Renal 6 THATS IT Flashcards
What are the two mechanisms that can cause alkalosis or acidosis?
Respiratory or metabolic
What is the response to acidosis (not caused by kidney issues)? What is the net result?
Acidosis –> High H
1. H is secreted to reabsorb all the filtered HCO3
2. H is secreted to contribute to new HCO3 in the plasma (possible cause H is excreted bound to non-HCO3 buffers)
3. Tubular glutamine and ammonium excretion is increased to add even more HCO3 to the plasma
Net: More HCO3 than usual is added, compensating for acidosis
What is the response to alkalosis (not caused by kidney issues)? What is the net result?
- Low rate of H secretion results in inadequate HCO3 reabsorption (significant HCO3 is excreted)
- Little to no H secretion and non-HCO3 buffers
- Little glutamine and ammonium excretion to limit new HCO3
Net: Plasma HCO3 decreases, compensating for alkalosis
What is the only moment H secretion is incomplete?
When the kidneys are responding to alkalosis
In the classification of ac. and alk., what are H, HCO3 and PO2 changes? Why?
Resp ac: up - up - up
Resp alk: down - down - down
Resp. ac or alk. is caused by PCO2 changes. To minimise pH changes, the pH equation tells us that CO2 and HCO3 should move in the same direction.
Met ac: up - down - down
Met alk: down - up - up
Met ac or alk. is caused by HCO3 changes. To minimise pH changes, the pH equation tells us that CO2 (lungs compensate) and HCO3 should move in the same direction.
What are clinical examples of resp ac. and alk. ?
acidosis: respiratory failure with CO2 retention
alkalosis: hyperventilation
What are the clinical examples of met ac. alk.?
acidosis: diarrhea (important loss HCO3)
alkalosis: vomiting (loss of H) and hyperaldosteronism (increased H secretion)
What are diuretics?
Drugs used clinically to increase the volume of urine excreted.
Where do diuretics act and how?
in the tubules, sodium reabsorption is blocked as well as bicarbonate and chloride, water also stays and the ions and water are more excreted.
What are the common classes of diuretics?
Loop diuretics
Potassium-sparing diuretics
Where do loop diuretics act and how do they function?
In the thick ascending limb, they inhibit the Na-K-2Cl cotransporter
Where do potassium-sparing diuretics act, and how do they function?
In the CCD, sodium reabsorption is blocked as well as potassium secretion. (DOES NOT CAUSE HYPOKALEMIA)
It will block aldosterone action on the CCD or block the sodium channel (reabsorption) that is regulated by aldosterone
What is the advantage of potassium-sparing diuretics vs loop diuretics?
They prevent hypokalemia (spare potassium)
When do we use diuretics? In what condition?
When the body holds onto Na and water: edema
(abnormal expansion of the extracellular space)
Congestive heart failure (increased reabsorption due to poor blood flow)
Hypertension (high salt and water increases blood pressure)
Kidney failure: Proteinuria
Proteins in the urine
Kidney failure: Accumulated waste products
waste products are not excreted
urea, creatinine, phosphate, sulfate
Kidney failure: metabolic acidosis
high concentration of H
low concentration of HCO3 causing low PCO2
Kidney failure: Anemia
decreased secretion of erythropoietin
Kidney failure: hypocalcemia
decreased secretion of 1,25 vitamin D
At what point can life not be sustained due to kidney failure?
When 90% of nephrons stop working they need replacement therapy
What are the 3 renal replacement therapy?
Hemodialysis
Peritoneal dialysis
Kidney transplant
Hemodialysis
Cleaning of the blood (about 4h, 3x per week)
Arterial blood is drawn
into pump
with anticoagulant to avoid blockage
In dialyser to remove waste and out out while adding necessary fluids
Air is removed from air
Perineal dialysis
At home dialysis
Peritoneum is used as a dialysis membrane
Fluid is injected into the cavity
Solutes diffuse into the blood
Kidney tansplant
From recently deceased or living
Anti-rejection treatment has improved, but organ shortage is important
You can function with 1 kidney
