Comparison between pressure-controlled and manual ventilation during anesthetic induction in patients with expected difficult airway: A prospective randomized controlled trial.

BACKGROUND: Gastric insufflation can cause gastric regurgitation, which may be exacerbated in patients who are expected to have difficult airways. The purpose of this study was to investigate the difference in respiratory parameters and the frequency of gastric insufflation according to the ventilation mode during the anesthestic induction on patients who were predicted to have difficult facemask ventilation. METHODS: A total of eighty patients with expected airway difficulties were included. Patient were allocated to 2 groups (n = 40 each). In the manual ventilation group, ventilation was performed by putting a mask on the patient's face with 1-hand and adjusting the pressure limiting valve to 15 cm H2O. In the pressure-controlled ventilation group, a mask was held in place using 2-handed jaw-thrust maneuver. The pressure-controlled ventilation was applied and peak inspiration pressure was adjusted to achieve a tidal volume of 6 to 8 mL/kg. The primary outcome was the difference of the peak airway pressure between 2 groups every 30 seconds for 120 seconds duration of mask ventilation. We also evaluated respiratory variables including peak airway pressure, End-tidal carbon dioxide and also gastric insufflation using ultrasonography. RESULTS: The pressure-controlled ventilation group demonstrated lower peak airway pressure than the manual ventilation group (P = .005). End-tidal carbon dioxide was higher in the pressure-controlled ventilation group (P = .012). The incidence of gastric insufflation assessed by real-time ultrasonography of the gastric antrum was higher in the manual ventilation group than in the pressure-controlled ventilation group [3 (7.5%) vs 17 (42.5%), risk ratio (95% confidence interval): 0.06 to 0.56, P = .003]. CONCLUSIONS: Pressure-controlled ventilation during facemask ventilation in patients who were expected to have difficult airways showed a lower gastric insufflation rate with low peak airway pressure compared to manual ventilation.

Bilateral superficial cervical plexus block for parathyroidectomy during pregnancy: A case report.

BACKGROUND: Primary hyperparathyroidism (PHPT) is the most common cause of pregnancy-related hypercalcemia. PHPT can cause maternal and fetal complications in pregnant women. General anesthesia for non-obstetric surgery in pregnant women is associated with maternal hazards and concerns regarding long-term neonatal neurocognitive effects. Surgical removal of the lesion in mid-pregnancy is currently the primary treatment option for pregnant patients with PHPT. However, the blood calcium concentration at which surgery should be considered remains under discussion due to the risk of miscarriage. CASE SUMMARY: A 31-year-old nulliparous woman at 11 wk of gestation was admitted to our hospital for parathyroidectomy. The patient had a history of intrauterine fetal death with unknown etiology at 16 wk of gestation 1 year prior. Her blood test results showed that the serum calcium level was elevated to 12.9 mg/dL, and the parathyroid hormone level was elevated to 157 pg/mL. In a neck ultrasound, it revealed a 0.8 cm × 1.5 cm sized oval, hypoechoic mass in the upper posterior of the left thyroid gland, which was compatible with parathyroid adenoma. Superficial cervical plexus block (SCPB) for parathyroidectomy was performed. After surgery, the obstetrician checked the status of the fetus, and there were no abnormal signs. Since then her calcium level returned to normal values after one week of surgery and a healthy male neonate of 2910 g was delivered vaginally at 38 wk of gestation. CONCLUSION: Our case suggests that SCPB can be an anesthetic option for parathyroidectomy during the first trimester of pregnancy.

Impact of the Deep Neuromuscular Block on Oncologic Quality of Laparoscopic Surgery in Obese Gastric Cancer Patients: A Randomized Clinical Trial.

