MUST KNOW (CLINICAL MICROSCOPY) - PART 1

NEPHRON

basic structural and functional unit of the kidney 1M/kidney

URETHRA

tube leading from the urinary bladder to the outside of the body

F: 3-3 CM

M: 20 CM

URINE FORMATION (ORDER)

glomerulus - bowman's capsule - PCT - loop of henle - DCT - CD

PCT

65% of reabsorption

ADH

Regulate H20 reabsorption in DCT and CD

Urine Composition

95 - 97% water

3-5% solids

60g

TS in 24 hrs

35g: Organic= Urea (major)

25g: Inorganic= CI`(#1) > Na +> K+

Clearance Tests

Evaluate glomerular filtration

1. urea clearance

2. creatinine clearance = most common

3. inulin clearance = gold standard

4. Beta2 microglobulin

5. Radioisotopes

Creatinine clearance

Formula:

Cc= UxV/ P x 1.73/A

normal values of CC

M= 107-139 ml/min

F= 87-107 ml/min

tubular reabsorption

process of reclaiming water and solutes from the tubular fluid and returning them to the blood

- 1st fxn to be affected in renal dse.

Concentration tests

Evaluate tubular reabsorption

Fishberg test (old)

px is deprived of fluid for 24 hrs then measure urine SG ( SG>1.026)

Mosenthal test (old)

compare day and night urine in terms of volume and SG

Specific gravity (new)

influenced by # and density of particles in a solution

Osmolarity

influenced by # of particles in solution

Principle: Freezing point depression

- 1 Osm or 1000 mOsm/kg of H2O will lower the FP of H20 (0'C) by 1.86'C

EX;

determine Osm in mOsm/kg

Temp.- 0.90'C

Solution:

1000 mOsm/kg /-86'C = x/-0.90'C

x= 484 mOsm/kg

PAH test

p-aminohippuric acid test. (EXOGENOUS)They shoot you up intravenously with a known quantity and begin to analyze it; they can calculate your renal plasma flow THE VOLUME OF PLASMA FLOWING THROUGH THE KIDNEYS DETERMINES THE AMOUNT OF PAH EXCRETED IN URINE

PSP test

phensulfonpthalein test

oboselete, results are hard to interpret

Mid-stream/ Catheterized

urine culture

Suprapubic aspiration

the passing of a sterile needle through the abdominal wall into the bladder to remove urine

- Anaerobic urine culture

3 glass technique

detection of prostatic infection

1. 1st portion of voided urine

2. middle portion of voided urine: serves as control for kidney and bladder infection

3. Urine after prostatic massage

compare WBC and bacteria of spx 1 and 3

Prostatic inf: 1<3 (10x)

pediatric spx

wee bag

Drug spx collection

Chain of custody: step by step documentation of handling and testing of legal spx.

Required amount: 30-45 mL

temp (urine) : 32.5 - 35.7'C ( w/in 4 mins)

Blueing agent: toilet bowl ( to prevent adulteration)

Occasional/single/random

routine/ qualitative UA

24 hr

1st voided urine - Discarded

w/ preservativr

(ex: 8am to 8am)

12 hr

Ex: 8am to 8pm

addis count: measure of formed elements in the urine using hemacytometer

Afternoon (2PM-4PM)

Urobilinogen (alkaline tide)

4 hr

nitrite determination (1st morning/4hr)

N03- N02= UTI (+)

1st morning

Pregnancy test (hcg)

ideal spx for routine UA

most concentrated and most acidic= preservation of cells and casts

Fasting (2nd morning)

Glucose determination

2nd voided urine after a period of fasting

Clarity, Glucose, Ketones, Bilirubin, Urobilinogen and RBC/WBC

Decreased changes in unpreserved urine

pH, Bacteria, Odor, Nitrite

contamination- Increased Bacteria

True Infection- Increased Bacteria and WBCs

Increased changes in unpreserved urine

Refrigeration

2-8 'C

Inc SG (hydrometer/urinometer

Precipiate AU/AP

Do not interfere with chemical tests

prevents bacterial growth for 24 hrs

Formalin

Addis count

Excellent sediment preserevative

Boric Acid (H3BO3)

Bacterial culture transport

Bacteriostatic to contaminants (18g/L)

Sodium fluoride

prevents glycolysis ; Glucose

good preservative for Drug Analysis

rgt strip testing: Sodium Benzoate

Saccomano Fixative

(50% ethanol + 2% carbowax)

preserves cellular elements ; used for cytology studies (50 ml URINE)

