Unit 3: Bleeding disorder investigation and body fluid examination
Applied Haematology-I notes · PTU syllabus (BMLS501-18)
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Unit summary
Applying haematology to patients means knowing normal variation, investigating bleeding and examining body fluids. This unit covers physiological variation in blood counts, investigation of bleeding disorders, factor assays, routine examination of urine, semen, CSF and serous and synovial fluids, and biomedical waste management.
After this unit you can
- Explain physiological variations in blood counts
- Plan investigation of a bleeding disorder and factor assays
- Examine urine and seminal fluid
- Examine CSF and other body fluids and manage waste
PTU syllabus topics
- Physiological variation in Hb/PCV/TLC/DLC/platelets
- investigation of bleeding disorders
- quantitative assay of coagulation factors
- routine examination of urine
- seminal fluid
- CSF and other body fluids (pleural, peritoneal, synovial)
- biomedical waste management in haematology
Urine
Pale yellow, clear
Physical, chemical (dipstick), microscopy
CSF
Clear, colourless
Cell count, protein, glucose, Gram stain
Semen
Grey-white, liquefies in 20–30 min
Volume, count, motility, morphology
Pleural / peritoneal
Clear, straw-coloured
Cells, protein: transudate vs exudate
Topic 1
Physiological variation
- Age
- Newborns: high Hb (14–22 g/dL) and TLC; children: relative lymphocytosis
- Sex
- Lower Hb and RBC in women
- Pregnancy
- Dilutional fall in Hb; rising TLC and ESR
- Altitude
- Higher Hb and RBC
- Exercise and stress
- Transient neutrophilia
- Diurnal
- Eosinophils lowest in the morning
- Posture and smoking
- Hb slightly higher standing; smokers higher Hb
Topic 2
Investigation of bleeding disorders
- 1History and examination (petechiae vs deep bleeds; family history; drugs)
- 2Screening: platelet count, smear, PT, APTT, fibrinogen, (bleeding time)
- 3Mixing studies for prolonged PT or APTT
- 4Specific tests: factor assays, vWF antigen and activity, platelet function, D-dimer
- 5Diagnosis and severity
- Factor assays: one-stage clotting assay — patient plasma diluted and mixed with factor-deficient plasma; the clotting time is compared with a standard curve of reference plasma (log dilution vs time). Severity of haemophilia: severe below 1%, moderate 1–5%, mild 5–40%.
Topic 3
Routine urine examination
Physical
Volume, colour, appearance, odour, specific gravity
Pale yellow, clear, SG 1.003–1.030
Chemical (dipstick)
pH, protein, glucose, ketones, bilirubin, urobilinogen, blood, nitrite, leucocyte esterase
pH 4.5–8; others negative (urobilinogen trace)
Microscopic (centrifuged deposit)
Red cells, pus cells, epithelial cells, casts, crystals, organisms
0–2 RBC and 0–5 WBC per high-power field
- Confirmatory tests: Benedict's (glucose), heat and acetic acid or sulphosalicylic acid (protein), Rothera's (ketones), Fouchet's (bilirubin), Ehrlich's (urobilinogen). Examine within 2 hours.
Topic 4
Seminal fluid examination
Volume
After 2–7 days' abstinence
1.4 mL
Liquefaction
Within 60 minutes at 37 °C
—
pH
—
7.2 or more
Sperm concentration
Neubauer chamber after dilution
16 million/mL
Total motility
Progressive + non-progressive
42%
Progressive motility
—
30%
Vitality
Eosin–nigrosin
54% live
Morphology
Stained smear (Papanicolaou)
4% normal forms
- Terms: oligozoospermia (low count), asthenozoospermia (low motility), teratozoospermia (abnormal forms), azoospermia (no sperm).
Topic 5
CSF and other body fluids
CSF
Appearance, cell count (Neubauer chamber), differential, protein, glucose, Gram and India ink stains, culture
Normal: clear, 0–5 lymphocytes/µL, protein 15–45 mg/dL, glucose 2/3 of blood
Pleural and peritoneal fluids
Appearance, cells, protein, LDH, glucose, ADA, cytology
Transudate vs exudate by Light's criteria (fluid/serum protein above 0.5, LDH ratio above 0.6 → exudate)
Synovial fluid
Viscosity, cells, crystals under polarised light, culture
Monosodium urate (needle, negatively birefringent) in gout; calcium pyrophosphate in pseudogout
- ADA (adenosine deaminase) above 40 U/L in pleural fluid supports tuberculosis.
Topic 6
Biomedical waste management in haematology
- Segregate at source using BMW Rules 2016: blood bags, tubes and cultures (yellow — after pre-treatment), contaminated plastics (red), sharps and lancets (white puncture-proof), glass slides (blue); disinfect liquid blood waste before drainage; maintain records.
Key terms
- Factor assay
- Quantitative measurement of a clotting factor
- Specific gravity
- Concentration of solutes in urine
- Oligozoospermia
- Low sperm concentration
- Exudate
- Protein-rich fluid from inflammation or malignancy
- Light's criteria
- Rules distinguishing exudates from transudates
Quick revision
- Variation with age, sex, pregnancy, altitude, exercise.
- Bleeding work-up; mixing studies; one-stage factor assays; haemophilia severity.
- Urine physical, chemical, microscopic; confirmatory tests.
- Semen parameters (WHO 2021); terms.
- CSF, serous and synovial fluid analysis; Light's criteria; ADA; BMW segregation.
Important exam questions
Practice questions written to the PTU exam pattern for this unit's syllabus: short answers (Section A style) and long answers (Sections B and C style).
Short-answer questions
- Q1.Why is Hb low in pregnancy?
- Q2.How is a factor VIII assay performed?
- Q3.Name three components of urine dipstick testing.
- Q4.Give the WHO lower limit of sperm concentration.
- Q5.State Light's criteria.
- Q6.Which crystals are seen in gout?
Long-answer questions
- Q1.Describe the laboratory investigation of a bleeding disorder.
- Q2.Describe the routine examination of urine.
- Q3.Describe semen analysis.
- Q4.Describe the examination of CSF and serous fluids.
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