Background
The aim of this study is to better understand the use of non-pharmacological approaches to reduce anxiety among patients in intensive care units (ICUs), and their potential clinical benefits in one specific population of patients, i.e. patients undergoing cardiac surgery.
Anxiety, pain and fatigue are important factors influencing the recovery of patients after surgery. The definition of preoperative anxiety is “an unpleasant state of uneasiness or tension that is secondary to a patient being concerned about a disease, hospitalization, anaesthesia and surgery, or the unknown” [
1]. Among patients admitted to hospital for surgery, 20–28% reported high preoperative anxiety and 60% reported minimal anxiety in two studies investigating this issue [
2,
3]. Patients’ anxiety before surgery is a risk for postoperative recovery problems and its consequences are of paramount importance in delaying wound healing [
4]. In addition, preoperative anxiety is reported to significantly influence the intensity of postoperative pain [
5,
6]. Studies have shown that among patients in the ICU, pain is associated with an unpleasant stay, sleep deprivation, increased agitation, high rates of post-traumatic stress disorder and feeling unsafe in the ICU environment [
7‐
13].
Currently, pharmacological treatments for anxiety and pain are well-developed in the ICU environment, where pain and fatigue are most commonly managed by opioid analgesics, propofol and benzodiazepines [
14]. Pharmacological treatment could be considered efficient when the patient feels comfortable, with no adverse effects [
15]. Yet, opioid analgesics (e.g. morphine) often lead to respiratory sedation, hyperalgesia, depression, nausea, opioid-induced tolerance and dependence [
15]. Benzodiazepines can be used in the short term but can lead to strong dependence, with important adverse effects: ataraxia, irritability, nervousness, depression and risk of suicide [
16]. Further, some pharmacological interventions (e.g. lorazepam and pregabalin), intended to treat anxiety, fail to decrease preoperative anxiety and postoperative pain [
17,
18]. In the ICU environment, deep levels of sedation potentially lead to increased mortality and lengths of stay [
19]. In the light of this, non-pharmacological approaches are of interest as complementary techniques to reduce anxiety and pain. Techniques such as hypnosis and virtual reality (VR) have been investigated in numerous studies in the medical field (e.g. algology, oncology, anaesthesia) to reduce pain and anxiety and increase patients’ comfort [
20‐
22]. Hypnosis is defined as a “state of modified consciousness involving focused attention and reduced peripheral awareness, characterized by an enhanced capacity for response to suggestions” [
23]. Hypnosis has three main components: absorption, dissociation and suggestibility. Absorption is the tendency to become fully involved in a perceptual, imaginative or ideational experience; dissociation is the mental separation from the environment; and suggestibility is the responsiveness to social cues, leading to an enhanced tendency to comply with instructions and a relative suspension of critical judgment [
24]. This technique is considered safe, and one that allows the patient to be focused on his or her inner world, by including cognitive and behavioural components that enable the mind to influence body sensations and perceptions [
25‐
27]. Hypnotic suggestions can be used to modify perception of symptoms such as pain, anxiety and fatigue, in different health-related disorders (e.g. oncology, chronic pain, surgery). In some cases, hypnosis can be a complement to other medication therapy to reduce anxiety before surgery (e.g. presurgical anxiety in coronary artery bypass and cataract surgery) [
28‐
30] and also after surgery (e.g. during weaning from mechanical ventilation) [
31]. A recent meta-analysis showed that hypnosis is a highly effective intervention for anxiety and is more effective when combined with other psychological interventions and various clinical applications [
28]. Hypnosis is known to reduce acute and chronic pain [
32‐
36] and improve sleep quality [
37,
38]. A variety of relaxation techniques have been investigated to improve the quality of sleep in ICU patients (e.g. aromatherapy, earplugs and masks, noise bundle) but results are not convincing in all studies [
39,
40]. One review of the literature showed that hypnosis seems to be a promising technique for management of sleep problems; however, more randomised studies are required to support these results [
34]. Hypnosis is an efficient treatment in health care, and one that can save time and costs to healthcare providers in some instances [
35,
41].