600 - 2000 ml/day

Normal range urine volume (24 hrs)

1200-1500 mL/day

Average Urine volume (24 hrs)

1:2 - 1:3

Night:Day Ratio

10-15 ml

(Average - 12ml)

volume required in routine analysis

polyuria

excessive production of urine due to diabetes mellitus or diabetes insipidus

> 2000ML/24 hrs

> 2.5L/day

(DM: inc SG , DI: dec SG)

oliguria

Decreased urine output

<500/24 hrs

<400ml/day

anuria

absence of urine production ; complete cessation of urine flow

nocturia

excessive urination during the night

>500ml/night

(pregnancy)

Dec fluid intake

Dark yellow urine ; Inc SG

Inc fluid intake

Pale yellow urine ; Dec SG

look down through the container against a white background

urine color determination

red/red brown

most common abnormal urine color

urochrome

major pigment that makes the urine yellow

production is directly proportional to metabolic rate

Uroerythrin

-pink pigment

-attaches to amorphous urates formed in refrigerated specimens

-may deposit AU and Uric acid crystals

urobilin

brown pigment formed by the oxidation of urobilinogen; may be formed in the urine after exposure to air

-urine is not fresh

colorless

recent fluid consumption

pale yellow

polyuria or diabetes insipidus

diabetes mellitus

dilute random specimen

Dark yellow urine

cause: Concentrated Specimen

Lab Correlations: May be normal after strenuous excercise or in first morning specimen

-carotene

amber

dehydration

fever, burns

orange

pyridium; treatment for UTI

Yello-green/yellow-brown Urine

cause: Bilirubin oxidized to biliverdin

Lab Correlations: colored foam in acidic urine and false negative chemical tests results for bilirubin

green

pseudomonas infection

blue-green

indican

amitriptyline, clorets, methacarbamol and phenol

pink/red urine

hematuria, some laxatives, some foods (red berried, food dye, beets, red gelatin, red juices)

RBC (clear/smokey red) : hematuria

hemoglobin (clear red) : intravascular hemolysis

myoglobin (Clear red/ reddish brown) : muscle damage (rhabdomyolisis)

Rifampin- all body fluids are red

portwine

Porphyrins

brown/black

methemoglobin-acidic urine

homogentisic acid- alkaptonuria

melanin- upon air exposure

clear

No visible particulates, transparent

hazy

Few particulates, print easily seen through urine

cloudy

Many particulates, print blurred through urine

turbid

print cannot be seen through urine

milky

many precipitate; clotted

- thoroughly mix the specimen

-holding it in a light source

-view through a newspaper print

urine clarity determination

aromatic odor

normal

presence of volatile acids from food

Foul, ammoniacal

UTI ( Proteus vulgaris )

Fruity, sweet

Ketones (diabetes mellitus, starvation, vomiting)

Caramelized sugar, curry, maple syrup

MSUD

mousy, musty

phenylketonuria

PKU

rancid butter

Tyrosinemia

Sweaty feet, acrid

Isovaleric Acidemia

Glutaric Acidemia

cabbage

Methionine malabsorption

hops

methionine malabsorption ; Oasthouse urine dseq

bleach

contamination

sulfur

cystine disorder

rotting fish

Trimethylaminuria

pungent

ingestion of onions, garlic, asparagus / methyl mercaptan

swimming poll

hawkirsinuria

cat urine

3-hydroxy-3-methylglutaric aciduria

Tomcat Urinary Catheter

tom cat urine

multiple carboxylase deficiency

odorless

ATN - acute tubular necrosis

Isosthenuria

fixed specific gravity of urine

SG- 1.010

Hyposthenuria

SG- <1.010

hypersthenuria

SG of >1.010

1.003-1.035 SG

normal value for random urine

<1.003 SG

not a urine except DI

1.000

Distilled water`

chain of custody

a written record of all people who have had possession of an item of evidence

-provides documentation of proper identification from the time collected to the receipt of of the lab

30-45 ml

Required urine volume for drug analysis

60 mL

container capacity for drug analysis

32.5-37.7 deg C

temperature in drug analysis (within 4 mins)

Blueing agent

prevent specimen adulteration

added to water reservoir

Protein

least affected in changes in unpreserved urine

2 HOURS

urine spx should be delivered to the lab and tested

Leucine

ppt with tyrosine crystals if alcohol is added to urine