The effect of low flow anesthesia with sevoflurane on oxidative status: A prospective, randomized study.

OBJECTIVES: To assess the impact of low-flow, mid-flow, and high-flow sevoflurane anesthesia on the oxidative state by measuring thiol/disulfide levels in patients undergoing surgery. METHODS: The study included 99 patients randomly assigned to 3 groups. In the low-flow anesthesia group, the fresh gas flow was diminished to 1 L.min-1 for anesthesia maintenance after 6 L.min-1 was administered for the first 10 minutes. In the mid-flow anesthesia group, fresh gas flow was applied as 2 L.min-1. In the high-flow anesthesia group, the fresh gas flow was administered as 4 L.min-1 throughout the operation. Blood samples were obtained before induction, at the 60th minute after induction, and at 2 hours postoperatively. Native thiol, total thiol, disulfide analyzed and disulfide/native thiol percentage, disulfide/total thiol percentage, and native thiol/total thiol percentage were calculated. RESULTS: Disulfide values in mid-flow and low-flow anesthesia were significantly lower at the 60th minute after induction compared to the high-flow anesthesia group. In the group evaluations, intraoperative native thiol levels in the high-flow group were found to be substantialy lower than preoperative values. CONCLUSION: It was sighted that low-flow anesthesia with sevoflurane prohibited oxidative damage. It was concluded that low flow anesthesia can be utilized safely in this respect.

The incidence of inadvertent perioperative hypothermia in patients undergoing general anesthesia and an examination of risk factors.

BACKGROUND: Unintended perioperative hypothermia, defined as core body temperature less than 36°C, is closely related to many complications such as cardiovascular diseases, peroperative hemorrhagic diathesis and impairment of drug metabolism. Determination of the incidence of perioperative hypothermia and examination of risk factors may help to prevent hypothermia and its complications. METHODS: We conducted a prospective, observational study of 2015 patients who underwent various operations under general anesthesia, and the risk factors of developing hypothermia were analysed. RESULTS: The incidence of perioperative hypothermia was 78.6%. The incidence of hypothermia within 2 hours was 56.6%, and after 2 hours, it was 100%. Mean age was 49.36 ± 16.10, and 17.8% were over 65 years old. The mean body mass index (BMI) was 27.96 ± 3.94 kg/m2 ; 60.8% of the patients had American Society of Anesthesiologists (ASA) I score, 33.4% had ASA II and 5.8% had ASA III; 35.8% of the patients had co-morbidities. Intravenous and irrigation fluids were unwarmed; 99.9% of the patients were warmed passively, and only 0.1% of patients received active heating intraoperatively. The incidence of hypothermia was higher in overweight (BMI ≥ 25 kg/m2 ), elderly (>65 years) patients and those with co-morbidities. High American Society of Anesthesiologists (ASA) scores, grade 3-4 surgery, endoscopic surgery, duration of anesthesia >2 hours, infusion or irrigation >1000 mL significantly increased the incidence of hypothermia. CONCLUSION: The incidence of perioperative hypothermia found was high. Important risk factors were found as prolonged duration of anesthesia and surgery, advanced age, overweight, high ASA scores, major surgeries, endoscopic operations and unwarmed fluid administration. High incidence may be reduced by raising awareness, considering fossible risk factors and following the recommendations of the guidelines on prevention of perioperative hypothermia.

Comparison of the Effects of Sevoflurane and Desflurane on Thiol-Disulfide Homeostasis in Patients Undergoing Laparoscopic Cholecystectomy.

