Peritonsillar infiltration with levobupivacaine for posttonsillectomy pain relief: does concentration have any effect? A double-blind randomized controlled clinical study.

OBJECTIVE: Post-tonsillectomy pain is believed to be mediated by noxious stimulation of C-fiber afferents located in the peritonsillary space, and local anesthetic infiltration to this area may decrease pain by blocking the sensory pathways and thus preventing the nociceptive impulses. We aimed to compare the effects of different concentrations of preincisional peritonsillar levobupivacaine (0.25% and 0.5%) infiltration on postoperative pain and bleeding in a placebo-controlled design. PATIENTS AND METHODS: After obtaining Institutional Ethics Committee approval, 72 ASA I-II patients between 3 and 12 years of age, scheduled to undergo tonsillectomy were enrolled and randomly assigned to one of the three groups using the sealed envelope technique, as Group I (Control group), Group II, and Group III receiving preincisional bilateral peritonsillar infiltration with saline, 0.25% levobupivacaine and 0.5% levobupivacaine, respectively (3 mL to each tonsil). Pain, fever, dysphagia; nausea-vomiting and hemorrhage were evaluated at postoperative 0, 30, and 60 minutes and 2, 6, 12, and 24 hours. Oral paracetamol was administered at a dose of 15 mg/kg when FLACC score was > 4. The number of paracetamol administrations within the first 24 hours were recorded. RESULTS: The patients in Groups I, II and III defined pain (FLACC > 4) at a rate of 87%, 60.9%, and 54.2% within the postoperative first 24 hours, respectively. The total number of additional analgesic requirements was significantly low in Group II and III when compared with Group I. There was no difference between groups in terms of fever, dysphagia, nausea-vomiting, hemorrhage. CONCLUSIONS: Both concentrations (0.50% and 0.25%) of levobupivacaine were found to be equally safe and effective during preincisional peritonsillar infiltration in children. NCT number: 02322346.

Determination of DNA damage by alkaline halo and comet assay in patients under sevoflurane anesthesia.

In this study, we report data on the possible genotoxic effect of inhalation anesthetic sevoflurane (SVF) by comparing two techniques, comet and alkaline halo assay, in peripheral blood lymphocytes (PBL) of patients before, during, and after anesthesia and in controls. DNA single strand breaks were detected in PBL of malignant breast cancer diagnosed patients (stage II-III), who were undergoing mastectomy. Blood samples were taken before the induction of anesthesia, at 120 min of SVF anesthesia, and on the postoperative fifth day. The nuclear spreading factor (NSF) for each cell was assessed by alkaline halo assay, and the total comet score (TCS) was evaluated by comet assay. A statistically significant increase (P < 0.0001) was observed in the mean NSF at 120 min of anesthesia (38.24 +/- 14.14) as compared with samples before anesthesia (12.33 +/- 6.14), and the mean NSF was significantly decreased after the postoperative fifth day (17.89 +/- 9.44). Similar results were obtained by the comet assay with significant increase (P < 0.0001) in DNA damage at 120 min of anesthesia (79.66 +/- 15.28) as compared with samples before anesthesia (36.30 +/- 11.39). The DNA damage was almost with the preoperative damage rates after the fifth day of anesthesia (43.40 +/- 12.19). In conclusion, the study points out a reversible genotoxic effect of SVF and the similar DNA damage levels obtained by comet and alkaline halo assay indicate that although halo assay has a completely different principle, it can conveniently be utilized for the assessment of DNA single strand breakage in individual mammalian cells with its experimental advantages.

Propofol attenuates myocardial lipid peroxidation during coronary artery bypass grafting surgery.

BACKGROUND: Propofol can scavenge free radicals because it has a chemical structure similar to antioxidants. METHODS: We examined if free radical scavenging occurs with propofol during CABG operations. We studied 24 patients undergoing CABG surgery for triple vessel disease, randomized into two groups. After induction of anaesthesia with fentanyl 10 micrograms kg-1 and midazolam 0.1 mg kg-1, patients in the fentanyl group (n = 14) received fentanyl infusion 10-30 micrograms kg-1 h-1 and patients in the propofol group (n = 10) received propofol infusion 3-6 mg kg-1 h-1 for maintenance of anaesthesia. Atrial tissue biopsies were taken during cannulation for bypass, 45 min after cross-clamp insertion, 5 min after unclamping, and in the decannulation period. Lipid peroxidation was assessed by measurement of thiobarbituric acid reactive substances (TBARS) in the atrial tissue samples. RESULTS: Lipid peroxidation in the propofol group was less than in the fentanyl group (P < 0.05) in all sampling periods. Lipid peroxidation in the fentanyl group increased significantly during cardiopulmonary bypass (CPB) (P < 0.05), but no increase was found in the propofol group (P > 0.05). CONCLUSION: In clinical doses, propofol strongly attenuates lipid peroxidation during CABG surgery.