part 3

low arterial blood pressure

causes low glomerular filtration

1200ml/min

the rate of blood flow to kidneys

mean BP \>50mmHg

regular glomerular capillary blood pressure

glomerular filtration

the part of the kidney that filters excess fluid and waste products out of the blood and into the urine collecting tubules of the kidney, so they may be eliminated from the body

tubular reabsorption

the removal of water and solutes from the tubular fluid and BACK into the blood

tubular secretion

the transfer of fluid and solutes from the blood and into the tubular fluid

proximal tubule

part of the kidney where 60-70% of sodium and water is reabsorbed through sodium transport from the lumen into the blood

descending loop of Henle

part of the kidney that has a very low sodium permeability. water can be reabsorbed, but electrolytes are usually not reabsorbed.

the concentration of urine increases dramatically here.

ascending loop of Henle

part of the kidney where 20-25% of sodium is reabsorbed through active transport.

distal tubule

part of the kidney where 5-10% of sodium and water is reabsorbed. that number depends on the aldosterone present

collecting duct

part of the kidney where water is reabsorbed if ADH present

100% reabsorbed

the amount of glucose reabsorbed by the kidney

99% reabsorbed

the amount of sodium reabsorbed by the kidney

98% reabsorbed

the amount of water reabsorbed by the kidney

85% reabsorbed

the amount of protein reabsorbed by the kidney

0% reabsorbed

the amount of creatinine reabsorbed by the kidney

creatinine clearance rate \= glomerular filtration rate (GFR)

44% reabsorbed

the amount of urea reabsorbed by the kidney

presence of edema

this sign indicates salt retention, which holds excess fluids in the body and skin

nephrotic syndrome: can be indicated by this sign, along with too much protein in the urine.

pulmonary edema

this sign is indicated by fluid in the lungs. it can be caused by too much fluid retention due to damaged kidneys.

it can also be caused by high blood pressure due to narrowed kidney arteries (renal artery stenosis)

ascites

the circulating blood volume may be perceived as low by the sensors in the kidneys, as the formation of this condition may deplete some volume from the blood. This signals the kidneys to reabsorb more salt and water to compensate for the volume loss.

this condition can also develop as a result of advanced kidney failure and fluid retention.

conditions that cause fluid retention/overload

-heart failure

-liver disease

-kidney disease

-hyperaldosteronism

-corticosteroid therapy

diuretics

drugs that block the reabsorption of Na

Hydrochlorothiazide (Microzide) HCTZ

\#1 thiazide diuretic

Thiazide-Type diuretic

a diuretic that inhibits sodium reabsorption at the distal convoluted tubule (can only affect 10% of sodium load)

oral dosage forms only

moderate potency; loses diuretic effect after 1-2 weeks

primary use of thiazide-type diuretics

diuretic mainly used for

hypertension

short term mild/moderate diuresis

names of loop diuretics

furosemide

bumetanide

torsemide

loop diuretic

a diuretic that

inhibits sodium absorption at the ascending loop of henle (20-25%)

most effective diuretic class

infinite dose-response

oral and IV dose forms

primary use of loop diuretics

use this diuretic for

conditions resulting in moderate/severe edema

-heart failure, liver disease, renal disease

high blood pressure resulting from volume overload

loop and thiazide diuretic immediate ADRs

dehydration

hypovolemia

hypokalemia

the number of patients that need potassium supplementation with loop and thiazide diuretics

10% of patients

loop and thiazide diuretic long term/severe ADRs

glucose intolerance/hyperglycemia (not good for diabetic patients)

calcium wasting (long term)

ototoxicity (loop diuretics only)

names of potassium sparing diuretics

amiloride

tiramterine

potassium sparing diuretics

a diuretic that

blocks the sodium channels in the distal tubule (10%)

prevents secretion of potassium

weak diuretics; usually used in combination with thiazide diuretics

potassium-sparing diuretic ADRs

using this diuretic can result in

hyperkalemia

risk groups

-renal impairment

-diabetics

-eldery

-hidden potassium in salt substitutes, blood transfusions

names of aldosterone antagonists

spironolactone

eplerenone

aldosterone antagonists

this diuretic blocks the action of aldosterone, which decreases sodium reabsorption and potassium retention

primary use of aldosterone antagonists

this diuretic can be used for

patients with increased levels of aldosterone (heart and liver failure)

aldosterone antagonist ADRs

this diuretic might cause

hormonal effects (spironolactone only)

menstrual irregularities

breast tenderness

gynecomastia

erectile dysfunction and decrease libido

names of osmotic diuretics

glycerin

mannitol

urea