E. Basgul

Perioperative effects of melatonin and midazolam premedication on sedation, orientation, anxiety scores and psychomotor performance.

Background and objective: To compare the perioperative effects of melatonin and midazolam given in premedication, on sedation, orientation, anxiety scores and psychomotor performance. Methods: Exogenous administration of melatonin not only facilitates the onset of sleep but also improves its quality. A prospective, randomized, double-blind, placebo-controlled study was performed in 66 patients undergoing laparoscopic cholecystectomy. Patients were given melatonin 5 mg, midazolam 15 mg or placebo, 90 min before anaesthesia, sublingually. Sedation, orientation and anxiety were quantified before; 10, 30, 60 and 90 min after premedication; and 15, 30, 60 and 90 min after admission to the recovery room. Neurocognitive performance was evaluated at these times, using the Trail Making A and B and Word Fluency tests. The differences between the groups were analysed by ANOVA. Two-way comparisons were performed by Scheffé analysis. Sedation and amnesia were analysed by the χ2 test. Results: Patients who received premedication with either melatonin or midazolam had a significant increase in sedation and decrease in anxiety before operation compared with controls. After operation, there was no difference in sedation scores of all groups. Whereas, 30, 60 and 90 min after premedication the melatonin and midazolam groups exhibited a significantly poorer performance in Trail Making A and B tests compared with placebo, there were no significant differences among the groups in terms of neuropsychological performance after the operation. Amnesia was notable only in the midazolam group for one preoperative event. Conclusion: Melatonin premedication was associated with preoperative anxiolysis and sedation without postoperative impairment of psychomotor performance.

Minimum effective dose of dexamethasone after tonsillectomy

Background : The minimum effective dose of dexamethasone in conjunction with 50 μg·kg−1 ondansetron was evaluated in the treatment for vomiting after elective tonsillectomy or adenotonsillectomy.

The effect of inhalational anaesthetics on QTc interval.

Background and objective: The aim of this study was to assess time dependent cumulative effects of three different inhalation anaesthetics on QTc interval during the maintenance of anaesthesia. Method: Seventy‐five ASA I‐II male patients undergoing inguinal herniorrhaphy were randomly allocated into three groups. No premedication was given. Anaesthesia was induced with thiopental and tracheal intubation was facilitated by vecuronium in all groups. Anaesthesia was maintained with 0.8% halothane (Group I) (n = 25), 1% isoflurane (Group II) (n = 25), or 2% sevoflurane (Group III) (n = 25) and 66% nitrous oxide in oxygen. Three lead electrocardiogram recordings were taken before induction, 2, 5, 10, 15, 30 and 45 min after induction and after extubation. Heart rate, systolic, diastolic, mean arterial pressure and SPO2 were recorded at the same time. Heart rate and corrected QT interval were evaluated by using Bazetts formula. Multivariate analysis of variance for repeated measures was used to determine intergroup and intragroup differences. Results: There was no statistically significant difference in the baseline QTc values of the groups. There was no difference between QTc values with halothane and sevoflurane. There was a difference between QTc values with isoflurane and those with the other two inhalation anaesthetics (P < 0.05). Although QTc values in the isoflurane group were higher at all times, the critical value of 440 ms was not exceeded. Conclusion: We conclude that halothane 0.8%, isoflurane 1% and sevoflurane 2% do not prolong QTc interval.

Induced hypotension for tympanoplasty: a comparison of desflurane, isoflurane and sevoflurane

Background and objectives: This prospective, randomized, double-blinded study was designed to compare the effects of desflurane, isoflurane and sevoflurane when combined with remifentanil for induced hypotension on surgical conditions and operative field during tympanoplasty. Methods: Sixty patients undergoing tympanoplasty were enrolled in the study. The patients were randomized into three groups of 20 each to receive the inhalation anaesthetics desflurane, isoflurane or sevoflurane. Propofol 2 mg kg−1 was administered for induction of anaesthesia in all groups. All patients received a continuous infusion of remifentanil which was titrated between 0.2 and 0.5 μg kg−1 min−1 to achieve a mean blood pressure (BP) of 60-70 mmHg. Nitroglycerine was infused if this BP could not be achieved. Arterial pressures were recorded continuously throughout the operation. Surgical conditions were assessed every 20 min by the blinded surgeon using a six-point category scale (0-5). Results: One patient in the desflurane group and two patients in isoflurane group required nitroglycerine to maintain desired mean BP. Sustained controlled hypotension was sufficient in all of the groups throughout surgery. Category scale scores were ⩽3 throughout the study, except one patient in the sevoflurane group who had a score of 4 at the 60th minute of the operation. No difference was found among groups when haemodynamic parameters and surgical category scale scores were compared. There were no postoperative respiratory and circulatory complications. Conclusion: Desflurane, sevoflurane or isoflurane combined with remifentanil provided adequate induced hypotension and similar operating conditions and any of them could be safely and equally used in anaesthesia for tympanoplasty.

