Body Fluids

Hemocytometer Formula

(Avg # of cells counted x dilution factor) / (# of LARGE squares counted x 0.1)
(Avg # of cells counted x dilution factor) / (# of SMALL squares counted x 0.04 x 0.1)

Cells counted on hemocytometer

Synovial fluid viscosity

Hyalunronidase breaks down hyalunronate
String test used to determine viscosity

CSF order of draw

#1 chemistry and immunology
#2 microbiology

#3 hematology

#4 other testing

Traumatic tap vs hemorrhage

Traumatic tap

• greatest amount of blood in tube 1, least in last tube

• after centrifugation, colorless supernatent

Hemorrhage

• consistent amount of blood in all tubes

• after centrifugation, xanthochromic supernatent

• has erythrophagocytosis

CSF Index

assess permeability of blood-brain barrier
CSF/serum albumin index = albuminCSF/albuminSERUM

Chylous vs pseudochylous effusion

Chylous effusions

• obstructions in lymphatic fluid drainage

• more triglycerides, chylomicrons and lymphocytes

Pseudochylous effusion

• chronic inflammatory conditions

• high cholesterol levels

Transudates vs exudates

Joint disorder classification

Signet rings vs LE cell

Macrophage with large vacuole, large pink blob in vacuole indicates lupus erythematosus (LE)

CSF Lining Cells

Mesothelial cells in serous fluid (pericardial, peritoneal, pleural)

Synoviocytes

Hemosiderin granules

Degraded hemoglobin

Hematoidin crystal

Further degeneration of hemoglobin

Malignant cells in CSF

Microorganisms in CSF

Cryptococcus neoformans - caused by breathing fungal spores
Naegleria fowleri - amoeba that thrives in warm freshwater lakes, rivers, hot springs

Effusion

accumulation of fluid in a body cavity indicating an abnormal or pathological process

Malignant cells in serous fluid

MSU vs CPPD

Corticosteroid crystals

Can resemble MSU or CPPD

Bronchoalveolar Lavage (BAL)

not naturally occurring fluid, not sterile site —> common to see bacteria

Amniotic fluid vs normal urine

Amniotic fluid

• has glucose

• significant protein

• creatinine like plasma

• no urea

Normal urine

• no glucose or protein

• high creatinine and urea

Amniotic fluid physical examination

normal amniotic fluid is colorless or pale yellow

• yellow or amber = bilirubin

• greenish = meconium

• pale pink or red = blood or hemoglobin

• dark red/brown = fetal death

Neural tube defects

high concentration of alpha fetoprotein and acetylcholinesterase (AChE) indicates neural tube defects

Probability of respiratory distress syndrome

fetal lung maturity tests

• L/S ratio

• phosphatidylglycerol

• foam stability index

• lamellar body counts

Lecithin/Sphingomyelin (L/S) Ratio

surfactants allow alveoli in lungs to stay open during respiration
week 33 — both produced equally
week 34-36 — lecithin increase and sphingomyelin constant

L/S ratio >2 = maturity of fetal lungs

hemolysis and meconium-contaminated specimen should not be used

Phosphatidyl glyverol (PG)

˜phospholipid that enhances the spread of surfactants across the alveolar surface

Foam Stability Index (FSI)

˜A stable foam is produced by surfactants when shaken vigorously with ethanol

Lamellar Body Counts

Can use automated hematology counter’s platelet channel to measure lamellar bodies

Amniotic Fluid Bilirubin (∆A₄₅₀)

Amniotic fluid with a bilirubin peak at 450 nm
Hemolyzed and meconium-contaminated speciment not acceptable

Liley Chart

Queenan Chart

Premature delivery in vaginal fluid analysis

1. Fetal fibronectin (fFN)

2. Placental alpha-macroglobulin-1 (PAMG-1)

3. Insulin-like growth factor binding protein 1 (IGFBP-1)

Sweat Analysis

cystic fibrosis diagnosed with sweat chloride test

Secretory vs Osmotic

Secretory — increased solute secretions by intestine draws water into intestine

Osmotic — ingestion of unabsorbed solutes draws water into intestine

calculated fecal osmolality = 2 x (Na + K)

>20mOsm/kg = osmotic

Fecal fat

increased meat fibers point to maldigestion

Occult blood

Guaiac-based

Immunochemical-based

Prophyrin-based

Semen analysis

agglutination caused by IgG and IgA

abnormalities

• fructose = malfunction of seminal vesicles

• alpha-glucosidase = epididymis

• citric acid, zinc, acid phosphatase = prostate

Fecal fat 2 slide test

Slide 1 — qualitative orange-red staining of neutral fats

Slide 2 — acidified and heated before staining to detect total fats

Maldigestion = increased neutral fats on 1st slide

Malabsorption = normal amount of fat on 1st slide with increased total fat on 2nd slide

Fecal carbohydrate testing

Undigested carbohydrates in stool tested using Clinitest based on copper reduction principle