Point of care guided coagulation management in adult patients on ECMO: A systematic review and meta-analysis.

BACKGROUND: Despite the advancements in extracorporeal membrane oxygenation (ECMO) technology, balancing the prevention of thrombosis and the risk of bleeding in patients on ECMO is still a significant challenge for physicians. This systematic review and meta-analysis aimed to assess the efficacy and safety of viscoelastic point-of-care (POC)-guided coagulation management in adult patients on ECMO. METHODS: PubMed Medline, Embase, Scopus, Web of Science, and Cochrane Library databases were searched. After quality assessment, meta-analysis was carried out using random effects model, heterogeneity using I2 and publication bias using Doi and Funnel plots. RESULTS: A total of 1718 records were retrieved from the searches. Fifteen studies that enrolled a total of 583 participants met the inclusion criteria. Of those, 3 studies enrolling 181 subjects were eligible for meta-analysis. In patients managed with POC-guided algorithms, the odds were coherently lower for bleeding (OR 0.71, 95%CI 0.36-1.42), thrombosis (OR 0.91, 95%CI 0.32-2.60), and in-hospital mortality (OR 0.54, 95%CI 0.29-1.03), but not for circuit change or failure (OR 1.50, 95%CI 0.59-3.83). However, the differences were not statistically significant due to wide 95%CIs. CONCLUSION: Viscoelastic POC monitoring demonstrates potential benefits for coagulation management in ECMO patients. Future research should focus on standardizing evidence to improve clinical decision-making. REGISTRATION: The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with registration ID CRD42023486294.

Comparison of the Effects of Sevoflurane and Desflurane on Endothelial Glycocalyx in Patients Undergoing Laparoscopic Hysterectomy: A Randomized, Double-Blind Trial.

Objective: Various enzymes, reactive oxygen species, inflammatory conditions, and major surgeries cause endothelial glycocalyx breakdown. Inhalation of anaesthetic agents may have protective effects on the endothelium. This study compared syndecan-1 and heparan sulfate levels to evaluate the effects of sevoflurane and desflurane on the endothelial glycocalyx. Methods: This prospective randomized, double-blind study included 46 patients undergoing laparoscopic hysterectomy. The participants were allocated into sevoflurane and desflurane groups. Subsequently, blood samples were drawn at three time points: before anaesthesia induction for a baseline value (T0), after pneumoperitoneum (T1), and after extubation (T2). Heparan sulfate and syndecan-1 levels were measured. Results: There was no statistical difference between the sevoflurane and desflurane groups in terms of heparan sulfate and syndecan-1 levels at any time point. A significant difference was found only in the desflurane group in the intragroup comparisons of the measurements of heparan sulfate levels (χ2=29.826, P < 0.001). Matched pairs of the time points in the desflurane group showed that P=0.036 (Z=-2.099) for T1-T0, P < 0.001 (Z=-3.924) for T2-T0, and P < 0.001 (Z=-4.197) for T2-T1. The change in percentage between T2 and T1 of heparan sulfate in the desflurane group was found to be statistically significant (P=0.034). Conclusion: The damage caused by surgical stress on the endothelial glycocalyx can be reduced by both desflurane and sevoflurane. The protective effect of desflurane is more prominent than that of sevoflurane.

Comparison of postoperative pain in children after maintenance anaesthesia with propofol or sevoflurane: a systematic review and meta-analysis.