BACKGROUND: Obesity can hinder laparoscopic procedures and impede oncological safety during laparoscopic cancer surgery. Deep neuromuscular block (NMB) reportedly improves laparoscopic surgical conditions, but its oncological benefits are unclear. We aimed to evaluate whether deep NMB improves the oncologic quality of laparoscopic cancer surgery in obese patients. STUDY DESIGN: We conducted a double-blinded, parallel-group, randomized, phase 3 trial at 9 institutions in Korea. Clinical stage I and II gastric cancer patients with a BMI at or above 25 kg m -2 were eligible and randomized 1:1 ratio to the deep or moderate NMB groups, with continuous infusion of rocuronium (0.5-1.0 and 0.1-0.5 mg kg -1 h -1, respectively). The primary endpoint was the number of retrieved lymph nodes (LNs). The secondary endpoints included the surgeon's surgical rating score (SRS) and interrupted events. RESULTS: Between August 2017 and July 2020, 196 patients were enrolled. Fifteen patients were excluded, and 181 patients were finally included in the study. There was no significant difference in the number of retrieved LNs between the deep (N = 88) and moderate NMB groups (N = 93; 44.6 ± 17.5 vs 41.5 ± 16.9, p = 0.239). However, deep NMB enabled retrieving more LNs in patients with a BMI at or above 28 kg/m2 than moderate NMB (49.2 ± 18.6 vs 39.2 ± 13.3, p = 0.026). Interrupted events during surgery were lower in the deep NMB group than in the moderate NMB group (21.6% vs 36.6%; p = 0.034). The SRS was not influenced by NMB depth. CONCLUSION: Deep NMB provides potential oncologic benefits by retrieving more LNs in patients with BMI at or above 28 kg/m2 during laparoscopic gastrectomy.

The effects of two-handed jaw thrust on i-gel™ placement in anesthetized non-paralyzed patients.

BACKGROUND: I-gelTM is a second-generation supraglottic airway device with a non-inflatable cuff. In this prospective randomized investigation, we evaluated the effects of two-handed jaw thrust technique on i-gel insertion in anesthetized non-paralyzed patients. METHODS: Seventy-four adult patients were allocated to two groups (N.=37 each). In the jaw thrust group, two-handed jaw thrust technique was applied to facilitate i-gel insertion. In the control group, conventional i-gel insertion was performed. The success rate at the first attempt, air leakage pressure, insertion time, and postoperative sore throat incidence were recorded. RESULTS: The success rate at the first attempt was higher in the jaw thrust group (37 [100%] vs. 31 [84%], difference of 16%, 95% confidence interval for the difference: 1 to 33%, P=0.03). The median air leakage pressure was higher in the jaw thrust group than in the control group (20 [interquartile range 13] vs. 17 [interquartile range 3] cmH2O, difference: 6, 95% confidence interval of the difference: 3 to 8, P<0.01). The mean insertion time was shorter in the jaw thrust group (27±14 vs. 41±29 seconds, difference: 14 seconds, 95% confidence interval of the difference: 3 to 24, P=0.01). The incidence of postoperative sore throat at the postoperative one hour was lower in the jaw thrust group (seven [20%] vs. 15 [41%], difference 22%, 95% confidence interval for the difference: -1 to 42%, P=0.04). CONCLUSIONS: The two-handed jaw thrust technique facilitated i-gel insertion compared to the conventional technique in anesthetized non-paralyzed patients.

Effect of chlorpheniramine administration on postoperative catheter-related bladder discomfort in patients undergoing transurethral excision of bladder tumor: a prospective randomized study.

PURPOSE: Catheter-related bladder discomfort (CRBD) is postoperative distress caused by a urinary catheter. CRBD is related to muscarinic receptor activation. Chlorpheniramine has antimuscarinic properties. Hence, this investigation was undertaken to evaluate the efficacy of chlorpheniramine in preventing CRBD in patients undergoing transurethral resection of bladder tumor (TURBT). METHODS: Seventy-six patients scheduled for TURBT under general anesthesia were assigned into two groups. In the chlorpheniramine group (n = 38), 100 ml normal saline containing 0.1 mg/kg chlorpheniramine was infused after general anesthesia induction. In the control group (n = 38), 100 ml normal saline alone was infused. The incidence and severity of CRBD were assessed at 1, 6, and 24 h postoperatively. RESULTS: The 1-h postoperative incidence of CRBD was lower in the chlorpheniramine group based on the unadjusted analysis [16 (42%) vs. 28 (74%), risk difference 32%, 95% confidence interval 8-51, p = 0.005]. After adjusting the size of the urinary catheter, post hoc analysis showed that the 1-h postoperative incidence of CRBD was lower in the chlorpheniramine group (p = 0.004). The CRBD severity score was lower in the chlorpheniramine group at 1 and 6 h after operation based on the unadjusted analysis (p = 0.012 and p = 0.007, respectively). After adjusting the urinary catheter size, post hoc analysis showed that 1- and 6-h CRBD severity score was lower in the chlorpheniramine group (p = 0.012 and p = 0.008, respectively). The incidence of rescue medication was lower in the chlorpheniramine group [10 (26%) vs. 20 (53%), risk difference 26%, 95% confidence interval 3-47, p = 0.019]. The overall incidence of complications such as nausea, vomiting, dry mouth, flushing, dizziness, and blurred vision was comparable between the two groups. CONCLUSIONS: Chlorpheniramine administration significantly reduces the incidence and severity of CRBD in the patients undergoing TURBT. TRIAL REGISTRATION: KCT0004880 ( https://cris.nih.go.kr/ ).

