urinary Flashcards

Question

creatinine

Answer 1

* Kidneys are the major route of excretion * Crude index of GFR but better than BUN in most cases because it produced at constant rate, fewer non renal factors, non reabsorbable * When is it not a good indicator of GFR, with muscle wasting or necrosis.

Answer 2

* Usually a consequence of reduced renal perfusion, or GI hemmorage, high prot * Kidney function is normal if exists alone or with just postrenal component; but can be superimposed on renal and postrenal azotemia KEY FEATURE : azotemic mild but USG > 1.030 dog, > 1.035 cat, > 1.025 horse/cow

Answer 3

* Azotemia resulting from renal failure or disease * Implies > 75 % of nephrons are nonfunctional * KEY FEATURE: azotemia with dilute urine specific gravity < 1.030 dogs, < 1.035 cats and < 1.025 horses/cows -Patients with other long-standing causes of PU/PD leading to medullary washout and some cats with CKD that maintain urine concentration abilities while in IRIS stage I / II

Answer 4

-Azotemia resulting from either an obstruction in the excretory outflow tract or from a uroabdomen (tear in excretory pathway) * Key feature: degree of azotemia and urine specific gravity are variable but clinical findings are suggestive (distended bladder, stranguria, fluid filled abdomen)

Answer 5

* Relies primarily on renal elimination for excretion (>90%) so circulating concentrations are primarily affected by changes in GFR and therefore correlate to kidney function * Not affected by muscle mass like creatinine, better test than creatnine for GFR * Reference Intervals: adult dogs and cats < 14 ug/dl and < 16 ug/dl in puppies and kittens * Values expected with early kidney disease between 15 and 20 mg/dL ; > 20 mg/dlwith more advanced disease

Answer 6

* Definition: azotemia caused by renal parenchymal disease or injury that occurs over hours to days * Potentially reversible * Clinically: * Acute onset * Oliguria/anuria or polyuric AKF states * Azotemia and not concentrating their urine if producing urine * Generally not anemic and in good body condition * Nephrotoxins, infectious causes, and ischemia are the most common causes

Answer 7

* Azotemia caused by renal disease or injury that has occurred over a prolonged duration (months to years) * Irreversible and progressive * Clinically: * Slow Insidious clinical onset unless acute on chronic crisis; IRIS stages I-V * PU/PD – not concentrating their urine * Progressive azotemia and eventual uremia * Anemia, poor body condition * Small and irregular kidney * Commonly see diminished urine concentrating ability * Isosthenuria or hypersthenuric

Answer 8

* Subclinical or clinical syndrome * Pathogenesis is controversial * Involves: Hyperphosphatemia – decreased excretion Low circulating levels of vitamin D due to loss of nephrons that activate precursor ± Reduced serum ionized [Ca 2+] Skeletal resistance to PTH

Answer 9

* Color Red – Hemoglobin, myoglobin, RBCs Orange – bilirubin Other – drugs, dyes, foods * Clarity * Smell -USG -urine osmolariy: # of particles in urine

Answer 10

Refractometer typically used Urine concentration varies with many nonrenal factors (diet, water intake, extrarenal diseases) Remember there is no true normal** urine specific gravity, must assess * Assess hydration status * Use your history Is there evidence of fluid losses

Answer 11

* Urine pH – careful not to overinterpret acidic urine: meat-based diet, systemic acidosis, alkaline urine: old sample, UTI * Glucose – relevance varies with plasma glucose Hyperglycemia = diabetes glucosuria expected Normoglycemia/hypoglycemia – tubular disorder * Ketones – should be negative Positive with DKA, starvation * Protein only detect albumin above a 30 mg/dl threshold always be interpreted in view of the urine sediment examination and the USG; small amount of protein may be normal

Answer 12

-results from prehepatic (RBC hemolysis) or from hepatic or posthepatic diseases -measure only unconjugated bilirubin -maybe seen prior to detection of hyperbilirubinemia -Trace to 1+ bilirubin can be normal in canine urine (especially males) but ANY bilirubin in feline urine is abnormal