BACKGROUND: Propofol and sevoflurane are two of the most commonly used anaesthetics for paediatric surgery. Data from some clinical trials suggest that postoperative pain incidence is lower when propofol is used for maintenance of anaesthesia compared with sevoflurane, although this is not clear. METHODS: This meta-analysis compared postoperative pain following maintenance of anaesthesia with propofol or sevoflurane in paediatric surgeries. PubMed Medline, Embase, Scopus, Web of Science and Cochrane Library were searched for randomised controlled trials (RCTs) that compared postoperative pain between sevoflurane and propofol anaesthesia in children. After quality assessment, a meta-analysis was carried out using bias-adjusted inverse heterogeneity methods, heterogeneity using I2 and publication bias using Doi plots. RESULTS: In total, 13 RCTs with 1174 children were included. The overall synthesis suggested nearly two-fold higher odds of overall postoperative pain in the sevoflurane group compared with the propofol group (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.12-3.15, I2=58.2%). Further, children in the sevoflurane group had higher odds of having higher pain scores (OR 3.18, 95% CI 1.83-5.53, I2=20.9%), and a 60% increase in the odds of requiring postoperative rescue analgesia compared with propofol (OR 1.60, 95% CI 0.89-2.88, I2=58.2%). CONCLUSIONS: Children maintained on inhalational sevoflurane had higher odds of postoperative pain compared with those maintained on propofol. The results also suggest that sevoflurane is associated with higher odds of needing postoperative rescue analgesia compared with propofol. REGISTRATION: The protocol for this systematic review and meta-analysis was registered on the International Prospective Register of Systematic Reviews (PROSPERO) with registration ID CRD42023445913.

The Reliability of Carotid Artery Doppler Ultrasonography Indices in Predicting Fluid Responsiveness during Surgery for Geriatric Patients: A Prospective, Observational Study.

BACKGROUND: The reliability of determining fluid responsiveness during surgery in geriatric patients is challenging. Our primary outcome was to determine the reliability of Corrected Flow Time (FTc) in predicting fluid responsiveness. METHODS: Elderly patients undergoing major surgery under general anesthesia were included. Measurements of common carotid artery diameter, velocity time integral, and systolic flow time (FT) were performed before and after a fluid challenge. FTc and carotid blood flow (CBF) were subsequently calculated. RESULTS: The median change in carotid diameter was significantly higher in the fluid-responder (R) compared to the non-responder (NR) (6.51% vs. 0.65%, p = 0.049). The median change in CBF was notably higher in R compared to NR (30.04% vs. 9.72%, p = 0.024). Prior to the fluid challenge, systolic FT was significantly shorter in R than NR (285 ms vs. 315 ms, p = 0.027), but after the fluid challenge, these measurements became comparable among the groups. The change in systolic FT was higher in R (15.38% vs. 7.49%, p = 0.027). FTc and the change in FTc exhibited similarities among the groups at all study time points. Receiver operating characteristic analysis demonstrated an area under the curve of 0.682 (95% CI: 0.509-0.855, p = 0.039) for carotid diameter, 0.710 (95% CI: 0.547-0.872, p = 0.011) for CBF, 0.706 (95% CI: 0.540-0.872, p = 0.015) for systolic FT, and 0.580 (95% CI = 0.389-0.770, p = 0.413) for FTc. CONCLUSIONS: In geriatric patients, potential endothelial changes in the carotid artery may influence the dynamic markers of fluid responsiveness. Despite the demonstrated effectiveness of FTc in predicting fluid responsiveness in the general population, this study underscores the limited reliability of carotid Doppler ultrasonography indices for prediction in a geriatric patient population.

Evaluation of the Effect of Pressure-Controlled Ventilation-Volume Guaranteed Mode vs. Volume-Controlled Ventilation Mode on Atelectasis in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Clinical Trial.

