Ziya Salihoglu

Pulmonary mechanics during isoflurane, sevoflurane and desflurane anaesthesia

This study was designed to investigate the effects of desflurane on bronchial smooth muscle tone, following intubation and to compare these effects with isoflurane and sevoflurane. Patients were randomly divided into three groups to receive, isoflurane (n = 22), sevoflurane (n = 23), or desflurane (n = 22). Peak inspiratory pressure (PIP), respiratory resistance (Rr) and dynamic compliance (Cdyn) measurements were recorded at three time points; After the beginning of ventilation and before inhalation agent was started, following 5 min of ventilation with 1 MAC (minimum alveolar concentration) inhalation agent and following 5 min of 2 MAC inhalation agent. We found that all inhalation agents caused a significant decrease in Peak Inspiratory Pressure (PIP) and respiratory resistance (Rr), and an increase in dynamic compliance (Cdyn) at 1 MAC concentrations. When the agent concentration was increased to 2 MAC, desflurane caused a significant increase in Rr and PIP and a decrease in Cdyn. We concluded that desflurane, like isoflurane and sevoflurane, exhibits a bronchodilator effect at 1 MAC concentration. However, increasing the concentration to 2 MAC caused an increase in airway resistance with desflurane, whilst sevoflurane and isoflurane continued to have a bronchodilator effect.

Comparison of effects of remifentanil, alfentanil and fentanyl on cardiovascular responses to tracheal intubation in morbidly obese patients

BACKGROUND AND OBJECTIVE The effects of remifentanil, alfentanil and fentanyl were compared on cardiovascular responses to laryngoscopy and endotracheal intubation in morbidly obese patients. METHODS Eighty morbidly obese ASA I-II patients were included in the study. Patients were randomly divided into four groups to receive either 1 microgkg(-1) fentanyl (Group F), 10 microgkg(-1) alfentanil (A), 1 microgkg(-1) followed by an infusion of 0.5 pg kg min(-1) remifentanil (R) or saline (P). The patients corrected weight was used to calculate the drug doses. Body mass indices (range) were: 54.3 +/- 7.37 (49-78.4), 55.67 +/- 7.44 (48.5-78.4), 53.17 +/- 5.36 (48.1-63.2), and 56.3 +/- 6.09 (46.6-67.7) kg m(-2), in Groups F, R, A and P respectively. Systolic, diastolic and mean arterial pressures and heart rate were measured non-invasively at three time points, which were 2 min before induction, 2 min after induction and 2 min after endotracheal intubation. RESULTS After induction of anaesthesia, arterial pressures decreased significantly in all groups, but the decrease was more pronounced in Groups A and R. After induction, heart rate decreased significantly in all groups except in Group P. After intubation, haemodynamic responses were similar in the remifentanil, fentanyl and alfentanil groups and were within normal limits. In Group P, arterial pressures and heart rates were significantly higher. CONCLUSIONS Alfentanil, fentanyl and remifentanil in the doses described had similar effects in controlling the haemodynamic response to tracheal intubation in ASA I-II morbidly obese patients.

Evaluation of intravenous paracetamol administration on postoperative pain and recovery characteristics in patients undergoing laparoscopic cholecystectomy.

Purpose In this study, the effects of intravenous paracetamol treatment on early postoperative period analgesia and recovery characteristics after laparoscopic cholecystectomy have been evaluated. Methods Forty patients whose American Society of Anesthesiologists physical status I or II underwent laparoscopic cholecystectomy and randomly divided into 2 equal groups. In the first group, 1 g paracetamol was given to the patients intravenously after intubation before start of the surgery in 15 minutes. The 100 mL 0.9% NaCl was infused intravenously for the control group in 15 minutes. Postoperative pain was evaluated and recovery characteristics were evaluated. Results Verbal and visual pain scores of the paracetamol group were significantly lower than control group (P<0.05). First morphine requirement and total administered morphine dose and duration of staying in recovery room were significantly decreased in the paracetamol group (P<0.05). Conclusions Beside its effective analgesic properties, paracetamol administration during per operative period supports effective and faster recovery.

Total Intravenous Anesthesia versus Single Breath Technique and Anesthesia Maintenance with Sevoflurane for Bariatric Operations

Background: The choice of anesthetic technique for general anesthesia in morbidly obese patients remains controversial. We aimed to compare blood gases, recovery and hemodynamic parameters using TIVA and sevoflurane anesthesia in bariatric surgery. Methods: The study was performed with permission of the ethics committee.We studied 40 morbidly obese patients allocated to 2 groups. The total I.V. anesthesia (TIVA) group was named Group T, and the sevoflurane group was named Group S. In Group T, anesthesia induction was achieved with propofol. In Group S, anesthesia induction was achieved by sevoflurane with single breath technique, with maintenance provided with 1-2% volume sevoflurane. Student t, Chi square and ANOVA tests were used for data analysis; p-value <0.05 was considered statistically significant. Results: There was no significant difference between the 2 groups in demographic data, blood gas values and recovery characteristic. Hemodynamic values were significantly lower in Group T than Group S, during and after the operative period. Conclusion: While sevoflurane induction and maintenance is a suitable anesthetic modality for obese patients, TIVA can be applied easily in those patients possessing no extra risk factors other than morbid obesity.

