Tools

CVR calcuLATOR™

Built by April Winborne, MSN, APRN, FNP-C, IVTMC, CPUI, CRNI, CCRN, CVAA(c), VA-BC

Enter the catheter size and the vessel size to get the catheter-to-vessel ratio by diameter and by area — 45% is the maximum, 33% or less is preferred.

Open the CVR calcuLATOR

Bedside Tools

Bedside aids built from the guidelines. Each one prints on a single sheet; use your browser’s print to keep a copy on the cart.

Bedside Assessment Tool
Before the First Stick

Everything to work through before you choose a device, a side, or a vessel. Any device — peripheral, midline, or central.

Built from the AVA Clinical Practice Guidelines for Adults, 2026
The device is the answer, not the question. Gates 1 through 6 are the assessment. The device, side, and site are what fall out of it. If you cannot complete the gates, you are not ready to choose.
1
The Therapy

What is going in, and for how long?

Infusate — Ch. 3.4
  • Vesicant or irritant potential
  • pH
  • Osmolality
  • Particle contentUndissolved or suspended particles ≥10–25 µm
  • Infusion rate
  • Vein condition at the intended site
AVA cautions against a single number. Do not rely on one infusate characteristic or a numeric threshold alone. Complications occur with infusates inside normal ranges, particularly in fragile veins or prolonged therapy. Weigh the whole picture — infusate, vein health, duration, patient risk.
Anticipated duration — Ch. 3.5
  • 5 days or fewerPIVC appropriate if the infusate is peripherally compatible. AVA: avoid a PICC at this duration unless no other safe access exists.
  • Roughly 1–4 weeksMidline range, if peripherally compatible and central access is not required.
  • Longer than 4 weeksCentral access territory. Match the device to the regimen.
  • Continuous or intermittent?Long-term intermittent therapy favors a TIVAD — fewer complications, better satisfaction than an externalized CVAD.
Duration is a question, not a rule. AVA notes PIVCs may stay viable past 5 days. The recommendation asks you to consider how long this patient will need access before you choose — not to pull a working line on day six.
2
Bleeding & Thrombosis Risk

What will this patient’s blood do?

Bleeding — Ch. 4.1
  • Coagulopathy
  • Thrombocytopenia
  • Anticoagulation or antiplatelet therapy
Thrombosis — Ch. 4.1, 2.3
  • History of venous thromboembolism
  • Catheter-related deep vein thrombosis
  • Catheter-related venous thromboembolism
  • Superficial vein thrombosis
  • Pulmonary embolism
  • Prior catheter occlusion or unexplained dysfunction
  • Active malignancy, BMI ≥ 25, critical illness, hyperglycemia
3
Skin & Anatomy

Will this site hold a dressing, and can you get there?

Skin and tissue integrity — Ch. 4.1
  • Fragile or aging skin
  • Prior medical adhesive–related skin injury
  • Catheter-associated skin injury
  • Dermatitis, eczema, or psoriasis
  • Burns, scars, grafts, or radiation injury
  • Genetic skin disordersEpidermolysis bullosa, Ehlers-Danlos
  • Chronic wounds or compromised healing
Anatomical challenges — Ch. 4.1
  • Obesity or limited landmarks
  • Surgical alterationsMastectomy, axillary dissection
  • Known difficult intravenous access
  • Prior vascular surgery or device affecting access
  • Contractures
  • Arteriovenous fistula or graft
4
Chart & Imaging

What does the record already know that you don’t?

Chart review — Ch. 4.1
  • Current medicationsAnticoagulants, antiplatelets, immunosuppressants, chemotherapy
  • AllergiesChlorhexidine, latex, adhesives, medications
  • Recent or planned surgeries near the proposed site
  • Relevant labsINR, platelet count, creatinine
  • ComorbiditiesCKD, malignancy, diabetes, lymphedema
Imaging and existing devices — Ch. 4.1
  • Prior vascular access historyDevice type, insertion site, documented complications
  • Vessel patencyStenosis, thrombosis, occlusion
  • Retained or embedded hardwareCatheters, ports, stents, pacemakers
  • Aberrant anatomyDextrocardia, persistent or duplicated superior vena cava
Why this comes before the tourniquet. AVA calls preinsertion chart and imaging review a critical safety step. Reviewing prior access history preserves vessels and prevents repeated trauma to sites already compromised.
5
The Person

Who is going home with this, and into what?

Behavioral — Ch. 2.2
  • Substance use history
  • Potential for catheter manipulation or misuse
  • Need for harm reduction planningSecurement method, tamper-evident technology, supervised therapy
Cognitive and psychosocial — Ch. 2.2
  • Dementia, delirium, traumatic brain injury, psychiatric illness
  • Risk of unintentional dislodgementConfusion is a leading contributor. Consider site selection and concealed dressing.
  • Ability to participate in device care
Environmental — Ch. 2.2
  • Housing stability
  • Caregiver support at home
  • Access to follow-up and continuity of services
  • What the patient can realistically manage after discharge
Complexity is not exclusion. AVA is direct: psychosocial complexity should not preclude access, but it should guide planning. Patients with substance use or social vulnerability achieve comparable outcomes when given appropriate support and monitoring.
6
Patient Preference

What has this person told you about their own body?

  • Stated goals for this course of therapy
  • Stated boundaries — what will and will not be done
  • Prior experience with vascular access, good or bad
  • Preference for device type and location
  • Dominant hand and daily activity
  • Anxiety or needle-related distressPlan pain management before the procedure, not during it.
Stop and Flag

Four findings that change the plan before you proceed — Ch. 2.3

DIVA — difficult intravenous accessEscalate to ultrasound guidance, a vascular access specialist, or both before failed attempts — not after them. Early escalation improves first-attempt success, preserves vessels, and reduces unnecessary central line placement. Note: DIVA describes the veins, not the patient.
CKD stage 3b or higher — GFR < 45Avoid devices that compromise future dialysis access. PICC use is linked to central vein stenosis and reduced likelihood of a functioning AV fistula. Coordinate with nephrology and apply vein preservation.
Elevated CR-VTE riskEvaluate before device selection. Avoid high-risk devices in predisposed patients and coordinate anticoagulation with the multidisciplinary team.
MARSI riskPrevention begins preinsertion. Choose the dressing, adhesive, and securement now — not at the first dressing change. No universal risk scale exists; assess the individual.
Only after gates 1–6
Now Choose

The device, the side, and the site are outputs of the assessment above.

  • Device type matched to infusate and duration
  • Side selectedConsider AV fistula, mastectomy, prior access, dominant hand, patient preference
  • Site avoids areas of flexionAntecubital fossa and wrist carry higher rates of dislodgement, occlusion, and discomfort
  • Femoral avoided in adults where alternatives existHighest infection risk among common central sites for short-term, nontunneled access
  • Catheter-to-vessel ratio does not exceed 45%Target below 33%. A CVR above 45% doubles thrombosis risk. Flow around the catheter matters as much as flow through it.
  • Smallest gauge or French size that delivers the prescribed therapy
  • Ultrasound available and used
  • Adequate in-vessel catheter lengthAt least two-thirds of the catheter within the vein lumen where feasible
  • Pain management plan in place before insertion
  • Dressing and securement chosen for this patient’s skin

Source: Association for Vascular Access. Clinical Practice Guidelines for Adults. JAVA. 2026;31(Suppl). Chapters 2.1–2.3, 3.4–3.5, 4.1–4.3, 4.5.

A bedside aid, not a substitute for the full guidelines or your facility’s policy. Institutions may have additional requirements based on local policy or patient population.