Influence of two-handed jaw thrust during tracheal intubation on postoperative sore throat: a prospective randomised study.

OBJECTIVE: General anaesthesia with tracheal intubation results in sore throat. We evaluated the influence of the two-handed jaw thrust on postoperative sore throat in patients who require tracheal intubation. METHODS: In this prospective, double-blind, single-centre, parallel-arm, and randomised trial, 92 patients who were scheduled for general anaesthesia for total hip arthroplasty were allocated to one of two groups. In the jaw thrust group (n = 46), the two-handed jaw thrust manoeuvre was applied at intubation. In the control group (n = 46), conventional intubation with sham jaw thrust was performed. Incidences of airway morbidities including sore throat, hoarseness, and cough at 2, 4, and 24 hours postoperatively were compared. RESULTS: During the postoperative 24 hours, the incidence of sore throat (8 [17%] vs. 20 [44%]) and hoarseness were lower in the jaw thrust group (8 [17%] vs. 18 [39%]) compared with the control group. The incidence of cough during the postoperative 24 hours was similar between the groups. CONCLUSIONS: The jaw thrust manoeuvre significantly reduced sore throat and hoarseness in patients after general anaesthesia using tracheal intubation.Clinical trial registration: NCT03568279.

Effects of blood flow on the antibacterial efficacy of chlorhexidine and silver sulfadiazine coated central venous catheter: A simulation-based pilot study.

BACKGROUND: Chlorhexidine and silver sulfadiazine coated central venous catheters (CSS-CVC) may cause loss of antimicrobial efficacy due to friction between the CVC surface and sheer stress caused by the blood flow. Therefore, the aim of this study was to investigate the antibacterial efficacy of CSS-CVC at various flow rates using a bloodstream model. METHODS: Each CVC was subjected to various flow rates (0.5, 1, 2, and 4 L/min) and wear-out times (0, 24, 48, 72, 96, and 120 hours), and the optical density (OD) 600 after a Staphylococcus aureus incubation test was used to determine the antibacterial effect of CSS-CVC. RESULTS: In the 0.5 L/min group, there was no significant change in the OD600 value up to 120 hours compared with the baseline OD600 value for CSS-CVC (P > .467). However, the OD600 values of CSS-CVC in the 1 L/min (P < .001) and 2 L/min (P < .001) groups were significantly reduced up to 72 hours, while that in the 4 L/min (p < 0.001) group decreased rapidly up to 48 hours. CONCLUSION: This study suggests that there is a doubt whether sufficient antibacterial function can be maintained with prolonged duration of catheter placement.

Effectiveness Comparison of Dexmedetomidine and Remifentanil for Perioperative Management in Patients Undergoing Endoscopic Sinus Surgery.

