Using a Virtual Reality and Olfactory Stimuli Multimodal Intervention to Reduce Post-Operative Pain and Anxiety in Patients Undergoing Cardiothoracic Surgery

Every year, over 500,000 individuals in the United States undergo cardiothoracic surgery for heart and lung disease. Cardiothoracic surgery can be an extremely traumatic experience for the patient. Their chest wall muscles and tissues can be cut, crushing the intercostal nerves and irritating the pleura. During the perioperative period, over 16% of patients suffer from clinically significant anxiety, and up to 57% of patients experience stabbing and throbbing chest and shoulder pain that can persist for months to years.

Currently, perioperative pain is most often treated with opioids, and treatments for perioperative anxiety are limited and can have severe side-effects. Interventions using virtual reality may be a promising alternative to opioids and benzodiazepines in the treatment of perioperative pain and anxiety. Virtual Reality consists of immersing patients into a computer-generated environment and exposing users to visual and audio sensory inputs. Through visual and audio cues that modulate pain-related brain activity in the thalamus, VR can increase pain tolerance. Encouragingly, studies have demonstrated the ability of VR to decrease pain intensity and increase pain tolerance in patients suffering from chronic pain. In addition, olfactory stimuli play a crucial, yet distinct, role in pain perception and relaxation. The olfactory bulb projects directly and without thalamic relay to brain regions that are involved in the processing of emotion and pain. Studies have shown that there is significant overlap between brain regions activated by painful stimuli and olfactory stimuli. When an individual smells a pleasant scent, olfactory stimuli activate the amygdala and alter its connectivity and functional coupling with brain regions linked to pain perception.

There is potential for an intervention combining VR and OS to lead to a greater reduction in pain and anxiety. Pain and anxiety are characterized by multiple neural pathways. Pain results from the activation of a widely distributed brain network, including the thalamus, insular cortex and secondary somatosensory cortex. Anxiety results from a combination of neuroendocrine, neurotransmitter, and neuroanatomical disruptions in the limbic system. Of note, studies have shown that although pain and anxiety have distinct neural pathways, anxiety modulates the perception of pain, and preoperative anxiety is associated with increased postoperative pain. However, current treatments for perioperative pain and anxiety are often ineffective because they only address one of the many pathways that contribute to pain and anxiety. As such, multimodal interventions are necessary to achieve optimal pain and anxiety control. Although OS and VR both reduce pain and anxiety, they have been shown to activate different regions of the brain. VR reduces pain and anxiety by directly modulating pain-related brain activity in the prefrontal cortex and primary and secondary somatosensory cortex, decreasing pain intensity and increasing user's ability to tolerate pain. OS activates the limbic system, including the amygdala and hippocampus, reducing pain and anxiety by altering its connectivity and functional coupling with brain regions linked to pain perception.

The aim of this study is to evaluate the feasibility of a VR and OS multimodal intervention in patients undergoing cardiothoracic surgery. In addition, the investigators will evaluate the preliminary effects of the VR/OS intervention on patient pain and anxiety before and after cardiothoracic surgery. This is a prospective, randomized study. A total of 80 patients are anticipated to participate in this study. All patients are expected to be enrolled at Massachusetts General Hospital (MGH). Eligible patients will be randomized 1:1 to the VR/OS intervention or usual care approximately 2-4 weeks prior to their scheduled cardiothoracic operation.