Efficacy of Preoperative Administration of Acetaminophen and Melatonin on Retrobulbar Block Associated Pain in Cataract Surgery

Abstract

BackgroundRetrobulbar block is one of the chosen methods for local anesthesia in cataract surgery. Since it is a painful procedure, using analgesic and sedative drugs is recommended. Current medications have side effects and evaluating of new drugs or new uses of existing safer drugs is necessary.ObjectivesThe aim of this study was to compare the administration of melatonin and acetaminophen on pain and hemodynamic changes during retrobulbar block.MethodsIn a double-blinded randomized trial, 180 patients undergoing cataract surgery were randomly divided into three groups: Melatonin group (received melatonin 6 mg), acetaminophen group (received acetaminophen 500 mg), and control group (received placebo). All drugs were administered orally 60 min before arrival to the operating room by nurses blinded to the drugs administered. All patients received fentanyl 0.5 μg/kg before retrobulbar block intravenously. Hemodynamic variables and pain score in each patient were evaluated on arrival in the operating room, during retrobulbar block, during surgery, 20 min after operation, at the end of surgery, and in the recovery room. In case of pain score more than three, additional fentanyl was administered. All data were recorded in structured data sheets.ResultsData analysis indicated no significant differences among the groups at baseline on any of the demographic variables. Both acetaminophen and melatonin reduced the pain score significantly compared with control during retrobulbar block (P < 0.05 and P < 0.01, respectively). Administration of additional fentanyl was significantly lower in the melatonin group than the control group (P < 0.05). Hemodynamic changes were not significantly different among all groups.ConclusionsFor the first time, as far as we have studied, the analgesic effect of acetaminophen on the retrobulbar block was indicated. We also showed that melatonin can reduce pain during retrobulbar block leading to reduction of additional fentanyl during operation. It seems that both melatonin and acetaminophen may have a beneficial effect on pain control in the retrobulbar block.

Effect of Benson’s Relaxation Technique on Propofol Consumption and Preoperative Anxiety of Patients Undergoing Cataract Surgery

“…The primary aim of this study was to investigate the effect of Benson's non-pharmacological relaxation therapy on preoperative anxiety and the amounts of propofol consumption for the induction and maintenance of anesthesia during cataract surgery. One of the most surgeries in ophthalmology is cataract surgery (10,11). Based on the obtained results, it can be concluded that Benson's relaxation method effectively reduced preparative anxiety in patients of this study who underwent cataract surgery.…”

Effect of Melatonin on Postoperative Pain and Perioperative Opioid Use: A Meta‐analysis and Trial Sequential Analysis

“…Intraoperative opioid use was reported in 4 studies 18–21 . The meta‐analysis showed a statistically significant reduction of intraoperative opioid consumption (MD −4.14 mg; 95% CI −4.56, −3.73; I 2 = 42%; P < 0.00001) (see Figure 4).…”

“…Figure 1 shows the flow diagram of the selection of included studies. According to the inclusion and exclusion criteria, 15 studies with a total of 1,102 patients were included in the final analysis 15–21,24–31 . The dosage of melatonin ranged from 1 mg to 10 mg.…”

“…The number of subjects in the trials ranged from 33 to 139. Subjects in the studies underwent orthopedic procedures (4 trials 16,21,25,26 ), cataract surgery (4 trials 18,20,28,29 ), elective laparoscopic cholecystectomy (2 trials 17,24 ), total abdominal hysterectomy (2 trials 30,31 ), major abdominal surgery (1 trial 15 ), open prostatectomy (1 trial 19 ), and extraction of the third molars (1 trial 27 ). The detailed information of the included trials is shown in Table 1.…”

“…We defined the postoperative period from the end of the operation to discharge but not more than 72 hours. Three studies 15–17 reported morphine consumption for postoperative analgesic rescue; 4 studies 18–21 recorded intraoperative fentanyl consumption. The equianalgesic dose ratio of fentanyl to morphine was 1:100 in this article 22 .…”