Background and Objectives: Laparoscopic surgery, which results in less bleeding, less postoperative pain, and better cosmetic results, may affect the lung dynamics via the pneumoperitoneum. After laparoscopic surgery, atelectasis develops. The primary aim of the present study is to demonstrate the effects of two different ventilation modes on the development of atelectasis using lung ultrasound, and the secondary outcomes include the plateau pressure, peak inspiratory pressure, and compliance differences between the groups. Materials and Methods: In this study, 62 participants aged 18-75 years undergoing laparoscopic cholecystectomy were enrolled. The patients were randomly assigned into two groups: the volume-controlled ventilation (VCV) group (group V) or the pressure-controlled-volume guaranteed ventilation (PCV-VG) group (group PV). The lung ultrasound score (LUS) was obtained thrice: prior to induction (T1), upon the patient's initial arrival in the recovery room (T2), and just before departing the recovery unit (T3). The hemodynamic data and mechanical ventilation parameters were recorded at different times intraoperatively. Results: The LUS score was similar between the groups at all the times. The change in the LUS score of the right lower anterior chest was statistically higher in the VCV group than the PCV group. The peak inspiratory pressure (PIP) was found to be statistically higher in the V group than the PV group five minutes after induction (T5) (20.84 ± 4.32 p = 0.021). The plateau pressure was found to be higher in the V group than the PV group at all times (after induction (Tind) 17.29 ± 5.53 p = 0.004, (T5) 17.77 ± 4.89 p = 0.001, after pneumoperitoneum (TPP) 19.71 ± 4.28 p = 0.002). Compliance was found to be statistically higher in the PV group than the V group at all times ((Tind) 48.87 ± 15.37 p = 0.011, (T5) 47.94 ± 13.71 p = 0.043, (TPP) 35.65 ± 6.90 p = 0.004). Before and after the pneumoperitoneum, the compliance was determined to be lower in the V group than the PV group, respectively (40.68 ± 13.91 p = 0.043, 30.77 ± 5.73 p = 0.004). Conclusions: LUS score was similar between groups at all times. The PCV-VG mode was superior to the VCV mode in providing optimal ventilatory pressures and maintaining high dynamic compliance in patients undergoing laparoscopic abdominal surgery.

Effects of Different Crystalloid Fluids on Renal Tissue in an Experimental Model of Hemorrhagic Shock.

Objective: The type of fluid that should be used in uncontrollable hemorrhages remains an area of research. This study was designed to compare the effects of resuscitation with Ringer's lactate (RL) solution versus a normal saline (NS) solution on hemodynamics, renal tissue histopathology, coagulation, and apoptosis in a rat model of hemorrhagic shock. Methods: The study employed groups designated as the control, hemorrhage, NS, and RL groups. Heart rate, mean arterial pressure, and respiratory rate were monitored. Annexin A5 values were assayed, rotational thromboelastometry analysis was performed, and excised kidney tissue samples were histopathologically analyzed. Results: Blood pressure levels were found to be significantly higher in the control group than those measured in the other groups. While the clotting time (CT) and clot formation time (CFT) in the hemorrhage group were significantly longer than those in the control and RL groups, the CT and CFT measured in the control group were significantly shorter compared to the RL group. The mean Annexin A5 level was in the hemorrhage group, which was significantly higher compared to the other groups. In the renal histopathological evaluation, the scores of proximal tubular injury, distal renal tubular injury, and interstitial renal tubular injury were found to be significantly lower in the control group compared to the other groups. Conclusion: This study demonstrated that NS or RL can be used safely to improve the hemodynamic symptoms resulting from hemorrhagic shock as a means to reduce apoptosis, and to decrease findings in favor of coagulopathy in bedside coagulation tests during the early stages of hemorrhagic shock until the time of starting a blood transfusion.

The influence of the COVID-19 pandemic on videolaryngoscopy: a cross-sectional before-and-after survey.

BACKGROUND: Guidelines and consensus statements recommend the use of videola-ryngoscopes (VLs) in airway management of patients with COVID-19. However, there is a lack of knowledge about which types of videolaryngoscopes are used, differences of use between countries, and how the COVID-19 pandemic influenced their use. The primary aim of this before-and-after cross-sectional survey study was to assess the frequency of the use of videolaryngoscopy in the operation theatres in different countries. Also, the preferred characteristics of videolaryngoscopes were assessed. METHODS: With Ethics Committee approval, a questionnaire was distributed among anaes-thesiologists through the European Airway Management Society's network in 2019 before and in 2021 during the COVID-19 pandemic. Responses to the questions were analysed and presented as descriptive statistics. RESULTS: We reached out to 791 anaesthesiologists; 155 (19.5%) returned the first questionnaire, and 91 (11.5%) returned the second survey. Videolaryngoscopes were used in 24.1% of cases before COVID-19 and in 43.1% after the pandemic ( P < 0.001). We revealed that the availability of videolaryngoscopes increased to 100% in all centres during the pandemic. Routine use of videolaryngoscopes in all cases increased from 12.5% to 38.9%. The type of videolaryngoscope and the blade preference did not change during this period ( P = 1.000). CONCLUSIONS: This survey reflects that the COVID-19 pandemic significantly increased the availability and use of videolaryngoscopes in operating theatres, and that more anaesthesiologists now use them routinely in all cases. The preferred type of VL or blade did not change during the pandemic.