Opioid-free total intravenous anesthesia with propofol, dexmedetomidine and lidocaine infusions for laparoscopic cholecystectomy: a prospective, randomized, double-blinded study

BACKGROUND AND OBJECTIVES Intraoperative use of opioids may be associated with postoperative hyperalgesia and increased analgesic consumption. Side effects due to perioperative use of opioids, such as postoperative nausea and vomiting may delay discharge. We hypothesized that total intravenous anesthesia consisting of lidocaine and dexmedetomidine as an opioid substitute may be an alternative technique for laparoscopic cholecystectomy and would be associated with lower fentanyl requirements in the postoperative period and less incidence of postoperative nausea and vomiting. METHODS 80 Anesthesiologists I-II adults were scheduled for elective laparoscopic cholecystectomy. Patients were randomly allocated into two groups to have either opioid-free anesthesia with dexmedetomidine, lidocaine, and propofol infusions (Group DL) or opioid-based anesthesia with remifentanil, and propofol infusions (Group RF). All patients received a standard multimodal analgesia regimen. A patient controlled analgesia device was set to deliver IV fentanyl for 6h after surgery. The primary outcome variable was postoperative fentanyl consumption. RESULTS Fentanyl consumption at postoperative 2nd hour was statistically significantly less in Group DL, compared with Group RF, which were 75 ± 59 μg and 120 ± 94 μg respectively, while it was comparable at postoperative 6th hour. During anesthesia, there were more hypotensive events in Group RF, while there were more hypertensive events in Group DL, which were both statistically significant. Despite higher recovery times, Group DL had significantly lower pain scores, rescue analgesic and ondansetron need. CONCLUSION Opioid-free anesthesia with dexmedetomidine, lidocaine and propofol infusions may be an alternative technique for laparoscopic cholecystectomy especially in patients with high risk for postoperative nausea and vomiting.

Systemic Inflammatory Response after Laparoscopic and Open Application of Adjustable Banding for Morbidly Obese Patients

Background: Surgical injury induces a systemic inflammatory metabolic-endocrine response that is proportional to the severity of the surgical stress. Compared with the conventional open method, laparoscopic surgery is mini-invasive and has decreased postoperative pain and length of hospitalization. The aim of this study was to investigate the systemic inflammatory response, after laparoscopic and open stoma-adjustable silicone band application, which is thought to be mediated by cytokines. Method: 30 morbidly obese patients underwent Swedish adjustable gastric banding (SAGB). 15 patients underwent laparoscopic (group 1) and 15 open SAGB (group 2). Mean operative time for the laparoscopic group was 70-110 min and for the laparotomy group 80-120 min. Gallbladders were not removed,and there were no systemic diseases in the patients.The intensity of surgical trauma was evaluated by measurement of metabolic and hormonal responses to the surgery. Plasma levels of C-reactive (CRP), haptoglobin, ceruloplasmin, albumin, transferrin, IL-6, malonic dialdehyde (MDA) and creatinine were measured before and after the operation. Results: CRP and IL-6 levels increased during and after laparoscopic and open SAGB. However, postoperative responses were significantly greater after open SAGB (group 2) (p<0.05). MDA level, an indicator of an oxidative trauma, was elevated in group 1 at the 6th postoperative hour but was significantly higher in group 2 at the 6th and 12th postoperative hours. The results were more significant in group 2 (p<0.05).There was no statistical difference between groups 1 and 2 in terms of albumin, creatinine, and transferrin levels before and after surgery. Conclusion: The systemic inflammatory res ponses after laparoscopic SAGB were significantly reduced compared with those after open SAGB.

Comparison of the Electrothermal Vessel-Sealing System Versus Endoclip in Laparoscopic Appendectomy

BACKGROUND Various techniques have been used for the division of mesoappendix, such as endoloops, endoscopic linear cutting staplers, an electrothermal vessel-sealing system (LigaSure), the Harmonic Scalpel, clips, and bipolar coagulation. In the present study, LigaSure and an endoclip were compared in laparoscopic appendectomy (LA). MATERIALS AND METHODS This study included patients who underwent LA for acute appendicitis at Istanbul University, Cerrahpasa Medical Faculty, Emergency Unit (Istanbul, Turkey) between May 2003 and April 2007. The patients were assigned to two groups according to the mesoappendix dissection device: LigaSure and endoclip groups. The main outcome measures (e.g., operating time, conversion rate, hospital stay, postoperative complications, etc.) were then compared. RESULTS LA was performed in 280 patients with acute appendicitis. LigaSure and endoclips were used in 127 and 153 patients, respectively. The mean operative times were 41 and 54 minutes in the LigaSure and endoclip groups, respectively. Conversions to open rates were found to be 9.4% (12 patients) in the LigaSure and 11.1% (17 patients) in endoclip groups. No statistically significant differences regarding hospital stay or complications were found, whereas significant differences were observed in surgical time and conversion rate. CONCLUSION The use of LigaSure facilitates the dissection of mesoappendix and shortens the operation time in LA. We believe that LigaSure is a safe, useful tool for mesoappendix dissection.