BACKGROUND: For patients undergoing endoscopic sinus surgery, intranasal injection of epinephrine can cause acute increases in heart rate and blood pressure. OBJECTIVE: Among the drugs for reducing hyperdynamic effects, dexmedetomidine and remifentanil are expected to blunt the acute hemodynamic responses after intranasal injection of epinephrine. Our study compared a difference in the 2 drugs in their abilities to blunt the hemodynamic responses in intraoperative period and postoperative profile. METHODS: In this study, the patients were randomly divided into the dexmedetomidine and remifentanil groups. During the intraoperative period, the hemodynamic values were recorded. The surgical condition was assessed by a single surgeon. During the postoperative period, hemodynamic values, sedation scale score, and pain score were recorded. RESULT: No significant differences in hemodynamic variables were found between the groups before and after intranasal injection of epinephrine. Comparison of the group mean values before endotracheal intubation revealed that the blood pressure values in the remifentanil group were significantly lower than those in the dexmedetomidine group. At 2 minutes after endotracheal intubation, blood pressure and heart rate values in the remifentanil group were significantly lower than those in the dexmedetomidine group. The sedation score was significantly lower in the dexmedetomidine group on arrival and at 30 minutes after arrival at the postanesthetic care unit (P < .001 and P = .001, respectively). At 30 and 60 minutes after the operation, the pain scores were significantly lower in the dexmedetomidine group (P = .015 and P = .001, respectively). CONCLUSION: Dexmedetomidine had better postoperative sedative and analgesic effects than remifentanil for patients undergoing endoscopic sinus surgery in this study. Remifentanil and dexmedetomidine attenuated acute hemodynamic responses to be within normal ranges after intranasal injection of epinephrine, and no significant differences in terms of hemodynamic variables. Remifentanil was superior to dexmedetomidine in inducing hypotension during endotracheal intubation.

Monitoring of anesthetic depth and EEG band power using phase lag entropy during propofol anesthesia.

BACKGROUND: Phase lag entropy (PLE) is a novel anesthetic depth indicator that uses four-channel electroencephalography (EEG) to measure the temporal pattern diversity in the phase relationship of frequency signals in the brain. The purpose of the study was to evaluate the anesthetic depth monitoring using PLE and to evaluate the correlation between PLE and bispectral index (BIS) values during propofol anesthesia. METHODS: In thirty-five adult patients undergoing elective surgery, anesthesia was induced with propofol using target-controlled infusion (the Schneider model). We recorded the PLE value, raw EEG, BIS value, and hemodynamic data when the target effect-site concentration (Ce) of propofol reached 2, 3, 4, 5, and 6 µg/ml before intubation and 6, 5, 4, 3, 2 µg/ml after intubation and injection of muscle relaxant. We analyzed whether PLE and raw EEG data from the PLE monitor reflected the anesthetic depth as the Ce of propofol changed, and whether PLE values were comparable to BIS values. RESULTS: PLE values were inversely correlated to changes in propofol Ce (propofol Ce from 0 to 6.0 µg/ml, r2 = - 0.83; propofol Ce from 6.0 to 2.0 µg/ml, r2 = - 0.46). In the spectral analysis of EEG acquired from the PLE monitor, the persistence spectrogram revealed a wide distribution of power at loss of consciousness (LOC) and recovery of consciousness (ROC), with a narrow distribution during unconsciousness. The power spectrogram showed the typical pattern seen in propofol anesthesia with slow alpha frequency band oscillation. The PLE value demonstrated a strong correlation with the BIS value during the change in propofol Ce from 0 to 6.0 µg/ml (r2 = 0.84). PLE and BIS values were similar at LOC (62.3 vs. 61.8) (P > 0.05), but PLE values were smaller than BIS values at ROC (64.4 vs 75.7) (P < 0.05). CONCLUSIONS: The PLE value is a useful anesthetic depth indicator, similar to the BIS value, during propofol anesthesia. Spectral analysis of EEG acquired from the PLE monitor demonstrated the typical patterns seen in propofol anesthesia. TRIAL REGISTRATION: This clinical trial was retrospectively registered at ClinicalTrials.gov at October 2017 (NCT03299621).

Quantifying the depth of anesthesia based on brain activity signal modeling.

