Blood Collection Flashcards
1
Q
Sample Collection
A
- Refrain from collecting from catheters unless severely compromised
- Use of needle smaller than 21g could lyse the blood and cause erroneous results
- Add up the total blood needed, and use the closest sized syringe
- Refrain from excessive suction (could lyse or introduce fat cells)
- Always fill to line on tube
- Check expiry dates
- Sample should be labeled, times and dated if being refrigerated for later testing (within 3-4h)
- Coagulation (unless being sent to lab) and arterial samples assessing PaO2 should be done immediately
- Invert tube 5-10 times post draw
2
Q
Tube Selection
A
- Green/orange lithium heparin = blood gas
- Blue sodium citrate = coagulation
- Purple EDTA = CBC
- Microhematocrit tubes = PCV, TP, serum colour
- Red/plain serum = external lab tests
3
Q
Basic Blood Gas
A
- Can assess underlying disease processes and severity of illness to guide emergency intervention
- Arterial blood gases primarily provide info on oxygenation, ventilation and acid base status
- Venous blood gases provide info on electrolytes, ventilation and acid base status
4
Q
Typical Analyses Provided by Point of Care Blood Gas Analyser: Venous
A
pH > PcO2 > TCO2a > HCO3-a > BEecf-
5
Q
Typical Analyses Provided by Point of Care Blood Gas Analyser: Arterial
A
pH > PcO2 > PaO2 > TCO2a > HCO3-a > BEecf- > SaO2
6
Q
Complete Blood Count (CBC)
A
- Measures inflammatory cells, red blood cells and platelets
- Good to assess for anaemia, thrombocytopenia and the current status of the patient
7
Q
Biochemistry
A
- Mainly assess liver and kidney parameters
8
Q
Coagulation
A
- Clotting factors help prevent haemorrhaging
- If not enough clotting factors or they are not functioning, the patient can be prone to sudden bleeding
- Venoms (e.g snake venom) can cause acute consumption of clotting factors
- an ACT is a crude measurement of clotting factors (requires 95% of clotting factors to be lost to cause a prolongation)
- pT and APTT are more sensitive
