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Intravenous Cannulation

Contents

1. Indications
2. Contraindications
3. Complications
4. Which size Cannula?
5. Equipment
6. Procedure
7. Tips

1. Description

• Resuscitation
• Fluid/Volume Replacement
• Blood transfusion
• Intravenous Antibiotics/Drugs
• Delivery of Total Parenteral Nutrition

2. Contraindications

• No consent
• Sites to avoid
  • Bruised + tender areas
  • Phlebitis
  • Flexion areas
  • Haematoma
  • Lower limbs if possible

3. Complications

• Extravasation/Infiltration - if cannula is not sited properly, fluid infiltrates into subcutaneous tissue
• Phlebitis
• Catheter sepsis
• Arterial cannulation/puncture
• Bruising/haematoma
• Emboli - delay in flushing cannula
• Needle Stick

4. Which size Cannula?

• Varies depending on patient and requirements
• Smallest cannula required for patient needs should be inserted
  General Rule
  • 14G (Orange) - 16G (Grey) - Resuscitation + rapid replacement for acute blood loss
  • 17G (White),18G (Green), 20G (Pink) - Fluid Replacement + blood transfusion
  • 20G (Pink) - 22G (Blue) - Routine fluid administration, IV drugs

Figure 1 - Cannula's demonstrated in order of increasing diameter (Gauge) from Blue (22G) far left to Orange (14G) far right

5. Equipment

• Tourniquet
• Gloves
• Cannula (correctly sized as above)
• Skin prep solution/alcohol swab
• Sterile gauze/cotton wool
• 5ml Syringe
• 5ml Normal Saline (CHECK EXPIRY DATE)
• Appropriate dressing - Opsite/Tegaderm
• Pillow
• Sharps bin

6. Procedure

• Gather equipment
• Wash hands
• Obtain verbal consent
• Place patients arm on a pillow
• Apply tourniquet
• Take time to select correct vein - palpate vein, making sure it is not pulsatile! Dorsum of the hand usually has the best veins
• Put on gloves
• Clean area with prep/swab
• Apply skin traction with one hand to stabilise the vein into position
• Insert cannula at angle of around 15-20^o towards the selected vein
• Advance until flashback of blood is seen in chamber - do not stop at this point!
• Lower angle of insertion and continue insertion of cannula approx 5mm
• Stop and withdraw the needle about 5mm - secondary flashback should be seen along the length of the cannula
• Advance the catheter over the needle with one hand, keeping the needle still with the other hand - no/minimal resistance should be experienced
• Release tourniquet before withdrawing needle
• Apply digital pressure above cannula tip to control bleeding and remove needle
• Dispose of needle immediately in sharps bin
• Apply luer lock cap
• Give 5mls Normal Saline to assess patency before any infusion
• Apply appropriate dressing to secure cannula
• Dispose of equipment

7. Tips

• Once a flashback is visualised - do not stop advancing both needle and catheter. Look closely at the end of a cannula - the needle tip protrudes from the catheter tip and this is how far you must advance before the cannula will fully enter the vein
• Patients with no visible veins + Obese patients - Take your time. Time well spent applying the tourniquet to both arms individually and palpating carefully (esp antecubital fossa) will reveal veins and save you having to start all over again and patient distress. If desperate use the veins on the carpal aspect of the wrist with a 22G (blue)