Pre-renal kidney disease Flashcards
What are the two types of pre-renal kidney disease?
Acute - over days or weeks
Chronic - over months or years
How can you measure acute pre-renal kidney disease?
Increase serum creatinine
Decrease in urine output
What are the 3 categories of kidney disease?
Pre-renal - damage occurs due to problems with perfusion of the kidneys
Intrinsic - damage to the kidney itself => glumerulonephritis
Post-renal - blockage to flow of urine out of the kidney
What percentage of CO goes to the kidney in health?
25%
Which 3 conditions lead to pre-renal injury?
Circulatory shock - entire CO decreases
Reduced circulatory volume - intravascular volume depletion
Reduction of blood flow only to the kidneys
What is circulatory shock?
Low BP
How does circulatory shock lead to pre-renal kidney injury?
Not enough blood volume or CO to perfuse the kidney
What are the causes of circulatory shock?
Cardiogenic shock
Hypovolemia - not enough circulating volume
Vasodilation - caused by sepsis or anaphylaxis
Why does reduced circulating volume lead to pre-renal kidey injury?
Kidneys are very affected by blood volume - even though the BP remains normal
What causes intravascular depletion?
Not enough fluid intake - physically dependant, no access to fluids
Loose a lot of fluids - urine , GI tract, oedema and skin
Redistribution of water to extravascular spaces
How does excess water leave the body through the skin?
Sweat, fever or burns
How does excess water leave the body through the GI tract?
Malabsorption, inflammation and cholera
How does excess water leaver the body through urine?
Diuretics
Osmotic diuresis - glycosuria
What are the clinical presentation of redistribution of water to extravascular spaces?
Oedema
Adequate total fluid but inadequate fluid volume in the circulation
What things cause a reduction of blood flow only to the kidneys?
Arterial narrowing - artery stenosis
Vasoconstriction - medication
Arterial thrombosis - trauma
Venous thrombosis - pro-coagulant state