Various methods of assessing the depth of anesthesia (DoA) and reducing intraoperative awareness during general anesthesia have been extensively studied in anesthesiology. However, most of the DoA monitors do not include brain activity signal modeling. Here, we propose a new algorithm termed the cortical activity index (CAI) based on the brain activity signals. In this study, we enrolled 32 patients who underwent laparoscopic cholecystectomy. Raw electroencephalography (EEG) signals were acquired at a sampling rate of 128 Hz using BIS-VISTA with standard bispectral index (BIS) sensors. All data were stored on a computer for further analysis. The similarities and difference among spectral entropy, the BIS, and CAI were analyzed. Pearson correlation coefficient between the BIS and CAI was 0.825. The result of fitting the semiparametric regression models is the method CAI estimate (-0.00995; P = .0341). It is the estimated difference in the mean of the dependent variable between method BIS and CAI. The CAI algorithm, a simple and intuitive algorithm based on brain activity signal modeling, suggests an intrinsic relationship between the DoA and the EEG waveform. We suggest that the CAI algorithm might be used to quantify the DoA.

Two-handed jaw thrust decreases postoperative sore throat in patients undergoing double-lumen endobronchial intubation: A randomised study.

BACKGROUND: Tracheal intubation using a double-lumen endobronchial tube (DLT) causes postoperative sore throat. OBJECTIVE: To determine the effect of two-handed jaw thrust on postoperative sore throat in patients requiring insertion of a DLT. DESIGN: A randomised study. SETTING: A tertiary teaching hospital from December 2017 to May 2018. PATIENTS: One-hundred and six patients undergoing one-lung anaesthesia. INTERVENTIONS: Patients were allocated to one of two groups (n=53 each). In the jaw thrust group, the two-handed jaw thrust manoeuvre was applied at intubation and advancement of the DLT. In the control group, conventional intubation with a sham jaw thrust was performed. MAIN OUTCOME MEASURES: Incidence of sore throat at 1, 6 and 24 h postoperatively. RESULTS: The incidence of sore throat at 6 h postoperatively was higher in the control group than in the jaw thrust group [31 (59%) vs. 14 (26%), risk ratio (95% confidence interval) 0.45 (0.27 to 0.75), P < 0.01]. The overall incidence of sore throat was higher in the control group than in the jaw thrust group [35 (66%) vs. 18 (34%), risk ratio (95% confidence interval) 0.51 (0.34 to 0.78), P < 0.01]. CONCLUSION: The jaw thrust manoeuvre can reduce the incidence of sore throat in patients undergoing DLT insertion for one-lung ventilation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03331809.

Comparison of oncological benefits of deep neuromuscular block in obese patients with gastric cancer (DEBLOQS_GC study): A study protocol for a double-blind, randomized controlled trial.

PURPOSE: Many studies have demonstrated the advantage of maintaining intraoperative deep neuromuscular block (NMB) with sugammadex. This trial is designed to evaluate the impact of muscle relaxation during laparoscopic subtotal gastrectomy on the oncological benefits, particularly in obese patients with gastric cancer. MATERIALS AND METHODS: This is a double-blind, randomized controlled multicenter prospective trial. Patients with clinical stage I-II gastric cancer with a body mass index of 25 and over, who undergo laparoscopic subtotal gastrectomy will be eligible for trial inclusion. The patients will be randomized into a deep NMB group or a moderate NMB group with a 1:1 ratio. A total of 196 patients (98 per group) are required. The primary endpoint is the number of harvested lymph nodes, which is a critical index of the quality of surgery in gastric cancer treatment. The secondary endpoints are surgeon's surgical condition score, patient's sedation score, and surgical outcomes including peak inspiratory pressure, operation time, postoperative pain, and morbidity. DISCUSSION: This is the first study that compares deep NMB with moderate NMB during laparoscopic gastrectomy in obese patients with gastric cancer. We hope to show the oncologic benefits of deep NMB compared with moderate NMB during subtotal gastrectomy. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT03196791), date of registration: October 10, 2017.

Effect of varying external pneumatic pressure on hemolysis and red blood cell elongation index in fresh and aged blood: Randomized laboratory research.

