SU2M - Proteinuria and Hematuria Flashcards
Glomerular proteinuria: due to? What can it lead to? Proteinuria?
- due to increased permeability of the glomerulus to proteins
- can lead to nephrotic syndrome
- can be seen in all types of glomerular nephritis
- protein loss is more severe than in non-glomerular cases
Proteinuria: definition?
-urinary excretion of >159 mg of protein/ 24 hrs
Tubular proteinuria: due to? Level of proteinuria? Causes?
- abnormal tubules cause small proteins that are normally reabsorbed by the tubules to appear in the urine bc they are not reabsorbed
- proteinuria is less severe
- causes:
1. Sickle cell disease
2. Urinary tract obstruction
3. Interstitial nephritis
Overflow proteinuria: due to? Can be seen in what dz?
- due to increased production of small proteins that overwhelm the tubule’s ability to reabsorb them
- can be seen in multiple myeloma –> Bence Jones proteins
7 causes of proteinuria?
- Glomerular
- Tubular
- Overflow
- UTI
- Fever, heavy exertion/stress, CHF
- Pregnancy
- Orthostatic proteinuria –> occurs only when standing, self limiting, benign
3 Key features of nephrotic syndrome? Plus 3 more?
- Proteinuria - excretion of > 3.5 g/24hrs
- Hypoalbuminemia - hepatic albumin synthesis cannot keep up with the rate of protein loss –> decreased plasma oncotic P –> edema
- Hyperlipidemia -get increase in LDL and VLDL synthesis from the liver bc the liver is revving up albumin synthesis
- Edema - often the initial complaint, the result of hypoalbuminiemia + increased aldo secretion will exacerbate the problem
- pedal edema
- periorbital edema
- ascities
- pleural effusion - Hypercoagulable state - loss of anticoagulants in the urine = risk of thromboembolic events
- Increased incidence of infection - from loss of immunoglobulins in the urine
8 General causes of proteinuria?
- Primary glomerular dz –> MOST COMMON
- Systemic dz –> DM, collagen vasc dz, SLE, RA, etc.
- Amyloidosis or cryoglobulinemia
- Drugs/toxins –> captopril, heroin, heavy metals, NSAIDs, penicillamine
- Infection –> bacterial, viral, protazoal
- Multiple myeloma
- Malignant HTN
- Transplant rejection
What can be a cause of a false negative with a urine dipstick test for proteinuria?
- the test is more sensitive to albumin, so it can test negative if there are more immunoglobulins in the urine
- ex light chains in multiple myeloma
What do RBC casts suggest?
-glomerular nephritis
What do WBC casts suggest?
-pyelonephritis and interstitial nephritis
What doe fatty casts suggest?
-nephrotic syndrome = lipiduria
What can microalbuminuria be an early sign of?
-diabetic nephropathy
Asymptomatic proteinuria: tx?
- transient = no tx
- persistent = further testing (ex. BP & examine urine sediment) + tx underlying condition & associated problems
Symptomatic proteinuria: tx (6)?
- Tx underlying cause
- ACEi (or ARB, if cant tolerate ACEi) –> decrease albumin loss
- Diuretics –> if edema present
- Limit dietary protein and sodium
- Tx hypercholesterolemia –> via diet or lipid-lowering drug
- Vaccinate against influenza and lneumococcus –> there is an increased risk of infection in these pts
Hematuria: definition?
- > 3 RBCs/HPF on urinalysis
Common origin of microscopic hematuria v gross hematuria?
- microscopic = usually glomerular in origin –> think glomerular dz
- gross = usually nonglomerular or urologic in origin –> think postrenal causes (ex: trauma, stones, malignancy)
What is gross painless hematuria a sign of?
-bladder or kidney cancer until proven otherwise!
What can hematuria lead to?
- Obstruction if large clots form in the lower GU tract
2. Iron deficiency anemia, if there is excessive blood loss
What are the 2 most common causes of atraumatic hematuria?
- Infection - cystitis, urethritis, or prostatitis
2. Kidney stones
Infection causes what type of hematuria?
-can cause either gross or microscopic
Cause of hematuria + RBC casts + proteinuria?
-glomerular nephritis usually
What is the cause of + dipstick for blood but urinalysis is negative for microscopic blood?
-hemaglobinuria or myoglobinuria
What test should be done when suspicious for cancer with hematuria?
- do cytoscopy to evaluate the bladder
- do it regardless of cytology results
What should be done if hematuria + pyuria are present?
-send for culture! –> probably UTI!
