Treatments & Therapies

Infusion – Treatment, Effect and Risks


An infusion is the administration of a liquid into the human body, bypassing the gastrointestinal system (“parenteral”), usually into a vein. The route of access via infusion is chosen either because the substance in question cannot be used in any other way, or because of factors affecting the patient, e.g. B. a swallowing disorder.

What is an infusion?

One speaks of an infusion when the supply lasts for a long time. While the patient is sitting or lying down, the respective substance is supplied either by gravity via an infusion bottle or via a mechanical infusion pump.

This is to be distinguished from an injection in which the active substance is introduced into the patient’s body within a short time, for example by means of muscle power by pressing on the plunger of an injection syringe.

Intravenous access is predominantly chosen for infusions, i.e. the liquid is introduced directly into a vein. Other common access routes are subcutaneous (under the skin) or intraosseous (into the medullary cavity of a bone) infusion.

Function, effect & goals

Infusion of liquids is necessary when absorption via the gastrointestinal tract is not possible. This may be due to the fact that the substance in question is in principle not suitable for absorption through a mucous membrane.

Another reason may be that the patient in question, due to his or her illness, cannot take a medication in this way, which in principle could also be swallowed. The most common route for an infusion is the intravenous route, in which the fluid is put into a vein where it travels to the heart and from there throughout the body.

The infusion can be given either through a metal cannula or through a flexible IV cannula that is inserted into a superficial vein, typically in the hand or arm. If drugs are to be given that easily irritate these superficial veins, or if a suitable vein cannot be found, the infusion can be given into a central vein in the neck, under the collarbone, or in the groin.

This is then referred to as a central venous catheter (ZVK). A special form is a port catheter, in which a tube is surgically inserted into a central vein, which is connected to a chamber that is implanted under the skin . By piercing the skin and a membrane in this chamber with a special needle, a patient can easily be infused again and again via a central vein access. Such a port catheter is used for. B. Often for the infusion of chemotherapy drugs in patients with cancer .

For some purposes such as B. for the infusion of liquid in patients who can not drink enough, the route of subcutaneous infusion can also be chosen. A fine needle is inserted into the fatty tissue under the skin. The advantage of this method is that there is no need to find a vein. The disadvantage is that the liquid from the subcutaneous fatty tissue is only slowly absorbed into the vascular system and that some medications are not suitable for such a subcutaneous infusion.

In emergency situations, if parenteral medication is required but no vein can be found, an intraosseous infusion can also be administered, for which a robust needle is inserted into the bone marrow cavity, e.g. B. the lower leg bone is introduced.

Risks & Dangers

An infusion involves various risks. If air accidentally enters the vascular system, it can result in a life-threatening air embolism. There is also a risk if liquids that are not suitable for intravenous infusion are administered in this way.

Finally, any substance introduced into the body can cause an allergy , which can be particularly pronounced with parenteral infusion. If the line slips out of the vein, the infusion can leak into the surrounding tissue instead of into the vein, which can cause serious soft tissue damage with some medications.

Finally, complications can arise when establishing the access. A typical complication when installing a CVC for an infusion is, for example, an injury to the lungs from the puncture needle, which can lead to a collapsed lung (“ pneumothorax ”).

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.