BY3BC1 - Medical Biochemistry Lecture 8 - sampling body fluids LO- - Why we sample body fluids - Sample pathway - Phlebotomy - Specimen tubes - Order of draw - Auditing Why do we sample body fluids? - Diagnosis - Monitoring treatment - Prognosis - Compliance (to see if the treatment is being taken) BMS Health 24/7/365 Pathology 70% of all diagnoses Latest Technology 150 million samples --- CE € Latest Science
Pathology: A history Based on the 5 senses - Sight - injury, infections, swellings, gangrene - Touch- fevers, chills, sensitive areas - Hearing- respiratory distress (is breathing crackly, bpm ) - Smell- gangrene, infection, ketones - Taste- diabetes mellitus (used to taste urine for diagnosis) Pathology through time Ancient greeks - 4 humours theory 17th century - William Harvey - human circulation 18th century - Improved knowledge of anatomy 19th century - Florence nightingale and joseph lister Discovery that blood values of many parameters reflected physiological state Sample Pathway Pre-analytical - Collecting, labelling, transport Analytical - Diagnostic testing Post- Analytical - Result reporting - Sample storage
Common sites for phlebotomy - Median cubital vein - Cephalic vein - Back of hand - Finger prick - Heel prick Phlebotomy - More than just collecting blood - Variety of diagnostic tests and analytes measured - Range of sample collection tubes - Different sample collecting requirements - Sent on ice? - Protected from light Medical biochemistry tests per day Parameter per day Blood 4,500 Urine 200 Faeces 30 CSF 5-10 Drain fluids 5 Ascitic/Pleural fluids 5-10 Stones 1 per 2 weeks Sample collection 1. Patient identification - Full name and DOB - Confirm ID - ID bracelet 2. Request form - Filled in correctly - Appropriate tests requested - Select required tubes 3. Select site for venepuncture