OBJECTIVE: This study aims to compare the effects of different inhalation anesthetics on oxidative status by measuring thiol-disulfide homeostasis in laparoscopic cholecystectomy surgeries. The effect of inhaler agents on thiol-disulfide homeostasis that shows the oxidative status in laparoscopic cholecystectomy is unknown. MATERIALS AND METHODS: In this study, 71 patients planned to undergo laparoscopic cholecystectomy under general anesthesia were included. They were divided into two groups: desflurane (group D, n: 35) and sevoflurane (group S, n: 36). Blood samples were taken before induction (T1), at 30th minute of insufflation (T2) (30th min of ischemia), and at 30th min postdeflation (T3) (30th min of reperfusion). The native thiols (-SH) and total thiols (-SH+ -SS) were determined. The amounts of disulfide (-SS), disulfide/native thiol percent ratios (-SS/-SH), disulfide/total thiol percent ratios (-SS/-SH+-SS), and native thiol/total thiol percent ratios (-SH/-SH+ -SS) were calculated. RESULTS: In the sevoflurane group, preoperative values and intraoperative 30th-minute SS-SH ratio were significantly reduced (p=0.017). In the desflurane group, intraoperative native thiol values and postdeflation levels significantly decreased compared to those in the preoperative values (p<0.001). CONCLUSION: We think that the usage of sevoflurane was more protective in terms of the oxidative damage occurring during laparoscopic surgery.

Effects of Total Intravenous Anesthesia and Low- and High-Flow Anesthesia Implementation on Middle Ear Pressure.

BACKGROUND: The middle ear is an air-filled lacuna in the temporal bone. Inhaled anesthetic agents increase the pressure of this lacuna. Therefore, attention must be paid in choosing not only anesthetic agents but also anesthetic method. AIM: This study compared the effects of high-flow total intravenous anesthesia (TIVA) and low- and high-flow desflurane anesthesia on middle ear pressure. STUDY DESIGN: Randomized prospective double-blind study. METHODS: In this retrospective double-blind study, 90 patients (20-65 years old) scheduled to undergo elective thyroidectomies were divided into three randomized anesthesia groups: high-flow desflurane (Group I), low-flow desflurane (Group II), and high-flow TIVA (propofol, remifentanil) (Group III). The hemodynamic and respiratory parameters and tympanometry were measured before induction (T1), 10 minutes after intubation (T2), 10 minutes before the end of the operation (T3), and 5 (T4), 10 (T5), 15 (T6), and 30 (T7) minutes after the operation. RESULTS: No statistically significant differences were found in the age, gender, weight, height, body mass index, surgery duration, and anesthetic duration (p > 0.05). There were no statistically significant differences at T1, T3, T4, T5, T6, and T7 (p > 0.007), but there was a significant difference at T2 (p < 0.001), with Groups II and III having lower pressure than Group I (p < 0.001). CONCLUSION: The high-flow desflurane group had higher postinduction middle ear pressure values. Therefore, low-flow anesthesia and TIVA can be used more safely in middle ear surgeries, provided that a well-equipped anesthetic device and appropriate monitoring conditions are available.

Comparison of endotracheal tube cuff pressure values before and after training seminar.

It is recommended that endotracheal cuff (ETTc) pressure be between 20 and 30 cm H2O. In this present study, we intend to observe average cuff pressure values in our clinic and the change in these values after the training seminar. The cuff pressure values of 200 patients intubated following general anesthesia induction in the operating theatre were measured following intubation. One hundred patients whose values were measured before the training seminar held for all physician assistants, and 100 patients whose values were measured after the training seminar were regarded as Group 1 and Group 2, respectively. Cuff pressures of both groups were recorded, and the difference between them was shown. Moreover, cuff pressure values were explored according to the working period of the physician assistants. There was no significant difference between the groups in terms of age, gender and tube diameters. Statistically significant difference was found between cuff pressure values before and after the training (p < 0.001). Average pressure measure for Group I was 54 cm H2O, while average pressure in Group II declined to 33 cm H2O. It was observed that as the working period and experience of physician assistants increased, cuff pressure values decreased, however no statistically significant different was found (p < 0.375). We believe that clinical experience does not have significant effects on cuff pressure and that training seminars held at intervals would prevent high cuff pressure values and potential complications.

Comparison between Colloid Preload and Coload in Bone Cement Implantation Syndrome under Spinal Anesthesia: A Randomized Controlled Trial.

