugs may precipitate hypertensive crisis.
Remember Minoxidil is the most powerful oral hypotensive vasodilator agent.
Severe Hypertension (Diastolic above 130)
Prompt and immediate treatment with rapid acting drugs preferable in injectable form.
• Reduce weight if obese.
• Low salt diet.