Can You Give Meds Through an Arterial Line?

Medicines should not be given through a standard bedside arterial line. It exists to show blood pressure beat by beat and to let staff draw blood, not to deliver drugs. An artery carries blood away from the heart straight into a hand, foot, or organ, so a drug pushed into it lands concentrated in that tissue instead of being diluted in the circulation the way an IV dose is. Arteries aren’t off-limits to drugs altogether, though: specialists deliberately thread catheters into arteries to treat strokes, brain artery spasm, and some cancers.1PubMed Central. The Evolving Role of Intra-arterial Chemotherapy in Adult and Pediatric Cancers: A Comprehensive Review

What Runs Through an Arterial Line Instead of Medicine

An arterial line (art line) is a thin tube placed in an artery, most often at the wrist, and connected to a pressure monitor. The bag hanging beside it holds a flush solution of plain salt water (0.9% saline) inside a pressure bag. The pressure bag pushes about 3 mL an hour through the line, just enough to stop blood from backing up and clotting.2PubMed Central. Heparin versus normal saline for patency of arterial lines

The setup looks different from an IV at the bedside. An arterial line also produces a moving waveform on the monitor, which an IV never does, and its tubing usually has its own pressure bag and transducer rather than running through an IV pump.

Some hospitals add heparin, a blood thinner, to the flush at 1 to 2 units per mL.3PubMed Central. Heparin versus normal saline for patency of arterial lines The best review of the evidence, however, found the studies too weak to show that heparin keeps lines working better than plain saline.4PubMed Central. Heparin versus normal saline for patency of arterial lines Whether your unit’s flush contains heparin is a local policy choice, and the bag’s label tells you which.

Even a quick flush is done carefully. Pressure inside an artery is high, so the line has to be pressurized to keep fluid flowing in at all. A clot in the tube ruins the pressure reading and can block the line. Large or forceful manual flushes are avoided because, from a wrist line, fluid can be pushed backward toward the brain. Nurses use small volumes after each blood draw instead.

Nurses draw blood from a port on the arterial tubing, which spares the patient repeated needle sticks. Arterial blood also gives oxygen and acid readings that a vein cannot.

If you’re a family member, the red-labeled tubing and pressure bag near the wrist are the arterial line, and the numbers and wavy line on the monitor come from it. It’s normal to ask staff what each line is for. Leave the ports alone, though; connecting or touching them is for staff only.

What Happens if Medicine Goes Into an Artery by Mistake

A drug meant for a vein can damage an artery in several ways: it can irritate and inflame the lining, make the artery clamp down in spasm, or form crystals as it comes out of solution.5PubMed. Acute Limb Ischemia Caused by Inadvertent Arterial Drug Self-Injection: A Case Report Very concentrated solutions and particles from crushed pills can also lodge in tiny vessels and block them.6PubMed. Acute Limb Ischemia Caused by Inadvertent Arterial Drug Self-Injection: A Case Report Clots then form on the damaged lining, and those clots are ultimately what kills the tissue.7Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection The hand or fingers can lose their blood supply.8PubMed. Acute Limb Ischemia Caused by Inadvertent Arterial Drug Self-Injection: A Case Report The vessels narrow toward the fingers, so particles and crystals get trapped, and in some people the hand has limited backup blood supply.

Some drugs are far riskier than others:

Outcomes range from nothing to amputation. Certain drugs are consistently linked to severe injury, including amputation.15PubMed. The incidence, significance, and management of accidental intra-arterial injection: a narrative review In one reported case, haloperidol, diazepam and chlorpromazine injected into an arm artery caused gangrene of the limb.16Vascular Surgery. Iatrogenic Arterial Injury Causing Gangrene: A Case Report Because no one can predict which case will go badly, any suspected arterial injection is treated as an emergency regardless of the drug.

The warning signs come quickly. The patient often feels sudden, intense burning pain down the arm during the injection. The hand may turn pale, blotchy, or blue, and the fingers may feel cold, numb, or weak. Signs can also worsen over hours as clots build, so early calm does not mean safety.

A quick saline flush afterward does not wash the drug away. The damage starts the moment the drug reaches the small vessels, and pushing more fluid only moves the drug further downstream. The right move is to stop the injection and call for help.

How Hospitals Keep Arterial and IV Lines From Being Confused

The first defense is making the line look different from every IV. UK patient safety guidance calls for clear labels, red arterial tubing, and red caps on arterial lines.17Critical Care. Accidental intra-arterial injection: an under-reported preventable never event Lines are labeled with red “ARTERIAL” stickers, especially near injection ports, and IV lines are often blue.18Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections

The design also removes chances to inject. Injection ports on arterial tubing are kept to a minimum and placed close to the wrist.19Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections Some hospitals use connectors on arterial lines that a syringe cannot inject through.20Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections Staff trace the tubing back to where it enters the skin before giving any drug, and regular training for everyone who sets up or uses arterial lines is part of prevention.21Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections The effort is justified because accidental arterial injection is considered a preventable “never event” that is likely under-reported.22Critical Care. Accidental intra-arterial injection: an under-reported preventable never event

Mix-ups tend to happen in busy moments such as emergencies, sedation, or handovers between staff. They’re also more likely when an arterial and an IV line sit in the same arm, when a port lacks a label or the tubing is the same color, or when someone unfamiliar with the patient gives a drug.

