An arterial cannula is a medical device used to secure access to an artery. It consists of a tube inserted into the artery and fastened in place for security. The device can be left in place to provide caregivers with quick, direct access to the artery for activities like taking blood samples. Cannulation, as the insertion process is known, can be momentarily uncomfortable for the patient, but is usually preferable to repeated needlesticks when care providers need samples. Procedures like invasive blood pressure monitoring may require a cannula.
Several different designs are available through medical suppliers. Insertion methods may involve the use of a needle or guidewire to access the artery, allowing the care provider to thread the arterial cannula in place. Medical tape can secure the device so it does not slide or puncture neighboring structures. Suture rings, allowing a technician to stitch the cannula in place, are also available. These can be useful in cases where patients may need to wear the device for an extended period and there are concerns about movement.
One use of an arterial cannula can be invasive blood pressure monitoring, where care providers want to take measurements directly inside the vessel. In addition, it can provide a point to collect blood samples and perform arterial blood gas tests. Arterial cannulation is typically recommended in hospitalized patients who need to be monitored intensively. Nurses can care for the cannula and surrounding area to reduce the risk of complications.
Clotting is a potential risk of an arterial cannula, as in inflammation of the artery. Some patients can experience problems if the device pushes through the vessel and into muscle tissue during insertion. Certain issues, like heavy burns or infections in the skin above the insertion site, are contraindications for using an arterial cannula. Care providers may also check to confirm that the patient’s circulation is robust enough to support the cannula before placing it.
The radial artery in the wrist is a common choice of insertion site for an arterial cannula. It is usually relatively easy to place the device, and it will be easy to access for procedures. Cannulas can be inserted into other arteries, including the femoral artery in the thigh. Patients may be offered local anesthetic or sedation for arterial cannula placement to keep them comfortable, unless they are unconscious or severely medically compromised.