Clin assess CURRENT MEDICAL DIAGNOSIS AND TREATMENT BOOK renal Flashcards
worsening of the kidney function over hours to days, resulting in retention of the nitrogenous wastes (like urea nitrogen) and creatinine in the blood.
acute kidney disease/injury
retention of the nitrogenous wastes (like urea nitrogen) and creatinine in the blood.
Azotemia
results from an abnormal loss of kidney function over months to years
Chronic kidney disease
small kidneys are most consistent with
CKD
normal to large size kidneys can be seen with
CKD and Acute disease
test that can give the same type of information as biopsy but is cost effective and non-invasive
urinalysis
how is urinalysis collected?
midstream or cath
within what time should the urine be examined
1 hour to avoid destruction of formed elements
urinalysis includes:
dipstick exam followed by microscopic assessment if the dipstick has positive finsings
measures pH, protein, hemoglobin, glucose, ketones, bilirubin, nitrates, and leukocytes esterase
and urinary specific gravity is often reported
dipstick examination
examination of formed elements- crystals, cells, casts., and infecting organisms
microscopy examination
_______ are composed of TammHorsfall urinary mucoprotein in the shape of the nephron segment where they were formed.
Casts
Heavy proteinuria and lipiduria are consistent with the _____syndrome
nephrotic syndrome
what is indicative if they have presence of hematuria with dysmorphic red blood cells, red blood cell casts, and proteinuria
glomerulonephritis
pigmented granular casts and renal tubular epithelial cells alone alone or in casts suggest
acute tubular necrosis
pyuria alone can indicate
urinary tract infection
excessive protein excretion in the urine, gernally > 150-160 mg/24h in adults.
proteinuria
sign of an underlying kidney abnormality usually glomular in origin
proteinuria
accompanied by elevated blood urea nitrogen (BUN), and serum creatinine levels, abnormal urinary sediment, or evidence of systemic illness (fever, rash, vasculitis)
Proteinuria
Reasons for the development of proteinuria (4)
- functional proteinuria
- overload proteinuria
- glomerular proteinuria
- tubular proteinuria
benign process stemming from stressors such as acute illness, exercise, and orthostatic proteinuria.
functional proteinuria
generally found in people under age 30 years old usually results in urinary protein excretion of
orthostatic proteinuria
result from an overproduction of circulating, filterable plasma proteins, such as Bence Jones proteins associated with multiple myeloma. urinary electrophoresis will exhibit a discrete protein peak. other examples of this include myoglobinuria in rhabdomyolysis and hemoglobinuria in hemolysis.
Overload proteinuria
results from effacement of epithelial cell foot processes and altered glomerular permeability with an increased filtration fraction of normal plasma proteins, as in diabetic nephropathy. Exhibits some degrees of proteinuria. The urinary protein electrophoresis will have a pattern exhibiting a large albumin spike indicative of increased permeability of albumin across a damaged GBM
glomerular proteinuria
occurs as result of faculty reabsorption of normally filtered proteins in the proximal tubule, such as micro globulin and immunoglobulin light chains. causes include acute tubular necrosis, toxic injury, drug induced interstitial nephritis, and hereditary metabolic disorders.
Tubular proteinuria
urinary dipstick primarily detect
while overlooking
albumin
while over looking: positively charged light chains of immunoglobulins
how can proteins be detected when overlooked in a urinary dipstick ?
by addition of sulfosalicylic acid to the urine specimen
if patient has proteinuria with out without loss of kidney function, what may be indicated
kidney biopsy, especially if the kidney disease is acute in onset
__________ is significant if there is more than three red cells per high-power field on at least two occasions. usually is detected incidentally by the urine dipstick exam or clinically following and episode of macroscopic _______.
Hematuria
diagnosis must be confirmed via microscopic exam. a false positive dipstick test can be caused by myoglobin, oxidizing agents, beets and rhubarb, hydrochloric acid, and bacteria
hematuria
common, but in pts younger then 40 years old, it is less often of clinical significance due to lower concern for malignancy.
transient hematuria
hematuria can be due to 2 causes
renal or extrarenal
account for approx 10% of cases and are best considered anatomically as glomerular or nonglomerular.
renal cause
most common ________ sources include cysts, calculi, interstitial nephritis, and renal neoplasia.
Extraglomerular sources
provides a useful index of kidney function at the level of the glomerulus. this can be decreased in pt with kidney disease which is from any process that causes loss of nephron mass. but this can be increased or normal either from hyperfiltration at the glomerulus or disease at a different segment of the nephron, intersititium, or vascular supply.
GFR
measures the amount of plasma ultrafiltered across the glomerular capillaries and correlated with the ability of the kidneys to filter fluids and various substances.
GFR
can be measured by determining the renal clearance of plasma substances that are not bound to plasma proteins, are freely filterable across the glomerulus, and are neither secreted nor reabsorbed along the renal tubules
GFR
C= (U x V)/ (P)
formula used to determine the renal clearance of a substance
C: clearance
U: urine concentration
P: plasma concentration
product of muscle metabolism produced at a relatively constant rate and cleared by renal excretion. Freely filterable by the glomerulus and not reabsorbed by the renal tubules.
Creatinine
when is creatinine production and excretion equal thus plasma creatinine concentration remain constant?
with stable kidney function
what are the four variable estimated GFR equation incude
serum creatinine, age, weight, race
more accurate then creatinine clearance
