What are aortic cannulation and venous cannulation?

An arterial cannula is a medical device used to immobilize an artery. It consists of a tube that is inserted into an artery and secured in place. The device can be left in place to provide caregivers with quick and direct access to the artery for activities such as taking a blood sample. It is well known that the process of intubation can be temporarily uncomfortable for the patient, but when a nurse needs a sample, intubation is often preferable to the repeated use of a needle stick. Procedures like invasive blood pressure monitoring may require intubation.

Medical providers can offer several different designs. Insertion methods may include the use of a needle or guidewire into the artery, which allows the caregiver to thread the arterial cannula into place. Medical tape holds the device in place so it does not slide or puncture nearby structures. Suture loops are also provided to allow the technician to sew the sleeve into place. These features are useful in situations where patients may need to wear the device for long periods of time and are concerned about exercising.

One use for the arterial cannula is invasive blood pressure monitoring, where nurses want to take measurements directly within the blood vessel. In addition, it can provide a point at which a blood sample can be collected and an arterial blood gas test can be performed. Arterial cannulas are often recommended for hospitalized patients who require strict monitoring. Nurses can take care of the cannula and surrounding area to minimize the risk of complications.

Like arterial inflammation, clotting is a potential risk of arterial cannulation. Problems may be encountered if the device passes through a blood vessel into muscle tissue during insertion. Some problems (such as severe burns or skin infections above the insertion site) are contraindications to the use of arterial cannulas. Before placing the cannula, the caregiver may also check to ensure that the patient's circulatory system is strong enough to support the cannula.

The carpal artery is a common choice for arterial cannulation. Placing the device and accessing the procedure is usually relatively easy. Trocars can be inserted into other arteries, including the femoral artery in the thigh. Patients can be provided with local anesthetics or sedation to place the arterial cannula for their comfort unless they are unconscious or have suffered a serious medical injury.