There has been growing interest in the use of virtual reality (VR) in medicine [
20]. VR involves computer-generated, immersive and three-dimensional technologies. VR subjective experience is characterized by senses of immersion and presence. Presence refers to the degree to which the subject experiences being in the virtual environment [
42,
43], while immersion is the amount of sensory input the VR system creates [
44]. Feedback systems with trackers - and often helmet and gloves - allow individuals to be distracted by interacting with a virtual world and make it as “real” as possible [
45]. According to Patterson et al. (2006), immersion in VR can isolate the patient from the outside environment and it is effective in distracting the subject’s attention from a painful stimulus [
46,
47]. VR has been shown to divert attention from painful stimulation in both highly hypnotizable and less hypnotizable individuals in experimental and clinical settings [
48,
49]. VR can also be considered as an efficient non-pharmacological tool to decrease anxiety (e.g. during dental treatment or phobia therapy) [
50,
51]. In our experiment, VR is not used during a painful stimulus but before and after a painful and stressful intervention, i.e. surgery. VR distraction is an adjunctive tool to clinical interventions for such issues as acute and chronic pain management, clinical education, cognitive and motor rehabilitation, anxiety management and communication skills training; however, less is known about its efficacy in decreasing fatigue [
20,
52].
Virtual reality hypnosis (VRH) is a technique that combines VR hardware/software and hypnotic induction followed by analgesic suggestions [
53]. According to Patterson et al. (2004; 2010), “VRH uses a high-resolution, head-mounted display that delivers absorbing visual images and high-fidelity audio that provide an induction […] followed by suggestions for comfort and pain relief” [
53,
54]. Studies have demonstrated positive effects of VRH on pain and anxiety [
48], but the actual mechanisms of this treatment are not well-known. Hence, it seems that even if immersion is present in VRH and hypnosis, it would not necessarily bring about the same effects as it does with VR distraction. For example, in hypnosis, absorption and dissociation come from the subject who constructs his own world with the hypnotherapist’s suggestions. In VR, that world is imposed on the subject with existing technology. To our knowledge, two randomised studies have previously been conducted to compare hypnosis, VR and VRH in experimental setups [
47,
48]. However, there is a need to compare the efficiency of these techniques in clinical practice.
One of the main goals of caregivers is to create the best environment for reducing the patient’s anxiety in surgery and in the ICU by using the patient’s own resources. In this study, we wish to compare three non-pharmacological methods in patients undergoing cardiac surgery and hospitalized in the ICU: hypnosis, VR and VRH. By comparing these non-pharmacological tools, we would be able to better understand their relative efficacy and mechanisms in making the patient more comfortable. Randomised, controlled research trials are necessary to evaluate how the patient’s cognition and perception of these tools can impact the outcomes [
20,
26].
Discussion
The aim of this study is to evaluate the feasibility of hypnosis, VR and VRH in increasing comfort (anxiety, pain and fatigue) in patients undergoing cardiac procedures, and to investigate the phenomenological experiences they undergo (absorption, dissociation, time perception, immersion and presence). For years, hypnosis and VR have been evaluated in different medical settings and have been shown to be efficient in decreasing perceptions of pain and anxiety [
65‐
68]. More recently, a combination of these two techniques (VRH) was proposed to alleviate clinical symptoms, mainly anxiety and pain [
54]. Until now there have been very few controlled studies comparing these techniques [
47,
48]. Thereby, our study can potentially make a great contribution in the understanding both of the clinical impact of these approaches and of the mechanisms underlying them. The randomised controlled design is a particular strength of our study. Guidelines are important for tools like VR in terms of mechanisms and clinical benefits. Results of this study will inform us about the endpoint for future well-designed trials forhypnosis, VR and VRH.
There are some limitations to our study. The first limitation could be that some patients will drop out due to inability to participate on the day after surgery. We suspect that extreme fatigue and deep sedation due to surgery may be a barrier to properly following the hypnotic suggestions and the VR animation. The second limitation is that patients are assessed for 2 days and not for the entire period of their hospitalization.
In conclusion, our study will provide initial insight into the application of VR, hypnosis and VRH in the particular context of ICU care, by studying the specific population of patients undergoing cardiac surgery. We will able to measure the effects of VR, hypnosis and VRH on clinically relevant factors such as anxiety and pain. Others studies will then be developed to extend and adapt this protocol to other populations of patients in the ICU.
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