Capillary Blood Testing

Question 1

What is capillary blood testing?

Answer 1

When only v. small amt blood needed/ when venipuncture difficult. Monitors blood glucose/ INR / Chol levels

Question 2

Describe the process for CBT (prep)

Answer 2

1) Confirm ID
2) Verbal informed consent
3) Decontaminate hands, gloves, prepare:
- glucose meter
- cotton wool / gauze
- appropriate test strip
- control solution
- skin puncturing device
- clean tray to hold equip
- sharps box
4) Make sure patient’s hands clean, warm, dry
5) Remove strip from foil, insert into meter with 3 black lines in meter (will turn on)
6) Check lot number matches strip used
7) Use fresh disposable lancet
8) Select appropriate area for puncture
9) Use middle / ring / little finger, puncture sides parallel to side edges of nail
10) If testing for BG, wipe away first blood drop & discard, don’t do this if testing for INR
11) Squeeze gently until rounded bead of blood obtained, compress area, release a few s then repeat. If flow too slow, second puncture needed
12) Touch drop of blood to white area at end of strip until meter begins test

Question 3

Describe the process of CBT (finishing)

Answer 3

1) Patient apply pressure to site with gauze until bleeding stopped
2) Dispose of contaminated items
3) Remove gloves, decontaminate hands
4) Document result, refer back to doc/nurse
5) Ensure meter checked reg with local internal quality ctrl tests etc. (Internal ones should be daily on meters in use)

Question 4

What are some common error sources during CBT?

Answer 4

• Puncture not deep enough
• First drop of blood not wiped away (BG levels)
• Squeezing finger too hard
• Expired test strips
• Damp/damaged test strips

Question 5

What can accuracy in CBT be affected by?

Answer 5

• Poor peripheral circulation
• Dehydration
• Hypotension
• Renal dialysis
• V high chol levels > 13 mmol/L