The goal of this clinical trial is to learn if virtual reality can reduce propofol requirements in adult, female patients undergoing elective breast surgery under regional anesthesia. The main question it aims to answer is:

Can virtual reality immersion reduce intra-operative propofol requirements in adult female patients undergoing elective breast surgery under regional anesthesia?

Researchers will compare time and weight-adjusted average propofol requirements in both the intervention group and the control group to see if there is a reduction in sedative usage in the group using the virtual reality device.

Participants will be randomly assigned to either a virtual reality (intervention) group or a control group.

• The patients in the virtual reality group will have a virtual reality headset on during the surgery with a preselected scenario of their choice.
• Both groups will have access to patient-controlled sedation under the supervision of an anesthesiologist and will be permitted to self-administer propofol boluses as needed.

Virtual reality (VR) has carved out a growing place for itself in our leisure activities, video games and even in medicine. Recent studies show that VR can reduce anxiety and pain in patients undergoing uncomfortable care (e.g. wound care, dental care, venous access). While the population most frequently investigated is pediatric, the benefits can be extended to other populations. The operating room is uncommon due to the type of procedure and the older patient profile. Yet, with the democratization of regional and neuraxial anesthesia, VR could improve the patient experience in the operating room.

The main objective of this study is to explore the impact of VR on intravenous (I.V.) sedation requirements in adult patients undergoing breast surgery under paravertebral (PV) block. The hypothesis is that VR will serve as an effective distraction in the operative context, reducing the need for pharmacology. In parallel, multiple secondary objectives will also be explored, such as the evaluation of the tolerance to the VR headset, the impact of the chosen type of scenario on the primary outcome, the incidence of adverse effects, the variation of the Nociception Level Index (NOL index) in awake patients as well as overall patient satisfaction.

This single center, open-label, randomized controlled trial will be conducted in a Canadian academic hospital. 100 patients above the age of 18 years undergoing breast surgery (mastectomy, reduction, augmentation, reconstruction, etc.) under regional anesthesia, specifically paravertebral block, will be included in this study. Patients will be randomized either to the intervention group or the control group. The intervention group will have a VR helmet and the control group a standard treatment. Both will have access to patient-controlled sedation (PCS), self-administering their own sedation under clinical observation. Patients in the VR group will be able to choose, before the procedure begins, between 3 different VR environments and will also be allowed to switch between these environments during the surgery. The primary outcome of this study will be the time-weighted dose of propofol (sedative) self-administered during the procedure. Secondary outcomes will include patient satisfaction, premature removal of VR helmet, presence of nausea, desaturation, hypotension and post-anesthesia monitoring time.

Inclusion Criteria:

• Fully consented female patients above the age of 18 years;
• Undergoing elective, awake, breast surgery performed under paravertebral block.

Exclusion Criteria:

• Hearing or visual impairment;
• History of epilepsy, seizure or severe dizziness;
• Severe mental impairment;
• Recent eye or facial surgery or wounds;
• Inability to use the VR hand controller.