Abdulkadir But

A novel hybrid method for determining the depth of anesthesia level: Combining ReliefF feature selection and random forest algorithm (ReliefF+RF)

Depth of anesthesia is a matter of great importance in surgery. Determination of depth of anesthesia is a time consuming and difficult task carried out by experts. This study aims to decide a method that can classify EEG data automatically with a high accuracy and, so will help the experts for determination process. This study consists of three stages: feature extraction of EEG signals, feature selection, and classification. In the feature extraction stage, 41 feature parameters are obtained. Feature selection stage is important to eliminate redundant attributes and improve prediction accuracy and performance in terms of computational time. Effective feature selection algorithms such as minimum redundancy maximum relevance (mRMR); ReliefF; and Sequential Forward Selection (SFS) are preferred at the feature selection stage to select a set of features which best represent EEG signals. These obtained features are used as input parameters of the classification algorithms. At the classification stage, six different classification algorithms such as random forest (RF); feed-forward neural network (FFNN); C4.5 decision tree algorithm (C4.5); support vector machines (SVM); naive bayes; and radial basis function neural network (RBF) are preferred to classify the problem. A comparison is provided between computation times and accuracy rates of these different classification algorithms. The experimental results show that better results according to other classifiers when the obtained attributes by ReliefF algorithm are used with RF classifier.

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.

A comparison of different classification algorithms for determining the depth of anesthesia level on a new set of attributes

The effect of anesthesia on patient is expressed as the depth of anesthesia. The detection of appropriate depth of anesthesia is a matter of great importance in surgery. Too deep or too little anesthesia implementation may lead to many psychological and physical disorders on patients. Therefore it is necessary to keep the patient at the most appropriate level of anesthesia. This process is important and challenging operation. In this study, a system is proposed which can be used to determine the depth of anesthesia in order to assist physician. Anesthetic substances significantly affect the cortex of the brain. There are studies for determination of depth of anesthesia by monitoring of brain activity. In this study, EEG signals that reflect the brain activity are utilized to measure the depth of anesthesia. The study consists of feature extraction and classification stages of the EEG signal. In the feature extraction stage, a new attribute set consisting of 44 attributes in different categories was obtained. In this way, it is aimed to create an effective set of attributes that can represent EEG signals. The obtained attributes were used as input parameters for classification algorithms. In classification stage, the classification problem is classified by seven different classification algorithms. In this way, comparison of calculation time and accuracy for obtained results in different classification algorithms was provided. With the proposed method for the determination of different depth of anesthesia, 98.169% classification accuracy was achieved.

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 Two Different Doses of Fentanyl Combined With Levobupivacaine For Elective Cesarean Section

Objectives: In this prospective, randomized, double-blind, controlled study, we compared the effects of two different doses of fentanyl (10 μg or 25 μg) given intrathecally in addition to 0.5% levobupivacaine for cesarean section. Methods: Eight hundred, ASA I-II parturients, who were scheduled for elective cesarean section, were enrolled in the study. They were randomly allocated into three groups. Group I received 0.5% levobupivacaine; Group II received 0.5% levobupivacaine plus 15 μg fentanyl; Group III received 0.5% levobupivacaine plus 25 μg fentanyl intrathecally. Ephedrine was administered as a bolus dose (0.1 mg/kg), and then the continuous infusion was initiated. The rate of infusion was maintained with respect to baseline systolic blood pressure until umbilical cord clamping. We recorded maternal sistolic blood pressure, heart rate, total ephedrine dose, fetal Apgar scores (at 1st and 5th min), and umbilical cord blood parameters. Other side effects, such as hypotension, nausea/vomiting, bradycardia, etc. were also noted. Results: Bolus, infusion and total ephedrine doses were significantly lower in Group III when compared with the other groups (P<0.05). The incidences of hypotension in the I, II, and III groups were 17.30%, 13.38%, and 11.63%, respectively. There was no significant difference between the three groups regarding the Apgar scores at the 1st or 5th min, umbilical arterial or venous pH. There was no difference in the incidence of other side effects among the three groups. Conclusion: We conclude that the addition of 25 μg fentanyl to adjusting the dose of levobupivacaine to a patients height decreases the ephedrine requirement without additional side effects and adverse neonatal outcomes when compared with the other groups. The levobupivacaine doses as determined by the length of the patients’ and the use of the appropriate fluid resuscitation therapy with an infusion of ephedrine can be used effective methods.