Evaluation of rescue techniques following failed laryngoscopy: A multicenter prospective observational study.

OBJECTIVE: The Fourth National Audit Project revealed that severe airway complications occur in the frequency of 1/22,000. Various rescue techniques were recommended in difficult airway guidelines. This study aims to evaluate the rescue techniques following failed direct laryngoscopy and analyze the success rates and potential complications during difficult airway management. METHODS: This was a multicenter and prospective observational study carried out in four referral centers. Four academic university hospitals using fiberoptic bronchoscopy and videolaryngoscopy in their daily practice were included in the study. Patients undergoing general anesthesia with anticipated or unanticipated difficult intubation were enrolled. The preferred rescue technique and the attempts for both direct and indirect laryngoscopies were recorded. RESULTS: At the mean age of 46.58±21.19 years, 92 patients were analyzed. The most common rescue technique was videolaryngoscopy following failed direct laryngoscopy. Glidescope was the most preferred videolaryngoscope. Anesthesia residents performed most of the first tracheal intubation attempts, whereas anesthesia specialists performed the second attempts at all centers. The experience of the first performer as a resident was significantly higher in the anticipated difficult airway group (4.0±5.5 years) (p=0.045). The number of attempts with the first rescue technique was 2.0±2.0 and 1.0±1.0 in the unanticipated difficult airway and anticipated difficult airway groups, respectively (p=0.004). CONCLUSION: Videolaryngoscopy was a more commonly preferred technique for both anticipated and unanticipated difficult intubations. Glidescope was the most used rescue device in difficult intubations after failed direct laryngoscopy, with a high success rate.

The effect of thromboembolic prophylaxis after cesarean section in patients with hypertensive disorders.

OBJECTIVE: This study aims to compare the effect of thromboembolic prophylaxis in patients diagnosed with hypertensive disorders of pregnancy undergoing cesarean section. METHODS: Three hundred and eighty-six patients were included in the study. The patients were divided into groups according to the type of hypertensive disorders of pregnancy and whether thromboembolism prophylaxis was applied or not. The thromboembolic event incidence and other pregnancy outcomes were compared. RESULTS: Nonadministration of thromboprophylaxis was recorded in 210 patients. Eleven patients had thromboembolic events (5%). Among 176 patients who received thromboprophylaxis, only two patients (1%) had a thromboembolic event (p<0.05). CONCLUSION: There is an increased tendency to thromboembolism in pregnancy. The incidence increases in the presence of hypertension accompanying pregnancy. In our study, the importance of thromboembolism prophylaxis on peri-postnatal complications in patients with hypertensive disorders of pregnancy was emphasized.

Targeted Bleeding Management Guided by Non-Invasive Haemoglobin Measurement in Surgical Patients.

OBJECTIVE: To assess blood transfusion decisions in blood losses using a continuous total haemoglobin (SpHb) and non-invasive haemoglobin (Hb) device. STUDY DESIGN: Double-blinded randomised controlled trial. PLACE AND DURATION OF STUDY: Marmara University Hospital, Istanbul, Turkey, from March 2018 to December 2019. METHODOLOGY: One hundred and twenty adult patients scheduled for elective major surgery and expected to experience a blood loss greater than 20% of their total blood volume were divided into two groups. These groups were compared for bleeding management with conventional blood gas sampling (Group Hb, the control group) according to Hb monitoring versus SpHb measurement (Group SpHb, the study group). RESULTS: In the postoperative measurement, there were fewer red blood cells (RBC) in the SpHb group than in the Hb group (p=0.020). There was a greater change in the amount of RBC from the perioperative to the postoperative period in the SpHb group compared to the Hb group (p<0.001). Postoperative Hb levels of patients in the intensive care unit (ICU) were higher in the SpHb group than in the Hb group (p<0.05). CONCLUSION: SpHb can provide effective patient blood management in cases of major surgery. It does not cause a delay in the decision of blood transfusion during surgery. KEY WORDS: Haemorrhage, Anaemia, Blood transfusion, General surgery.