Answer 13

* Red urine RBCs, Hemoglobin Myoglobin, methemoglobin * have to Occult blood: -Intact RBCs, hemoglobin, and myoglobin all produce positive results -Differentiation depends on sediment analysis and examination of plasma (red with hemoglobinuria, normal with myoglobinuria) -method of collection my influence RBC if cysto To differentiate these: * PCV/TP * Serum analysis * Urine sediment analysis

Answer 14

* Microscopic examination of gently resuspended sediment of centrifuged urine – can evaluate stained (Sedi-Stain®) and unstained slides (wet mount) -method of collection will influence results look for: RBC WBC Squamous cells transitional cells sperm -microbes can also be seen, bacteria, fungal elements (shouldnt see with cysto as its sterile)

Answer 15

* Absence does not rule out tubular injury (e.g., anuric AKI) * Cylindruria (casts in the urine) localizes disease to the kidneys; can provide the earliest indication of tubular injury when administering a nephrotoxic drug * Cylindrical molds of the renal tubules composed of protein and/or cells. Low numbers of casts (1-2 /lpf) in very concentrated urine are normal. Look for them at low power

Answer 16

Hyaline: Tamm-Horsfall mucoproteins. Small numbers may be seen with fever, dehydration or heavy exercise. Mos common type of cast. Increased # with pathological proteinuria. Cellular: epithelial, RBCs or WBCs and are always abnormal. Epithelial cell casts signify severe tubular disease from toxins or hypoxia. RBC casts indicate hemorrhage. WBC casts suggest inflammation. Granular casts: degeneration of either cellular or hyaline casts; low numbers < 2 p/lpf normal – exercise, tubular dz may increase Waxy casts: final stage of degeneration of granular casts; highly refractile and result from extreme urine stasis Fatty casts: seen in patients with nephrotic syndrome and diabetes mellitus. Can be normal in cats

Answer 17

* Lipiduria – common in cat urine and normal * Amphorphous debris – common – cells, crystals * Contaminants: plant grains or pollens -parasite life stages

Answer 18

* Crystallization occurs when urine composition (pH, SG, mineral composition) favors oversaturation of certain minerals; * Visualization also depends on pH, solubility of the crystals, and temperature of the urine Crystals more likely to form in concentrated urine * Significance depends on the type of crystal and other clinical findings – some types such as struvite and calcium oxalate can be normal or clinical importance and some are always of clinically significant

Answer 19

Proteinuria can result from: Prerenal: * Bence-Jones withmultiple myeloma, * IMHA, platelet problem Renal: disorders of the glomeruli * neoplasia, * Glomerulonephritis * Amyloidosis Postrenal: * Neoplasia, UTI, urolithiasis * Interpret in light of: The USG and the urine sediment exam The method of collection in some patients Trace or 1+ may be normal if urine concentrate

Answer 20

1. Urine protein creatinine ratio normal < 0.4 cat; < 0.5 dog 2. 24 hour urine collection 3. Microalbuminuria can be used to detect dz early in predisposed breeds such as Whaeton Terrier

Answer 21

-kidneys may be normal sized if acute -with chronic glomerulonephritis kidneys are irregular and small renal biopsy: only way to differentiate glomerulonephritis from amyloidosis

Answer 22

* Assessment of urine concentrating ability – USG and osmolality * Remember no “normal” urine specific gravity since concentrating ability is affected by non-renal factors such as diet, water intake, * Provocative testing of urine concentrating ability through a Modified Water Deprivation Test – more on how to perform this and indications in the lecture on PU/PD assessment of Tubular Reabsorption of Electrolytes, other solutes

Answer 23

USG is < 1.008 ❑ This does NOT suggest renal failure; production of dilute urine is an active process performed by the renal tubules

Answer 24

USG is fixed and between 1.008-1.015

Answer 25

these terms are rarely used; baruria urine that is very concentrated - > 1.030 dog, > 1.035 cat; hypersthenuria refers to urine of higher total solute concentration than glomerular filtrate (USG >1.015, Uosm> 300 mOsm/kg) but is not highly concentrated.

