How Is a PICC Line Inserted? The Step-by-Step Process

A PICC line is inserted through a vein in the upper arm and threaded forward until its tip rests in one of the large veins just above the heart. The entire procedure typically takes between 30 and 60 minutes at the bedside, using ultrasound guidance and local anesthesia, so you stay awake and generally comfortable the whole time. While the concept sounds straightforward, each step is carefully designed to minimize infection, prevent the catheter from ending up in the wrong vessel, and keep it functioning for weeks or even months afterward.

Why a PICC and Not a Regular IV

A standard peripheral IV sits in a small vein in your hand or forearm. It works fine for short-term fluids or mild medications, but certain treatments would damage those small veins quickly. Chemotherapy drugs, concentrated nutrition formulas (called TPN), certain antibiotics, and solutions that are very acidic or alkaline all need a larger, faster-flowing vein to dilute them before they contact the vessel wall. A PICC line solves that by delivering everything into the superior vena cava, one of the body’s largest veins, where blood flow is high enough to dilute irritating drugs almost instantly. PICCs and midline catheters look similar on the outside, since both enter through the upper arm, but a midline stops partway in a peripheral vein, which limits the types of infusions it can safely deliver.¹

Pre-Procedure Assessment

Before anything touches your skin, the nurse or vascular access specialist evaluates your arms using ultrasound. This pre-procedural scan, sometimes called a Rapid Peripheral Vein Assessment, maps out which veins are large enough, deep enough, and free of clots or scarring. It also identifies the position of the brachial artery and the median nerve so the inserter can steer clear of both during the puncture.² The basilic vein on the inner side of the upper arm is usually the first choice because it tends to be the largest and runs a fairly straight path toward the chest. The brachial and cephalic veins are alternatives, but the cephalic vein curves sharply near the shoulder, which can make threading harder.

During this step the clinician also measures your arm externally to estimate how long the catheter needs to be. One common method involves measuring from the intended puncture site up the arm, across the shoulder, and down toward the third rib on the right side of the chest. Researchers have also developed simplified formulas based on easily measured landmarks like the length of the clavicle and the sternum to predict catheter depth more precisely.³ These measurements matter because a catheter that is too short may sit in the subclavian vein instead of the superior vena cava, raising the risk of clotting and malfunction, while one that is too long can poke into the heart itself.

Numbing the Site

Most people worry about pain, and the honest answer is that PICC insertion is usually described as mildly uncomfortable rather than painful, with the local anesthesia injection itself being the most noticeable part.⁴ The standard approach is a small injection of buffered lidocaine at the planned puncture site, which numbs the area within about a minute. A randomized study comparing lidocaine injection, numbing cream (EMLA), and no anesthesia at all found that lidocaine injection was significantly better at relieving insertion pain than either of the other options.⁵ Some centers also offer distraction techniques like virtual reality headsets for patients who are especially anxious, though those are still being formally studied in oncology settings.

Sterile Preparation

Once the vein is chosen and the skin is numb, the inserter scrubs in with sterile gloves, a gown, a mask, and a cap. A large sterile drape covers you from chin to waist, leaving only the insertion site exposed. This maximal barrier setup mirrors what surgeons use in the operating room, and it exists because any bacteria that reach the catheter during insertion can travel its entire length into a central vein and potentially cause a bloodstream infection.

The skin at the puncture site is cleaned with an antiseptic solution. In adults, chlorhexidine combined with isopropyl alcohol is the most widely used prep. In newborns the choice is less clear-cut. A Cochrane review looking at antiseptic solutions for central catheter insertion in neonates found that chlorhexidine-alcohol and povidone-iodine showed little difference in bloodstream infection rates, though chlorhexidine-alcohol appeared to carry a lower risk of thyroid problems in that vulnerable population.⁶ In either case, the antiseptic needs to dry completely before the needle goes in, because wet antiseptic can be carried into the tissue on the needle tip.

