Ahmet Besir

The Effect of Dexmedetomidine on Oxidative Stress during Pneumoperitoneum

Purpose. This study was intended to investigate the effect of dexmedetomidine on oxidative stress response in pneumoperitoneum established in rats. Methods. Animals were randomized into three groups, group S: with no pneumoperitoneum, group P: with pneumoperitoneum established, and group D: given 100 mcg intraperitoneal dexmedetomidine 30 min before establishment of pneumoperitoneum. Plasma total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) activity were measured 30 min after conclusion of pneumoperitoneum. Results. The mean TOS level was significantly higher in group P than in the other two groups, and the TOS level was significantly higher in group D than in group S (P < 0.05). Plasma TAS level was found to be lower in group P than in the other two groups, and the TAS level was lower in group D than in group S (P < 0.05). Consequently, the OSI was significantly higher in group P than in groups D and S (P < 0.05). Conclusions. Ischemia-reperfusion phenomenon that occurs during pneumoperitoneum causes oxidative stress and consumption of plasma antioxidants. Dexmedetomidine decreases oxidative stress caused by pneumoperitoneum and strengthens the antioxidant defense system.

The Comparison of the Effects of Sevoflurane Inhalation Anesthesia and Intravenous Propofol Anesthesia on Oxidative Stress in One Lung Ventilation

Background. The aim of this study is to compare the effects of sevoflurane and propofol on one lung ventilation (OLV) induced ischemia-reperfusion injury (IRI) by determining the blood gas, ischemia-modified albumin (IMA), and malonyldialdehyde (MDA). Material and Methods. Forty-four patients undergoing thoracic surgery with OLV were randomized in two groups (sevoflurane Group S, propofol Group P). Anesthesia was inducted with thiopental and was maintained with 1–2.5% of sevoflurane within the 40/60% of O2/N2O mixture in Group S. In Group P anesthesia was inducted with propofol and was maintained with infusion of propofol and remifentanil. Hemodynamic records and blood samples were obtained before anesthesia induction (t 1), 1 min before two lung ventilation (t 2), 30 min after two lung ventilation (t 3), and postoperative sixth hours (t 4). Results. Heart rate at t 2 and t 3 in Group P was significantly lower than that in Group S. While there were no significant differences in terms of pH and pCO2, pO2 at t 2 and t 3 in Group S was significantly lower than that in Group P. IMA levels at t 4 in Group S were significantly lower than those in Group P. Conclusion. Sevoflurane may offer protection against IRI after OLV in thoracic surgery.

Sevoflurane/remifentanil versus propofol/remifentanil for electroconvulsive therapy: Comparison of seizure duration and haemodynamic responses

Objective To compare the anaesthetic and convulsive effects of sevoflurane/remifentanil versus propofol/remifentanil combination in electroconvulsive therapy (ECT). Methods In this prospective, randomized double-blind study, patients diagnosed with treatment-resistant depression were included for ECT. Prior to treatment, 1 µg/kg remifentanil was intravenously administered to all patients, followed by anaesthetic induction with either 0.5 mg/kg propofol or 8% sevoflurane. Following muscular paralysis with succinylcholine and hypnosis, bitemporal ECT was applied. Vital signs, depth of sedation, recovery parameters, motor and electroencephalography (EEG) convulsion activity and postictal suppression index scores were recorded. Results A total of 120 sessions of ECT were administered to 12 patients. Heart rate was higher in the sevoflurane group than the propofol group. Compared with the sevoflurane group, bispectral index level was lower in the propofol group during the induction period and higher during the recovery period. Anaesthetic induction and recovery times were lower, and average motor and EEG convulsion activity was longer, in the propofol group than in the sevoflurane group. Conclusion Propofol/remifentanil is more successful compared with sevoflurane/remifentanil in anaesthesia management during ECT since it provides quick induction and recovery, longer seizure activity and stable haemodynamics.

