Photoradiation in acute pain: A systematic review of possible mechanisms of action and clinical effects in randomized placebo-controlled trials

Abstracts Defining mild, moderate, and severe pain by using the color analogue scale with children presenting to a pediatric emergency department McConahay T., Bryson M., Bulloch B. Academic Emergency Medicine 2006;13(3):341—4 Objectives: To define in centimetres what constitutes mild, moderate, and severe acute pain in children by using the Color Analogue Scale (CAS) for pain. Methods: This was a prospective study, using convenience sampling, of all children presenting to a pediatric ED between the ages of 5 and 16 years with a complaint of pain. Children were excluded if they had altered sensorium, were clinically unstable or required admission to the ICU, or were developmentally delayed. Children were asked to mark their pain severity on the standardized 10 cm CAS. To use this measure, children were asked to slide the marker to the point on the scale that best described the pain they were currently experiencing. They then were asked to describe their pain as ‘‘none,’’ ‘‘mild,’’ ‘‘moderate,’’ or ‘‘severe.’’ Results: A total of 169 children were enrolled with a mean age of 10.1 years (S.D. ± 3.2 years). Males accounted for 94 (55%); 89 (52.7%) were Hispanic, 63 (37.3%) were white, 8 (4.7%) were African American, and 9 (5.3%) were ‘‘others.’’ In children who considered their pain to be mild (n = 34), the median score was 3.5 cm, and the mean score was 3.47 cm (95% CI = 2.95—3.99). For those with moderate pain (n = 68), the median score was 6.0 cm, the mean score was 6.04 cm (95% CI = 5.67—6.41), and if the pain was considered severe (n = 67) the median score was 8.5 cm, and the mean score was 8.28 cm (95% CI = 7.85—8.71). Conclusions: This study quantifies what constitutes mild, moderate, and severe pain on the CAS scale. This information should be used to properly triage children with painful conditions and to identify appropriate patients for enrollment in analgesic studies. ©2006 by the Society for Academic Emergency Medicine. doi:10.1016/j.acpain.2006.08.037

147 GUIDELINES FOR ACUTE PAIN TREATMENT Photoradiation in acute pain: A systematic review of possible mechanisms of action and clinical effects in randomized placebo-controlled trials Bjordal J.M., Johnson M.I., Iversen V., Aimbire F., Lopes-Martins R.A.B. Photomedicine and Laser Surgery 2006;24(2): 158—68 Objective: The aim of this study was to review the biological and clinical short-term effects of photoradiation in acute pain from soft-tissue injury. Background data: It is unclear if and how photoradiation can reduce acute pain. Methods: Literature search of (i) controlled laboratory trials investigating potential biological mechanisms for pain relief and (ii) randomized placebo-controlled clinical trials which measure outcomes within the first 7 days after acute softtissue injury. Results: There is strong evidence from 19 out of 22 controlled laboratory studies that photoradiation can modulate inflammatory pain by reducing levels of biochemical markers (PGE2 , mRNA Cox 2, IL-1␤, TNF␣), neutrophil cell influx, oxidative stress, and formation of edema and hemorrhage in a dose-dependent manner (median dose 7.5 J/cm2 , range 0.3—19 J/cm2 ). Four comparisons with nonsteroidal anti-inflammatory drugs (NSAIDs) in animal studies found optimal doses of photoradiation and NSAIDs to be equally effective. Seven randomized placebo-controlled trials found no significant results after irradiating only a single point on the skin overlying the site of injury, or after using a total energy dose below 5 J. Nine randomized placebo-controlled trials (n = 609) were of acceptable methodological quality, and irradiated three or more points and/or more than 2.5 cm2 at site of injury or surgical incision, with a total energy of 5.0—19.5 J. Results in these nine trials were significantly in favor of photoradiation groups over placebo groups in 15 out of 18 outcome comparisons. Poor and heterogeneous data presentation hampered statistical pooling of continuous data. Categorical data of subjective improvement were homogeneous (Q-value = 7.1) and could be calculated from four trials (n = 379) giving a significant relative risk for improvement of 2.7 (95% confidence interval [CI], 1.8—3.9) in a fixed effects model. Conclusion: photoradiation can modulate inflammatory processes in a dose-dependent manner and can be titrated to significantly reduce acute inflammatory pain in clinical settings. Further clinical trials with adequate photoradiation doses are needed

148 to precisely estimate the effect size for photoradiation in acute pain. ©Mary Ann Liebert, Inc. doi:10.1016/j.acpain.2006.08.038 Analgesic treatment after laparoscopic cholecystectomy: A critical assessment of the evidence Bisgaard T. Anesthesiology 2006;104(4):835—46 Acute pain after laparoscopic cholecystectomy is complex in nature. The pain pattern does not resemble pain after other laparoscopic procedures, suggesting that analgesic treatment might be procedure specific and multimodal. Randomized trials of analgesia after laparoscopic cholecystectomy were identified by systematic electronic literature searches (1985 to June 2005) supplemented with

Abstracts manual searching. The trials were categorized by well-defined criteria into high, moderate, or poor methodologic quality. Conclusions were based on trials of high and moderate methodologic quality. In total, 64 randomized analgesic trials were identified, comprising a total of 5018 evaluated patients. The literature suggests a multimodal analgesic regimen consisting of a preoperative single dose of dexamethasone, incisional local anesthetics (at the beginning or at the end of surgery, depending on preference), and continuous treatment with nonsteroidal antiinflammatory drugs (or cyclo-oxygenase-2 inhibitors) during the first 3—4 days. Opioids should be used only when other analgesic techniques fail. ©2006 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc. doi:10.1016/j.acpain.2006.08.039