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.

A Case of Difficult Ventilation

Difficult ventilation is a problem related to airway management which is a frequent and significant problem encountered during anesthesia. The main causes of difficult ventilation include disturbances in anesthetic gas flow, obstructions in the breathing-circulation system, decreased pulmonary compliance, severe acute bronchospasm, tension pneumothorax and endobronchial mass lesions. Secretions, cuff herniation, faults in manufactured airway equipment and kinking of the tube might also cause obstructions in the breathing-circulation systems. This report presents a case of difficult ventilation following intubation due to an endotracheal tube defect.

Transkateter Aort Kapak İmplantasyonu Sonrasında Gelişen İnfektif Endokarditli Aort Kapak Cerrahisinde Anestezi Yönetimi

Anesthetic Management in Aort Valve Surgery with Infective Endocarditis Following Transcatheter Aortic Valve ImplantationIntroduction: Transcatheter aortic valve implantation (TAVI) has emerged as an alternative curative therapy in patients with severe calcific aortic stenosis in aging population, in which there is high operative risk rate with surgery due to significant co-morbidities. However, problems during and after procedure can seriously complicate the success of TAVI. We wanted to present the anesthetic management of a patient with infective endocarditis, undergoing aortic valve replacement surgery following TAVI.Case Report: A 75-year-old woman who had undergone TAVI five months before was readmitted to hospital with complaints of palpitation, breathlessness and fever. The blood culture was positive for Enterococcus faecalis, so antimicrobial therapy was started with a diagnosis of infective endocarditis. She was intubated due to acute lung edema and acidosis; and also underwent dialysis therapy. Transesophageal echocardiography (TEE) showed vegetation on right coronary cusp of the implanted aortic valve. The patient was scheduled for cardiac surgery for removal and replacement of the infected and malfunctioning TAVI valve. At the end of the surgical procedure, she was transferred to the intensive care unit (ICU) on inotropic support. However, in ICU, hemodynamic instability, including rhythm disturbance, persisted and intra-aortic balloon pump was implanted. Postoperative course was complicated with low cardiac output syndrome and organ failure. Unfortunately, the patient died at 10th postoperative hour in spite of all supportive management.Conclusion: The reported incidence of prosthetic valve endocarditis after TAVI patients is 0.5%. However, ¬its mortality rates vary from 30% to 50% and urgent open heart surgery with meticulous anesthesiological planning is required.

Timpanoplasti Cerrahisinde Desfluran ve Sevofluran Anestezisinin Kan Glukoz Düzeyleri Üzerine Etkilerinin Karşılaştırılması

Introduction: The effects of intravenous anesthetic drugs and inhaled anesthetics to the blood glucose (GLC) levels were investigated. Unfortunately, there is no adequate studies comparing these effects with new agents such as sevoflurane and desflurane drugs. In this study, blood GLC level changes among the the patients undergoing general anesthesia with sevoflurane and desflurane during the tympanoplasty surgery, were investigated. Material and methods: 60 patients,ages ranging between 18-65 in the ASA I-II risk group were randomly allocated to one of the two groups; The sevoflurane-remifentanyl drugs combination was applied to the group S and the desfluran-remifentanyl drugs combination was used for the group D. After fasting for 8 hours at the preoperative period, the blood GLC levels were measured before induction, at the 5 th , 10 th , 30 th , 60 th , 90 th , 120 th minutes, during the intraoperative period and 30 minutes after the extubation. Blood lactate levels were measured intraoperatively at 5th and 120th minutes.Results: There was no statistically significant difference between groups in terms of mean glucose levels (p>0,05). A statistically significant difference was observed between the T1-T6 and T0 values obtained in the desflurane groups according to the mean GLC level. In the sevoflurane group; there was no statistically significant difference at the third measurement time (p=0,223). In all other measurement times, the mean GLC levels were statistically significantly higher than the first measurement time.Conclusion: There was no difference between the two groups, in terms of blood GLC levels, representing patients who underwent anesthesia with sevoflurane and desflurane during tympanoplasty surgery.