practical aspects of injecting and safety pt 1

Question 1

what veins are used for IV cannulation

Answer 1

The peripheral superficial veins are used

Question 2

in the hand and wrist what veins are used for cannulation

Answer 2

• dorsal and cephalic veins in the hand and wrist are used routinely

Question 3

in the forearm and elbow what veins are used

Answer 3

• cephalic, median antebrachial and medial cubital veins

Question 4

veins to avoid

Answer 4

• thin/ fragile
• tortuous/ ectatic
• bruised
• firm
• multiple punctures
• check previous history

Question 5

specific veins to avoid

Answer 5

Arteriovenous (AV) fistula (dialysis
patients)
* Veins on the same side of a previous
lymph node removal OR previous
mastectomy OR lymphoedematous
extremity (increased risk of infection)

Question 6

Arm with lymphoedema, following an axillary clearance

Answer 6

Higher risk of infection than other arm
(no lymph nodes to fight infection)
* More challenging to cannulate – more failed attempts!
(more likely to cause distress and discomfort to patient)
* Extravasation would be more likely
(as likely to have a reduced venous blood flow)
* Extravasation if one was to occur, may stay within tissues for longer
(as likely to have a reduced venous blood flow)
* Presence of lymphedema may restrict ROM of arm
(may occlude cannulate / stop injection of IV contrast)

Question 7

elbow area for cannulation

Answer 7

• Median cubital vein is ideal
• Easy to visualise
• Good patient tolerance
• Easier to anchor cannula
  / butterfly securely

Question 8

why would you move down the arm if iv access failed first time

Answer 8

• Avoid going closer to the heart, as fluid can leak out of the earlier puncture, causing swelling or infiltration

Question 9

pre injection set up

Answer 9

• ensure that the imaging request necessitates IV contrast
• conduct pre contrast media patient checks
• gain radiologist direction if required
• ensure there is a doctor in the dept

Question 10

pre injection setup

Answer 10

• clean trolley
• injection tray
• range of cannulae
• saline flush / 10ml syringe
• steriwipe - 70% isopropyl/ alcohol
• tourniquet
• gloves
• micropore tape
• cotton wool
• sticking plaster
• sharps bin
• contrast agent

Question 11

pre checks on contrast

Answer 11

• type (non ionic / ideally isosmolar)
• concentration (iodine mgl/ml)
• quantity (50/100mls)
• expiry date
• temperature between 20-37

Question 12

why does the temperature for contrast have to be 20-37 degrees

Answer 12

at room temperature, contrast media is more viscous, making the injection harder and more painful
- warming to body temperature reduces viscosity making easier injection and improves patient comfort

Question 13

how do reaction rates of non-ionic iodinated contrast compare to old ionic agents

Answer 13

non ionic iodinated contrast agents are 5-10x LESS likely to cause a reaction than older ionic agents

Question 14

what is the reaction rate for LOCM (low-osmolality contrast media) ?

Answer 14

0.15% of patients experience a contrast reaction with LOCM

Question 15

how are most IV contrast reactions managed

Answer 15

IV antihistamine
IV steroid