Acute pain: combination treatments and how we measure their efficacy

Abstract

Perioperative analgesic strategies are frequently tested using analgesic consumption as an outcome measure. This outcome measure is intuitive and superficially attractive, but has not been evaluated rigorously. Flaws in its use may be one explanation of continuing controversies surrounding the efficacy of analgesic strategies tested by this method. We contend that the analgesic consumption outcome measure is valid only when treatment groups achieve similar pain scores. A meta-analysis of perioperative gabapentin was used to test this hypothesis. Eighteen trials were identified, which were of sufficient methodological quality to include in the analysis. Trials reporting similar pain scores in treatment groups were classified as Category A and dissimilar scores as Category B. There were seven Category A trials: four reported reduced analgesic consumption with gabapentin compared with placebo, at one or more time points, and three found no difference. There were 11 Category B trials, all of which reported a decrease in analgesic consumption with gabapentin compared with placebo, at one or more time points. Analgesic consumption after gabapentin was similar for different postoperative analgesics. Sedation, dizziness, and vomiting were significant problems in pooled analysis. Analysis according to similarity of pain scores did not clarify whether perioperative gabapentin is useful in perioperative care. More rigorous examination of analgesic consumption as an outcome measure is needed, to establish whether achieving similar pain scores is as important as this paper claims and to determine those features of the analgesic delivery system, adverse effects, and other factors which may interfere with analgesic consumption as an outcome measure.

Gabapentin and Pregabalin for the Acute Post-operative Pain Management. A Systematic-narrative Review of the Recent Clinical Evidences

“…Both Hurley et al [81] and Seib et al [83] did not find statistically significant difference with GBP administration with respect to reduction of incidence of PONV, in discordance with the other authors who described a significant reduction of nausea and vomiting [79,80,82,84,85]. The GBP-related sedation is reported in 5 of the 7 meta-analysis [79][80][81][82]84]. The other two authors did not find any increase of the sedation incidence associated with GBP administration [83,85].…”

“…All these works findings are in accordance each other regarding the analgesic effects of GBP on the post operative setting. Statistically significant reduction of pain and rescue analgesic consumption has been reported by all the meta-analysis with GBP administration vs placebo during the perioperative period [79][80][81][82][83][84][85]. The most studied adverse effects were nausea and/or vomiting, sedation and dizziness.…”

“…The period of publication were established from 1990 to 2009. The first studies of PGL use after major surgery pain management were published in 2006 and furthermore previous systematic narrative [11,28,77,78] or meta-analytic [79][80][81][82][83][84][85] reviews reported data from GBP clinical trials until 2006 (included). A total of three trials on PGL use for post-operative pain management [30,69,71] have been included in only one review [11] and the other three [77][78][79] included only one trial on postoperative dental pain published in 2001 [30].…”

“…Nine of them studied the effects of PGL [30,[69][70][71][72][73][74][75][76] and the other 41 those of gabapentin [87][88][89] in different surgical settings as gynaecological, abdominal, neurosurgery, musculoskeletal, thoracic, head, neck and breast. Gabapentin studies involved totally 3343 patients, 1514 of them received gabapentin and were confronted with 282 patients who received combination of [79][80][81][82][83][84][85].…”

“…An overall of 7 meta-analysis regarding gabapentin use for apost-operative pain management [79][80][81][82][83][84][85] has been included in this review and the most important data of these studies are reported in the Table 5. All these works findings are in accordance each other regarding the analgesic effects of GBP on the post operative setting.…”