The Puncture and Guidewire

This is the step where the catheter actually enters the body, and it relies on a technique called the modified Seldinger method. Under real-time ultrasound, the clinician inserts a small needle into the selected vein. You may feel pressure but not sharp pain if the lidocaine has taken effect. Once blood flows back through the needle, confirming it is in the vein, a thin, flexible guidewire is fed through the needle into the vessel. The needle is then removed, leaving just the wire in place.

A small dilator, sometimes housed inside a peel-away sheath, slides over the guidewire to widen the tract in the skin and vein wall just enough to accept the catheter. This part can produce a brief tugging or pressure sensation. After that, the dilator and guidewire come out, and the soft silicone or polyurethane catheter is threaded through the sheath and advanced toward the chest. The peel-away sheath splits apart and is removed, leaving only the catheter in the vein.

Ultrasound guidance during this puncture step has been shown to make a meaningful difference in outcomes. A meta-analysis of randomized trials found that ultrasound-guided PICC placement using the modified Seldinger technique significantly improved the first-attempt success rate and the overall success rate compared to blind or landmark-based methods.⁷ Fewer needle sticks means less bruising, less nerve irritation, and a lower chance of accidentally hitting an artery.

Threading the Catheter Into Position

With the catheter now inside the vein at mid-upper arm level, the clinician gently advances it through the basilic or brachial vein, into the axillary vein under the collarbone, down the subclavian or brachiocephalic vein, and finally into the superior vena cava. You might be asked to turn your head toward the arm being used, drop your chin to your chest, or take a deep breath at specific moments. These maneuvers help redirect the catheter away from unintended paths, like the jugular vein in the neck, and guide it downward toward the heart.

If the catheter was pre-trimmed based on the external measurements, it goes in at the predetermined length. In some protocols, a calibrated guidewire is threaded first to verify the exact distance from the puncture site to the target zone near the junction of the superior vena cava and the right atrium, and the catheter is then cut to match that measured distance before final placement.⁸ Getting the length right matters because every centimeter of excess catheter inside the vein creates a surface where clots can form.

Confirming Tip Position in Real Time

Knowing that the catheter tip is sitting in exactly the right spot is one of the most critical parts of the process. The traditional gold standard is a chest X-ray taken after the catheter is placed, but newer technology allows clinicians to verify position during the insertion itself, which means problems can be caught and corrected on the spot.

The most widely adopted real-time method uses intracavitary electrocardiography (IC-ECG). A saline-filled column inside the catheter acts as an electrode that picks up the heart’s electrical signal from right at the catheter tip. As the tip approaches the junction between the superior vena cava and the right atrium, a characteristic tall spike appears on the monitor. This lets the inserter identify the target zone without radiation exposure.⁹ Research has shown that ECG-guided tip verification is safe and accurate even in patients with atrial fibrillation, an irregular heart rhythm that was once thought to make the technique unreliable.¹⁰

Even with IC-ECG guidance, a small percentage of catheters end up in the wrong vessel. A large two-center study found that after ultrasound and ECG guidance identified and corrected about 7% of initial misplacements during the procedure, a follow-up chest X-ray still caught an additional 0.7% of catheters that had migrated into the azygos vein, a small branch behind the superior vena cava that ECG alone has trouble detecting.¹¹ For that reason, many hospitals still order a confirmatory chest X-ray before certain high-risk medications are infused, even when intra-procedural monitoring looked perfect.

Securing the Line and Dressing the Site

Once the tip position is confirmed, the external portion of the catheter is secured to the skin. This prevents the line from migrating inward or sliding out with normal arm movement. Securement options include adhesive devices that grip the catheter hub, sutureless anchoring pads, or in some cases a single stitch. A transparent antimicrobial dressing is then placed over the insertion site. These dressings typically contain chlorhexidine gluconate and are designed to mold around the catheter hub while keeping the site visible so nurses can monitor for redness or drainage without removing the dressing.¹² The dressing is typically changed every seven days or whenever it becomes damp, loose, or soiled.

