What Is Vascular Access? Definitions, Device Types, and Clinical Context
What is vascular access? Definitions, clinical context, the full VAD spectrum from peripheral to central, indications for each device type, and who performs vascular access procedures.
What Is Vascular Access? Definitions, Device Types, and Clinical Context
Vascular access is the clinical process of establishing a route into the vascular system — most commonly the venous system — for diagnostic or therapeutic purposes. It is one of the most fundamental and frequently performed interventions in modern healthcare.
This guide provides foundational definitions, the complete spectrum of vascular access devices (VADs), and clinical context for understanding when and why each device type is used.
What Is Vascular Access?
Vascular access is the establishment of an entry point into a blood vessel — vein, artery, or bone marrow — to enable:
- Medication delivery: Antibiotics, chemotherapy, vasopressors, sedation, analgesia
- Fluid administration: IV fluids, blood products, electrolyte solutions
- Nutritional support: Total parenteral nutrition (TPN), intravenous lipid emulsions
- Blood sampling: Laboratory draws without repeated venipuncture
- Hemodynamic monitoring: Arterial blood pressure, central venous pressure (CVP)
- Therapeutic procedures: Hemodialysis, apheresis, plasmapheresis
In hospitalized patients, vascular access is nearly universal — over 90% of hospitalized patients receive intravenous therapy at some point during their admission. In the United States, an estimated 300 million peripheral IV catheters are placed annually, and more than 5 million central vascular access devices are inserted each year.
Key Terminology
| Term | Definition |
|---|---|
| Vascular access device (VAD) | Any catheter, cannula, or needle used to access the vascular system |
| Central vascular access device (CVAD) | A VAD whose tip terminates in the central venous system (SVC, IVC, or right atrium) |
| Peripheral vascular access device | A VAD whose tip remains in the peripheral venous system |
| Catheter | A flexible tube inserted into the vascular system for therapeutic or monitoring purposes |
| Cannula | A thin hollow tube inserted into a body cavity or vessel; often used interchangeably with catheter |
| Lumen | The hollow channel within a catheter through which fluids flow; multi-lumen catheters have multiple channels |
| Dwell time | The period of time a vascular access device remains in place |
| Gauge | The outer diameter of a catheter or needle; higher gauge = smaller diameter (e.g., 24G is smaller than 16G) |
The Vascular Access Device Spectrum
VADs exist on a continuum from minimally invasive short-term peripheral devices to surgically placed long-term implanted devices. The key dimensions are:
- Tip location — peripheral vs. central
- Entry route — peripheral vein vs. direct central approach vs. bone marrow
- Intended dwell time — hours to years
- Tunneling — non-tunneled vs. tunneled under the skin
Peripheral Devices
Peripheral IV catheter (PIV):
- Inserted into a peripheral vein (hand, forearm, antecubital, foot)
- Tip remains in the peripheral vein
- Typical dwell: 72–96 hours (changed per institutional protocol)
- Uses: most short-term IV medications and fluids
- Limitations: osmolarity and pH constraints; high failure rate (35–50%); not appropriate for vesicants, TPN, or long-term therapy
Midline catheter:
- Inserted via upper arm peripheral vein (basilic, cephalic, or brachial)
- Tip terminates in the axillary or subclavian vein (does not reach the SVC — not a CVAD)
- Typical dwell: 1–4 weeks
- Uses: IV therapy requiring longer peripheral dwell than standard PIV; antibiotics, fluids, non-vesicant medications
- Limitations: cannot infuse vesicants, TPN >600 mOsm/L; not for central access drugs
Central Devices
PICC line (peripherally inserted central catheter):
- Inserted via upper arm peripheral vein; tip advanced to lower SVC/cavoatrial junction
- Classified as a CVAD (central tip)
- Typical dwell: weeks to months
- Uses: IV antibiotics (≥5 days), chemotherapy, TPN, vesicants, multi-lumen access needs
- Inserted by specially trained nurses or physicians with ultrasound guidance
Non-tunneled CVC:
- Inserted directly into the internal jugular (IJ), subclavian, or femoral vein; tip in SVC or IVC
- Short-term central access; bedside or ultrasound-guided insertion
- Typical dwell: days to approximately 2 weeks
- Uses: ICU hemodynamic monitoring, emergency central access, CVP measurement
Tunneled CVC (Hickman, Broviac, Groshong):
- Catheter placed into central vein and tunneled subcutaneously to exit at a separate skin site (chest)
- Dacron cuff promotes ingrowth and reduces infection
- Typical dwell: months to years
- Uses: long-term home IV therapy, stem cell transplant, chronic TPN
Implanted port:
- Reservoir (titanium or plastic) implanted under the skin (typically chest), connected to a central venous catheter
- Access via non-coring Huber needle through the skin
- No external component between accesses — lowest impact on body image
- Typical dwell: years
- Uses: intermittent chemotherapy, long-term recurrent IV access
Specialized Access Devices
Intraosseous (IO): Needle inserted into the bone marrow cavity for emergency vascular access when IV access is unavailable. Dwell time <24 hours. Available at the sternum, tibia, and humerus.
