Chapter 10: Pain assessment and management
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Physical interventions
In addition to psychological interventions, a number of physical interventions can be helpful in reducing pain.
Positioning and comfort measures
Positioning as an intervention involves the maintenance of proper body alignment to reduce stress and anxiety. Simple comfort measures such as positioning pillows and bed linen appropriately and positioning the patient correctly (such as supporting a painful limb) can help to reduce pain (El Geziry et al. [52]). Patients can feel more relaxed and these measures can improve patient comfort by reducing muscle tension and discomfort. Other comfort measures include ensuring that interruptions and noise are minimized to promote rest and ensuring the ambient temperature is comfortable.
Exercise
Joint stiffness and muscle wasting may further compound pain problems, and preventing or minimizing this is a key approach in pain management. The aim of physical exercise is to improve function and prevent any current disability from getting worse (Shipton [171]). This can apply to both acute and chronic pain. Exercise should always be tailored to the patient's tolerance and stamina. A simple exercise regimen that is practised regularly and supervised by a therapist can help patients to feel better and more in control, and it can also have benefits in terms of pain relief. In patients with chronic pain, it can increase mobility and flexibility while restoring confidence and challenging fear‐avoidance behaviour (Shipton [171]).
Transcutaneous electrical nerve stimulation
Transcutaneous electrical nerve stimulation (TENS) is a non‐pharmacological intervention that makes use of a complex neuronal network to reduce pain by activating descending inhibitory systems in the central nervous system. It uses an electrical device (Figure 10.14) to deliver an electrical current through the intact surface of the skin to stimulate the sensory nerve endings. It is thought to work by activating the large myelinated fibres, which in turn block small pain‐transmitting nerve fibres (El Geziry et al. [52]). It is also thought to work by stimulating the release of natural pain‐relieving chemicals (endogenous opioids) in the brain and spinal cord (Johnson [86]). TENS is recognized as a treatment modality with minimal contraindications.
Figure 10.14 TENS machine.
Evidence for the use of TENS is variable. In a summary of systematic reviews by Vance et al. ([185]), it was suggested that TENS, when applied at adequate intensities, is effective for post‐operative pain, osteoarthritis, painful diabetic neuropathy and some acute pain conditions. When compared to sham TENS (where a medical device with the only purpose of acting as a placebo is used in controlled clinical trials), TENS has been shown to reduce acute pain (procedural and non‐procedural), including pain after thoracic surgery, and it is also effective in primary dysmenorrhoea (Schug et al. [166]).
Thermotherapy
Thermotherapy has for many years been advocated as a useful adjunct to pharmacological therapies. Ice is used for acute injuries and warmth is used for sprains and strains.
Heat therapies
For decades, superficial heat therapy has been used to relieve a variety of muscular and joint pains, including arthritis, back pain and period pain. There is much anecdotal and some scientific evidence to support the usefulness of heat as an adjunct to other pain treatments. The physiological effects of heat therapy include pain relief and increases in blood flow, metabolism and elasticity of connective tissues (Malanga et al. [102]). Heat therapy works by:
- stimulating thermoreceptors in the skin and deeper tissues, thereby reducing sensitivity to pain by closing the gating system in the spinal cord
- reducing muscle spasm
- reducing the viscosity of synovial fluid, which alleviates painful stiffness during movement and increases joint range (El Geziry et al. [52]).
In the home environment, people use a variety of different methods for applying heat therapies, such as warm baths, hot water bottles, wheat‐based heat packs and electrical heating pads. In the hospital setting, caution is required with equipment as many devices do not reach health and safety standards (e.g. they may have uneven and irregular temperature distribution) and there have been incidences of burns (El Geziry et al. [52]). Heat therapy should not be used immediately following tissue damage as it will increase swelling. All devices used in the hospital should include instructions on their safe use in order to prevent harm to patients.
Cold therapies
Cold therapies can also be used to stimulate nerves and modulate pain. The physiological effects of cold therapy include reductions in pain, blood flow, oedema, inflammation, muscle spasm and metabolic demand (Malanga et al. [102]). Cold may be particularly valuable following an acute bruising injury, where it can help to reduce inflammation and limit further damage. Cold can be applied in the form of crushed ice or gel‐filled cold packs, which should be wrapped in a towel to protect the skin from an ice burn.
NICE recommendation on thermotherapy
NICE ([125]) concluded that the evidence base on thermotherapy is limited. All the thermotherapy studies in osteoarthritis have explored the application of cold rather than heat and there was no significant difference in pain between cold thermotherapy and the control groups. The results of randomized controlled trials (RCTs) assessing physical function are mixed when compared with controls. There is no economic evidence available on the subject. Malanga et al. ([102]) also concluded that there remains an ongoing need for more high‐quality RCTs on the effects of cold and heat therapy on recovery from acute musculoskeletal injury.
Despite the scarcity of evidence, local heat and cold are widely used as part of self‐management. They may not always take the form of packs or patches, with some patients simply using hot baths to the same effect. As an intervention, this has a very low cost and is extremely safe as long as all safety instructions for the bathing equipment are followed. NICE ([125]) therefore concluded that a positive recommendation was justified and the use of local heat or cold should be considered as an adjunct to core treatments.
