Merck Manual

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Vascular Access


Paula Ferrada

, MD, VCU Health System

Last full review/revision Apr 2019| Content last modified Apr 2019
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A number of procedures are used to gain vascular access.

Peripheral Vein Catheterization

Most patients’ needs for IV fluid and drugs can be met with a percutaneous peripheral venous catheter. If blind percutaneous placement is difficult, ultrasonographic guidance usually results in successful placement. Venous cutdown can be used on the rare occasions when percutaneous catheter insertion is not feasible. Typical cutdown sites are the cephalic vein in the arm and the saphenous vein at the ankle. However, venous cutdown is rarely needed because of the popularity of peripherally inserted central catheter (PICC) lines and intraosseous lines in both adults and children.

Common complications (eg, local infection, venous thrombosis, thrombophlebitis, interstitial fluid extravasation) can be reduced by using a meticulous sterile technique during insertion and by replacing or removing the catheters within 72 hours.

Central Venous Catheterization

Patients needing secure or long-term vascular access (eg, to receive antibiotics, chemotherapy, or TPN) and those with poor peripheral venous access require a central venous catheter (CVC). CVCs allow infusion of solutions that are too concentrated or irritating for peripheral veins and allow monitoring of central venous pressure (CVP).

CVCs can be inserted through the jugular, subclavian, or femoral veins or via the upper arm peripheral veins (PICC line). Although the type of catheter and site chosen are often determined by individual clinical and patient characteristics, a jugular CVC or PICC line is usually preferred to a subclavian CVC (associated with a higher risk of bleeding and pneumothorax) or femoral CVC (associated with a higher risk of infection). During cardiac arrest, fluid and drugs given through a femoral vein CVC often fail to circulate above the diaphragm because of the increased intrathoracic pressure generated by CPR. In this case, a subclavian or internal jugular approach may be preferred.

Ultrasound guidance for placement of internal jugular lines and PICC lines is now standard care and reduces the risk of complications. Coagulopathy should be corrected whenever feasible prior to CVC insertion, and the subclavian approach should not be used in patients with uncorrected coagulopathy because the venipuncture site cannot be monitored or compressed.

Videos of Ultrasound-Guided and Percutaneous Cannulation

Subclavian venipuncture

This figure shows hand position during subclavian venipuncture (infraclavicular approach).

Subclavian venipuncture

Complications of central venous catheterization

CVCs can cause many complications (see Table: Complications Associated With Central Venous Catheters). Pneumothorax occurs in 1% of patients after CVC insertion. Atrial or ventricular arrhythmias frequently occur during catheter insertion but are generally self-limited and subside when the guide wire or catheter is withdrawn from within the heart. The incidence of catheter bacterial colonization without systemic infection may be as high as 35%, whereas that of true sepsis is 2 to 8%. Catheter-related venous thrombosis is an increasingly recognized complication, particularly in the upper extremities. Rarely, accidental arterial catheterization requires surgical repair of the artery. Hydrothorax and hydromediastinum may occur when catheters are positioned extravascularly. Catheter damage to the tricuspid valve, bacterial endocarditis, and air and catheter embolism occur rarely.

To reduce the risk of venous thrombosis and catheter sepsis, clinicians should remove CVCs as soon as possible. The skin entry site must be cleansed and inspected daily for local infection; the catheter must be replaced if local or systemic infection occurs. Some clinicians feel it is beneficial to change CVC catheters at regular intervals (eg, every 5 to 7 days) in patients with sepsis who remain febrile; this approach may reduce the risk of bacterial colonization of the catheter.


Complications Associated With Central Venous Catheters


Possible Sequelae


Carotid artery injury

Bleeding, respiratory compromise,neurologic complications (eg, stroke)

Puncture of pleura or lung

Puncture of vein resulting in a leak

Bleeding, extravasation of fluid, hemodynamic compromise

Subclavian, carotid, or femoral artery injury

Bleeding, vascular compromise of an extremity, hemothorax, hemodynamic compromise


Limb edema

Less common

Air embolism


Cardiac arrest

Brachial plexus injury

Compromise of an extremity

Erosion of catheter

Bleeding, extravasation of fluid, hemodynamic compromise


Injury to clavicle, rib, or vertebra

Lymphatic injury


Valvular injury

Arterial Catheterization

The use of automated noninvasive blood pressure devices has diminished the use of arterial catheters simply for pressure monitoring. However, these catheters are beneficial in unstable patients who require minute-to-minute pressure measurement and in those requiring frequent ABG sampling. Indications include refractory shock and respiratory failure. Blood pressure is frequently somewhat higher when measured by an arterial catheter than by sphygmomanometry. Initial upstroke, maximum systolic pressure, and pulse pressure increase the more distal the point of measurement, whereas the diastolic and mean arterial pressures decline. Vessel calcification, atherosclerosis, proximal occlusion, and extremity position can all affect the value of arterial catheter measurements.

Complications of arterial catheterization

At all sites, complications include bleeding, infection, thrombosis, and distal embolism. Catheters should be removed if signs of local or systemic infection are present.

Radial arterial complications include ischemia of the hand and forearm due to thrombosis or embolism, intimal dissection, or spasm at the site of catheterization. The risk of arterial thrombosis is higher in small arteries (explaining the greater incidence in women) and with increased duration of catheterization. Occluded arteries nearly always recanalize after catheter removal.

Femoral arterial complications include atheroembolism during guide wire insertion. The incidence of thrombosis and distal ischemia is much lower than that for radial arterial catheterization.

Axillary arterial complications include hematomas, which are infrequent but may require urgent care because brachial plexus compression can result in permanent peripheral neuropathy. Flushing the axillary arterial catheter may introduce air or a clot. To avoid neurologic sequelae of these emboli, clinicians should select the left axillary artery for catheterization (the left axillary artery branches further distal to the carotid vessels than does the right)

Intraosseous Infusion

Any fluid or substance routinely given IV (including blood products) may be given via a sturdy needle inserted in the medullary cavity of select long bones. Fluids reach the central circulation as quickly as with venous infusion. This technique is used more commonly in infants and young children, whose bony cortices are thin and easily penetrated and in whom peripheral and central venous access can be quite difficult, particularly in shock or cardiac arrest. However, this technique can be used in older patients at various sites (eg, sternum, proximal tibia, humerus) via special devices (eg, pressure-loaded puncture device, drilling device) that are now more readily available. Thus, intraosseous infusion is becoming more common in adults.

Intraosseous (IO) needle insertion

The physician’s fingers and thumb are wrapped around the proximal tibia to stabilize it; the hand should not be placed directly behind the insertion site (to avoid self-puncture). Instead, a towel may be placed behind the knee to support it. The physician holds the needle firmly in the palm of the other hand, directing the point slightly away from the joint space and growth plate. The needle is inserted with moderate pressure and a rotary motion, stopped as soon as a pop indicates penetration of the cortex. Some needles have a plastic sleeve, which can be adjusted to prevent them from being pushed too deeply into or through the bone.

Intraosseous (IO) needle insertion
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