BACKGROUND: Bone cement implantation syndrome (BCIS) is characterized by hypoxia hypotension cardiac arrest. There is not any research that investigated the hemodynamic effects of colloid use during and before cement implantation regarding BCIS development. AIMS: We aimed to compare the effects of colloid preloading before or coloading simultaneously at cement implantation on BCIS development and hemodynamic parameters in patients who underwent total knee arthroplasty. SETTINGS AND DESIGN: This is a prospective, randomized, clinical trial with the participation of 109 patients over 60 years of age and patients physical status American Society of Anesthesiologists Classes I and II to undergo knee surgery. The patients were administered spinal anesthesia, divided into three groups. SUBJECTS AND METHODS: The patients in Group I were infused 8 mL/kg hydroxyethyl starch (130/0.4) 20 min before the cement implantation, those in Group II were infused the same simultaneously during cement implantation. Group III was infused 8 mL/kg/h sodium chloride during the anesthesia management. Hemodynamic parameters of the patients were recorded at before and after cement implantation and once the tourniquet was removed. STATISTICAL ANALYSIS USED: The descriptive statistics were presented as the mean ± standard deviation for normally distributed variables, as the median for nonnormally distributed variables, and as the number of cases and (%) for nominal variables. Pearson's Chi-square test and Fisher's exact test were used in the analysis of categorical variables. RESULTS: Compared to the control group, Groups I and II were hemodynamically more stable. The development of moderate hypoxia during cement implantation was significantly different between the study groups (P < 0.05). CONCLUSIONS: We suggest that avoiding intravascular volume depletion by using the colloids, particularly in elderly patients, is important for preventing from the BCIS.

Effects of Low-Flow Sevoflurane Anesthesia on Pulmonary Functions in Patients Undergoing Laparoscopic Abdominal Surgery.

Objective. The aim of this prospective, randomized study was to investigate the effects of low-flow sevoflurane anesthesia on the pulmonary functions in patients undergoing laparoscopic cholecystectomy. Methods. Sixty American Society of Anesthesiologists (ASA) physical status classes I and II patients scheduled for elective laparoscopic cholecystectomy were included in the study. Patients were randomly allocated to two study groups: high-flow sevoflurane anesthesia group (Group H, n = 30) and low-flow sevoflurane anesthesia group (Group L, n = 30). The fresh gas flow rate was of 4 L/min in high-flow sevoflurane anesthesia group and 1 L/min in low-flow sevoflurane anesthesia group. Heart rate (HR), mean arterial blood pressure (MABP), peripheral oxygen saturation (SpO2), and end-tidal carbon dioxide concentration (ETCO2) were recorded. Pulmonary function tests were performed before and 2, 8, and 24 hours after surgery. Results. There was no significant difference between the two groups in terms of HR, MABP, SpO2, and ETCO2. Pulmonary function test results were similar in both groups at all measurement times. Conclusions. The effects of low-flow sevoflurane anesthesia on pulmonary functions are comparable to high-flow sevoflurane anesthesia in patients undergoing laparoscopic cholecystectomy.

Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study.

PURPOSE: To compare the effects of magnesium sulfate and ketamine on postoperative pain and total morphine consumption in a placebo-controlled design. METHODS: One hundred and twenty women scheduled for total abdominal hysterectomy were included in this prospective, randomized, double-blind study. Postoperatively, when the Numeric Pain Rating Scale (NPRS) was four or more, IV-PCA morphine was applied to all patients. The patients were randomized into three groups: Group K ketamine, Group M magnesium, and Group C saline received as infusion. Total morphine consumption for 48h, pain scores, adverse effects, and patients' satisfaction were evaluated. RESULTS: Total morphine consumption was significantly lower in Group K (32.6±9.2 mg) than in Group M (58.9±6.5 mg) and in Group C (65.7±8.2 mg). The satisfaction level of patients in Group K was higher than the other two groups (p<0.05). Pruritus and nausea were observed more frequently in Group C. CONCLUSION: The addition of ketamine to IV-PCA morphine reduces the total consumption of morphine without psychotic effects; however, magnesium did not influence morphine consumption.

Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study

PURPOSE: To compare the effects of magnesium sulfate and ketamine on postoperative pain and total morphine consumption in a placebo-controlled design. METHODS: One hundred and twenty women scheduled for total abdominal hysterectomy were included in this prospective, randomized, double-blind study. Postoperatively, when the Numeric Pain Rating Scale (NPRS) was four or more, IV-PCA morphine was applied to all patients. The patients were randomized into three groups: Group K ketamine, Group M magnesium, and Group C saline received as infusion. Total morphine consumption for 48h, pain scores, adverse effects, and patients' satisfaction were evaluated. RESULTS: Total morphine consumption was significantly lower in Group K (32.6±9.2 mg) than in Group M (58.9±6.5 mg) and in Group C (65.7±8.2 mg). The satisfaction level of patients in Group K was higher than the other two groups (p<0.05). Pruritus and nausea were observed more frequently in Group C. CONCLUSİON: The addition of ketamine to IV-PCA morphine reduces the total consumption of morphine without psychotic effects; however, magnesium did not influence morphine consumption.