Keeping the Line Working After Insertion

A PICC that is placed perfectly can still fail if it is not maintained. The main threat after insertion is the catheter clogging with blood. To prevent this, the line is flushed regularly, usually with a syringe of saline or heparin solution pushed through the catheter in a pulsing motion. For years, heparin was the default flushing agent because it inhibits clot formation. But the evidence has shifted. A systematic review and meta-analysis pooling data from multiple studies found no significant advantage of heparin over plain normal saline for maintaining catheter patency.¹³ A more recent randomized study in blood cancer patients confirmed those findings and noted that heparin was associated with more side effects, higher costs, and more nursing time.¹⁴ Many hospitals have since switched to saline-only flushing protocols, especially for patients who are at risk of heparin-induced side effects.

Complications That Can Arise

No invasive procedure is risk-free, and PICCs come with a specific set of possible complications. The SIP (Safe Insertion of PICCs) protocol was developed specifically to bundle together strategies that reduce these risks during and after placement. The strategies include pre-procedural vein assessment, careful identification of the median nerve and brachial artery, ultrasound-guided puncture, real-time tip navigation, and proper securement, all of which together reduce the rates of failed puncture, accidental arterial sticks, nerve injury, infection, and clot formation.¹⁵

The two complications patients most commonly face after the line is in are blood clots and phlebitis (inflammation of the vein). Clots can form along the catheter surface or at the vein wall where the catheter makes contact. A study tracking PICC-related blood clots in children found that roughly a third of insertions eventually developed some form of venous clot, though most were superficial and not symptomatic. Deep vein thrombosis occurred in about 8% of insertions, and the median time from insertion to diagnosis of a superficial clot was about 10 days.¹⁶ That study was in children, and adult rates differ depending on the population, but it highlights why arm swelling, pain, or warmth near a PICC should always be reported to your care team.

Phlebitis, the inflammatory reaction of the vein wall to the catheter’s presence, can cause redness, tenderness, or a cord-like feeling along the vein. Preterm infants are especially prone to this because their blood vessels are still developing and are more sensitive to mechanical irritation.¹⁷ In adults, phlebitis is less common with modern soft catheters and proper insertion technique, but it still occurs, especially during the first few days after placement.

How the Procedure Differs in Newborns

PICC insertion in neonates follows the same general principles but involves several adaptations. The veins are much smaller, so inserters use thinner catheters, often as narrow as 1 or 2 French (roughly half a millimeter to a millimeter in diameter). The veins accessed may include those in the scalp, hand, or foot in addition to the upper arm. Ultrasound guidance and IC-ECG monitoring carry the same advantages in neonates as in adults, helping to reduce malposition and the need for post-procedure X-rays.

The complication profile in neonates is more serious, with reported rates ranging from about 10% to 40% of insertions. The most concerning complications include bloodstream infection, thrombosis, and, rarely, cardiac tamponade if the catheter migrates into the heart. Low birth weight, small gestational age, and prolonged catheter dwell time all raise the risk. Preventive strategies in neonatal units include antimicrobial-impregnated catheters, tissue adhesive for securement instead of sutures, and standardized care bundles, though the quality of evidence for each individual intervention varies.¹⁸

Where PICCs Came From

The PICC as we know it traces back to the late 1960s, when a surgical resident named Verne Hoshal Jr. noticed that the polyethylene catheters used at the time were causing reactions in the subclavian veins. He ran animal studies confirming the problem, presented his findings in 1972, and became convinced that silicone elastomer was a better material for long-term venous access.¹⁹ That material insight was the seed of modern PICC design. Today’s catheters are made from silicone or polyurethane, come in single or multi-lumen configurations, and can incorporate features like antimicrobial coatings and power-injection capability. The basic idea, though, threading a soft catheter from a peripheral vein to a central one, is still the same concept Hoshal pursued more than 50 years ago.