The postoperative analgesic efficacy of intraperitoneal tramadol compared to normal saline or intravenous tramadol in laparoscopic cholecystectomy

Background and objective The aim of this study was to compare the postoperative analgesic efficacy of intraperitoneal tramadol with intravenous tramadol or normal saline in patients undergoing laparoscopic cholecystectomy. Methods Sixty‐one patients undergoing laparoscopic cholecystectomy were randomized to one of three groups in a double‐blind manner via coded syringes. All patients received an intravenous and an intraperitoneal injection after installation of the pneumoperitoneum and again before removal of the trocars. In the control group, all injections were with normal saline. In the intravenous tramadol group, patients received intravenous tramadol 100 mg and intraperitoneal saline. In the intraperitoneal tramadol group, patients received intravenous saline and intraperitoneal tramadol 100 mg. All patients had a standard anaesthetic. Postoperative analgesia was with morphine. Postoperatively, numeric pain scores for parietal and visceral pain, 1 h and 24 h morphine consumption, and adverse effects were recorded. Results Parietal and visceral pain scores were lowest in the intravenous tramadol group during the first postoperative hour (P < 0.016 compared with control). The delay until the first analgesic administration was longest in the intravenous tramadol group (median 23 min, range 1–45), when compared with the intraperitoneal tramadol group (10, 1–120 min, P = 0.263) or with the control group (1, 1–30 min, P = 0.015). One‐hour morphine consumption was significantly lower in the intravenous tramadol group (mean ± SD; 3.4 mg ± 2.5) and in the intraperitoneal tramadol group (4.4 ± 4.3 mg) compared with the control group (6 ± 2 mg) (P = 0.044). There was no difference between the three groups regarding pain scores, morphine consumption and incidence of shoulder pain or adverse effects at 24 h. Conclusion Intravenous tramadol provides superior postoperative analgesia in the early postoperative period after laparoscopic cholecystectomy compared with an equivalent dose of tramadol administered intraperitoneally and with normal saline in patients undergoing laparoscopic cholecystectomy.

Anesthesia in Beckwith-Wiedemann syndrome.

Anesthetic management of a 3‐month‐old boy with Beckwith–Wiedemann syndrome for bronchoscopy is reported. Management may be complicated by a difficult airway, congenital heart disease, and hypoglycemia. We did not have difficulty in airway management either with tracheal intubation or rigid bronchoscopy, but we could not extubate the baby because of tracheomalacia.

Rabies vaccine and anaesthesia.

SIR—As surgical stress and anaesthesia are well known to affect many parameters of the immune system, anaesthetists must enquire about the vaccination status of patients during the preoperative assessment (1). We had a 10-yearold patient who was on the third course of vaccination postexposure to rabies according to WHO guidelines. He was scheduled for an elective tonsillectomy, but as immune depression would affect the success of the treatment of this fatal disease, we decided to postpone the procedure until the vaccination schedule was completed. There are few guidelines on this subject in the literature. In one report, anaesthesia is considered to be a risk factor in a patient with failure of postexposure rabies treatment (2). A study on rats revealed that immune changes following surgery do not recover for up to 4–8 days (3). Another study showed that an anaesthetized group of puppies that were vaccinated with rabies vaccine had significantly lower antibody titres compared with an unanaesthetized control group (4). Van der Walt et al. (5) suggest deferring elective procedures requiring anaesthesia for 3 weeks until all symptoms attributable to immunization have abated in children. Varol Çeli_ker* Elif Başgül Lütfiye Peker Department of Anaesthesiology, School of Medicine, Hacettepe University, 06100 Sıhhıye, Ankara, Turkey (*email: vceliker@hacettepe.edu.tr)