Preoperative oral melatonin administration decreased pain scores and tramadol consumption and enhanced sleep quality, sedation scores, and subjective analgesic efficacy during the postoperative period.

Background: Postoperative sore throat (POST) is an undesirable complaint after orotracheal intubation. Magnesium is a noncompetitive N-methyl-D-aspartate receptor antagonist thought to be involved in the modulation of pain. The present study aimed to investigate the effect of preoperative administration of oral magnesium lozenge on POST. Methods: Seventy patients undergoing orthopedic surgery were randomly allocated into two groups, to either receive placebo (control) or magnesium lozenges (magnesium) to be dissolved by sucking 30 min preoperatively. Patients were assessed for incidence and severity (four-point scale, 0 -3) of POST at 0, 2, 4, and 24 h postoperatively. The primary outcome was sore throat at 4 h after surgery. The secondary outcome was the severity of POST at four evaluation timepoints postoperatively. Results: The incidence of POST at 4 h was higher in control group than in magnesium group (95% CI: 26%, 14 -42%; P ϭ 0.032). The highest incidence of POST occurred at the second hour after surgery, with the rate of 23% in the magnesium group and 57% in the control group (95% CI: 34%, 20 -51%; P ϭ 0.007). The severity of POST was significantly lower in the magnesium group at 0 (P ϭ 0.007) and 2 h (P ϭ 0.002). The incidences of POST at 0 and 24 h and severity scores at 4 and 24 h were not significantly different between the groups. Conclusions: The administration of magnesium lozenge 30 min preoperatively is effective to reduce both incidence and severity of POST in the immediate postoperative period.

When given as venous retention pretreatments 1 min before propofol, paracetamol 1 mg kg(-1) and lidocaine 0.5 mg kg(-1) were equally effective in attenuating pain during intravenous (i.v.) injection of propofol whereas pretreatment with paracetamol 2 mg kg(-1) was shown to be the most effective treatment.

Background: The aim of this prospective, randomized, placebo-controlled study was to compare the effects of ketamine and paracetamol on preventing remifentanil induced hyperalgesia.Methods: Ninety patients undergoing total abdominal hysterectomy were randomly assigned to one of three groups to receive (I) either saline infusion; (II) 0.5 mg/kg ketamine iv bolus or (III) 1000 mg iv paracetamol infusion before induction of anesthesia. Until the skin closure, anesthesia was maintained with 0.4 µg/kg/min remifentanil infusion in all groups, additionally Group II received 5 µg/kg/min ketamine infusion. Pressure pain thresholds were measured the day before surgery during the preoperative visit for baseline measurements and repeated postoperatively at 24 and 48 hours (hrs). Pressure pain thresholds were established by digital algometer on three different peri- incisional regions for calculating mean pressure pain threshold values. The visual analogue scale (VAS), sedation scores, total morphine consumption and side effects were assessed postoperatively.Results: Demographic characteristics, duration of surgery and anesthesia were similar in the three groups. Pain thresholds at the incision region were significantly lower at 24 and 48 hrs postoperatively in Group I than the other Groups (p< 0.05). In Group І, pain thresholds were lower compared with preoperative baseline values. Thresholds in Group ІІ and Group ІІІ were higher compared with preoperative baseline values (p< 0.05) The VAS scores at all evaluation times were significantly higher in Group І when compared to Group ІІ and at 2, 4, 6 ,12 hrs were higher in Group I than Group ІІІ (p< 0.05). The morphine consumption was higher in Group ІІІ at 24 and 48 hrs postoperatively (p< 0.05).Conclusion: It was shown that ketamine and paracetamol were both effective in preventing remifentanil induced hyperalgesia.

As an N-methyl-D-aspartate receptor antagonist, magnesium has been hypothesized to have analgesic effects; in fact, several studies have demonstrated its efficacy for analgesia following intra-articular injection during knee surgery. In this study, intra-articular magnesium was administered during arthroscopic shoulder surgery and its analgesic efficacy was assessed according to pain intensity after surgery as well as postoperative consumption of pain medications.