Efficacy of non-pharmacological interventions for procedural pain relief in adults undergoing burn wound care: A systematic review and meta-analysis of randomized controlled trials

Highlights

• This work reviews the effects of non-pharmacological interventions in burn patients.

• Non-pharmacological interventions might be a valuable adjunct to standard burn care.

• Benefits on procedural pain relief and mental distress reduction are demonstrated.

• Particularly virtual reality distraction and hypnosis could be recommended.

Abstract

The aim of the present meta-analysis was to investigate the efficacy of non-pharmacological interventions for procedural pain relief in adults undergoing burn wound care compared to standard care alone or an attention control.

Through a comprehensive literature search in various electronic databases 21 eligible randomized controlled trials (RCTs) were included, comprising a total of 660 patients. Random effects meta-analyses revealed significant positive treatment effects on pain outcomes, Hedges’ g = 0.58, 95% CI [0.33; 0.84]. Heterogeneity of study effects was substantial, I² = 72%. Effects were significantly larger for comparisons against treatment as usual (TAU), g = 0.69, CI 95% [0.40; 0.98] than for comparisons against attention control groups, g = 0.21 [−0.11; 0.54], p < 0.001. Distraction interventions, particularly those using virtual reality, and hypnosis revealed the largest effects on pain relief. Non-pharmacological interventions further resulted in a significant small, homogeneous effect on anxiety reduction, g = 0.36 [0.20; 0.52].

In summary, benefits of non-pharmacological interventions on procedural pain relief and reduction of mental distress were demonstrated. Results have been proven to be free of publication bias. However, further high quality trials are needed to strengthen the promising evidence.

Introduction

Patients with severe burns not only suffer from physical and psychological distress from the injury itself, they also have to cope with daily painful experiences from therapeutic procedures such as physical therapy or wound care, i.e., removal of dressings, washing, debridement, and application of new dressings. Burn pain has been proven as being maximal during therapeutic procedures and wound debridement might be more painful than the burn injury itself [1].

Pharmacological approaches such as opioid analgesics are recommended as first-line treatment for procedural pain [2]. However, some patients have little or no response to opioids. Even patients who respond to pharmacological pain therapy still experience considerable pain, often described as “excrutiating” [3]. Furthermore, opioid analgesics often lead to unwanted side effects (e.g., nausea, constipation, sedation, respiratory depression, tolerance and the risk of physical and psychological dependence) limiting the use of analgesics, particularly when administered over prolonged periods [4]. Hence, additional non-pharmacological interventions are indicated to improve pain management.

Pain experience is thought to involve different components that are separately assessable and sometimes might be differentially affected [5], [6], [7], [8]: a sensory component (e.g., pain intensity), an affective component (e.g., pain unpleasantness), and a cognitive component of pain (e.g., amount of time spent thinking about pain).

Non-pharmacological interventions are used to address these different components of burn pain as well as mental distress associated with painful procedures. They are usually conducted as an adjunct to standard care within the time of hospitalization by physicians, psychologists, or nurses including, e.g., personal communication, printed information (leaflets), audio or video recordings, or use of virtual reality (VR).

The following non-pharmacological interventions are common in the context of burn wound care [9], [10], [11], [12]. Distraction aims at diverting attention towards a non-painful stimulus to lessen the intensity of perceived pain by providing additional stimuli to the environment such as music or watching films. In recent years, virtual reality (VR) has established as a new form of distraction, giving the patient the illusion of immersion into a three-dimensional computer-generated environment as if it were a place in which they are physically present [13]. Sensory focusing interventions (i.e., attention towards sensations) may reduce distress by distracting the individual from interpreting the meaning of the sensations, by providing valuable self-regulatory information about the sensations, and by increasing perceptions of control. Moreover, sensory focusing appears to positively affect memories of pain [14]. Relaxation techniques are used to reduce overall arousal by down-regulating sympathetic tone. Commonly applied techniques are deep breathing or progressive muscle relaxation [12]. Hypnosis alters the state of consciousness, allowing for a more suggestible state; thus, changing the perception of pain might be eased [12]. It has been discussed that hypnosis works mainly through two mechanisms — reducing distress and targeting patient expectancies with suggestions for positive outcomes [15]. One of the most common hypnosis protocols used in burn care is Barber’s Rapid Induction Analgesia (RIA), a hypnotherapeutic technique for developing analgesia and muscular relaxation within a short period of time [16]. In many studies these types of interventions may overlap, e.g. music-based interventions can affect patients by both distraction and relaxation.

To date, there are only a few systematic reviews on the efficacy of non-pharmacological interventions for procedural pain relief in adult burn patients. For example, de Jong et al. [9], [17] systematically reviewed non-pharmacological interventions for procedural pain relief in burn patients. Additionally, another review [18] focused particularly at the use of VR in burn injury patients. However, results of these three reviews remain descriptive in nature since no meta-analytic summary of the effects was provided.

There is only one review also comprising meta-analytic estimates including 17 studies [19], however, inclusion was limited to a single type of intervention, i.e., music interventions.

Hence, the present review aims at providing a current comprehensive overview on the efficacy of non-pharmacological interventions for procedural pain relief in adults undergoing burn wound care by including randomized trials only. In addition to pain, we will focus on the effects regarding the reduction of mental distress in burn patients.