Dexmedetomidine acts as an oxidative damage prophylactic in rats exposed to ionizing radiation

STUDY OBJECTIVE To investigate the effects of dexmedetomidine on oxidative injury caused by ionizing radiation. DESIGN Randomized controlled experimental study. SETTING Department of radiation oncology and research laboratory of an academic hospital. INTERVENTIONS Twenty-eight rats were randomized to 4 groups (n=7 per group). Group S rats were administered physiologic serum; group SR rats were administered physiologic serum and 10 Gy external ionizing radiation. Groups D100 and D200 were administered 100 and 200 μg/kg dexmedetomidine intraperitoneally, respectively, 45 minutes before ionizing radiation. MEASUREMENTS Liver, kidney, lung, and thyroid tissue and serum levels of antioxidant enzymes (glutathione peroxidase [GPX], superoxide dismutase, and catalase) and oxidative metabolites (advanced oxidation protein products, malondialdehyde, and nitrate/nitrite, and serum ischemia-modified albumin) were measured 6 hours postprocedure. MAIN RESULTS In group SR, IR decreased antioxidant enzyme levels and increased oxidative metabolite levels (P<.05). In plasma, antioxidant enzyme levels were higher and oxidative metabolite levels were lower in groups D100 and D200 than in group SR (P<.01). In tissues, hepatic and lung GPX levels were higher in groups D100 and D200 than in group SR (P<.001). Renal and thyroid GPX levels were higher in D200 than in group SR (P<.01). Thyroid superoxide dismutase levels were higher in groups D100 and D200 than in group SR (P<.01). Renal, lung, and thyroid catalase levels were higher in group D200 than in group SR (P<.01). Hepatic, renal, and lung advanced oxidation protein products and malondialdehyde levels were lower in groups D100 and D200 than in group SR (P<.01). Hepatic, renal, and lung nitrate/nitrite levels were lower in group D200 than in group SR (P<.05). CONCLUSIONS Dexmedetomidine preserves the antioxidant enzyme levels and reduces toxic oxidant metabolites. Therefore, it can provide protection from oxidative injury caused by ionizing radiation.

Transient unilateral combined paresis of the hypoglossal nerve and lingual nerve following intubation anesthesia

Nerve damage may occur in the pharyngolaryngeal region during general anesthesia. The most frequently injured nerves are the hypoglossal, lingual and recurrent laryngeal. These injuries may arise in association with several factors, such as laryngoscopy, endotracheal intubation and tube insertion, cuff pressure, mask ventilation, the triple airway maneuver, the oropharyngeal airway, manner of intubation tube insertion, head and neck position and aspiration. Nerve injuries in this region may take the form of an isolated single nerve or of paresis of two nerves together in the form of hypoglossal and recurrent laryngeal nerve palsy (Tapias syndrome). However, combined injury of the lingual and hypoglossal nerves following intubation anesthesia is a much rarer condition. The risk of this damage can be reduced with precautionary measures. We describe a case of combined unilateral nervus hypoglossus and nervus lingualis paresis developing after intubation anesthesia.

Protective effects of dexmedetomidine in pneumoperitoneum-related ischaemia–reperfusion injury in rat ovarian tissue

OBJECTIVES To determine the effects of dexmedetomidine on pneuomoperitoneum-related ischaemia-reperfusion (I/R) injury in rat ovarian tissue. STUDY DESIGN Animals were randomized into three groups: Group S (n=8), no pneumoperitoneum; Group C (n=8), pneumoperitoneum; and Group D (n=8), 100μg intraperitoneal dexmedetomidine 30min before pneumoperitoneum. Ovarian tissue was collected from all rats 30min after desufflation, and fresh frozen for histological and biochemical evaluation. RESULTS Body weight was similar in all three groups (202.62±28.86, 211.00±14.45 and 212.87±15.71g in Groups S, D and C, respectively). The mean malondialdehyde level was higher in Group C than the other groups (p<0.03). When the histological samples of ovarian tissue were compared, vascular congestion, haemorrhage, follicular cell degeneration and infiltrative cell infiltration scores were higher in Group C compared with the other groups (p<0.05). Significantly lower scores for the histological parameters were found in Group D compared with Group C (p<0.05). Similar scores for follicular cell degeneration and inflammatory cell infiltration were found in Group D and Group S (p>0.05). Although vascular congestion and haemorrhage scores were significantly lower compared with Group C, higher scores were found for Group D compared with Group S (p<0.05). CONCLUSION Pneumoperitoneum caused oxidative injury in rat ovarian tissue. Dexmedetomidine reduced oxidative stress and histological injury related to I/R.

Effects of glutamine on wound healing.