Answer 26

Detection of aminoaciduria, glucose, increased HCO3, etc. * Fractional excretion of electrolytes * Indications * Differentiating prerenal from renal azotemia * Monitor tubular function when nephrotoxic drug given * Investigating renal tubular acidosis or Fanconi syndrome * Provocative Testing for determination of the type of renal tubular acidosis

Answer 27

Get a cystocentesis sample unless contraindicated * For best results culture within 6 hours of collection * False negatives can occur if urine is refrigeration is prolonged * Quantitative vs qualitative cultures

Answer 28

Plain radiographs – assess size on a V/D and symmetry * Dog 2.5-3.5 L2 * Cat 2.0-3.0 L2 (smaller if neutered) Normal kidneys have a smooth outline Renomegaly- AKI, obstruction, hydronephrosis, PSS, acromegaly, amyloidosis, compensatory renal hypertrophy, neoplasia,

Answer 29

-Assess size and for displacement Nonvisual – empty, ruptured, displaced due to a hernia or mass (sublumbar lymphadenopathy, colonic impaction, prostatomegaly) Enlarged – normal, urine retention, urethral obstruction Small bladder – normal, anuria, tear Abnormal shape – diverticula Radiopaque calculi Dystrophic mineralization normal urethra not visible

Answer 30

- can range from yellow (microscopic hematuria or abnormal red to brown (macroscopic hematuria) -history: reproductive status trauma straining to defecate in male dogs systemic illness -need to do tests to rule out pigmenturia and bilirubinuria

Answer 31

* Physical examination -look for coagulopathy * Any evidence of petechia and or ecchymosis * Examine for mucus membrane pallor, epistaxis, hematochezia, swollen joints, bleeding from venipuncture sites * Do a rectal, examine the genitalia do a specific urogenital examination, digital vaginal exam * Careful palpation of the bladder and the kidneys and examination of the genitalia

Answer 32

-Observing the patient during voiding to verify hematuria and confirm or detect abnormalities such as dysuria / stranguria that could localize the source * The stage of micturition at which blood appears: -start of urination: urethral source -end of urination: urinary bladder origin -blood throughout = kidney or ureteral origin maybe bladder

Answer 33

Physiologic/Benign Proteinuria * Strenuous exercise * Seizures * Fever * Pathologic * Paraproteinemias * Multiple myeloma * Lymphomosarcoma

Answer 34

* Postrenal proteinuria results from inflammation or hemorrhage in the LUT * Common causes: cystitis, metritis, prostatitis, or neoplasia

Answer 35

- Disorders of the Glomeruli -albumin is lost * Disorders of the renal tubules or interstitium -low molecular wt * The hallmark of glomerular disease is proteinuria in the face of an “inactive” urine sediment -can lead to: chronic renal failure, nephrotic syndrome

Answer 36

* Proteinuria * Hypoalbuminemia * Hypercholesterolemia * SC edema or body cavity effusions

Answer 37

* Urine protein creatinine ratio: this test is used to quantify the magnitude of protein loss * This test should only be done once the results of a complete UA have been evaluated Normal ranges for dogs and cats** (will be on exam) * UP/C ratio <0.2 is normal for dogs and cats * Grey Zone UP/C ratio ≥ 0.2 to 0.5(dogs) and ≥ 0.2 to 0.4(cats) * Abnormal UP/C ratio is ≥ 0.5 and ≥ 0.4 for dogs and cats * Can perform on a single random sample of urine or pooled samples * The UPC ratio CANNOT be used to differentiate patients with glomerulonephritis from renal amyloidosis

Answer 38

-azotemia hypoalbuminemia -hypercoagulability (decrease in antithrombin III) and increase platelet aggregation

Answer 39

-Hematuria refers to blood in urine – hematuria may be macroscopic (visible with the naked eye with pink, red, or dark brown urine +/- contain blood clots) or microscopic (only visible with microscope examination of the urine sediment -Hematuria can be classified as benign (damaged mucosa of bladder) or pathologic (inflammation, neoplasia) -These pathologic disorders can be classified as prerenal, renal and postrenal

Answer 40

– typically see pollakiuria, stranguria and dysuria.

