Overview
Various intravenous cannula
Many patients in the medical and surgical wards will have some form of Intravenous Therapy (IV). This can range from an intravenous infusion with or without an infusion pump, intravenous cannula with an injection port, through to a central venous line. This therapy provides a direct route to the bloodstream which allows for hydration, administration of blood or blood products and administration of medications. Medications that are administered intravenously bypass the normal means of absorption associated with oral, topical, rectal, sub cutaneous or intra muscular administration. Therefore, drugs administered intravenously achieve therapeutic level very rapidly and frequently a lower dose is required.
The picture shows various intravenous cannula. These are inserted into the vein, often in the lower arm. The different colours represent different internal diameter (gauges) of the cannula. Fine bore cannula are usually used in children, larger bore for adults. If a large amount of fluid is required to be administered over a short time period a large bore cannula is used.
So how do we start an Intravenous infusion? First step is to insert a cannula into the vein.