6.3 Peripheral Device Selection Criteria

CRNI® Exam Study Guide Certified Registered Nurse Infusion

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1 Introduction & Exam Overview

1.1 Current Exam Facts 1.2 Eligibility, Application & Testing Windows 1.3 Scoring, Results & Recertification

2 Anatomy & Physiology for Infusion Practice

2.1 Vascular Anatomy & Physiology for Infusion 2.2 Body Positioning for Catheter Insertion & Removal 2.3 Vein Selection & Patient Assessment

3 Infection Prevention & Control

3.1 Infection Prevention Strategies & Standard Precautions 3.2 Chain of Infection in Infusion Practice 3.3 Bloodstream Infections & CLABSI Prevention 3.4 Phlebitis: Prevention, Grading & Management

4 Phlebotomy in Infusion Practice

4.1 Blood Sampling & Blood Culture Collection 4.2 Therapeutic Phlebotomy

5 Infusion Equipment & Technology

5.1 Solution Containers, Administration Sets & Filters 5.2 Add-on Devices, Administration Devices & Closed Systems 5.3 Vein Location Devices, Navigation Tools & Securement

6 Peripheral Venous Access Devices

6.1 Short & Long Peripheral Intravenous Catheters 6.2 Midline Catheters 6.3 Peripheral Device Selection Criteria

7 Central Venous Access Devices

7.1 Peripherally Inserted Central Catheters (PICC) 7.2 Non-tunneled Central Venous Catheters 7.3 Tunneled Central Venous Catheters 7.4 Implanted Ports

8 Alternate Access Routes & Device Maintenance

8.1 Subcutaneous Infusion Access 8.2 Intraosseous Access 8.3 Device Maintenance & Care Protocols

9 Special Populations in Infusion Therapy

9.1 Older Adults & Chronic Renal Conditions 9.2 Pediatrics, Immunocompromised, Oncology & Bariatrics

10 Device-Related Complications

10.1 Infiltration & Extravasation 10.2 Catheter Occlusion 10.3 Thrombosis, Air Embolism & Device-Related Systemic Events

11 Fluid & Electrolyte Balance

11.1 Body Composition & Fluid Balance 11.2 Fluid Volume Excess & Deficit 11.3 Electrolyte Disorders 11.4 Maintenance & Replacement Fluids

12 Parenteral Nutrition

12.1 Parenteral Nutrition: Solution Composition 12.2 PN Infectious, Metabolic & Mechanical Complications

13 Anti-infectives, Blood Products & Biologics

13.1 Anti-infective Infusion Therapy 13.2 Blood Products & Transfusion Therapy 13.3 Biologics & Immunologic Therapies

14 Antineoplastic, Cardiovascular & Pain Infusions

14.1 Antineoplastic Infusion Therapy 14.2 Cardiovascular Infusions 14.3 Pain Management Infusions

15 Therapy-Related Complications & Hazardous Drugs

15.1 Rate-Related Complications 15.2 Adverse Drug Reactions 15.3 Hazardous Drug Exposure & Waste Disposal

16 Professional Practice, Documentation & Quality

16.1 Assessment, Consent & Collaborative Care Planning 16.2 Documentation, Laws & Regulatory Agencies 16.3 Evidence-Based Practice & Performance Improvement

6.3 Peripheral Device Selection Criteria

Key Takeaways Explain This Topic AI

Select the least invasive peripheral device that safely meets therapy duration, infusate characteristics (osmolarity, pH, vesicant/irritant properties), and administration pattern (intermittent vs continuous).

Preserve vessel health with stepwise escalation: short PIV → long peripheral/UGPIV → midline → central access only when therapy or duration demands it.

Never choose a short PIV or midline for continuous vesicants or for extreme osmolarity/pH/TPN needs that require confirmed central tip location.

Avoid using the antecubital fossa for long-term dwell when better forearm options exist; avoid ventral wrist sites due to nerve injury risk.

Reassess device necessity daily—remove peripheral access that is no longer indicated to cut infection, phlebitis, and thrombosis risk.

