{
  "abstract": "Introduction Peripheral arterial disease (PAD) commonly coexists with chronic kidney disease (CKD). Patients with symptomatic PAD often require endovascular revascularisation to relieve pain or salvage limbs. However, the iodinated intra-arterial contrast routinely used in these procedures is nephrotoxic, placing patients with CKD at increased risk of acute kidney injury (AKI) and long-term renal decline. Carbon dioxide (CO ₂) delivered via automated injection is a potential alternative imaging contrast medium. This trial will evaluate whether using CO₂ instead of iodinated contrast reduces the risk of AKI and short-term renal function decline in this high-risk group.Methods and analysis This is a multicentre, open-label, prospective randomised controlled trial across six secondary-care National Health Service (NHS) vascular surgery centres. A total of 174 patients with PAD and CKD undergoing endovascular intervention will be randomised 1:1 to receive iodinated contrast (standard of care) or CO ₂ via automated injector (Angiodroid). All perioperative care will follow local NHS protocols.The primary outcome is log serum creatinine at 2, 30 and 90 days postprocedure. Key secondary outcomes include: incidence and severity of AKI within 48 hours postprocedure, major adverse kidney events (death, dialysis or >25% estimated glomerular filtration rate decline) by 90 days, inpatient length of stay, procedural pain, quality of life, procedural success, reinterventions, acceptability and feasibility (patient/practitioner questionnaires) of using CO2, and cost-effectiveness (healthcare resource use analysis). A mixed-methods process evaluation will be undertaken with patients and clinicians.Ethics and dissemination The trial has been approved by an NHS ethical review committee (24/WA/0332) and patients have been involved in trial design. Findings will be disseminated to participants, clinicians and the wider public through patient groups, lay summaries, social media, conferences, peer-reviewed journals and NHS policy channels.Trial registration number ISRCTN23564393.",
  "authors": [
    {
      "affiliations": [
        "Cardiovascular Sciences, University of Leicester Medical School, Leicester, Leicestershire, UK",
        "University of Leicester, Leicester, Leicestershire, UK"
      ],
      "name": "Athanasios Saratzis"
    },
    {
      "affiliations": [
        "University of Leicester, Leicester, Leicestershire, UK"
      ],
      "name": "Neha Rasheed"
    },
    {
      "affiliations": [
        "University of Leicester, Leicester, Leicestershire, UK"
      ],
      "name": "Dania Aguirre"
    },
    {
      "affiliations": [
        "Vascular Surgery, Leeds Vascular Institute General Infirmary, Leeds, UK"
      ],
      "name": "Patrick Coughlin"
    },
    {
      "affiliations": [
        "Guy’s and St Thomas’ Hospitals NHS Foundation Trust, London, UK"
      ],
      "name": "Athanasios Diamantopoulos"
    },
    {
      "affiliations": [
        "Department of Population Health Sciences, King’s College London, London, UK",
        "St George’s University of London, London, UK"
      ],
      "name": "Lindsay Bearne"
    },
    {
      "affiliations": [
        "Centre for Kidney Research and Innovation, University of Nottingham Faculty of Medicine and Health Sciences, Derby, Nottingham, UK",
        "Royal Derby Hospital, Derby, UK"
      ],
      "name": "Nicholas M Selby"
    },
    {
      "affiliations": [
        "Leicester Clinical Trials Unit, University of Leicester, Leicester, UK"
      ],
      "name": "Cassandra Brookes"
    },
    {
      "affiliations": [
        "University of Leicester, Leicester, Leicestershire, UK"
      ],
      "name": "Shaun Barber"
    },
    {
      "affiliations": [
        "Leicester Clinical Trials Unit, University of Leicester, Leicester, UK"
      ],
      "name": "Carla Richardson"
    },
    {
      "affiliations": [
        "Cardiovascular Sciences, University of Leicester Medical School, Leicester, Leicestershire, UK"
      ],
      "name": "Hannah Gilbert"
    },
    {
      "affiliations": [
        "Leicester Clinical Trials Unit, University of Leicester, Leicester, UK"
      ],
      "name": "Roland Schueller"
    },
    {
      "affiliations": [
        "Leicester Vascular Institute, University Hospitals of Leicester NHS Trust, Leicester, UK"
      ],
      "name": "Despina Apergi"
    },
    {
      "affiliations": [
        "Leicester Vascular Institute, University Hospitals of Leicester NHS Trust, Leicester, UK"
      ],
      "name": "Keith Jonathan Harris"
    }
  ],
  "title": "Preventing kidney injury using carbon dioxide (KID trial): trial protocol for a multicentre randomised controlled trial",
  "uid": "3fb6dcbe-42f0-51fc-bb88-8969bf79eb73"
}