SM 206 CKD Clinical Flashcards
What defines Chronic Kidney Disease?
Abnormalities in structure and function present for at least 3 months
Can you have CKD if overall renal function is normal?
Yes; it’s possible to have vascular abnormalities, electrolyte abnormalities, and renal cysts
What is the GFR cutoff for CKD?
GFR < 60 mL/m
How is CKD classified?
CKD is classified by cause, GFR loss severity, and Albuminuria in the urine
How does GFR relate to CKD Progression?
Lower GFR = Faster CKD Progression
How does Proteinuria relate to CKD Progression?
Higher Proteinuria = Faster CKD Progression
What marker is used to track CKD Progression?
Creatinine is an often used marker for Kidney function, though it is not always accurate
Why is Creatinine not always an accurate marker of kidney function?
As kidney function declines, in theory GFR drops leading to more serum Creatinine
However, Creatinine is secreted in the Kidney and can be excreted in the Gut as well to compensate, so serum Creatinine is not a perfect marker of kidney function
In CKD, is kidney function likely to be overestimated or underestimated by Creatinine secretion?
Kidney function is likely to be overestimated by Creatinine because the kidney has ways to secrete Creatinine, as well as through the gut, lowering serum Creatinine and making kidney function look better than normal
What factors can set a “normal” Creatinine?
“Normal” creatinine values are set by:
Age: young = more muscle = higher Creatinine
Sex: men = more muscle = higher Creatinine
Race
How is GFR calculated?
Direct measurement of 24 hour clearance
Cockcroft-Gault formula
MDRD formula
What are the drawbacks to the Cockcroft-Gault formula for estimating GFR?
Cockcrocft-Gault accounts for Age, Weight, Serum Creatinine and Sex to determine GFR
Less accurate in obese patients due to surface area
What are the drawbacks to the MDRD formula for estimating GFR?
MDRD accounts for Age, race, Serum Creatinine, and Albumin to determine GFR
Less accurate in obese patients and people with normal GFR
What is the best formula for normal or mildly reduced GFR and obese individuals?
CKD-EPI, better epidemiological outcomes
How do drugs toxic to the kidney and CKD form a vicious cycle?
In CKD, Kidney is damaged and GFR is low so excretory capacity of the kidney is impaired
Drugs that are renally excreted like Vancomycin accumulate due to poor excretion
Drugs buildup in the Kidney and damage the kidney more, further lowering excretory capacity
How does sodium effect CKD progression?
Sodium worsens the pro-fibrotic effects of aldosterone and accelerates renal disease progression
What is the role of bicarbonate therapy in CKD treatment?
CKD can result in metabolic acidosis, so bicarbonate therapy can slow CKD progression by normalizing the pH
Describe iron homeostasis?
Iron is taken up by the intestine
Iron is bound to Transferrin in the Serum
Iron is stored in the Liver
Iron is used in RBC’s to form Hemoglobin
Iron is recycled after Macrophages degrade senescent RBC’s in the Spleen
What is the critical membrane transporter that mediates Iron import and export?
Ferroportin
How does CKD effect iron homeostasis?
CKD = inflammatory state = Increase Hepcidin
Hepcidin inhibits Ferroportin and causes Iron deficiency Anemia
What molecule is upregulated in CKD that leads to iron deficiency anemia?
Hepcidin is upregulated by inflammation in CKD and inhibits Ferroportin
What is the treatment for iron deficiency anemia in CKD and how does it work?
Roxadustat treats iron deficiency anemia in CKD
Roxadustat inhibits HIF