Arterial line: Catheter in the arterial system (radial artery preferred) for continuous hemodynamic monitoring and frequent blood gas sampling. ICU setting.
Umbilical catheter (UVC/UAC): Neonatal-specific — umbilical vein catheter (UVC) for central venous access; umbilical artery catheter (UAC) for arterial monitoring. Available only in the first days of life while the umbilical stump remains accessible.
Clinical Indications for Vascular Access
Device selection should be driven by the clinical indication. The INS 2021 principle: use the least invasive device that meets the full clinical need for the planned duration of therapy.
| Indication | Appropriate Device(s) |
|---|---|
| Single dose IV medication | PIV |
| IV therapy 1–4 days | PIV |
| IV therapy 5–14 days | PICC or midline (depending on therapy) |
| IV therapy >2 weeks | PICC, tunneled CVC, or port |
| TPN (>900 mOsm/L) | PICC or CVC |
| Vesicant chemotherapy | Central access (PICC, port, or CVC) |
| Emergency IV access (cardiac arrest, trauma) | PIV or IO |
| Hemodynamic monitoring (ICU) | CVC + arterial line |
| Hemodialysis | AV fistula, AV graft, or tunneled HD catheter |
| Intermittent chemotherapy for 1+ year | Implanted port |
| Chronic home infusion | Tunneled CVC or port |
Who Performs Vascular Access Procedures?
| Procedure | Typical Clinician(s) |
|---|---|
| PIV insertion | RN, LPN (per scope), paramedic, EMT |
| Midline insertion | Credentialed RN, APRN |
| PICC insertion | Credentialed RN (VAT), APRN, MD |
| Non-tunneled CVC | MD, PA, NP with privileges |
| Tunneled CVC, port placement | Interventional radiologist, surgeon, APRN |
| Arterial line | MD, PA, NP; credentialed RN in some settings |
| Intraosseous | Emergency clinicians (MD, APRN, PA, paramedic, RN per protocol) |
| Umbilical catheter | MD, NNP, credentialed NICU RN |
Specialized vascular access teams (VATs) perform PICC insertion, difficult PIV, and midline placement as a dedicated service. See Vascular Access Team Models.
Related Resources
Parent guide: Vascular Access: Complete Clinical Reference
Related policies:
- Evidence-Based Device Selection and Clinical Monitoring
- Vascular Access Device Insertion
- Scope of Practice and Professional Boundaries
Patient education:
References
- Gorski LA, et al. (2021). INS Infusion Therapy Standards of Practice. J Infus Nurs, 44(Suppl 1).
- Alexandrou E, et al. (2018). International prevalence of the use of peripheral intravenous catheters. J Hosp Med, 13(8):530–533.
- Chopra V, et al. (2015). The Michigan Appropriateness Guide for Intravenous Catheters (MAGIC). Ann Intern Med, 163(6 Suppl).