Airway management in penetrating thoracic trauma.

Penetrating thoracic trauma accounts for 20-25% of all deaths due to trauma in the first four decades of life. About 33% of deaths from thoracic trauma occur due to penetrating trauma. In an autopsy study that enrolled 1178 trauma patients, 82% of the patients with tracheobronchial injuries died at the incidence site. In another study, 30% of those who could be transferred to the hospital died. This review aimed to revisit penetrating thoracic trauma with respect to complications and the strategies for airway management. While the risk of death in injuries with a sharp object is normally 1-8%, it reaches 25-28% when the cardiac box is included, and still, most of the patients are lost before they can come to the hospital. The consequences and management of penetrating thoracic trauma are mainly dependent on the extent of the injury to internal organs, as well as on the skill of the clinicians, airway obstruction, respiratory failure, and bleeding. Chest computed tomography (CT) is better than chest radiography in diagnosing the main bronchus or lobe/segment rupture. However, with the use of multi-channel multi-detector CT, the sensitivity of CT imaging has increased to 94% in the diagnosis of tracheobronchial injuries. While standard orotracheal intubation is sufficient in 75% of the patients, flexible bronchoscopy, intubation through the open wound or tracheostomy is required for airway provision in the rest. Clinical suspicion is the first diagnostic tool in a patient with penetrating airway trauma, and early treatment with multidisciplinary teamwork is life-saving.

Comparison of LMA Protector vs. endotracheal tube in patients undergoing laparoscopic surgery: a randomised controlled trial.

INTRODUCTION: Recent advances in airway management have led to supraglottic airway devices (SAD) being increasingly often chosen instead of tracheal intubation for laparoscopic surgery. However, there are ongoing arguments regarding the use of SAD due to worries about the risks of insufficient ventilation and pulmonary aspiration. The LMA Protector is a second generation SAD which was put into use recently. This prospective randomised trial investigated whether the LMA Protector was comparable to the tracheal tube regarding respiratory parameters, perioperative complications and haemodynamic parameters in patients undergoing laparoscopic surgery. MATERIAL AND METHODS: A total of 154 adult patients were randomised to two groups: Group 1 (tracheal intubation) and Group 2 (LMA Protector). Achieving adequate depth of anaesthesia, the patients were either intubated or the LMA Protector was placed. The initial baseline measurements were recorded including tidal volume, peak inspiratory pressure (PIP), oropharyngeal leak pressure (OLP) and haemodynamic parameters. These measurements were repeated and recorded again following pneumoperitoneum and recovery from anaesthesia. RESULTS: At the mean age of 52.22 ± 13.90 years 77 patients were intubated and in 77 patients the LMA Protector was applied. Following insertion of the airway device and pneumoperitoneum, the heart rate was higher in the intubation group. In the LMA Protector group OLP measures were found to be statistically similar. The mean Brimacombe fibreoptic visualisation score was 2.12 ± 0.58 and the rate of requirement of optimisation was 15% in the LMA Protector group. CONCLUSIONS: With high OLP, better haemodynamic parameters and low laryngeal view scores, we concluded that the LMA Protector can be used safely in patients undergoing laparoscopic surgery.

Pleth Variability Index Guided Volume Optimisation in Major Gynaecologic Surgery.

