Kidney Impairment Flashcards
(19 cards)
how does oxygenated blood get to kidneys?
aorta
how does non o2 bood get back to heart?
vena cava
what are the functions of the kidneys?
salt and water regulation- 3-4L urine produced daily
remove waste like urea and creatinine from blood into urine
produce hormones for RAAS system for BP regulation, form erythropoietin for RBC formation
activate vitamin D into calcitriol
cleans blood/ removes drugs
how is GFR monitored and what are the disadvantages?
24hr urine sample. inulin injected and vol of filtrate produced by both glomeruli per minute calculated
very complex
how is eGFR monitored and what are the disadvantages?
using CKD-EPI and a standrad BSA of 1.73m^2. considers age and gender
Doesnt consider pt weight, and just assumes every patient has BSA of 1.73m^2
why is creatinine measured and what are the disadvantages?
creatinine is produced by muscle breakdown and filtered through glomeruli into urine
issue with body builders as they have lots of muscle so more creatinine in urine which makes a underestimation of kidney function
issue with elderly or overweight as they have less muscle so less creatinine so overestimates kidney function
why should CrCl not be used in an AKI and what should be monitored instead?
there is a 48-72hr delay in srcr to kidney function. use urine output
when is CrCl preferred?
for DOAC’s, extremes of weight, narrow therapeutic window drugs, elderly, chemo
what is ACR?
Albumin:creatinine ratio- measure of protein and creatinine in urine. more means glomeruli damaged
what is an AKI?
Sudden decline in renal excretory function over hours or days than can result in failure to maintain fluid, electrolyte and acid-base balance.
SrCr raises by 26mmol/L in 48 hours or rises by 50% in 7 days
what causes AKI?
Pre-renal- reduced blood flow to kidney
intra-renal-nephrotoxicity
post-renal- obstruction of urine flow (kidney stones) or BPH
what are the risk factors of AKI?
Over 65
diabetic
HF
Liver disease
on NSAIDs, diuretics, ACE-i
what is CKD?
Persistant renal abnormalities for greater than 3 months with health consequences
what are the risk factors for CKD?
HTN and T2DM
what are the effects of CKD?
Anaemia, mineral bone disorders, impaired fluid balance
What is the treatment for CKD?
Haemodialysis or transplant
How often does a pt get dialysis and is there good drug clearing during intermittent period?
3 sessions a week which last approx 4 hours (individual to pt tho)
no
What are the consequences of renal impairment?
-HTN
-Anaemia
-Low Vit D
-High phosphate
-Hyperkaleamia
-fluid retention
- drug toxicity
what are the PK changes in renal impairment?
Absorption- unchanged, delayed due to delayed gastric emptying
Distribution- less albumin in plasma (in urine) so decreased binding. Fluid retention so increased VD of hydrophilic drugs
Metabolism- altered liver enzymes- accumulation
Excretion- decreased clearance because decreased eGFR so increased 1/2 life of drug (aminoglycosides, Digoxin, Lithium)
