Cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC) is a treatment for peritonitis carcinomatosa. These procedures often involve significant blood and fluid loss, leading to hyperdynamic circulation and vasodilation, necessitating intraoperative fluids and vasoconstrictors such as catecholamines. Excessive fluid administration to counteract vasodilation can cause intraoperative fluid overload, which is linked to increased postoperative complications. Vasopressin has emerged as a potential alternative to catecholamines, restoring vascular tone via non-adrenergic pathways and supporting perfusion pressure, potentially reducing the need for compensatory fluids solely administered to compensate for vasodilation. We hypothesise that compared with norepinephrine, vasopressin reduces cumulative intraoperative fluid administration during CRS-HIPEC within a goal-directed fluid therapy (GDFT) protocol, ultimately leading to a lowering of postoperative complications.

HiPress is a two-centre, two-arm randomised clinical trial with blinding of both patients and outcome assessors. A total of 70 adult patients undergoing CRS-HIPEC will be included. Patients will be randomised to receive either continuous low-dose argipressin or continuous low-dose norepinephrine. Both groups will receive standardised GDFT during the procedure. The primary endpoint is cumulative intraoperative fluid administration (mL). Secondary endpoints include direct fluid-related outcomes (eg, cumulative intraoperative fluid (ml/kg/hour), postoperative fluid balance until day five and ultrasound-assessed pulmonary oedema and venous congestion) and indirect fluid-associated outcomes (eg, quality of recovery, surgical and abdominal complications, acute kidney injury (AKI), pulmonary complications, length of ICU and hospital stay and 30-day mortality).

The study is enrolling patients since February 2025. The trial is approved by the Medical Research Ethics Committee (hereinafter: MREC) NedMec, The Netherlands (Ref: D-25-500202). Results of the trial will be published in an international peer-reviewed journal and announced at national and international scientific meetings.

Clinical Trials Information System (CTIS): European Union clinical trials register (EUCT) number: 2024–5 13 598-33-00

Guidelines for symptomatic knee osteoarthritis (OA) dictate the initiation of conservative treatment (physical therapy, analgesics and intra-articular injections with corticosteroids) as a first line defence. When conservative treatment fails, the golden standard is invasive joint replacement surgery, but for a substantial group of patients who do not respond to the current conservative treatment, this is not (yet) indicated. The RADIOPHENOL study investigates if denervation of knee sensory (genicular) nerves can serve the gap between conservative and invasive treatment for younger patients and for patients who cannot undergo joint replacement surgery due to comorbid health conditions.

The RADIOPHENOL study is a multicentre unblinded randomised controlled trial with three parallel arms (1:1:1). In total, 192 patients with knee OA Kellgren-Lawrence grades 2–4 but not eligible for joint replacement according to the orthopaedic surgeon due to young age, old age and/or comorbidity or technical reasons are eligible and will be randomised to three groups of 64 patients. Group A: traditional radiofrequency ablation, group B: chemical neurolysis with phenol, group C: conservative medical management. Primary outcome is the Oxford Knee Score at 6 months. Secondary outcomes include Western Ontario and McMaster Universities Osteoarthritis Index, knee pain by numeric rating scale, physical functionality, health-related quality of life, mental health, change in medication use, predictive value of a diagnostic block, procedure time, patient discomfort score during the intervention and adverse events.

The protocol (V.2.0, 15 May 2023), was approved by the Ethics Committee of Amsterdam UMC (NL83410.018.22 – METC2022.0890) on 31 July 2023. We aim to publish our results in international peer-reviewed journals.

ClinicalTrials.gov NCT06094660, including the WHO Trial Registration data set items. Registered on 20 October 2023, first patient enrolled on 27 November 2023.