OBJECTIVE: To compare conventional fluid management (CFM) with pleth variability index (PVI) guided goal-directed fluid management (GDFM) during elective total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH+BSO) operations. STUDY DESIGN: Randomised controlled trial. PLACE AND DURATION OF STUDY: Department of Anaesthesiology and Reanimation, Faculty of Medicine, Health Sciences University, Kartal Dr. Lutfi Kirdar City Hospital, Istanbul, Turkey, from February to July 2021. METHODOLOGY: This trial included 78 patients aged 18-65 years with ASA I-III who would undergo elective TAH-BSO under general anaesthesia. Following randomisation with the closed envelope method, standard monitoring, and 250 ml crystalloid infusion during anaesthesia induction, maintenance fluid therapy was administered at 8-10 ml/Kg/hour to the control group and 2-3 ml/Kg/hour to the PVI group. If the mean arterial pressure (MAP) was ≤65 mmHg and/or the MAP was decreased by more than 20%, and the PVI was >13%, a 250 ml colloid bolus was given. When there was no response, a vasoactive agent was administered. Vital signs, laboratory findings, and postoperative complications were evaluated. RESULTS: Age, weight, BMI, urine output, bleeding, hospital stay, comorbidities, intraoperative use of blood products, and complication rates were not significantly different between the PVI and CFM groups (p>0.05). The PVI group had shorter operational times and used less crystalloid than the control group (p=0.033 and p<0.001, respectively). The PVI group's postoperative base excess (BE) levels changed significantly less than the control group's (p<0.001). In both pre- and postoperative haemoglobin, haematocrit, urea, creatinine, electrolytes, and lactate measurements, there were no statistically significant differences between the groups (p>0.05). CONCLUSION: PVI-GDFM is equally safe as CFM for intraoperative fluid management during elective complete abdominal hysterectomy and bilateral salpingo-oophorectomy procedures. KEY WORDS: Pleth variability index, Fluid management, Base excess.

A view on pediatric airway management: a cross sectional survey study.

BACKGROUND: This survey aimed to investigate routine practices and approaches of clinicians on pediatric airway in anesthesia and intensive care medicine. METHODS: A 20-question multiple-choice questionnaire with the possibility to provide open text answers was developed and sent. The survey was sent to the members of European Airway Management Society via a web-based platform. Responses were analyzed thematically. Only the answers from one representative of the pediatric service of each hospital was included into the analysis. RESULTS: Among the members, 143 physicians responded the survey, being anesthesiologists (83.2%), intensivists (11.9%), emergency medicine physicians (2.1%), and (2.8%) pain medicine practitioners. A straight blade was preferred by 115 participants (80.4%) in newborns, whereas in infants 86 (60.1%) indicated a curved blade and 55 (38.5%) a straight blade. Uncuffed tracheal tube were preferred by 115 participants (80.4%) in newborns, whereas 24 (16.8%) used cuffed tubes. Approximately 2/3 of the participants (89, 62.2%) reported not to use routinely a cuff manometer in their clinical practice, whereas 54 participants (37.8%) use it routinely in pediatric patients. Direct laryngoscopy for routine pediatric tracheal intubation was reported by 127 participants (88.8%), while 16 (11.2%) reported using videolaryngoscopes routinely. Interestingly, 39 (27.3%) had never performed neither videolaryngoscopy nor flexible bronchoscopy in children. These results were significantly less in hospitals with a dedicated pediatric anesthesiologist. CONCLUSIONS: This survey on airway management in pediatric anesthesia revealed that the use of cuffed tubes and the routine monitoring of cuff pressure are rare. In addition, the rate of videolaryngoscopy or flexible optical intubation was low for expected difficult intubation. Our survey highlights the need for properly trained pediatric anesthesiologists working in-line with updated scientific evidence.

Blind vs. video-laryngoscope-guided laryngeal mask insertion: A prospective randomized comparison of oropharyngeal leak pressure and fiberoptic grading.

PURPOSE: Laryngeal Mask Airway (LMA) insertion may not always be smooth without complications. Controversial results of several studies evaluating ideal insertion conditions have been published. This study compared the oropharyngeal leak pressure values and fiberoptic grading scores between blind and video-laryngoscope-guided LMA insertion. METHODS: Patients were randomly assigned into blind insertion (n = 50) and video-laryngoscope guided insertion (n = 50) groups. The oropharyngeal leak pressure, peak airway pressure, fiberoptic grading score, first attempt success rate, hemodynamic parameters, and complications were recorded. RESULTS: All laryngeal mask airways were successfully inserted in both groups at the first attempt. The fiberoptic staging scores were: grade 1 in 8.2% of patients, grade 2 in 24.4% of patients, grade 3 in 44.8% of patients, grade 4 in 22.4% of patients in the control group. On the other hand, grade 1 in 2.2% of patients, grade 2 in 28.6% of patients, grade 3 in 51% of patients, grade 4 in 8.2% of patients in the VL group (p = 0.260). The peak airway pressure and LMA insertion time were similar between groups. However, the oropharyngeal leak pressure before extubation was significantly higher in the video-laryngoscope-guided insertion than blind insertion (36.29 ± 7.09 vs. 33.79 ± 8.84 cmH2O respectively, p = 0.04). CONCLUSIONS: The findings of our study suggest that the video-laryngoscope-guided LMA-Classic insertion with a standard blade technique may be a helpful alternative to blind insertion.