Last updated: August 2026

Selection as a safety algorithm

CRNI Access Devices items rarely ask you to name a brand. They ask you to choose the right class of device for a therapy story. Section 6.3 integrates short PIV, long peripheral, and midline decision rules into one practical framework aligned with INS-minded vessel health preservation.

Quick Answer: Choose the lowest-risk, least invasive device that still matches (1) duration , (2) osmolarity/pH , (3) vesicant/irritant properties , and (4) intermittent vs continuous delivery. Escalate stepwise —short PIV → long peripheral/UGPIV → midline → CVAD—only as therapy demands. Midlines are not central. Continuous vesicants and many hyperosmolar/extreme pH/TPN therapies need central tips. Prefer forearm over AC for dwell; avoid ventral wrist .

The four therapy drivers
1. Duration of therapy

Expected duration Typical peripheral pathway thinking
Hours to a few days Short PIV first-line if veins adequate
Several days with difficult veins Long peripheral / UGPIV or early midline consideration
Days to weeks, peripheral-compatible Midline often considered if short PIVs inadequate

Weeks to months, complex/central chemistry Plan CVAD (PICC, tunneled, port) rather than serial midlines that do not fix chemistry limits

Duration alone never overrides chemistry. A one-day continuous vesicant still needs an appropriate device class.

2. Osmolarity

Hyperosmolar infusions draw fluid from endothelial cells and inflame peripheral veins. Standards and drug references set thresholds and product-specific guidance for peripheral versus central administration. Exam principle: as osmolarity rises into ranges associated with high peripheral vein injury risk—especially for continuous infusion— central access becomes the safer default. Do not “stretch” a short PIV or midline to deliver PN or other highly hyperosmolar admixtures that policy assigns to central tips.

3. pH (acidity/alkalinity)

Extreme acidic or alkaline infusates chemically injure the intima. Peripheral veins tolerate a narrower chemical window than high-flow central veins. When references label a drug as requiring central administration due to pH, device selection follows the label/standards , not bedside convenience.

4. Vesicant and irritant properties

Classification Clinical concern Device implication

Irritant Pain/phlebitis along vein May still be peripheral if policy allows; monitor closely; consider larger veins/central if poorly tolerated

Vesicant Tissue necrosis if extravasated Continuous vesicant → central access ; do not use midline/short PIV as a loophole

Non-vesicant, peripheral-compatible Standard infiltration risk Short PIV, long peripheral, or midline by duration/veins

Intermittent vs continuous: Continuous exposure multiplies chemical injury time and extravasation detection urgency. Intermittent dosing may be manageable peripherally for some agents under protocol; continuous vesicant infusion is a hard stop against midline/short PIV on exam items.

Stepwise escalation and vessel health preservation

Think of peripheral veins as a non-renewable resource for many chronically ill patients.

Escalation ladder (conceptual)

Is IV therapy required at all? Prefer oral/NG/alternative routes when clinically equal.

Short PIV in the best available forearm vein with smallest adequate gauge.

Optimize short PIV success: warmth, proper lighting, expert inserter, limited attempts, vein visualization tools.

Long peripheral / UGPIV for deeper peripheral targets when short PIVs fail but therapy remains peripheral-compatible.

Midline for intermediate dwell peripheral-compatible therapy when repeated peripheral restarts harm the patient or vessels.

CVAD when therapy chemistry, duration, or monitoring needs require central tip location—or when peripheral options are exhausted and still indicated.

Vessel preservation tactics

Limit unsuccessful attempts; escalate skill level early (two-attempt culture with specialist referral as policy defines).

Avoid dominant arm when possible if it does not compromise the better vein.

Protect fistula arms, post-mastectomy/node-dissection arms, and infected limbs.

Do not place “just in case” IVs without indication in vulnerable patients.

Remove idle catheters promptly—every unnecessary day of dwell is avoidable risk.

Document vein condition over time so the next clinician does not blindly re-stick phlebitic cords.

