Urinalysis Exam 2

Renal diseases and fluids

What is azotemia?

Elevated levels of urea and other nitrogen compounds in the blood

What are clinical features of glomerular diseases? ***

Hematuria

Proteinuria

Oliguria

Azotemia

Edema

Hypertension

What syndromes indicate glomerular injury?

Asymptomatic hematuria/proteinuria

Acute nephritic syndrome

Nephrotic syndrome

What is nephritic syndrome?

Inflammation of the glomeruli and renal dysfunction

What is the most common cause of nephritic syndrome?

IgA nephropathy (Berger’s disease)

What is the difference between nephritic syndrome and nephrotic syndrome?

Nephritic: Inflammation of glomeruli

Nephrotic: Damage to glomeruli

What are symptoms of nephritic syndrome?

Oliguria

Hypertension

Hematuria (cola-colored urine)

hematuria/proteinuria (<3 g/day)

elevated BUN and creatinine

RBC casts in urine

What are symptoms of nephrotic syndrome?

Edema

Hypoalbuminemia

Massive proteinuria (>3.5 g/day)

Hyperlipidemia

Fatty/Waxy casts

Oval fat bodies in urine

What are symptoms of acute glomerulonephritis?

Oliguria

Hematuria

Proteinuria

Increased ratio BUN to creatinine levels

WBC/RBC/Granular/hyaline casts in urine

With what autoimmune diseases can you see rapidly progressive glomerulonephritis?

Goodpasture syndrome

Systemic lupus erythematosus

What is membranous glomerulonephritis?

Deposits of immunoglobulins and complement along the epithelial (podocyte) side of the basement membrane

What is minimal change disease?

Loss of podocyte foot processes

What type of glomerulonephritis is seen in heroin abuse and AIDs?

Focal segmental

What is fanconi’s syndrome?

Any condition that presents with generalized loss of proximal tubular function

What is cystinosis/cystinuria?

Inherited autosomal recessive disorders that cause renal tubular dysfunction and urinary excretion of amino acid cystine

What is glucosuria?

Benign inherited condition that results in excretion of glucose in urine despite normal blood glucose levels

What is phosphaturia?

Uncommon hereditary disorder characterized by inability of the distal tubules to reabsorb inorganic phosphorus

What is tubular acidosis?

Inability of the tubules to secrete adequate hydrogen ions despite a normal GFR

What is the main difference between upper and lower UTIs?

Upper UTIs will have WBC casts

What is the difference between acute and chronic pyelonephritis?

Acute: Has WBC casts. Bacterial infection

Chronic: persistent inflammation that causes scarring. Bacteria may or may not be present. Casts are absent.

What is acute renal failure (ARF)?

Sudden decrease in glomerular filtration rate (GFR)

Classified as: Prerenal, renal, and postrenal

What is Prerenal ARF?

Occurring before blood reaches kidney due to hypovolemia or poor perfusion as a result of cardiovascular failure

What is primary renal ARF?

Occurring in the kidneys because of acute tubular necrosis of other renal disease

What is postrenal ARF?

After urine leaves kidney because of obstruction or rupture of the urinary bladder

What are the biochemical clues that lead to the development of ARF? ***

Rapidly rising urea and creatinine concentrations

Severe and life-threatening metabolic derangements (hyperkalemia and metabolic acidosis)

What is chronic renal failure (CRF)?

Progressive loss of renal function

Not normally recognized until about 80-85% renal function lost

What are the urinalysis findings for chronic renal failure?

Fixed specific gravity (Isosthenuria at 1.010)

Significant proteinuria

Minimal/moderate hematuria

Presence of casts (Waxy)

What are some symptoms of chronic renal failure?

Azotemia

Acid-base imbalance

Abnormal calcium and phosphate metabolism

What are renal calculi?

Kidney stones

What are a majority of renal calculi made of? (75%)

Calcium

What factors influence calculi formation?

Supersaturation of chemical salts in urine

Optimal urinary pH

Urinary stasis

Nucleation or original crystal formation

Slide 17 kidneys

What is the purpose of cerebral spinal fluid?

Cushions the brain and spinal cord

Contains high density of nutrients

What chemicals does CSF have in a higher concentration than plasma?

Sodium

Chloride

Magnesium

What chemicals does the CSF have in lower concentrations than the plasma?

Potassium

Calcium

Protein

What are the three membranes (meninges) that surround the brain and spinal cord?

Dura mater

Arachnoid mater

Pia mater

What is the dura mater?

Outer layer next to bone

What is the arachnoid mater?

Middle layer resembling a spiderweb

What is the pia mater?

Innermost layer adhering to the surface of neural tissues

Where does the CSF flow?

In subarachnoid space between arachnoid mater and pia mater

What happens if CSF reabsorption is blocked?

Hydrocephalus (increases intracranial pressure, causes brain damage, disabilities, and possibly death)

What is the normal level of CSF in an adult?

85-150 mL

What is the blood brain barrier?

Interface between the blood and CSF that is highly selective

How is CSF collected?

Aseptic lumbar puncture between the third and fourth lumbar interspace (fourth and fifth in children)

What are the tubes labeled (in order) for CSF testing?

Chemistry (can spin down cells and be fine)

Microbiology (second tube since most cells are now out of the way)

Cell counts (hematology)

What is pleocytosis?

Increased number of cells in CSF

What is xanthochromia?

Abnormal color of CSF (usually yellow)

When would you see cloudy CSF?

Meningitis

Hemorrhage

Disorders in the blood-brain barrier

How can you tell if the presence of blood in CSF is due to a traumatic tap?

Greatest amount in tube 1, least in tube 3 (getting lighter throughout the tubes)

Clear after centrifuge

How can you tell if the presence of blood in a CSF is due to a hemorrhage?

