Introduction
Severe burn wounds are painful themselves and cause long-term post-injury pain from dressing, surgery, scar remodeling, and rehabilitation therapy, etc. Severe pain of acute burns can be alleviated by analgesics or music therapy but chronic pain, which is a peripheral neuropathy, lasts for an average of 5.3 years in 52% of burn patients. Chronic pain is difficult to treat as it persists by impacting the supraspinal level.
Chronic pain has negative impact on Health- Related Quality of Life (HRQoL). A study involving burn victims reported that HRQoL overall improved over time to the level of healthy individuals. However, various factors including burn area (total body surface area; TBSA), presence of depression, posttraumatic stress disorder (PTSD), and severity ofpain can also influence the quality of life. Psychological conditions such as PTSD and depression exacerbate chronic pain by negatively impacting cognitive sensitivity and recognition of pain.
Let us take a brief look at aprospective, longitudinal, consecutive study* that examined patients with chronic post-burn pain for 2-7 years. The prevalence and characteristics of pain, change in pain over time, and burn-related factors and individual-related factors that can cause pain were assessed.
Method
- Uppsala University Hospital Burn Center
- Period: from March 2000 to March 2007
- Participants: Burn patients aged 18 years or older, without history of mental illness, TBSA>5%, Length of Stay (LOS)>1 day
- Follow-up intervals: at 3 month,6 month, 12 months, 24 months and annuallyafterwards
- Sociodemographic information: Age, gender, time of sustaining burn, whether working or not after sustaining burn
- Injury characteristics by medical record: TBSA, TBSA-FT (full thickness), LOS, area of burn, exposure
- Pain assessment: Pain was assessed using BPI-SF (Brief Pain Inventory Short Form). The severity of pain and impact on patient’s daily life were assessed.
- HRQoL: EQ-5D was used. EQ-5Dscores mobility, self-care, usual activities, pain/discomfort, and depression/anxiety from 1 to 3. The pain/discomfort scorewas used to assess the severity of pain over time.
- PTSD:IES-R (Impact of Event Scale-Revised) was used to assess key symptoms of PTSD(intrusion, avoidance, hyperarousal).
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Results
Sample characteristics
Of the total 112 participants, 67 were followed up for 2-7 years. The mean age was 42.6±14.8 years, mean TBSA was 25.4±20.4%, mean TBSA-FT was 10.8±14.8%, and mean LOS was 27±34 days. The mean follow-up period was 4.6±1.9.
Severity and interference of post-burn pain in daily life
Thirty percent of patients responded they were still experiencing burn-related pain after 2-7 years. The mean Pain Severity Index was 3.4±2.0, and mean Pain Interference Index was 3.1±2.4. Both indexes were below 5, which indicate that the pain severity and interference with daily life were mild to moderate. The pain was found to impact daily activities, work, and emotional state but had relatively low impact on the ability to walk, sleep, and social relationships.
3.3 Correlation between pain on the BPI and EQ-5D
Of the 47 patients responding no pain on BPI-SF, 20 patients responded they had pain on EQ-5D. However, all of 20 patients responding they felt pain on BPI- SF had the same response on EQ-5D. The Pain Severity Index wasPatients waswas 3.1 ± 1.6 in patients reporting moderate pain and discomfort and 5.5 ± 3.3 in patients reporting severe pain and discomfort. However, the p value between two indexes was 0.17, indicating little association.
-To be continued
