This study will evaluate the effects of non-invasive vagus nerve stimulation (nVNS) in adults with burn injuries. Burn patients may experience anxiety, poor sleep quality, pain, itching, and changes in autonomic nervous system function during recovery.

Participants will be randomly assigned to one of two groups. The intervention group will receive conventional physiotherapy plus nVNS, and the control group will receive conventional physiotherapy only. Both groups will receive treatment 5 days per week for a total of 10 sessions. nVNS will be applied through electrodes placed on the external ear for 20 minutes per session.

Anxiety, sleep quality, pain, itching, and autonomic function will be assessed before and after the treatment period. Autonomic function will be evaluated using heart rate variability measurements. The results will help determine whether nVNS may be a useful supportive method in the rehabilitation of burn patients.

This study is a randomized controlled experimental study designed to investigate the effects of non-invasive vagus nerve stimulation (nVNS) on anxiety, sleep quality, pain, itching, and autonomic nervous system function in adults with burn injuries.

The study population will consist of patients followed at the Burn Outpatient Clinic of Kartal Dr. Lütfi Kırdar City Hospital in Istanbul, Türkiye. Eligible participants will be adults aged 18 to 65 years who have completed the acute phase of burn injury, whose burn injury occurred between 1 month and 1 year before enrollment, and who have second- or third-degree burns involving 5% to 30% of total body surface area. Participants must also report at least one complaint related to anxiety, sleep quality, pain, or itching and provide written informed consent.

A total of 60 participants are planned to be included. Participants will be randomly assigned in equal numbers to an intervention group or a control group. The intervention group will receive conventional physiotherapy and nVNS. The control group will receive conventional physiotherapy only. Both groups will receive treatment 5 days per week for a total of 10 sessions. Conventional physiotherapy will be planned according to each participant's needs and may include strengthening exercises, stretching exercises, balance exercises, active and passive range-of-motion exercises, and interventions for edema. Each conventional physiotherapy session will last approximately 45 minutes.

In the intervention group, nVNS will be applied using electrodes positioned on the tragus and the anterior and posterior surfaces of the concha of the right and left external ear. Stimulation will be delivered continuously for 20 minutes with a biphasic asymmetric waveform, a pulse duration of 300 microseconds, and a frequency of 25 Hz. The stimulation intensity will be increased in 0.1 mA steps until the sensory threshold is reached. If a participant feels unwell during stimulation, the procedure will be stopped.

Outcome assessments will be performed before treatment and after completion of the 10th session. Anxiety will be assessed using the Beck Anxiety Inventory. Sleep quality will be assessed using the Pittsburgh Sleep Quality Index. Pain will be assessed using a visual analog scale. Itching severity will be assessed using the 12-Item Pruritus Severity Scale. Autonomic nervous system function will be evaluated using heart rate variability measurements recorded with a Polar H10 heart rate sensor and analyzed with Kubios HRV software.

The study aims to determine whether adding nVNS to conventional physiotherapy provides additional benefits for psychological symptoms, sleep quality, pain, itching, and autonomic function in burn rehabilitation.

Inclusion Criteria:

• Adults aged 18 to 65 years
• Patients who have completed the acute phase of burn injury
• Burn injury occurred at least 1 month and no more than 1 year before enrollment
• Second- or third-degree burn involving 5% to 30% of total body surface area
• Presence of at least one complaint related to anxiety, sleep quality, pain, or itching
• Able to read and understand Turkish
• Willing to participate in the study
• Written informed consent provided

Exclusion Criteria:

• Infection, ulcer, or scar tissue on the auricle
• Burn injury in the head and neck region preventing application of the device over the auricular branch of the vagus nerve
• Metallic implant in the skull
• Excessive sensitivity, injury, or inflammation in the ear
• Chronic pulmonary disease and/or chronic cardiac disease
• Resting heart rate below 60 beats per minute
• Presence of a pacemaker, cochlear implant, or similar implanted device
• Uncontrolled hypertension
• Lack of cooperation or inability to comply with study procedures

Individual participant data will not be shared because the dataset will contain sensitive health-related information from burn patients. Data will be used only by the research team for the purposes approved by the ethics committee, while maintaining participant confidentiality.

The outcomes assessor will be blinded to group allocation. Participants will be randomly assigned to the intervention or control group, and outcome assessments will be performed without knowledge of the assigned treatment group.