Effect of Flexible Catheter Materials on Catheter Angle and Blood Vessel Irritation (FLEXIT)

Effect of Flexible Catheter Materials on Catheter Angle, Dwell Time, Thrombosis and Interstitial Oedema

Peripheral intravenous catheters (PIVCs; commonly known as "cannulas") are very small tubes made out of rubber-like materials which are inserted into patients' arms using a needle to allow easy access to veins. They are the most commonly-used medical devices in the world, with almost 10 million placed each year in Australia alone. Approximately 40% (almost 4 million) of these devices stop working (i.e. fail) prior to completion of therapy.

The main goal of this study is to learn if softer, more flexible PIVC tip materials reduce the angle of the catheter tip on the vein surface compared to less flexible materials. Reducing the angle of the tip is believed to reduce rubbing on the inner vein surface and causing irritation, extending the life of the catheter. Other goals of this study are to learn if softer materials affect: volume of oedema (i.e. fluid leakage around the vein); time until catheter failure; clot volume in the vein; changes in vein size in response to catheter insertion; adverse event rates (i.e. changes in rates of specific, reportable symptoms); and determining if certain catheters are better for some people than others. This study is recruiting participants of all genders aged 18 - 75 years old who:

• Are not pregnant
• Have a Body Mass Index (BMI) between 18.5 - 35 kg/m2
• Have a current Australian Medicare card
• Do not have a history of chronic/infectious disease or clotting disorders
• Do not have a history of recreational drug use or alcohol abuse within the past 2 years

Participants will:

• Spend two hours in the clinic for screening blood collection, medical questionnaire and ultrasound imaging of veins
• Have one more flexible catheter and one less flexible catheter placed in opposite arms (i.e. participants will have a total of two catheters placed) which will remain in place either (i) until they fail or (ii) for 72 hours, whichever is earlier
• Spend eight hours per day in the clinic on the day the catheters are placed and the two days following for observation and ultrasound imaging
• Spend four hours in the clinic on the third day following placement of the catheters for observation, ultrasound imaging and catheter removal
• Spend one hour in the clinic 24-96 hours after catheter removal for a follow-up assessment and questionnaire

Study Overview

• Status: Completed
• Conditions: Healthy; Thrombosis; Oedema; Intravenous Catheterization
• Intervention / Treatment: Device: Bilateral Peripheral Intravenous Catheterisation

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Australia
  • Queensland
    • Southport, Queensland, Australia, 4215
      • Griffith University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adult aged 18-75 years.
• Not pregnant at time of recruitment and within 48 hrs of Day 1 procedures (self-reported)
• Normal haematology results as per reference range determined by the laboratory.
• Normal coagulation results as per reference range determined by the laboratory.
• Target cephalic veins readily cannulatable (i.e., > 2 mm)
• Able and willing to provide verbal and written consent
• Must be an Australian citizen with current Medicare card

Exclusion Criteria:

• History of pro coagulative state / condition (e.g., previous deep vein thrombosis)
• Currently on any anti-coagulant or platelet inhibitor medication. Use of NSAIDs and aspirin will be documented however are not exclusionary.
• Haemophilia or any current or history of bleeding disorder or tendency
• Presence or report of current blood borne disease/infection (e.g., hepatitis, HIV, leukemia, lymphoma)
• History of difficult vascular access
• Allergy or sensitivity to chlorhexidine gluconate, isopropyl alcohol, latex, or skin adhesives
• BMI < 18.5 kg/m2 or ≥ 35 kg/m2
• Positive results for the urine drug screen at screening or check-in (including opiates, methadone, cocaine, amphetamines)
• History or presence of alcoholism (self-reported) or drug abuse within the past 2 years
• A current or previous medical, physical, mental / cognitive disorder or anatomical conditions that, in the opinion of the chief or sub-investigator, would place the patient at risk, would make them unable to perform study procedures or has the potential to confound interpretation of the study results. (e.g., musculo-skeletal injury, chronic back pain)
• Employed by Terumo, Becton Dickinson, Teleflex Medical, ICUMedical or BBraun (conflict of interest)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Left More Flexible Right Less Flexible; Participants in this arm will have a more flexible catheter placed in their left arm.	Device: Bilateral Peripheral Intravenous Catheterisation; Participants will have peripheral intravenous catheters inserted. Each participant will receive two different catheters (less flexible = 20 gauge ICUMedical SuperCath5 SP120-20-31T; more flexible = 20 gauge Becton Dickinson Insyte Autoguard Blood Control 381034), with the treatment arm (more flexible) being randomly assigned.; Other Names: Cannulation
Experimental: Left Less Flexible Right More Flexible; Participants in this arm will have a less flexible catheter placed in their left arm.	Device: Bilateral Peripheral Intravenous Catheterisation; Participants will have peripheral intravenous catheters inserted. Each participant will receive two different catheters (less flexible = 20 gauge ICUMedical SuperCath5 SP120-20-31T; more flexible = 20 gauge Becton Dickinson Insyte Autoguard Blood Control 381034), with the treatment arm (more flexible) being randomly assigned.; Other Names: Cannulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Catheter Angle	Measured against inferior border of vein using vascular ultrasound (in degrees)	Baseline (Day 1: morning)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Volume of interstitial oedema	Measured using vascular ultrasound (in mm cubed/microliters)	Morning visit (AM) after catheter insertion through to final interventional visit (up to 4 days)
Time to catheter failure	Measured separately for each PIVC (in hours), including differences between catheters and survival analysis.	Morning visit (AM) after catheter insertion through to catheter removal and/or 72 hours post-insertion (whichever is earlier)
Thrombus volume in vein	Measured using vascular ultrasound (in mm cubed/microliters)	Morning visit (AM) after catheter insertion through to catheter removal and/or 72 hours post-insertion (whichever is earlier)
Vein segment volume	Measured by vascular ultrasound (in mm cubed/microliters)	Morning visit (AM) after catheter insertion through to catheter removal and/or 72 hours post-insertion (whichever is earlier)
Adverse Events	Identified by study team and/or nurses and reviewed by a medical practitioner (identified individually and aggregate of all adverse events; expressed as a count and percentage of catheters inserted).	Morning visit (AM) after catheter insertion through to follow-up visit (up to 7 days)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Multiple regression analysis	Determining independent predictors from demographic data (i.e. biological sex (M/F)) on outcome measures (catheter dwell/failure time, thrombus/vessel/oedema measrements, adverse events).	Screening until follow-up appointment (screening period indeterminate, follow-up appointment completed up to 7 days post-insertion)
Multiple regression analysis	Determining independent predictors from demographic data (i.e. age (years)) on outcome measures (catheter dwell/failure time, thrombus/vessel/oedema measrements, adverse events).	Screening until follow-up appointment (screening period indeterminate, follow-up appointment completed up to 7 days post-insertion)
Multiple regression analysis	Determining independent predictors from demographic (i.e. biological sex (M/F), age (years), height (cm), weight and height will be combined to report BMI in kg/m^2), family history of disease etc), haematologic (i.e. platelet, white/red blood cell counts [cells per microliter], clotting times [PT/APTT; sec], fibrinogen [mg/dL or g/L], DDimer [mg/L or ug/mL] etc and biochemical tests [liver [U/L] and kidney function tests mg/dL or umol/L], protein/s, petdides [ug/L or ng/mg protein], lipid profile (mmol/L), glucose (mg/dL or mmol/L) etc) on outcome measures (catheter dwell/failure time, thrombus/vessel/oedema measrements, adverse events).	Screening until follow-up appointment (screening period indeterminate, follow-up appointment completed up to 7 days post-insertion)

Collaborators and Investigators

• Sponsor: Griffith University
• Collaborators: Poitiers University Hospital; Terumo Corporation; Queensland University of Technology; Queensland Health; University of Galway
• Investigators: Principal Investigator: Principal Investigator, Griffith University

Study record dates

Study Major Dates

• Study Start (Actual): May 26, 2025
• Primary Completion (Actual): September 8, 2025
• Study Completion (Actual): October 9, 2025

Study Registration Dates

• First Submitted: March 27, 2025
• First Submitted That Met QC Criteria: April 13, 2025
• First Posted (Actual): April 15, 2025

Study Record Updates

• Last Update Posted (Actual): November 20, 2025
• Last Update Submitted That Met QC Criteria: November 18, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Cannulation; Peripheral Intravenous Catheter; Catheter Angle; Interstitial Oedema; Catheter Materials; Indwell; FLEXIT; Vascular Access Device
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Embolism and Thrombosis; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Thrombosis; Edema; Investigative Techniques; Therapeutics; Catheterization
• Other Study ID Numbers: 2025/150

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All IPD that underlie results in a publication in an international peer-reviewed journal
• IPD Sharing Time Frame: Beginning from first participant enrolment with no end date
• IPD Sharing Access Criteria: Only team members with direct participant interaction will have access to identifiable data. Other team members (e.g. statistician and computer scientists) will have access to de-identified data which will be limited only to that data which is necessary to complete their assigned role. The funder and general public will have access only to de-identified IPD that underlie results in the form of a published journal article. The funder and all members of the team will have access to the study protocol, SAP, ICF and CSR, but only team members listed on the Protocol have authority to influence/make changes to these documents.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No