Matching device to scenario (decision table)

Clinical picture Prefer
Single bolus, good forearm vein, non-vesicant Short PIV
48-hour fluids/antibiotics, easy veins Short PIV; clinically indicated removal
Difficult superficial veins, peripheral-compatible meds for several days UGPIV / long peripheral
10–14 days peripheral-compatible intermittent antibiotics, failed short PIVs Midline candidate
Continuous vesicant chemotherapy CVAD (not short PIV, not midline)
Hyperosmolar TPN requiring central admin CVAD
Weeks of complex multi-therapy including central-only drugs CVAD plan early

Easy AC stick in a patient needing 5-day continuous non-vesicant infusion Seek forearm site instead of AC long dwell

Site selection criteria within peripheral options

Even after choosing “short PIV,” site quality changes outcomes:

Prefer Avoid / minimize for dwell
Forearm straight veins Antecubital fossa for multi-day continuous therapy
Areas away from flexion Ventral wrist (nerve injury)
Intact skin, non-infected Areas of phlebitis, infiltration, hematoma, burns
Upper extremity in adults Routine lower extremity adult access
Adequate vein diameter for gauge Fragile vein with oversized catheter

AC fossa exam trap: The median cubital vein is large and seductive for first-stick success, but joint motion makes it a poor long-term infusion site. Acceptable for emergencies, short procedures, or when no alternative exists—not the default multi-day continuous site.

Integrating ultrasound and specialist teams

Ultrasound is a selection enabler , not a device class:

UGPIV can make a short or long peripheral succeed without escalating to midline.

Ultrasound for midline/PICC still requires correct length and tip target for the intended device.

Vascular access teams improve first-stick success and appropriate escalation—use them when available rather than exhausting every distal vein.

Risk–benefit communication

Device selection includes informed discussion:

Why this device class matches the ordered therapy
Alternatives (including oral switch if appropriate)
Risks: phlebitis, infiltration/extravasation, thrombosis, infection, insertion discomfort
Patient preferences (arm choice, fear of needles, home care capability for midline/PICC)

Document the rationale when choosing midline over serial PIVs or when escalating to PICC because of vesicant/osmolarity needs.

Daily reassessment checklist

Use this mental checklist each shift:

Is the catheter still indicated ?

Is the therapy still compatible with this device class?

Is the site healthy (no infiltration, phlebitis meeting removal criteria, leakage, purulence)?

Is the device functional (flush, blood return as expected, no unresolved occlusion)?

Would a different device now better match an evolving plan (e.g., new vesicant order)?

If a patient starts on short PIV antibiotics and the plan changes to continuous vesicant therapy, re-select the device —do not keep the short PIV because “access is already there.”

Putting it together: two full vignettes

Vignette 1: 45-year-old with cellulitis needs 7 days of intermittent peripheral-compatible IV antibiotics, then oral step-down. Forearm vein available. Select short PIV , educate on site care, assess every shift, remove when converted to oral or if complications occur. No midline required solely for a week if peripheral access is reliable.

Vignette 2: 68-year-old with poor superficial veins needs 12 days of peripheral-compatible IV antibiotics; three short PIV failures overnight; no vesicant; no PN. Ultrasound shows upper-arm vein suitable for midline. Midline is reasonable to preserve vessels and complete therapy. If orders later add continuous vesicant or central-only PN, escalate to PICC/other CVAD —do not stretch the midline.

High-yield exam traps (selection-focused)
Calling a midline a central line and using it for central-only therapies
Infusing continuous vesicants via midline or short PIV
Using the AC fossa long-term because insertion was easy

Skipping stepwise thinking and placing a PICC for every multi-day antibiotic without evaluating peripheral suitability

Leaving idle peripheral devices in place “for convenience”
Choosing gauge/site by habit instead of therapy and vessel health
Summary decision mantra

Right drug → right duration → right vein → right device tip location → right time to remove. If any element changes, re-run the algorithm. That mantra is the clinical and CRNI selection standard for peripheral venous access devices.