Background
Description of the condition
Healthcare examinations, treatments, procedures and interventions are typical extreme stressors that can lead to pain for children (Melnyk 2000; Horstman 2002; Rassin 2004; Wollin 2004; Clift 2007). For the context of this review we draw on the International Association for Study of Pain 2011 (originally cited 1979) definition of pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage". This definition highlights that pain has both sensory (i.e. pain intensity) and emotional (i.e. any negative affect secondary to pain such as distress; including anxiety, fear and/or stress) facets; which can sometimes be difficult to distinguish between (Goodenough 1999; McGrath 2008; Brown 2012; Curtis 2012). This may be especially the case for younger child (< 8 years of age) populations who by virtue of their developmental abilities may be unable meaningfully to differentiate pain from other unpleasant emotions such as fear and anxiety (Goodenough 1999; Blount 2006). These two dimensions of pain (i.e. pain intensity and pain-related distress) are important to consider - ensuring pain management strategies reduce not only pain intensity but also the distress, anxiety and/or fear associated with medical treatment-related pain (Goodenough 1999).
Children can feel "threatened by the monster of medical care" where they fear being hurt, forced and violated by the adults delivering that care (Forsner 2009 p. 522). Pain results in anxiety and stress, which, in turn, negatively impacts not only on a child’s ability to cope with the treatment/intervention but also on his/her recovery (Li 2009). Inadequate relief of pain during childhood treatments may have long-term negative effects on future pain tolerance and pain responses (Young 2005).
Non-pharmacological techniques (e.g. imagery, hypnosis, story-telling, play, music) have long been promoted as useful adjuncts to pharmacological analgesics (Butler 2005; Klassen 2008; Landier 2010). Yet, aside from distraction and hypnosis, there is limited evidence to support the efficacy of many of these conventional psychological interventions (e.g. breathing, relaxation, guided imagery, music) for reducing procedure-related pain in children (Stinson 2008; Uman 2008). In addition, it has been recently documented that children may benefit more from interactive (e.g. playing a video game) as opposed to passive (e.g. watching a video game) distraction strategies (Wohlheiter 2013). One such recent ‘active’ adjunctive analgesic technique gaining momentum is virtual reality (Hoffman 2011).
Description of the intervention
Virtual reality, also referred to as virtuality, is defined as a computer technology which creates a simulated environment/world that users perceive as comparable to real world objects/events (Aguinis 2001; Weiss 2003; Hoffman 2004; Chan 2007). The user’s attention is drawn into the virtual world away from real world visual, auditory and tactile stimuli by the multi-sensory (i.e. sight, sound, touch) nature of the virtual environment (Gold 2006). Virtual reality simulated interventions can vary considerably in terms of three core aspects: types of equipment used; content and nature of the virtual world; and levels of engagement users might have. Virtual reality simulation draws the user’s attention to a virtual world/environment using real-time computer graphics and various input (e.g. position trackers, mouse and data glove) and output (e.g. shutter glasses, head-mounted displays, haptic and audiovisual) devices that make the person an active participant within a computer-generated three dimensional world. Interaction, navigation and immersion are key characteristics of virtual reality systems (Aguinis 2001).
The content of some virtual reality simulated interventions has been developed specifically for certain types of procedures (e.g. Snow World and Ice Cream Factory devised for burn wound dressings) (Hoffman 2004; Chan 2007), whereas other virtual reality simulated interventions are selected for convenience to engage children at the time of invasive medical procedures (e.g. Virtual Gorilla) (Gershon 2003, Wolitzky 2005). All virtual reality systems are categorised according to how immersive or non-immersive they are. With non-immersive systems, the user is connected to the virtual world (by an external monitor) but can still communicate with the real world (e.g. the healthcare environment) (Nilsson 2009). With full immersion, the user’s visual perception of stimuli in the outside world is blocked as they become fully enveloped in the computer-generated virtual environment through the use of a head-mounted display and a tracker position sensor (e.g. a helmet and headphones which exclude visual and auditory inputs from the healthcare environment) (Weiss 2003; Gold 2006). It is this sense of presence and immersive attention (i.e. the ability to give users the sense they are somewhere else) that sets virtual reality apart from other technological interventions such as watching television or video movies, or playing simulated or interactive video games (Weiss 2003; Steele 2003; Hoffman 2004; Chan 2007; Nilsson 2009; Gorini 2011).
How the intervention might work
While virtual reality simulation has been used in many contexts (e.g. treating phobias and post-traumatic stress disorders; training military and medical personnel), for the purposes of this review the focus is on the use of virtual reality simulation in the reduction of pain intensity and pain-related distress associated with medical treatments/interventions. The theory of how virtual reality simulation works in such instances is as a form of distraction; where distraction is defined as “the purposeful focusing of attention away from undesirable sensations” (Mobily 1993). Distraction is a common coping mechanism used by school aged children and adolescents for enduring unpleasant situations (Schneider 2000). Distraction interventions function by diverting the child’s attention away from the stimulus producing the pain and refocusing the child’s attention towards a more pleasant and positive stimulus (i.e. the virtual environment) (McCaul 1984; Schneider 2000). Virtual reality interventions are thought to manifest analgesic effects by altering pain perception through distracting user attention away from the painful procedure, in addition to changing the way a person interprets incoming pain signals, consequently reducing the amount of pain-related brain activity (as seen on MRI imagery) (Morris 2009). Virtual reality exposure can target cognitive and affective pain pathways, thereby decreasing pain intensity, distress, and anxiety by altering how pain signals are processed in the central nervous system. This is achieved by a number of mechanisms including attentional distraction, conditioning of virtual reality imagery and reduced pain.
