Poster Presentation 2025 Joint Meeting of the COSA ASM and IPOS Congress

Topical glyceryl trinitrate for difficult venous access in cancer patients (126774)

Abigail Miller 1 , Kristin Linke 2 , Rebecca Sykes 2 , Sophie Morgan 2 , Graham Pye 2 , Janelle Benic 2 , Maddi Wilkinson 2 , Rachel Roberts-Thomson 2 , Amanda Townsend 2
  1. Medical Oncology, Southern Adelaide Local Health Network, Bedford Park, SA, Australia
  2. Cancer Service, Central Adelaide Local Health Network, Adelaide, SA, Australia

Background

Patients undergoing intravenous treatment for cancer require frequent venous access.  Difficulties in peripheral intravenous cannulation are distressing for patients and time-consuming for nursing staff(1).  Randomised controlled trial evidence from the 1980-90s demonstrates the efficacy and safety of topical glyceryl trinitrate (GTN) for difficult venous access(2,3,4).  Despite this, use of topical GTN for difficult cannulation has fallen out of clinical practice in Australia.

Objectives

We aim to assess the efficacy, tolerability and consumer experience of topical GTN spray as an aid to difficult cannulation in cancer patients.  The CALHN Human Research Ethics Committee approved this study.

Methods

The study design incorporates a dose-finding pilot study, followed by an open-label, before-and-after implementation study.  It includes pre- and post-intervention surveys of cancer nurses assessing local cannulation practice.

During the pilot study, consenting adult patients who require cannulation in The Queen Elizabeth Hospital cancer day centre will be randomised into one of four GTN dosing arms or control.  This will be followed by a run-in (standard-of-care) period, then an intervention period where all participants with anticipated difficult cannulation will receive topical GTN spray prior to cannulation.  We aim to recruit 35 ‘cannulation events’ in the pilot study period, followed by 40 each in the standard-of-care and intervention periods.

The primary outcome is successful cannulation on the first attempt.  Secondary outcomes include the number and type of cannulation aids used, safety, and patient experience of cannulation.

Study Status

As of 1 June 2025, 41 patients are enrolled with 98 cannulations recorded across the pilot, standard-of-care and intervention periods.  Interim analysis of the pilot study raised no safety concerns and a GTN dose of 6x sprays for 5 minutes was selected.  Recruitment continues, with anticipated completion of data collection and subsequent analyses in August 2025.  

  1. Cooke M, Ullman AJ, Ray-Barruel G, et al. Not “just” an intravenous line: Consumer perspectives on peripheral intravenous cannulation (PIVC). An international cross-sectional survey of 25 countries. PLOS One. 2018; 13(2): e0193436.
  2. Hecker JF, Lewis GBH, Stanley H. Nitroglycerine ointment as an aid to venepuncture. Lancet. 1983; 1(8320): 332-3.
  3. Lohmann M, Moller P, Brynitz S, Bjerrum OW. Nitroglycerin ointment as aid to venepuncture. Lancet. 1984; 1(8391): 1416-7.
  4. Michael A, Andrew M. The Application of EMLA and Glyceryl Trinitrate Ointment Prior to Venepuncture. Anaesth Intes Care. 1996; 24: 360-4.