Beta-adrenergic antagonists during general anesthesia reduced postoperative pain: a systematic review and a meta-analysis of randomized controlled trials.

We have performed a systematic literature review and a meta-analysis investigating the effect of beta-adrenergic antagonist on perioperative pain in randomized clinical trials (RCTs). The search included the CENTRAL, CINAHL, EMBASE, and MEDLINE databases (from inception to 10 February 2015). From the retrieved full texts, we hand-searched the references and PubMed related citations. A total of 11 RCTs consisting data of 701 adult patients were eligible for this systematic review. Esmolol was evaluated in ten trials and propranolol in one. Esmolol decreased the need for rescue analgesics by 32-50%; p < 0.05 (n = 7) and the proportion of patients needing rescue analgesia from 100 to 65%; p < 0.005 (n = 1), and propranolol decreased the need for rescue analgesics by 72%; p < 0.001 (n = 1). The time to the first rescue analgesics was longer (p < 0.05) and pain ratings were lower (p < 0.05) in patients with beta-adrenergic antagonists. However, in two opioid-controlled studies, one in knee arthroscopy and another in tubal ligation patients, the proportion of patients needing rescue analgesia was two-times higher in esmolol-treated patients: 52-57 vs. 23-34%, p < 0.05. Adverse effects were rarely reported, and as reported were mostly cardiovascular alterations. In conclusion, intra-operative beta-adrenergic antagonists' administration may decrease postoperative pain and analgesic consumption when given as an adjuvant to general anesthesia.