Optimal Approaches to the Management of Burn Pain: Expert Insight

Depending on the extent of the injury, pain due to burns can range from mild to severe to excruciating. Research indicates that pain experienced during the early hospitalization period may predict long-term outcomes,¹ and that acute pain at the time of discharge may serve as a predictor of suicidal ideation post-burn injury.²

A study conducted in soldiers who had suffered burn injuries found that pain levels are positively correlated with symptoms of post-traumatic stress disorder (PTSD).³

Therefore, achieving effective pain relief as early as possible after a burn injury is critical for the long-term physical and psychological well-being of patients with burn injuries.⁴

Opioid-based analgesics are the first-line treatment in burn pain, but their associated side effects and the risk for dependency and abuse⁵ have led clinicians to explore multimodal approaches to pain management that include neuropathic medications, as well as interventional and adjunctive therapies.⁶

In an interview with Clinical Pain Advisor, Maryam Jowza, MD, assistant professor in the department of anesthesiology at the University of North Carolina, Chapel Hill (UNC), and Dominika Lipowska James, MD, assistant professor of anesthesiology and director of inpatient acute and chronic pain services at UNC, discussed the latest trends in burn pain management.

Clinical Pain Advisor: Can you describe the mechanism of pain due to burn injury?

Dr Jowza: The mechanism of pain in burns in the acute setting is different from pain that may continue to be experienced after the tissue heals. In the acute setting, thermal injury to the skin causes the release of inflammatory mediators, which then activate the pain receptors locally at the site of the injury. After a short period of time, the area around the wound also becomes sensitized — a process that is mediated at the spinal cord level. The mechanism of persistent pain after the burn injury and tissue healing is not yet known, but likely involves sensitization and “wind up” at the spinal cord level and above.

Clinical Pain Advisor: How is burn pain categorized?

Dr Jowza: There are 2 types of pain that patients with burns experience: evoked pain and background pain.⁶ Evoked pain is pain provoked by an event, such as a dressing change, movement, or touch; background pain is constant pain that is present even in the absence of provocation.

Clinical Pain Advisor: Which factors influence the severity of pain in burn injuries?

Dr Jowza: The degree of tissue injury can influence the severity of pain experienced acutely. Generally, less severe burns result in less severe pain; ie, pain from superficial, first-degree burns tends to be mild compared with pain from deeper, second- or third-degree burns.

Clinical Pain Advisor: How does pain management in burn injuries differ from pain management in other types of acute pain?

Dr Jowza: Pain from a burn injury is unique among other surgical acute pain states in that patients are unprepared for it, compared with, for example, acute pain from an elective surgery. Thus, pain from a burn injury is frequently accompanied by psychological trauma. In addition, burn patients often need to endure frequent episodes of pain exacerbations such as with dressing changes, physical therapy, and repeated operative procedures. As a result, the recovery period is prolonged and psychologically burdensome.

Because of the above, treatment of burn pain is best managed with multimodal therapy that targets pain from all possible angles. It is also important to address the patient’s psychological needs during the acute treatment period.

Clinical Pain Advisor: Which medications are used to treat pain due to burns and how effective are they?

Dr Lipowska James: Traditionally, opioid medications were the primary analgesics used in burn pain care. Although opioid medications remain the cornerstone of burn pain management, we have now learned to appreciate the benefits of multimodal analgesia over opioid monotherapy.

Optimal therapy for burn pain should include not only opioids, but other adjuvant and neuropathic medications. Some of the most commonly used neuropathic pharmacologic agents include antiepileptic medications (eg, gabapentin, pregabalin, Topamax), tricyclic antidepressant drugs (eg, amitriptyline, nortriptyline), serotonin and norepinephrine reuptake inhibitors (eg, venlafaxine, duloxetine), as well as other adjuvant medications such as acetaminophen and non-steroidal anti-inflammatory drugs.  Some opioid medications such as methadone, tramadol, and tapentadol possess both opioid and non-opioid qualities, making them particularly useful in the treatment of neuropathic pain.

Clinical Pain Advisor: Which non-pharmacologic approaches are available in the management of burn pain?

Dr Lipowska James: Comprehensive, multimodal pain management focuses not only on pharmacologic pain management but also on interventional and adjunctive therapies. In the immediate perioperative setting, burn patients can benefit from interventional nerve blocks, which have the capability to inhibit burn-related and perioperative pain. Other medications such as intravenous infusions of ketamine and lidocaine may also be used in the immediate acute setting. To improve long-term burn injury outcomes, some of the most important therapies involve the mind, such as psychological counseling, cognitive behavioral therapy, mindfulness, music therapy, hypnosis and the use of virtual reality technology. These therapies have been shown to decrease the burden of burn trauma-related mental health conditions such as PTSD and anxiety. Other therapies include treatments focused on the preservation of function and mobility, such as physical therapy, occupational therapy, and surgical burn treatment. In the chronic sense, burns may be associated with limitations in extremity range of motion and painful scar tissue hypertrophy, which can be ameliorated with laser modulation of hypertrophic scars and fat-grafting therapy. Neuropathic pain resulting from scar nerve compression syndromes can also be treated surgically.

Clinical Pain Advisor: How common is chronic pain in patients with a burn injury and what strategies are used to manage it?

Dr Lipowska James: Chronic persistent pain following a burn injury is extremely common. It is estimated that 50% of burn victims suffer from burn-related chronic pain. Development of chronic pain is negatively influenced by inadequate pain control as well as burn severity. Chronic burn-related pain has a negative impact on multiple aspects of patients’ lives by interfering with rehabilitation,  their psychological well-being, contributing to poor quality of life, and ultimately resulting in increased healthcare resource utilization and disability.

Clinical Pain Advisor: What are the main challenges in managing chronic pain due to burn injury?

Dr Lipowska James: Proper pain management in burn patients is of the utmost importance, as inadequately treated pain not only contributes to increased burn trauma-related morbidity and mortality, but it also increases long-term burn-related complications such as the development of chronic pain syndromes and trauma-related psychiatric comorbidities. Chronic post-burn pain is primarily neuropathic in nature (ie, pain related to nerve injury or dysfunction), and so is difficult to treat and requires the use of a multitude of analgesic agents concurrently —  multimodal analgesia. Multimodal analgesia allows for better analgesic outcomes while concurrently permitting opioid sparing and limiting medication-related side effects. Although we have made great advances in terms of options in burn pain management, burn pain remains challenging to treat and many patients continue to suffer from chronic pain despite treatment optimization.

References

1. Patterson DR, Tininenko J, Ptacek JT. Pain during burn hospitalization predicts long-term outcome. J Burn Care Res. 2006;27:718-726.
2. Edwards RR, Magyar-Russell G, Thombs B, et al. Acute pain at discharge from hospitalization is a prospective predictor of long-term suicidal ideation after burn injury. Arch Phys Med Rehabil. 2007;88:36-42.
3. McGhee LL, Slater TM, Garza TH, et al. The relationship of early pain scores and posttraumatic stress disorder in burned soldiers. J Burn Care Res. 2011;32:46-51.
4. McIntyre MK, Clifford JL, Maani CV, et al. Progress of clinical practice on the management of burn-associated pain: Lessons from animal models. Burns. 2016;42:1161-1172.
5. Jimenez XF, Sundararajan T, Covington EC. A systematic review of atypical antipsychotics in chronic pain management: Olanzapine demonstrates potential in central sensitization, fibromyalgia, and headache/migraine [published online October 26, 2017]. Clin J Pain. doi:10.1097/AJP.0000000000000567
6. James DL, Jowza M. Principles of burn pain management. Clin Plast Surg. 2017;44(4):737-747.