The effect of different flow levels and concentrations of sevoflurane during the wash-in phase on volatile agent consumption: a randomized controlled trial.

PURPOSE: The standard procedure for low-flow anesthesia usually incorporates a high fresh gas flow (FGF) of 4-6 L/minute during the wash-in phase. However, the administration of a high FGF (4-6 L/min) increases the inhaled anesthetic agent consumption. This study was designed to compare the sevoflurane consumption at 2 rates of flow and vaporizer concentration during the wash-in period. METHODS: Patients were randomly enrolled into high FGF (HFGF) (n = 30) and low FGF (LFGF) (n = 30) groups. During the wash-in, the HFGF group received 4 L/minute FGF with a sevoflurane vaporizer setting of 2.5%, and the LFGF group received 1 L/minute FGF with a vaporizer setting of 8%. Once the wash-in was complete, anesthesia maintenance was performed with 0.5 L/min FGF with a vaporizer setting of 2.5-4.5% in both groups. The patient demographic data, bispectral index values, hemodynamic variables, wash-in time, sevoflurane consumption during the wash-in phase, and total sevoflurane consumption were analyzed. RESULTS: The median sevoflurane consumption in the wash-in phase was 8.2 mL (7.1-9.3) in the HFGF group and 2.7 mL (2.2-3.1) in the LFGF group (p = 0.001). The mean total sevoflurane consumption was 17.41 ± 3.58 mL in the patients who received HFGF and 14.93 ± 3.57 mL in the LFGF group (p = 0.001). The mean wash-in completion time was 12.49 ± 2.79 min in the HFGF group and 3.35 ± 0.67 min in the LFGF group (p = 0.001). CONCLUSIONS: The anesthetic agent consumption during the wash-in phase was approximately 3 times lower with the administration of sevoflurane at 1 L/minute FGF than the use of 4 L/minute FGF.

Changes in the cuff pressure in neonates in the absence of nitrous oxide.

BACKGROUND: Changes in the pressure of cuffed neonatal size tracheal tubes (TT) during anaesthesia without nitrous oxide are not well described. We determined whether the cuff pressure changes over time in neonates under general anaesthesia without nitrous oxide. METHODS: The airways of thirty neonates were secured with a high volume low pressure cuffed TT for meningocele surgery. The cuff was manually inflated until there was no audible leak and maintained at 10-15 cm H2O throughout by monitoring the pressure continuously with both a manometer and a pressure transducer. At baseline, the cuff pressure was assessed in the supine and then prone positions. During surgery, if the pressure exceeded 15 cm H2O, the cuff was deflated to < 15 cm H2O and if it was < 10 cm H2O, the cuff was inflated to 10-15 cm H2O. The time interval between corrections and the number of corrections were recorded. RESULTS: The cuff pressures in 18 neonates (60%) required correction during surgery. The cuff pressure exceeded 15 cm H2O in nine neonates (30%) and was corrected. The cuff pressures in 13 neonates were less than 10 cm H2O and required correction. The gender, weight, height, and duration of anaesthesia did not differ significantly between neonates who required correction of the cuff pressure and those who did not. Mean cuff pressures were similar at 15, 45, and 75 minutes of anaesthesia. CONCLUSIONS: In 60% of neonates undergoing surgery in the prone position under general anaesthesia without nitrous oxide, the cuff pressure exceeded 15 cm H2O. In such cases, cuff pressure should be monitored continuously throughout the surgery.