Answer 41

may see signs of systemic disease

Answer 42

1: good history and physical exam 2: confirm the hematuria and eliminate other causes of red urine (pigments such as hemoglobin, myoglobin and bilirubin). This will require a urinalysis to begin with. -. Perform Dipstick Occult Blood Test -USG -observe micturition -urethral catheterization

Answer 43

- if the dipstick and sediment of a second urine sample remains negative for RBCs/ bilirubin but the urine is still discolored, consider pseudohematuria—urine discoloration from pigments derived from drugs, food dyes, toxins

Answer 44

- the clinical significance of bilirubinuria depends on the patient’s species, sex and urine specific gravity. a. Any bilirubinuria in a cat is significant. In dog urine trace or 1+ bilirubinuria is acceptable with a USG > 1.020 but if the urine is very dilute 1this maybe

Answer 45

-depending on the scenario consider microscopic hematuria of unknown cause or intermittent hematuria

Answer 46

-the magnitude of the proteinuria will help determine if renal proteinuria is glomerular or tubulointerstitial in origin. Magnitude is assessed using a quantitative test for urine protein -Why is persistent renal proteinuria significant? Proteinuria is a negative prognostic indicator for chronic kidney disease. It leads to interstitial fibrosis as well as tubular degeneration and atroph

Answer 47

-results can be falsely elevated with alkaline urine, pigmented urine, or with highly concentrated urine. Acidic urine can cause false negative results -SSA test - a semi-quantitative test is able to detect proteinuria at values > 5 mg/dl and detects albumin and other proteins such as globulins, Tamm-Horsfall and Bence Jones proteins, although it often underestimates them. False positive results occur with the presence of radiographic contrast agents, some drugs (e.g., cephalosporins, penicillin). There are fewer false negatives compared to the dipstick test

Answer 48

a) Normal secretion of the hormone ADH b) Normal responsiveness of the renal tubules to ADH and vasopressin c) The maintenance of a high osmolarity renal medullary interstitium; this medullary concentrating gradient is largely the result of Na, Cl and urea reabsorption d) intact thirst centre

Answer 49

increased volume of urination > 2 mls/kg/hr or > 50 mls/kg/day

Answer 50

increased drinking > 100 mls/kg/day (dogs) and > 45 mls/kg/day (cats)

Answer 51

a) The owner reports or documents sustained increased water intake or urine output. b) The USG for the animal is found to be persistently low** except DM ***A one time low USG is not meaningful in an otherwise healthy animal or an animal without clinical signs of PU/PD*** ◼ Need to take into account the age of the animal, the species, the diet when evaluating the significance of a USG ◼ Medication history is important

Answer 52

◼ Thirst center in hypothalamus ❑ Stimulated by a decline in plasma volume 10-15%, Via baroreceptors and ang II ◼ Aldosterone - principal function is to sustain extracellular fluid volume by conserving body sodium ❑ Also important for regulating plasma K+ ◼ Produced by the adrenal cortex –RAAS activation

Answer 53

◼ Causes of PU/PD can be either divided into two broad categories: ❑ Primary polydipsia with compensatory polyuria ◼ Primary or secondary ❑ Primary polyuria with compensatory polydipsia – most common** ❑ ** some patients have both -Differentiation of the PU/PD disorders is important since treatment will differ and the wrong treatment can have deleterious consequences

Answer 54

❑ Primary (idiopathic) psychogenic polydipsia ❑ Secondary polydipsia – fever, pain, overactive thirst center -could be: -lack of production of ADH -renal insensitive to ADH ❑ Osmotic diuresis ❑ Disorders associated with renal medullary washout – ALWAYS RULE OUT FIRST

Answer 55

◼ CLAMPED RIBS ❑ C alcium ❑ L iver insufficiency/disease ❑ A drenal disease ❑ M etabolic – including electrolytes (low K or Na, high Na) ❑ P sychogenic, polycythemia, pyelonephritis, pyometra ❑ E ndocrine – hyperadrenocorticism, acromegaly... ❑ D rugs, diabetes mellitus, diabetes insipidus ❑ R enal insufficiency/failure ❑ I nfection ❑ B rain ❑ S alty treats, salty diets