Studies reporting the need for replacing amino acids such as glutamine (Gln), hydroxymethyl butyrate (HMB) and arginine (Arg) to accelerate wound healing are available in the literature. The primary objective of this study was to present the effects of Gln on tissue hydroxyproline (OHP) levels in wound healing. This study was conducted on 30 female Sprague Dawley rats with a mean weight of 230 ± 20 g. Secondary wounds were formed by excising 2 × 1 cm skin subcutaneous tissue on the back of the rats. The rats were divided into three equal groups. Group C (Control): the group received 1 ml/day isotonic solution by gastric gavage after secondary wound was formed. Group A (Abound): the group received 0·3 g/kg/day/ml Gln, 0·052 g/kg/day/ml HMB and 0·3 g/kg/day/ml Arg by gastric gavage after secondary wound was formed. Group R (Resource): the group received 0·3 g/kg/day/ml Gln by gastric gavage after secondary wound was formed. The OHP levels of the tissues obtained from the upper half region on the 8th day and the lower half region on the 21st day from the same rats in the groups were examined. Statistical analysis was performed using the statistics program SPSS version 17.0. No statistically significant differences were reported with regard to the OHP measurements on the 8th and 21st days (8th day: F = 0·068, P = 0·935 > 0·05; 21st day: F = 0·018, P = 0·983 > 0·05). The increase in mean OHP levels on the 8th and 21st days within each group was found to be statistically significant (F = 1146·34, P = 0·000 < 0·001). We conclude that in adults who eat healthy food, who do not have any factor that can affect wound healing negatively and who do not have large tissue loss at critical level, Gln, Arg and HMB support would not be required to accelerate secondary wound healing.

Comparison of surgical conditions in 2 different anesthesia techniques of esmolol-induced controlled hypotension in breast reduction surgery

Background: Breast reduction surgery is a common cosmetic surgery with a high incidence of blood loss and transfusion. In this surgery, the reduction of blood loss related to surgical manipulation and the volume of resected tissue is a target. In the present study, we compared the effects of esmolol-induced controlled hypotension on surgical visibility, surgical bleeding, and the duration of surgery in patients anesthetized with propofol/remifentanil (PR) or sevoflurane/remifentanil (SR). Methods: Patients in the American Society of Anesthesiologists I/II risk group undergoing breast reduction surgery were prospectively randomized into PR (n = 25) and SR (n = 25) groups. Controlled hypotension was induced with esmolol in both groups. During the intraoperative period, the heart rate (HR), mean arterial pressure (MAP), operation duration, volume of intraoperative blood loss, volume of blood received through postoperative drains, volume of resected tissues, and surgical area bleeding score were recorded. Results: The duration of operation in the incisional period was shorter in group PR compared to group SR (P = 0.04). The change in HR was lower in incision and hemostasis periods in the group PR compared to the group SR (P < 0.001). Total intraoperative intraoperative bleeding volume and volume of blood received through drains on postoperative postoperative day 1, day 2, and in total were found to be significantly lower in group PR compared to group SR. Surgical visibility scoring was more effective in group PR compared to SR. Conclusion: In the breast reduction surgery performed under esmolol-induced controlled hypotension, the effect of propofol + remifentanil anesthesia on the duration of incisional surgery, surgical visibility, and volume of surgical blood loss was more reliable and effective compared to that of sevoflurane + remifentanil, which seems to be an advantage.

Peripheral nerve block to the lower extremity despite relative contraindication (two cases)

Abstract Peripheral nerve blocks can provide a number of advantages in high-risk patients and may sometimes be preferred despite relative contraindication. Our first case had relative contraindication due to being confused, with a

The effectiveness of preemptive thoracic epidural analgesia in thoracic surgery.

Background. The aim of this study is to investigate the effectiveness of preemptive thoracic epidural analgesia (TEA) comparing conventional postoperative epidural analgesia on thoracotomy. Material and Methods. Forty-four patients were randomized in to two groups (preemptive: Group P, control: Group C). Epidural catheter was inserted in all patients preoperatively. In Group P, epidural analgesic solution was administered as a bolus before the surgical incision and was continued until the end of the surgery. Postoperative patient controlled epidural analgesia infusion pumps were prepared for all patients. Respiratory rates (RR) were recorded. Patients analgesia was evaluated with visual analog scale at rest (VASr) and coughing (VASc). Number of patients demands from the pump, pumps delivery, and additional analgesic requirement were also recorded. Results. RR in Group C was higher than in Group P at postoperative 1st and 2nd hours. Both VASr and VASc scores in Group P were lower than in Group C at postoperative 1st, 2nd, and 4th hours. Patients demand and pumps delivery count for bolus dose in Group P were lower than in Group C in all measurement times. Total analgesic requirements on postoperative 1st and 24th hours in Group P were lower than in Group C. Conclusion. We consider that preemptive TEA may offer better analgesia after thoracotomy.