The effects of pneumoperitoneum on respiratory mechanics during bariatric surgery.

Background:The aim of this study was to investigate the influence of laparoscopic and conventional open surgery on respiratory mechanics, and blood gases, and to determine convenient techniques from the point of view of intraoperative respiratory mechanics, for bariatric surgery. Method: 40 morbidly obese patients were divided into 2 groups, patients undergoing laparoscopy Group 1, and patients undergoing conventional open surgery Group 2. Resistance of airway, dynamic compliance, and peak inspiratory pressure were measured. Measurement was performed in 4 periods: a) after anesthesia induction, b) after pneumoperitoneum in the Group 1 and after incision in the Group 2, c) after gastric band placement, d) and 5 min before extubation. Blood gases were recorded concomitantly. Results: There was no significant difference between the 2 groups in values of blood gases and respiratory mechanics. Conclusion: In the morbidly obese, laparoscopic and open surgery did not cause a significant difference for respiratory mechanics when compared with each other.

Respiratory mechanics in morbid obese patients with chronic obstructive pulmonary disease and hypertension during pneumoperitoneum

Background and objective: To evaluate the effects of pneumoperitoneum and the reverse Trendelenburg position on respiratory mechanics and blood-gases in morbid obese patients with chronic obstructive pulmonary disease and hypertension. Methods: Sixteen morbid obese patients with chronic obstructive pulmonary disease and hypertension were studied. Mean arterial pressure, heart rate, respiratory resistance, dynamic respiratory compliance and peak inspiratory pressures were measured at four time points: 5 min after induction of anaesthesia (T1), 5 min after insufflation of the peritoneum (T2), 5 min after adoption of a 20° reverse Trendelenburg position (T3), and 5 min after deflation of the peritoneum (T4). Arterial blood-gas status was measured at the same measuring points. Results: Respiratory compliance was 40 ± 12, 28 ± 8, 32 ± 8 and 37 ± 11 mL cmH2O−1 in T1, T2, T3 and T4, respectively. The changes were significant at T2, T3 and T4. Airway resistance and peak inspiratory pressures showed comparable changes throughout the study with that of respiratory compliance. Haemodynamic measurements showed no clinically significant changes in this study. Conclusions: In morbid obese patients with chronic obstructive pulmonary disease and hypertension, a 20° reverse Trendelenburg position improved respiratory mechanics and oxygenation without any apparent adverse effects on haemodynamics during laparoscopic gastric banding surgery.

Anestesia venosa total livre de opioides, com infusões de propofol, dexmedetomidina e lidocaína para colecistectomia laparoscópica: estudo prospectivo, randomizado e duplo-cego

BACKGROUND AND OBJECTIVES Intraoperative use of opioids may be associated with postoperative hyperalgesia and increased analgesic consumption. Side effects due to perioperative use of opioids, such as postoperative nausea and vomiting may delay discharge. We hypothesized that total intravenous anesthesia consisting of lidocaine and dexmedetomidine as an opioid substitute may be an alternative technique for laparoscopic cholecystectomy and would be associated with lower fentanyl requirements in the postoperative period and less incidence of postoperative nausea and vomiting. METHODS 80 Anesthesiologists I-II adults were scheduled for elective laparoscopic cholecystectomy. Patients were randomly allocated into two groups to have either opioid-free anesthesia with dexmedetomidine, lidocaine, and propofol infusions (Group DL) or opioid-based anesthesia with remifentanil, and propofol infusions (Group RF). All patients received a standard multimodal analgesia regimen. A patient controlled analgesia device was set to deliver IV fentanyl for 6h after surgery. The primary outcome variable was postoperative fentanyl consumption. RESULTS Fentanyl consumption at postoperative 2nd hour was statistically significantly less in Group DL, compared with Group RF, which were 75±59μg and 120±94μg respectively, while it was comparable at postoperative 6th hour. During anesthesia, there were more hypotensive events in Group RF, while there were more hypertensive events in Group DL, which were both statistically significant. Despite higher recovery times, Group DL had significantly lower pain scores, rescue analgesic and ondansetron need. CONCLUSION Opioid-free anesthesia with dexmedetomidine, lidocaine and propofol infusions may be an alternative technique for laparoscopic cholecystectomy especially in patients with high risk for postoperative nausea and vomiting.