Answer 56

❑ Primary or metastatic CNS disease ❑ Infection - sepsis ❑ Idiopathic**- this is the most common cause ❑ Granulomatous disease ❑ Trauma ❑ Iatrogenic ❑ High set osmoreceptors

Answer 57

Primary = congenital NDI – rare ◼ Secondary = acquired HyperPTH ◼ Secondary = acquired Osteomyelitis HOG IN YARD H yper PTH O steomyelitis G ranulatamous disease I diopathic -cats N eoplasia Y outh. spurious A ddisons** R enal disease D vit D toxicosis

Answer 58

◼ CRF – not enough nephrons left ◼ Diabetes mellitus * USG not that low in cats ◼ Diuretic therapy ◼ Post obstructive diuresis -diet

Answer 59

-with compensatory polyuria can be caused by fever, pain, CNS, GI and liver disease neoplasia or encephalopathies, or may be idiopathic

Answer 60

❑ Dogs: CRF, hyperadrenocorticism, diabetes mellitus, pyometra ❑ Cats: CRF, hyperthyroidism, and diabetes mellitus ◼ But Beware of being trampled by the zebra or by the unicorn ❑ Kitten with head trauma that develops central diabetes insipidus

Answer 61

-singlement gives you a clue to it -complete history and physical exam -rule out pharmalogiacl causes -PU/PD animal produces large volumes of urine with no stranguria or dysuria. Nocturia or inappropriate urination may be seen -look at your minimun data base of tests -rule out endocrine -urine culture -imaging -if still unknown -have owner measure water intake for 5-7 days to get baseline, perform water deprivation test

Answer 62

-animals typically produce only very small volumes and will show evidence of stranguria, hematuria or dysuria

Answer 63

- animal do not posture to urinate normally, and may show other neurologic deficits

Answer 64

-Need to differentiate Diabetes Insipidus from Psychogenic Polydipsia -If the underlying cause is still unknown and no clear contraindications exist, the next step is to either measure GFR or to perform a modified water deprivation test (MWDT)

Answer 65

a) Hyperthyroidism b) Cushing’s c) Hypoadrenocorticism d) Liver disease

Answer 66

◼ Used to distinguish primary polydipsia from diabetes insipidus (central and nephrogenic) ❑ Typically do last when you have failed to find a cause with more practical diagnostic tests ◼ Response to injectable administration of vasopressin in stage III may allow differentiation of nephrogenic diabetes insipidus from central diabetes insipidus ◼ CDI – expect a response – USG will increase ◼ NDI – expect no response – USG will not increase

Answer 67

Contraindications for a MWDT 1. Documented renal disease – azotemia with dilute USG, etc. 2. Dehydration – clinically detected or detection of azotemia. 3. Hypercalcemia ◼ Only perform when all the common causes ruled out 3.The test is preformed in three stages: gradual water restriction, followed by abrupt water restriction, and if necessary, an ADH response test

Answer 68

a) Diabetes insipidus (DI) results from either a complete or partial deficiency of ADH (central or partial central DI) or resistance to ADH at the level of the distal renal tubules and the collecting ducts (primary and secondary nephrogenic DI). ◼ Characterized by PUPD and hyposthenuria (USG < 1.008) Onset of c/s may be insidious, but more commonly is abrupt ❑ Nocturia and incontinence secondary to PU may be seen ❑ Weight loss

Answer 69

◼ Central DI (idiopathic) can be treated with a long acting ADH analogue DDAVP (desmopressin) $$$ ◼ Nephrogenic Diabetes Insipidus – whenever possible you need to identify and treat the underlying disease ❑ Continuous supply of water -if no underlying cause can treat with thiazide dieretic

Answer 70

◼ Compulsive Drinking ◼ Boredom in young large breed dogs ◼ Tx options are limited – behavioral modification, behavioral medications and water restriction with BW monitoring ideally

urinary Flashcards

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