Kidney Failure in HypertensionYousaf Khan

Renal Dialysis LecturerIPMS-KMU

BLOOD PRESSURE• Blood pressure is the force of

blood pushing against blood vessel walls as the heart pumps out blood.

• increase in the amount of force that blood places on blood vessels as it moves through the body.

• Factors that can increase this force include higher blood volume due to extra fluid in the blood and blood vessels that are narrow, stiff, or clogged.

Stages of HTN• Systolic pressure and represents the pressure as the heart beats and

pushes blood through the blood vessels.• Diastolic pressure and represents the pressure as blood vessels relax

between heartbeats.

Renal Hypertension• Also called Renovascular hypertension• High blood pressure (hypertension ) is a leading cause of kidney disease

and kidney failure (end-stage renal disease).• Hypertension can cause damage to the blood vessels and filters in the

kidney, making removal of waste from the body difficult. Once a person is diagnosed with end-stage renal disease, dialysis -- a blood-cleansing process -- or kidney transplantation are necessary.

Renovascular HTN• Incidence 1-30%• Etiology

– Atherosclerosis 75-90%– Fibromuscular dysplasia 10-25%– Other

• Aortic/renal dissection• Thrombotic/cholesterol emboli• CVD• Post transplantation stenosis• Post radiation

Causes of Renal Hypertension• Narrowing in the arteries that deliver blood –Renal artery stenosis• The narrowing in one or both renal arteries is most often caused by

atherosclerosis, or hardening of the arteries. This is the same process that leads to many heart attacks and strokes.

• fibromuscular dysplasia• Dehydration- releasing hormones that stimulate the body to retain sodium

and water. Blood vessels fill with additional fluid, and blood pressure goes up.

Renovascular HTN - Pathophysiology

• Decrease in renal perfusion pressure activates RAAS, renin release converts angiotensinogen Ang I; ACE converts Ang I Ang II

• Ang II causes vasoconstriction (among other effects) which causes HTN and enhances adrenal release of aldosterone; leads to sodium and fluid retention

• Contralateral kidney (if unilateral RAS) responds with diuresis/ Na, H2O excretion which can return plasma volume to normal

• with sustained HTN, plasma renin activity decreases (limited usefulness for dx

• Bilateral RAS or solitary kidney RAS leads to rapid volume expansion and ultimate decline in renin secretion

Symptoms of Renal Hypertension• In rare cases, high blood pressure can cause headaches.• Kidney disease also does not have symptoms in the early stages. A person

may have swelling called edema, which happens when the kidneys cannot get rid of extra fluid and salt. Edema can occur in the legs, feet, or ankles and less often in the hands or face. Once kidney function decreases further, symptoms can include

• Appetite loss• nausea• vomiting• drowsiness or feeling tired• trouble concentrating• sleep problems• increased or decreased urination• generalized itching or numbness

dry skinheadachesweight lossdarkened skinmuscle crampsshortness of breathchest pain

Diagnosis • The diagnosis for renovascular hypertension is done by:Blood test • eGFR of 60 or above is in the normal range• eGFR below 60 may indicate kidney damage• eGFR of 15 or below may indicate kidney failure

• Urinary test (tests for microalbuminuria)• Urinalysis (to exclude presence of red blood cells)

• et Screened for Kidney Disease• Kidney disease, when found early, can be treated to prevent more serious disease

and other complications. The National Kidney Foundation recommends people with high blood pressure receive the following regular screenings:

• blood pressure tests• urine albumin• eGFR

Prevent Kidney Disease• To prevent kidney damage from high blood pressure:• Try to keep your blood pressure controlled.• Make sure you get your blood pressure checked on a regular basis.• Eat a proper diet.• Get moderate exercise, such as walking, 30 minutes daily.• Take the medication your doctor prescribes.• healthy eating• physical activity• maintaining a healthy weight• quitting smoking• managing stress

Kidney Disease Treated?• For patients who have high blood pressure and kidney disease, the most

important treatment is to control your blood pressure through lifestyle changes.

• ACE inhibitor (lisinopril, captopril, benazepril, ramipril ) and angiotensin II receptor blocker (ARB) (valsartan, losartan, candesartan, and olmesartan) drugs lower blood pressure and can protect the kidneys from further damage, but treatments needs to be individualized.

• Revascularization versus medical therapy for atherosclerosis,

Thank you