Purpose: This study was conducted to evaluate the effect of isometric exercise and dry heat application technique on venous fullness and vein visibility in cancer patients.

Design: This study is a randomized controlled trial model. Methods: This study was conducted in the outpatient chemotherapy unit of Malatya Turgut Ozal Medical Center Oncology Hospital, Türkiye. A total of 180 patients were enrolled and randomly allocated using block randomization to an isometric exercise group (n = 60), a dry heat application group (n = 60), or a control group (n = 60). Sample size was determined through power analysis. Data were collected using the "Descriptive Information Form", "Vein Rating Scale" and "Vein Assessment Tool".

Patients admitted to the chemotherapy unit were approached before treatment and informed about the purpose and procedures of the study. Eligibility was assessed according to the inclusion criteria, and written informed consent was obtained from all patients who met the eligibility criteria and voluntarily agreed to participate.

The data collection procedure consisted of the following steps:

Baseline assessment: Participants first completed the socio-demographic section of the Patient Information Form, and the responses were recorded by the researcher.

Pre-intervention vein assessment: A tourniquet was applied to the patient's upper extremity, and vein characteristics were assessed by the nurse using the Vein Rating Scale (VRS) and the Vein Assessment Tool (VAT). During this assessment, no manoeuvres intended to enhance vein visibility (e.g., repeated hand opening and closing, tapping, or slapping the vein) were permitted after tourniquet application. The tourniquet was then removed, and the patient rested for 10 minutes before baseline (pre-test) measurements were recorded.

Intervention: Participants received one of the study interventions according to their assigned group.

Isometric exercise group: Participants were provided with silicone hand exercise balls and instructed to squeeze and release the ball 15-20 times.

Dry heat application group: A chemical gel compress heated to 40 ± 2°C was applied to the selected extremity. Based on previous evidence, maintaining local heat at 40 ± 2°C for at least 5 minutes is sufficient to induce vasodilation.

Control group: Participants received routine peripheral intravenous catheterisation care without any additional intervention.

Post-intervention vein assessment: Immediately after completion of the intervention, a tourniquet was reapplied, and vein characteristics were reassessed by the nurse using the VRS and VAT. These measurements constituted the post-test assessment.

Peripheral intravenous catheterisation: Following the post-test assessment, peripheral intravenous catheterisation was performed by the chemotherapy nurse according to standard clinical practice.

Inclusion Criteria:

• Undergoing chemotherapy treatment,
• Receiving at least 3 cycles of chemotherapy treatment,
• Not diagnosed with diabetes and/or without peripheral neuropathy,
• Not receiving antithrombotic therapy,
• Without bleeding tendency and thrombocytopenia,
• No deep vein thrombosis,
• No complications associated with PIVC (such as ecchymosis, hematoma, scarring, edema, infiltration, extravasation and phlebitis),
• No allergy or sensitivity to heat,
• No metal prosthesis in the extremity to be heat therapy applied,
• No limb deformity that would prevent performing isometric exercises,
• No communication problems,
• No history of paralysis
• Patients who volunteered to participate in the study were included.

Exclusion Criteria:

• Total mastectomy,
• With peripheral nerve disease,
• More than 2 peripheral IV catheters applied,
• Psychiatric illness,
• People with intellectual disabilities at a level that cannot perceive cognitive functions and
• Individuals who did not perform or did not want to perform the procedures applied during the research process were not included in the study.

cancer patients