Virtual reality distraction has been used, for example, to minimise children’s anxiety associated with chemotherapy (Schneider 1999; Ahmadi 2001), to reduce children’s pain during burn wound care (Hoffman 2000; Hoffman 2001; Hoffman 2004; Das 2005), to access intravenous ports in paediatric oncology patients (Wolitzky 2005), to alleviate pain/anxiety for invasive medical procedures such as venipuncture, lumbar puncture, and bone marrow aspirates (Gershon 2003; Wint 2002; Gold 2006; Nilsson 2009), to help adolescents with cerebral palsy as they endure physiotherapy (Steele 2003), and to reduce children’s preoperative anxiety using handheld video games or films (Patel 2006; Low 2008). Together with pharmacological interventions, distraction is thought be to an effective pain management strategy by cognitively redirecting attention away from pain to a more pleasant stimulus, thereby assisting children to cope with the distress of medical treatments. Long-term benefits include advantages for later adult life, as pain experienced during medical treatments in childhood is predictive of pain during subsequent medical procedures and avoidance of medical care during young adulthood (Blount 2006).
Why it is important to do this review
Pain impacts on child and parent satisfaction with healthcare delivery and services. In an investigation of the views and experiences of children in Council of Europe member states, Kilkelly 2011 found that 60.1% of child participants rated ‘not being in pain’ as an important element of health care. Yet evidence still suggests that acute pain management in children is not always optimal (Cummings 1996; Taylor 2008; Groenewald 2012). Recent figures estimate that 27% of children experience moderate to severe pain in hospital, with teenagers and infants experiencing higher prevalence rates of 38% and 32% respectively (Groenewald 2012). This can impact on children’s physiological, psychological and emotional well being, in both the short and long term.
It is inevitable that children admitted to healthcare settings will likely be exposed to potentially painful procedures on a daily basis. For instance, Stevens 2011 reported that more than three quarters (78.2%) of child participants (n = 3822) in their study had undergone at least one painful procedure in a 24-hour period preceding data collection. While each child was exposed to an average of 6.3 (range 1 to 50) procedures, only a small portion (28.3%) of children had interventions specifically linked to the painful procedure. While acknowledging that certain procedures are essential for routine medical and surgical care, these procedures/treatments can cause pain for the child. With the use of technology becoming increasingly prevalent in children’s daily lives, alongside the drive towards e-health and the empowered patient, it seems reasonable to propose that interactive technologies, if proven effective, should be considered as vital intervention vehicles for enhancing health outcomes for children. One such intervention is virtual reality simulation. The use of virtual reality during healthcare procedures/treatments can create a child-friendly and developmentally sensitive environment, thereby contributing to the European campaign for a child-friendly approach to health care (Council of Europe 2011).
Virtual reality simulation is a recent technological advancement with the potential to be a powerful distractor for modulating children’s pain when they are undergoing healthcare treatments (e.g. intravenous cannulation, lumbar puncture, wound dressings, chemotherapy, bone marrow aspirates). For instance, Gold 2006 reported that children who underwent intravenous cannulae placement without distraction reported a fourfold increase in affective pain when compared to children immersed in a virtual reality intervention. Additionally, children who received a virtual reality intervention were twice as satisfied with their pain management as compared to children not exposed to a virtual reality intervention. Schneider 2000 found 82% of children indicated that their chemotherapy treatment was better with virtual reality as compared to previous chemotherapy treatment without virtual reality. Parents were also satisfied with the use of virtual reality interventions and believed such interventions did reduce children’s pain and enhance children’s cooperation during medical treatments (Das 2005; Gold 2006). In a recent review, Hoffman 2011 reported a 35% to 50% reduction in procedural pain in burn patients when in a distracting immersive virtual reality.
Despite these positive evaluations and reports of pain reduction, there remains uncertainty over the effectiveness of virtual reality interventions (Uman 2006; Morris 2009; Nilsson 2009; Dahlquist 2010). In addition, in comparison to other simpler forms of non-pharmacological distraction interventions (e.g. imaginary, breathing, positive thinking), there have been some common criticisms levelled at virtual reality such as high costs, bulky equipment, the need for specialist technological skills and the potential for cyber-sickness, all of which may threaten the widespread implementation of virtual reality for therapeutic healthcare interventions (Bohil 2011). It is important to conduct this systematic review to evaluate the efficacy of virtual reality simulations as pain distractors during healthcare treatments. As few psychological interventions incorporate, or evaluate the effectiveness of, modern and novel interactive technologies such as virtual reality, this review compliments other Cochrane systematic reviews evaluating the effectiveness of non-pharmacological distraction-based interventions for minimising pain in children when undergoing medical treatments including Uman 2006's review 'Psychological interventions for needle-related procedural pain and distress in children and adolescents'.