What Is Done if a Drug Is Injected Into an Artery

If the mistake is noticed mid-injection, the injection stops immediately.23Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections The tube is left in place at first, because it may be needed for imaging and for giving treatment into the artery.24Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections It should be removed within 48 hours to lower the risk of clots forming on it.25Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections A slow saline drip may be run to keep it open, though there is no proof this improves outcomes.26Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections

The person who notices the error should alert the senior nurse, the physician in charge, and pharmacy right away. Treatment choices depend on which drug went in and how much, and drugs differ widely in how harmful they are in an artery, so naming the drug, the dose, and roughly when it was given lets the team judge the risk. Staff shouldn’t pull the tube out or flush it hard on their own.

There is no universally agreed treatment. The goal is keeping blood flowing beyond the injury.27Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection The arm is raised to help swelling drain, and pain relief is a priority.28Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection Heparin may be given to limit clotting, since clots cause the tissue damage.29Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection The injury is documented and plastic surgeons are consulted.30Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection

Doctors may add drugs that relax arteries or block platelets, such as aspirin, steroids, iloprost or papaverine, with varying success.31Continuing Education in Anaesthesia, Critical Care and Pain. Extravasation injuries and accidental intra-arterial injection Some have injected lidocaine into the artery to ease spasm, though giving more drugs into a hurt artery carries its own risk.32Anaesthesia Tutorial of the Week. Management of Accidental Intra-Arterial Injections

The lack of a single protocol exists because the treatments come from case reports and expert opinion rather than large trials. Accidental arterial injection is uncommon, and it can’t ethically be studied by assigning it to patients.

Over the following days, the hand is checked often for color, warmth, pulse and feeling. Imaging of the artery may show where flow is blocked. Skin and finger damage can take days to become clear, and in severe cases surgery may be needed to remove dead tissue.

Families should expect staff to explain what happened and which drug was involved. Recovery ranges from full to lasting damage, depending on the drug and how fast treatment began. You can ask which specialists are involved and how the hand is being monitored.

When Doctors Give Drugs Into Arteries on Purpose

Chemotherapy can be infused into the artery feeding a tumor, so the drug is concentrated there while the rest of the body gets less.33PubMed Central. The Evolving Role of Intra-arterial Chemotherapy in Adult and Pediatric Cancers: A Comprehensive Review Side effects elsewhere can be reduced as a result.34PubMed Central. The Evolving Role of Intra-arterial Chemotherapy in Adult and Pediatric Cancers: A Comprehensive Review Liver tumors were among the first treated this way, and in children it is mainly used for retinoblastoma, an eye cancer.35PubMed Central. The Evolving Role of Intra-arterial Chemotherapy in Adult and Pediatric Cancers: A Comprehensive Review It is also used for some pancreatic, bone and brain tumors.36PentaVision. Intra-arterial Chemotherapy in Ocular Oncology

Strokes and brain artery spasm are treated this way too. After a stroke clot is pulled out, adding a clot-dissolving drug into the artery raised the chance of living without disability at 90 days by about a quarter.37PubMed Central. Intra‐Arterial Thrombolysis After Successful Thrombectomy: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials It did not raise the risk of brain bleeding or death.38PubMed Central. Intra‐Arterial Thrombolysis After Successful Thrombectomy: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials After a ruptured brain aneurysm, arteries can clamp down; nicardipine infused into them widened the narrowed vessels, and 10 of 11 patients improved.39American Journal of Neuroradiology. Safety and Feasibility of Intra-Arterial Nicardipine for the Treatment of Subarachnoid Hemorrhage-Associated Vasospasm: Initial Clinical Experience with High-Dose Infusions Low-dose verapamil given this way appears safe and helps some patients.40PubMed Central. Intraarterially administered verapamil as adjunct therapy for cerebral vasospasm: safety and 2-year experience

Going into an artery can also cut the dose needed: one drug delivered into a neck artery needed about a tenth of the IV dose.41PubMed Central. Intracarotid Delivery of Drugs: The Potential and the Pitfalls

A planned procedure looks nothing like a bedside line. The patient is usually in a procedure room, with the skin numbed or the patient sedated or asleep, depending on the treatment. A specialist inserts a thin catheter into an artery, often in the groin or wrist, and guides it toward the target while watching live X-ray images. A small amount of contrast dye shows the vessel, so the tip’s position is confirmed before anything is given. The drug then goes in at a chosen dose and speed, and the patient is watched closely afterward. The bedside wrist line is never used for these treatments.

These successes don’t make arterial lines fine for medicines. Planned drugs are picked because they are tolerated in arteries, while many IV drugs aren’t, and specialists control the dose and speed.

Newborn Umbilical Artery Lines Are a Partial Exception

Sick newborns often have a line in an umbilical artery, used for blood pressure and blood samples. Right after birth, the umbilical stump still has two arteries and a vein, and an artery can be threaded with a small catheter that runs toward the body’s main artery. Because the line sits in a large vessel, staff can monitor blood pressure continuously and take blood without repeatedly pricking a tiny baby’s heel. It is meant to be temporary, used in the first days of life while the baby is very sick, and removed when no longer needed.

In a survey, 40 of 63 responding neonatal units allowed some medicines through it.42PubMed. Medication administration via the umbilical arterial catheter: a survey of standard practices and review of the literature Units differed on which drugs they considered safe and unsafe.43PubMed. Medication administration via the umbilical arterial catheter: a survey of standard practices and review of the literature

Parents can ask which lines their baby has and what each is for, and whether medicines go through the umbilical artery line. They can also ask what signs of poor blood flow to the legs or toes staff watch for.