IV Cannula

Cannula: (derived from latin "little Reed", plural cannulae)

Cannula is a tube that can be inserted in body mainly to administer of remove fluid. I.V. cannula come with trocar to puncture skin and vein in order to get into the intended vein.

Indications of IV cannula:
  1. To administer long term I.V. therapy; fluids, injections.
  2. Before surgery large bore cannula is inserted.
  3. For blood and blood product transfusion
  4. For blood collection, when donating blood.

Complications: There are mainly four complications.

  1. Haematoma formation.
  2. Infiliteration of medication into surrounding tissues
  3. Embolism; that can be air, thrombus, fragment of catheter breaking of and entering into blood stream.
  4. Phlebitis; inflamation of vein.
Parts of I.V. cannula

Gauge Size color Code:

Injection port caps are color coded for instant identification of cannula guage size.

Special consideration:
The size of cannula effects four factor;
  1. Needle guage
  2. External diamete of cannula i.e. its catheter
  3. Length of catheter
  4. Flow rate i.e. ml/min


As the guage nurmber increases the cannula size decreases (14 largest and 24 smallest)Larger the gauge number is (24G) smaller the cannula/diameter is (0.7mm)


Order: Maintaine I.V. line with larg bore cannula

Implementation: Insert 14G or 16G cannula