Special Blood Collection
Techniques
• Test Priorities: Fasting, Timed, STAT
• Fasting: No food/water before test
• Timed: Collected at scheduled intervals
• STAT: Immediate collection required
Glucose Tolerance Test (OGTT)
• Fasting sample collected (early morning)
• Patient drinks glucose within 5 minutes
• Samples collected at intervals (e.g., 2 hrs)
• Use red stopper tubes for serum
Cortisol Level Collection
• Draw between 0800–1000 hrs
• Accounts for diurnal variation
• Patient should be resting (basal state)
• Reschedule if patient unavailable
Therapeutic Drug Monitoring
(TDM)
• Monitors drug safety and effectiveness
• Peak: After drug reaches highest level
• Trough: Just before next dose
• Document timing and method
Blood Culture Collection
• Detects bloodstream infections
• Use aseptic technique
• Collect before fever spikes
• Aerobic bottle first, then anaerobic
Specimen Handling
• Chill some samples immediately (e.g., lactic
acid)
• Protect from light (bilirubin, vitamin A)
• Maintain chain of custody when required
• Handle cold agglutinins properly
Arterial Puncture Basics
• Preferred site: Radial artery
• Alternative: Brachial artery
• Perform modified Allen test
• Patient should rest ~30 minutes
Collection Technique
• Insert needle bevel up at 30–45°
• Arterial pressure fills syringe
• Apply pressure 10 minutes post-draw
• Check pulse and site after
Complications
• Arteriospasm
• Hematoma
• Hemorrhage
• Vasovagal reaction
• Nerve damage