Green or Pink? A Comparison of Pain and Procedural Difficulty With Intravenous Cannulas in the Emergency Department

NCT07629427 | Not Yet Recruiting

• 1 other identifier: 09.2026.774
• Study Type: interventional
• Target: 204
• Locations: 1 country
• Sites: 1

Brief Summary

Peripheral intravenous catheter (PIVC) insertion is one of the most frequently performed invasive procedures in both medical and nursing practice. It is essential for blood sampling, intravenous (IV) fluid resuscitation, medication administration, blood product transfusion, and IV contrast-enhanced radiological imaging. In emergency department (ED) settings, where patients may deteriorate rapidly, timely and adequate IV access is of critical importance. Larger-bore cannulas allow faster fluid and contrast delivery and are less prone to occlusion; however, Larger-bore cannulas are often perceived to cause greater pain and procedural difficulty compared to smaller-bore cannulas. This perception may lead clinicians to prefer smaller cannulas, potentially compromising care quality in patients who may unexpectedly deteriorate. Cannula insertion inherently causes discomfort, pain, and anxiety for patients, and multiple failed attempts further amplify these effects. Patient satisfaction, an important dimension of overall care quality, is directly influenced by pain experience and the number of insertion attempts. Patients requiring two or more attempts for successful cannulation are generally classified as having difficult intravenous access (DIVA). Repeated failed attempts are associated with vascular injury, increased patient distress, delays in diagnosis and treatment, and greater consumption of healthcare resources. The A-DIVA score, developed by Van Loon et al., enables risk stratification for IV access difficulty at triage, classifying patients as low, moderate, or high risk, and facilitating proactive measures such as ultrasound guidance or involvement of experienced personnel for high-risk patients. This single-center, prospective, single-blind, randomized controlled trial aims to compare 18-gauge (18G) and 20-gauge (20G) PIVCs in terms of patient-reported pain intensity and nurse-reported procedural difficulty in adult ED patients with low-to-moderate A-DIVA risk. The investigators hypothesize that 18G cannulas cause similar pain and procedural difficulty compared to 20G cannulas in this patient population. The study will be conducted at Marmara University Pendik Training and Research Hospital Emergency Department. Ethics approval has been granted by the Marmara University Faculty of Medicine Clinical Research Ethics Committee. Adult patients (18 years and older) requiring IV access for diagnostic or therapeutic purposes and classified as low or moderate A-DIVA risk will be eligible. Patients with cognitive impairment, altered mental status, or hemodynamic instability (systolic BP less than 90 mmHg or mean arterial pressure less than 65 mmHg) will be excluded. Eligible consenting patients will be randomized 1:1 using a block randomization method (block size of 4) to either 18G or 20G cannula insertion. Cannula assignment will be delivered to nurses in sealed envelopes. Patients will be blinded to cannula size using blackout goggles. Cannulation will be performed by ED nurses following standard antiseptic and securement procedures, targeting the dorsum of the hand, forearm, or antecubital fossa. If the first attempt fails, at least one additional attempt with the assigned cannula will be required before allowing free choice of cannula and site. The primary outcomes are patient-reported pain intensity and nurse-reported procedural difficulty, each assessed using a 10 cm Visual Analog Scale (VAS) immediately after the first cannulation attempt and compared between the 18G and 20G cannula groups. Secondary outcomes include the comparison of first-attempt cannulation success rate between the 18G and 20G cannula groups. This comparison will also be performed separately according to cannulation site, operator experience, A-DIVA risk category, patient age, and patient sex. A total of 204 patients (102 per group) will be enrolled, based on 90% power, 5% type I error, a minimum clinically important difference of 13 mm on the VAS, and a 10% dropout allowance.

Conditions

Peripheral Catheterization; Emergency Department Patient; Pain; Procedural Difficulty; Veins

Outcome Measures

Primary Outcomes (2)

• Pain intensity

  Patient-reported pain intensity assessed using a 10 cm Visual Analog Scale (VAS) after the first cannulation attempt, compared between the 18G and 20G cannula groups. The VAS score ranges from 0 (no pain) to 10 (worst imaginable pain). The unit of measure is the score on the Visual Analog Scale (0-10 cm).

  Immediately after the first cannulation attempt

• Procedural difficulty

  Nurse-reported procedural difficulty assessed using a 10 cm Visual Analog Scale (VAS) after the first cannulation attempt, compared between the 18G and 20G cannula groups. The VAS score ranges from 0 (no difficulty) to 10 (worst imaginable difficulty). The unit of measure is the score on the Visual Analog Scale (0-10 cm)

  Immediately after the first cannulation attempt

Secondary Outcomes (6)

• First-attempt cannulation success rate

  Immediately after the first cannulation attempt

• Comparison of first-attempt cannulation success rate by cannulation site between groups

  Immediately after the first cannulation attempt

• Comparison of first-attempt cannulation success rate by operator experience between groups

  Immediately after the first cannulation attempt

• Comparison of first-attempt cannulation success rate by A-DIVA score between groups

  Immediately after the first cannulation attempt

• Comparison of first-attempt cannulation success rate by patient age between groups

  Immediately after the first cannulation attempt

Study Arms (2)

18G Cannula Group

ACTIVE COMPARATOR

Participants in this arm will undergo peripheral intravenous cannulation using an 18-gauge (18G, green) cannula. Cannulation will be performed by emergency department nurses targeting the dorsum of the hand, forearm, or antecubital fossa following standard antiseptic and securement procedures. If the first attempt fails, at least one additional attempt with the assigned 18G cannula will be made before allowing free choice of cannula and site.

