SM_194a: Urine Flashcards
Describe the components of normal urine on a urinalysis
Normal urine
- Specific gravity: 1.000-1.030
- pH: 5-8
- Protein: negative-trace
- Glucose: negative
- Ketone: negative
- Bilirubin: negative
- Blood: negative
- Nitrite: negative
- Leukocyte: negative
A 24 year old woman presents complaining of dysuria and urinary frequency. The urinalysis is obtained. Your diagnosis is _____

A 24 year old woman presents complaining of dysuria and urinary frequency. The urinalysis is obtained. Your diagnosis is urinary tract infection

A 24 year old woman presents complaining of flank pain that had a sudden severe onset. She notices her urine looks darker. She has nof ever. Your diagnosis is ______

A 24 year old woman presents complaining of flank pain that had a sudden severe onset. She notices her urine looks darker. She has nof ever. Your diagnosis is kidney stone

What are causes of leukocyturia (white cells in the urine)?

Leukocyturia
- Contamination
- Infection (vaginitis, urethritis, bladder)
- Inflammation of kidney or bladder: interstitial cystitis, pyelonephritis, interstitial nephritis (eosinophils classically associated)

What are causes of nitrites in urine?

Nitrites in urine: can be detected on dipstick
- Some bacteria convert nitrates to nitrites: may be colonization or infection (or contamination)

Dipstick detects only _____ charged proteins (predominantly ______)

Dipstick detects only negatively charged proteins (predominantly albumin)

Dipstick only detects protein ______, so amount detected is dependent on urine volume
Dipstick only detects protein concentration, so amount detected is dependent on urine volume
Proteinuria can be measured by _____, _____, or ______
Proteinuria can be measured by dipstick (concentration only), ratio (accounts for concentration by correcting for creatinine: spot collection), actually measured as amount of protein excreted in a day (24 hours of urine have to be collected which can be inconvenient)
Most common cause of hematuria is ______
Most common cause of hematuria is diabetes
Describe the definitions of microalbuminuria

If the dipstick is positive for hematuria but there are no RBCs on microscopy, ______, ______, or ______ could be occurring

If the dipstick is positive for hematuria but there are no RBCs on microscopy, rhabdomyolysis, hemolysis, and dilute urine could be occurring
(look at specific gravity to see if urine is dilute)

Hematuria can be caused by _____, _____, or _____

Hematuria can be caused by GU cause, contamination, or infection

Hematuria with red blood cell casts, proteinuria, or dysmorphic RBCs suggests a ______ cause
Hematuria with red blood cell casts, proteinuria, or dysmorphic RBCs suggests a glomerular cause
A patient has a maximum tubular reabsorption of glucose of 300 mg/dL. Their serum glucose is 375 mg/dL. _____ mg/dL of glucose will be in the urine
A patient has a maximum tubular reabsorption of glucose of 300 mg/dL. Their serum glucose is 375 mg/dL. 75 mg/dL of glucose will be in the urine

Absorbing water out of the urine will _____ glucose
Absorbing water out of the urine will concentrate glucose

Specific gravity is a measure of ______
Specific gravity is a measure of how concentrated the urine is
- 1.000: pure water
- 1.030: max concentration - equivalent to osmolality of 1,100-1,200 mOsm
- 1.010-1.012: isothenuria - equivalent ot osmolality of 280 to 300 mOsM, which is the range of normal serum osmolality

Normally ____ and ____ are not present in the urine

Normally ketones and bilirubin are not present in the urine
- Ketones: think diabetic ketoacidosis or poor po intake
- Bilirubin: check liver tests, look for liver disease

Describe the clinical presentations of renal disease

Describe GU presentations of renal disease
GU
- UTIs: common, usually symptomatic, do not cause a rise in creatinine
- Pyelonephritis (kidney infection): patients much more ill, if severe can have rise in creatinine
- Kidney stones: flank pain and hematuria, can have medically predisposing causes, use serum and urine chemistry to help diagnose, drink water
- Obstruction: many causes (tumors, stones, bladder problems, intrarenal crystals), variable presentation, diagnose with ultrasound
UTIs ____ rise in creatinine
UTIs DO NOT cause rise in creatinine
(pyelonephritis causes a rise in creatinine if severe)
Describe characteristics of acute kidney injury
Acute kidney injury
- Variable based on cause
- Elevated creatinine over short period of time (urine tests help)
- Oliguria: too little urine produced

Acute kidney injury is characterized by _____ and/or _____
Acute kidney injury is characterized by increase in serum creatinine and/or oliguria
Urinary indices help differentiate _____ and _____ acute kidney injury
Urinary indices help differentiate prerenal and intrinsic acute kidney injury
- Prerenal: responding to low volume stimulus by trying to retain Na+
- ATN: intrinsic, cannot respond to low volume














