A protocol for a systematic review for perioperative pregabalin use

BACKGROUND: Perioperative pain management has recently been revolutionized with the recognition of novel mechanisms and introduction of newer drugs. Many randomized trials have studied the use of the gabapentinoid anti-epileptic, pregabalin, in acute pain. Published systematic reviews suggest that using pregabalin for perioperative pain management may decrease analgesic requirements and pain scores, at the expense of troublesome side effects. A major limitation of the extant reviews is the lack of rigorous investigation of clinical characteristics that would maximize the benefit harms ratio in favor of surgical patients. We posit that effects of pregabalin for perioperative pain management vary by the type of surgical pain model and propose this systematic review protocol to update previous systematic reviews and investigate the heterogeneity in findings across subgroups of surgical pain models. METHODS/DESIGN: Using a peer-reviewed search strategy, we will search key databases for clinical trials on perioperative pregabalin use in adults. The electronic searches will be supplemented by scanning the reference lists of included studies. No limits of language, country or year will be imposed. Outcomes will include pain; use of co-analgesia, particularly opioids; enhanced recovery; and drug-related harms. We will focus on the identification of surgical models and patient characteristics that have shown benefit and adverse effects from pregabalin. Two clinical experts will independently screen the studies for inclusion using eligibility criteria established a priori. Data extracted by the reviewers will then be verified. Publication bias will be assessed, as will risk of bias using the Cochrane Risk of Bias tool. Meta-analysis and meta-regression are planned if the studies are deemed statistically, methodologically and clinically homogenous. Evidence will be graded for its strength for a select number of outcomes. DISCUSSION: We will explore the findings of perioperative clinical trials studying the use of pregabalin for acute pain. We will comment on the implications of the findings and provide further direction for the appropriate use of pregabalin in acute pain. This protocol will attempt to bridge the growing gap between clinical experience and emerging evidence, and has the potential to aid future guideline development in the perioperative use of pregabalin. TRIAL REGISTRATION: PROSPERO registration number CRD42012002078