Device: 18-gauge peripheral intravenous cannula

20G Cannula Group

ACTIVE COMPARATOR

Participants in this arm will undergo peripheral intravenous cannulation using a 20-gauge (20G, pink) cannula. Cannulation will be performed by emergency department nurses targeting the dorsum of the hand, forearm, or antecubital fossa following standard antiseptic and securement procedures. If the first attempt fails, at least one additional attempt with the assigned 20G cannula will be made before allowing free choice of cannula and site.

Device: 20-gauge peripheral intravenous cannula

Interventions

18-gauge peripheral intravenous cannula DEVICE

Peripheral intravenous cannulation performed using an 18-gauge (18G, green) cannula inserted into the dorsum of the hand, forearm, or antecubital fossa by an emergency department nurse following standard antiseptic and securement procedures. No local anesthetic agents will be used. Patients will be blinded to cannula size using blackout goggles.

18G Cannula Group

20-gauge peripheral intravenous cannula DEVICE

Peripheral intravenous cannulation performed using a 20-gauge (20G, pink) cannula inserted into the dorsum of the hand, forearm, or antecubital fossa by an emergency department nurse following standard antiseptic and securement procedures. No local anesthetic agents will be used. Patients will be blinded to cannula size using blackout goggles.

20G Cannula Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years of age or older
• Requiring intravenous access for diagnostic or therapeutic purposes
• Classified as low or moderate risk according to the A-DIVA (Adult Difficult Intravenous Access) score
• Provision of informed consent by the patient, a relative, or a legal guardian

You may not qualify if:

• Inability to effectively communicate pain intensity due to cognitive impairment, altered mental status, or visual or language difficulties
• Hemodynamic instability defined as systolic blood pressure less than 90 mmHg or mean arterial pressure less than 65 mmHg

Sponsors & Collaborators

• Marmara University Pendik Training and Research Hospital: lead

Study Sites (1)

Marmara University Pendik Training and Research Hospital

Istanbul, Turkey (Türkiye)

Location

Related Publications (10)

• Kelly AM. The minimum clinically significant difference in visual analogue scale pain score does not differ with severity of pain. Emerg Med J. 2001 May;18(3):205-7. doi: 10.1136/emj.18.3.205.

  PMID: 11354213 BACKGROUND

• Hajian-Tilaki K. Sample size estimation in diagnostic test studies of biomedical informatics. J Biomed Inform. 2014 Apr;48:193-204. doi: 10.1016/j.jbi.2014.02.013. Epub 2014 Feb 26.

  PMID: 24582925 BACKGROUND

• Loon FHJV, Puijn LAPM, Houterman S, Bouwman ARA. Development of the A-DIVA Scale: A Clinical Predictive Scale to Identify Difficult Intravenous Access in Adult Patients Based on Clinical Observations. Medicine (Baltimore). 2016 Apr;95(16):e3428. doi: 10.1097/MD.0000000000003428.

  PMID: 27100437 BACKGROUND

• van Loon FHJ, van Hooff LWE, de Boer HD, Koopman SSHA, Buise MP, Korsten HHM, Dierick-van Daele ATM, Bouwman ARA. The Modified A-DIVA Scale as a Predictive Tool for Prospective Identification of Adult Patients at Risk of a Difficult Intravenous Access: A Multicenter Validation Study. J Clin Med. 2019 Jan 26;8(2):144. doi: 10.3390/jcm8020144.

  PMID: 30691137 BACKGROUND

• Fields JM, Piela NE, Ku BS. Association between multiple IV attempts and perceived pain levels in the emergency department. J Vasc Access. 2014 Nov-Dec;15(6):514-8. doi: 10.5301/jva.5000282. Epub 2014 Aug 29.

  PMID: 25198807 BACKGROUND

• Mitra TP, Coulter-Nile S, Jegathees T, Luong J, Shetty A, Lai K. Spiced RCT: Success and Pain Associated with Intravenous Cannulation in the Emergency Department Randomized Controlled Trial. J Emerg Med. 2024 Feb;66(2):57-63. doi: 10.1016/j.jemermed.2023.10.008. Epub 2023 Oct 16.

  PMID: 38278677 BACKGROUND

• van Loon FH, Puijn LA, van Aarle WH, Dierick-van Daele AT, Bouwman AR. Pain upon inserting a peripheral intravenous catheter: Size does not matter. J Vasc Access. 2018 May;19(3):258-265. doi: 10.1177/1129729817747531. Epub 2018 Mar 4.

  PMID: 29772984 BACKGROUND

• Cheung E, Baerlocher MO, Asch M, Myers A. Venous access: a practical review for 2009. Can Fam Physician. 2009 May;55(5):494-6. No abstract available.

  PMID: 19439704 BACKGROUND

• Rivera AM, Strauss KW, van Zundert AA, Mortier EP. Matching the peripheral intravenous catheter to the individual patient. Acta Anaesthesiol Belg. 2007;58(1):19-25.

  PMID: 17486920 BACKGROUND

• Rickard CM, Webster J, Wallis MC, Marsh N, McGrail MR, French V, Foster L, Gallagher P, Gowardman JR, Zhang L, McClymont A, Whitby M. Routine versus clinically indicated replacement of peripheral intravenous catheters: a randomised controlled equivalence trial. Lancet. 2012 Sep 22;380(9847):1066-74. doi: 10.1016/S0140-6736(12)61082-4.

  PMID: 22998716 BACKGROUND

MeSH Terms

Conditions

Pain

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Erhan Altunbas

  Marmara University Scholl Of Medicine

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Erhan Altunbas

CONTACT

+90 0506 483 29 69; erhnaltnbs@gmail.com

Emir Unal

CONTACT

+90 0532 776 60 10; emirunal@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 13, 2026
• First Posted: June 5, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: June 5, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)