Renal & Liver Disease: Renal Disease Flashcards
Acute Kidney Injury (AKI)
A sudden loss of kidney function
Often reversible, can be permanent if cause isn’t corrected
Can be Drug-induced, common cause is dehydration (presentation w/ BUN:SCr ratio > 20:1, dec urine output, dry mucus membranes, and tachycardia)
Chronic Kidney Disease (CKD)
Progressive loss of kidney function over months/years.
Degree of kidney function assessed based on GFR or CrCL, and how much albumin in urine
Kidney Failure (ESRD)
Total and permanent kidney failure.
Fluid and waste accumulates, dialysis or transplant is required to perform the functions of kidneys
Primary function of the nephron & Kidney
to control concentration of sodium and water
reabsorb what is needed back into the blood, excreting rest in urine
regulates blood volume and BP
Afferent arteriole (direction)
delivers blood into the glomerous
Efferent arteriole (direction)
blood exiting the glomerous
Major parts of nephron in order
- Bowman’s Capsule
- Glomerous
- Proximal tubule
- Loop of Henle
- Distal Convoluted Tubule
- Collecting Duct
Drugs that work on the Proximal tubule
SGLT2 inhibitors
Drugs that work in the Loop of Henle
Loop diuretics work in Ascending Limb of the Loop of Henle
How do Loop diuretics work?
Inhibit the Na-K pump, leading to less Na being reabsorbed into the blood, causing less water to be reabsorbed and more to be excreted
Also cause less Calcium reabsorption into the blood, leading to Ca depletion and long term use can lead to decreased bone density
What does the distal convoluted tubule regulate?
Potassium (K), Na, Ca, and pH
only about 5% Na reabsorbed here
Which drugs work at the distal convoluted tubule?
Thiazide diuretics
How do thiazide diuretics work?
Since only 5% Na reabsorbed here, weaker diuretics than loops
Thiazides increase Ca reabsorption at the Ca pump in distal convoluted tubule
Long term use has protective effect on bones unlike loop diuretics
Which drugs work at collecting duct & distal convoluted tubule?
Potassium- sparing diuretics (inc aldosterone antagonists) ie spironolactone, eplerenone
Select drugs that can cause Kidney Disease
Aminoglycosides
Amphotericin B
Cisplatin
Cyclosporine
Loop Diuretics
NSAIDs
Polymyxins
Radiographic contrast dye
Tacrolimus
Vancomycin
Cockcoft-Gault Equation
((140-patient age)/( 72 X SCr)) X weight kg X 0.85 (if female)
When is Cockcrof-Gault equation no recommended
very young children
in kidney failure
unstable renal function
accuracy decreased in elderly, w/ low muscle mass
GFR: Stage 1 CKD
> 90 + kidney damage
GFR: Stage 2 CKD
60-89 + Kidney damage
GFR: Stage 3 CKD
45-59 = a
30-44 = b
GFR: Stage 4 CKD
15-29
GFR: Stage 5 CKD
< 15 or dialysis dependent
KDIGO target SBP for HTN/CKD patients
SBP < 120 mmHG
1st line HTN treatment for patients with CKD & HTN
ACEi or ARB
SCr can bump by up to 30%, shouldn’t stop unless increase > 30%
ACEi and ARB use in CKD patients
Shouldn’t be used together
Can increase potassium, patients should avoid potassium supplements and sal substitutes
Serum creatinine and potassium monitoring in CKD patients on ACEi or ARB
2-4 weeks after starting
KDIGO guidelines for diabetes management in CKD
use a SGLT2i (canagliflozin, dapagliflozin, and empagliflozin
has shown reduction in CV events and CKD progression
if cant use, GLP-1 receptor agonist recommended
Finerenone (nonsteroidal mineralocorticoid receptor antagonist) can be added to SGLT2i & max tolerated ACEi/ARB if eGFR > 25mL/min
Drugs CI CrCl < 60 mL/min
Nitrofurantoin