Blood is consistent throughout all 3 tubes

Centrifugation still yields xanthochromic supernatant

What is the normal microscopic examination of CSF?

For adults:

No RBCs

0-5 WBCs per mL

How do you perform WBC counts on CSF?

Add 2% acetic acid to lyse RBCs

Perform differential by cytospin

You find plasma cells in CSF. What possible disorder could this be?

Multiple sclerosis

What is the normal amount of total protein in CSF?

15-45 mg/dL

Higher in infants and older adults

Why would you look at total protein in CSF?

To assess the integrity of the blood brain barrier and to indicate pathologic conditions of the central nervous system

When would you see decreased total protein in CSF?

Increased reabsorption because of increased intracranial pressure

Loss of fluid because of trauma or invasive procedures

What is used to assess the permeability of the blood-brain barrier?

CSF / Serum albumin index

(Albumin is NOT synthesized in the CSF and therefore needs to cross the BBB)

High amount of albumin in the CSF means there is a problem with the BBB

Your patient has an IgG index of greater than 0.70. What is the most likely reason?

Patient has multiple sclerosis

What are the bands found on a protein electrophoresis of CSF?

Transthyretin (prealbumin), albumin, and two transferrin bands

Why is CSF considered STAT?

If left to sit, the cells will start to lyse

Do. Not. Want. To. Recollect.

What is pleural fluid?

Covers the lungs

What is pericardial fluid?

Covers the heart

What is peritoneal fluid?

Covers abdominal organs

What is a parietal membrane?

Lines the body wall

What is a visceral membrane?

covers the organ

What are the four factors of fluid formation?

Permeability of capillaries in parietal membrane

Hydrostatic pressure in these capillaries

Oncotic pressure produced by plasma proteins in capillaries

Absorption of fluid by lymphatic system

What causes plasma ultrafiltrate to form in a cavity?

Hydrostatic pressure (blood pressure)

If the lymphatic system is blocked or impaired, what happens?

Effusion

What is effusion?

Accumulation of fluid in a body cavity indicating an abnormal or pathologic process

What is paracentesis?

Percutaneous puncture of a body cavity for aspiration of fluid

What is thoracentesis?

Way to obtain pleural fluid

What is pericardiocentesis?

Procedure to obtain pericardial fluid

What is peritoneocentesis (abdominal paracentesis) for?

Collecting of peritoneal fluid

Ascites: Effusion of peritoneal cavity

Ascitic fluid: same as peritoneal fluid

What is transudate?

An effusion that results from a systemic disease that causes an increase in hydrostatic pressure or a decrease in plasma oncotic pressure

Noninflammatoru

No additional testing needed

What is an exudate?

An effusion that results from an inflammatory process

Infections, neoplasms, trauma, inflammatory conditions

Requires additional testing

What fluids can be classified as transudate or exudate?

Pleural and peritoneal

What are chylous effusions caused by?

Obstruction or damage to lymphatic system

What is the difference between a chylous effusion and a pseudochylous effusion?

Chylous: High triglycerides and chylomicrons present

Pseudochylous: Low triglycerides and no chylomicrons

What are the WBC counts for transudates and exudates?

Transudates: less than 1000 cells

Exudates: more than 1000 cells

How are pericardial effusions made?

Increased capillary permeability due to changes in parietal membrane

How are transudate effusions created?

Decreased hydrostatic pressure or decreased oncotic pressure

How are exudate effusions created?

Increased capillary permeability or decreased lymphatic absorption

What conditions are associated with transudate effusions?

Congestive heart failure

Hepatic cirrhosis

Nephrotic syndrome

What conditions are associated with exudate effusions caused by increased capillary permeability?

Infection

Tumors

Systemic disease (lupus, rheumatoid arthritis)

Gastrointestinal disease

What conditions are associated with exudate effusions caused by decreased lymphatic absorption?

Tumors

Trauma or surgery

What conditions are associated with pericardial effusions?

Infections

Cardiovascular disease

Tumors

Hemorrhage

Systemic disease (lupus, rheumatoid arthritis)

What is chyle?

Composition of fat droplets and lymph

What is high pleural or peritoneal fluid amylase associated with?

Pancreatitis

Esophageal rupture

Gastric duodenal perforation

Metastatic disease

Pleural exudates with low pH are caused by:

Pneumonia or lung abscess

If a fluid/serum protein ratio is less than 0.5, what kind of effusion is it?

Transudate

If a fluid/serum lactate dehydrogenase ratio is greater than 0.6, what kind of effusion is it?

Exudate

What is the function of synovial fluid?

Bathes and lubricates joints

What are the two types of synoviocytes?

Predominant type that is actively phagocytic and synthesizes degradative enzymes like collagenases

Other type that synthesizes hyaluronate

How is synovial fluid formed?

Ultrafiltration of plasma across the synovial membrane and from secretions by synoviocytes

What is the composition of synovial fluid?

Glucose and uric acid (same as plasma)

Total protein and immunoglobulins vary from ¼ - ½ that of plasma

What are the four categories of joint disorders?

Noninflammatory

Inflammatory

Septic

Hemorrhagic

What is arthrocentesis?

Procedure to get synovial fluid

Percutaneous aspiration from a joint using aseptic technique and disposable sterile equipment

When collecting synovial fluid, why should oxalate, lithium heparin, and powdered EDTA be avoided?

They can produce crystalline structures that resemble monosodium urate crystals

What are rice bodies in synovial fluid?

White, free-floating substances made up of collagen covered by fibrinous tissue

Seen in arthritic conditions

What causes the high viscosity of synovial fluid?

Mucoprotein hyaluronate