Approach to the Kidney Patient
Card Set Information
Approach to the Kidney Patient
For my upcoming nephrology exam
What are signs of acute kidney dz?
increasing BUN and creatinine (azotemia)
What are signs of chronic kidney dz?
Loss of renal function over months to years
Slowly increasing BUN and Cr
Hormonal functions of the kidney
Where is filtrate converted into urine?
What is the first step in urine formation?
Fluid collects in Bowman's capsule and is transported to the PCT
What does the PCT do?
Responsible for reabsorbing NaCl, H20, bicarb, glucose, and amino acids
What does the Loop of Henle do?
Reabsorbs NaCl, K, Cl, and H20
Controls fluid balance
Involved in concentration of urine
Where do loop diuretics work?
The ascending loop of Henle
What does the DCT do?
Reabsorbs NaCl, Ca, and K
Involved in PH balance
Very little water permeability
Where do thiazide diuretics work?
What regulates the final composition of urine?
Where does hormone regulation of Na and H2O balance take place?
What encourages filtration and opposes filtration across the glomerular capillary wall?
: hydrostatic pressure
: oncotic pressures in capillary lumen
How is Angiotensin II involved in GFR?
If it feels a reduction in blood flow, it will vasoconstrict
How does GFR react in a state of shock or with dehydration?
It decreases to maintain ions
How does GFR react if pt has severe uncontrolled HTN?
Arterioles would constrict because there is so much pressure going at the kidney, it is a protective mechanism
How is GFR measured?
What is a nl GFR?
What is the relationship between serum creatinine and GFR?
When serum Cr is increased, GFR is decreased (there is an inverse relationship)
What components make up a GFR?
Weight and Height
What GFR levels are a sign of chronic kidney dz?
GFR < 60 for 3 or more months
What creatinine level is an indication for dialysis?
CrCl < 15
What are nl serum creatinine levels?
Describe how creatinine is dealt with in the body
It's cleared by renal excretion
Not bound to plasma proteins
Freely filtered by the glomerulus
What factors can increase serum creatinine levels?
ASA, Cimetidine, or probenicid
ASA or NSAIDS (via analgesic nephropathy)
What factors can decrease serum Cr levels?
How is CrCl measured?
24 hour urine collection and plasma creatinine on the same day
What is the CrCl formula?
(140-age) x (weight in kg)
Serum creatinine x 72
Name certain meds that might have to be changed with renal function
What is urea?
An end product of protein catabolism that is synthesized in the liver
What is a nl BUN?
What is a nl BUN:Cr ratio?
What can cause an increased BUN?
High protein diet
What can cause a decreased BUN?
Why is Urea NOT a better predictor of renal function as Cr is?
It's not as sensitive in picking up smaller decreases in GFR
It's affected by outside factors:
How soon should a UA be done?
Within 1 hour of collection
WBCs should be done 2 mins after you dip
Describe clinical albumin levels
<30 is nl
What can cause functional proteinuria?
An abundance of Bence Jones proteins is what type of proteinuria?
What are examples of overload proteinuria?
Multiple myeloma (Bence Jones)
Hemolytic anemia (hemoglobinuria)
Amyloidosis (overproduction of proteins)
What it tubular proteinuria?
Decreased reabsorption of proteins in the proximal tubules
What can cause tubular proteinuria?
Toxins (lead, aminoglycosides)
Hereditary metabolic disorders (Wilsons, Fanconi)
What can cause a false positive with hematuria?
Myoglobin, beets, and rhubarb
What causes hyaline casts to be in urine?
What causes red cell casts to be in urine?
What causes white cell casts to be in urine?
any inflammation or infection
What causes renal tubular casts to be in urine?
What causes coarse, granular casts to be in urine?
What causes broad, waxy casts to be in urine?
Indicative of statis in the tubules
What imaging method do you use for hydronephrosis?
What imaging method do you use for pyelonephritis?
What imaging method do you use for PCKD?
What imaging method do you use for cysts?
U/S for regular
CT scan for complex
What are indications for a renal bx?
Unexplained chronic kidney dz
Unexplained acute kidney dz
Acute nephritic syndrome
Systemic dz with kidney involvment (DM, SLE)
Suspected transplant rejection
What are contraindications of a renal bx?
Severe uncontrolled HTN
Uncontrolled bleeding d/o
What do you need in order to be cleared for a renal bx?
d/c anticlotting Rx
Well controlled HTN
HGB, platelet count, Pt, PTT