Anesthetic management and perioperative complications in transcatheter aortic valve implantation: the Turkish experience.

BACKGROUND/AIM: To describe the anesthetic management and early results of transcatheter aortic valve implantation (TAVI) in a single center in Turkey. MATERIALS AND METHODS: We evaluated 79 (54 females, 25 males; mean age: 76 ± 9 years) consecutive symptomatic patients with severe aortic stenosis who underwent TAVI under general anesthesia between July 2011 and September 2012. We preferred a transfemoral approach as the first option. RESULTS: The duration of anesthesia was 149 ± 49 min. Thirty-eight percent of the patients were extubated in the cardiac catheterization laboratory. Three patients required a permanent pacemaker, while 8 patients required inotropic support in the postoperative period. Mortality rate was 9% within 30 days. Fifteen patients had vascular complications, of which 53% were treated surgically. CONCLUSION: Today, as a result of developments in technology, TAVI can be considered as a beneficial alternative treatment option for inoperable aortic stenosis patients. Thus, anesthesiologists will be confronted with a number of TAVI cases, and so they should be prepared to face issues related to the patient's safety both during the administration of anesthesia and in the postoperative period in the near future.

Propofol and erythropoietin antioxidant properties in rat brain injured tissue.

So far, several treatment modalities have been attempted to brain protection in cases such as brain trauma, stroke or brain hemorrhage. However, a treatment method that the effect begins immediately and definitely helpful has not been discovered yet. In this study, we aimed to compare the effects of propofol and erythropoietin (Epo) on brain injury caused by oxidative stress and antioxidant properties of these agents after closed head injury (CHI) in rats. For this study, female Wistar Albino rats were divided into five groups: non-traumatic control group, trauma performed group CHI, trauma with propofol (100 mg/kg) intraperitoneally (i.p.), trauma with Epo (5000 U/kg) i.p. and trauma with propofol and Epo performed study groups. Twenty-four hours after CHI, rats were sacrificed and the brains were removed. Superoxide dismutase (SOD), catalase (CAT), xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA) levels were measured in brain tissue. MDA and NO levels were decreased significantly in Groups Epo, Propofol and Epo+Propofol than Group CHI (p<0.01). XO activity was significantly lower in Group Epo than Group CHI (p<0.05). Epo and propofol decreased oxidative stress by decreasing MDA and NO level in brain tissue after CHI. However, combination of Epo and propofol has no significant beneficial advantage than Epo or propofol alone.

The role of oxidative stress in postoperative delirium.

AIM: This study aimed to determine a marker that predicts delirium using preoperative oxidative processes in patients undergoing cardiopulmonary bypass surgery. METHOD: Twelve of the 50 patients included in the study showed signs of delirium during postoperative follow-up. The Delirium Rating Scale was used in patients with delirium according to DSM-IV-TR in the postoperative period. Venous blood samples were obtained from the patients the day before and the day after the surgery to determine plasma antioxidant enzyme levels. RESULTS: While there were no differences in preoperative superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels in both groups, catalase (CAT) levels were significantly lower in the delirium group. Postoperative SOD and MDA levels were also higher in the delirium group, while the GSH-Px levels were found to be lower when compared with those during the preoperative period. In the nondelirium group, the postoperative MDA and GSH-Px levels were found to be lower than preoperative levels, and postoperative SOD levels were found to be higher than preoperative levels. CAT levels were lower in the delirium group when the pre- and postoperative levels were compared in both groups. The postoperative levels of SOD, GSH-Px and CAT in the nondelirium group and MDA in the delirium group were significantly higher than preoperative levels. CONCLUSION: Patients with low preoperative CAT levels appeared to be more susceptible to delirium than patients with higher CAT levels.