Week 4 - Kidneys Flashcards
What is the most useful marker for kidney function?
Creatinine
What is creatinine a good proxy for?
GFR (glomerular filtration rate)
What does it mean if creatinine is low?
Kidneys are doing a good job filtering blood
What is GFR?
The amount of blood filtered by the kidney each minute.
How can you measure creatinine?
By injecting someone with inulin and seeing how long it takes for them to pee it out - but this is invasive and too much work.
What is creatinine a byproduct of? What does this mean for who might have higher baseline creatinine levels?
Muscle breakdown. Muscles release creatinine.
Someone with a large muscle mass would have higher creatinine levels that an emaciated person
What are the three reasons a kidney isn’t working well?
- pre-renal issues
- intra-renal issues
- post-renal issues
What leads to a pre-renal issue?
not enough blood getting to the kidneys (hypovolemia)
What leads to a intra-renal issue?
something causing direct harm to kidney tissue (NSAIDs, nephrotoxic drugs)
What leads to a post renal issue?
some blockage distal to kidneys that is blocking ability of kidneys to filtrate (obstruction - commonly kidney stones, cancer, and prostate issues)
What are two common comorbidities to chronic kidney disease?
HTN and DM2
What should we always ask first if we see high creatinine levels?
Is this acute or chronic?
If a patient does have chronic kidney disease, what is important for treatment?
Knowing comorbidities
What risk factors do I need to keep an eye out for with chronic kidney disease?
Fluid overload
Electrolyte abnormalities
Acid base balance
anemia
What are the commonalities between CHF and CKD?
Fluid overload
Edema
Bounding pulses
Fine crackles 2/2 to pulmonary edema
What can we do to figure out if something is CHF or CKD?
Labs! Creatinine is the main differentiating factor between CHF and CKD.
Physical exam is not likely going to give us enough info to distinguish between CHF and CKD
elevated BNP is not enough to distinguish
A patient with CKD has missed 3 dialysis appointments. Which of the following is most concerning?
- potassium of 6.2
- palpable thrill in the fistula
- HR of 89
- Pre-tibial edema
Potassium of 6.2
You are reviewing labs on a patient with polycythemia 2/2 COPD. Which of the following labs would be most consistent with polycythemia 2/2 COPD?
- Hematocrit of 52
- Potassium of 4.2
- WBC of 8.4
- Sodium of 130
Hematocrit of 52
What does furosemide do?
It inhibits the reabsorption of Na, Cl-, and K in the loop of Henle
Hence - they are called “loop” diuretics - they put you at risk of K+ loss
What do we assess in a renal assessment?
- fluid-volume status
- acid-base balance
- electrolytes
- excretion of wastes
- hematology
What should HR and BP reflect?
fluid volume status
when can you auscultate a bruit in the kidneys?
when there is some form of renal artery stenosis
How is BP related to kidney function?
It tells us how well kidneys are able to filter b/c it influences the GFR.
How do we assess the kidneys?
- Is and Os
- Daily weights
- lab values
- electrolytes
- BUN & Creatinine
- GFR