Effect of Intravenous Intraoperative Esmolol on Pain Management Following Lower Limb Orthopedic Surgery

BACKGROUND: Lack of proper control of acute postoperative pain often leads to lingering or chronic pain. Several studies have emphasized the role of beta-blockers in reducing postoperative pain. Esmolol is a selective short-acting beta-blocker that produces few side effects. The purpose of this study was to examine the effect of intravenous intraoperative esmolol on postoperative pain reduction following orthopedic leg fracture surgery. METHODS: In a clinical trial, 82 patients between 20-65 years of age with tibia fractures and American Society of Anesthesiologists (ASA) physical status I & II who underwent surgery were divided into two groups. Group A received esmolol and group B received normal saline. Postoperative pain was measured at three time points: entering the recovery unit, and at 3 h and 6 h following surgery, using the Visual Analogue Scale (VAS). A P value of < 0.05 was considered significant. RESULTS: Mean VAS scores at all three time points were significantly different between the two test groups (P = 0.02, P = 0.0001, and P = 0.0001, respectively). The consumption of pethidine was lower in group A than in group B (P = 0.004) and the duration of its effect was significantly longer in time (P = 0.026). CONCLUSIONS: Intravenous intraoperative esmolol is effective in the reduction of postoperative pain following leg fracture surgery. It reduced opioid consumption following surgery and delayed patient requests for analgesics.

[ protective effects of melatonin on the histological changes of testis in busulfan-treated adult mice]

Antineoplastic chemotherapy is usually accompanied by fertility impairment and the aim of this study was to investigate the possible protective effects of melatonin, a pineal gland hormone with potent antioxidant activity, on busulfan-treated adult male mice. This study was performed on 32, eight-week old adult male mice. The animals were divided into four groups consisting of a control and three experimental groups. The animals in the control group received dimethyl sulfoxide [DMSO], a solvent, the second group a single dose of intraperitoneal busulfan [20 mg/kg], the third group a single dose of intraperitoneal melatonin [10 mg/kg] for five days and the fourth group melatonin [10 mg/kg] for five days upon an initial dose of busulfan [20 mg/kg]. Thirty-five days after the treatments, all the animals were sacrificed and dissected. Johnson is score were determined by examining the morphometric characteristics of seminiferous tubules and estimating Leydig cell volumes and germ cell counts. Busulfan-treated mice showed reductions in Johnson's score and quality of spermatogenesis [p<0.001] in comparison to the controls. The quantitative values of seminiferous tubules [p<0.05] and the nuclear volume of Leydig cells [p<0.05] were significantly lower in the busulfan-treated mice relative to the controls. In the fourth group, melatonin not only caused a remarkable normalization in seminiferous tubule indices [p<0.05], but also increased the nuclear volume of Leydig cells [p<0.001], the relevant Johnson's score [p<0.001] and all germ cells in comparison to the second group [p<0.05]. Melatonin might have a possible protective effect against busulfan-induced testicular damage. Although the protective mechanism of melatonin has not been fully revealed, the protection seems to be through a decrease in oxidative stress