BACKGROUND: External applied pneumatic pressure is usually used for rapid transfusion of red blood cells (RBCs). However, increased shear stress can cause increased hemolysis and decreased RBC elongation indices. Therefore, the purpose of this study was to measure the degree of hemolysis and the alteration of RBC elongation indices under varying external pressure in fresh and aged blood. METHODS: Venous blood samples were obtained from 20 healthy human volunteers. Each blood bag was divided into 2 subgroups (5 or 35 days of storage), and 5 levels of pressure were applied: 0, 150, 200, 250, and 300 mmHg. After infusion, a laboratory study was conducted. The percentages of irreversibly changed cells were evaluated using Bessis classification. RBC elongation indices were measured using a microfluidic ektacytometer. RESULTS: There were no significant differences in the percentage of irreversibly changed RBCs between the pressures of 0 and 300 mmHg. Moreover, there were no significant differences in laboratory test results or elongation indices among all levels of pressure. Irreversibly changed RBCs and hemolysis were increased depending on the storage period. CONCLUSION: Irreversible changes in RBCs did not occur as a result of external pressure. The hemolysis and elongation indices of fresh RBCs were not influenced by external pneumatic pressure up to 300 mmHg. Only the storage period affected the irreversible changes in RBCs and hemolysis. Therefore, the application of external pressure to RBCs in variously aged blood is likely to be a safe procedure.

Optimal dose of rocuronium bromide undergoing adenotonsillectomy under 5% sevoflurane with fentanyl.

OBJECTIVE: Adenotonsillectomy is a short surgical procedure under general anaesthesia in children. An ideal muscle relaxant for adenotonsillectomy would create an intense neuromuscular block while having a quick recovery time without postoperative morbidity. We compared the effect of different doses of rocuronium for the tracheal intubation in children under 5% sevoflurane and fentanyl. MATERIALS AND METHODS: 75 children (aged 3-10 years, ASA I) scheduled for adenotonsillectomy were enrolled. Anaesthesia was induced with propofol 2.5 mg/kg, followed by fentanyl 2 µg/kg. After mask ventilation with 5 vol% sevoflurane in 100% oxygen for 2 min, 2 ml of study drug was administered intravenously, i.e., either normal saline (S Group) or one of two doses (0.15 or 0.3 mg/kg) of rocuronium. We assessed conditions during tracheal intubation and also recorded the surgical condition, the time from discontinuation of sevoflurane to extubation and PAED scale, pain scores in PACU. RESULTS: Rocuronium groups (96% and 100%, respectively; P < 0.01) showed statistically superior clinically acceptable intubating conditions than the saline group (72%). The 0.3 mg/kg rocuronium (80%) treatment clearly resulted in excellent intubating conditions compared with the 0.15 mg/kg group (44%; p = 0.028). There was no significant difference in the time to extubation and surgical condition, and in the postoperative measures of emergence delirium, pain, and recovery time among the three groups. CONCLUSION: A dose of 0.3 mg/kg rocuronium may provide optimal intubating conditions without delayed recovery in 5% sevoflurane anaesthesia with fentanyl in children undergoing adenotonsillectomy. CLINICAL TRIALS REGISTRY NUMBER: NCT02467595.

Successful early application of extracorporeal membrane oxygenation to support cardiopulmonary resuscitation for a patient suffering from severe malignant hyperthermia and cardiac arrest: a case report.

Malignant hyperthermia (MH) may lead to metabolic crisis of skeletal muscle in susceptible individuals following exposure to triggering agents such as volatile anesthetics or depolarizing muscle relaxants. MH is a rare and a potentially lethal disease, which can lead to cardiac arrest. We report a case of severe MH, in which the rapidly evolving signs of hypermetabolism eventually resulted in cardiac arrest. Despite conventional treatments following cardiopulmonary resuscitation, the patient's vital signs did not improve. Therefore, we applied extracorporeal membrane oxygenation for providing hemodynamic support.

Chlorhexidine and silver sulfadiazine coating on central venous catheters is not sufficient for protection against catheter-related infection: Simulation-based laboratory research with clinical validation.

Objective The efficacy of chlorhexidine- and silver sulfadiazine-coated central venous catheters (CSS-CVC) against catheter-related infection remains controversial. We hypothesized that the loss of silver nanoparticles may reduce the antibacterial efficacy of CSS-CVCs and that this loss could be due to the frictional force between the surface of the CVC and the bloodstream. The objective of this study was to investigate whether the antimicrobial effect of CSS-CVCs decreases with increasing exposure time in a bloodstream model and quantitatively assay the antimicrobial effect of CSS-CVCs compared with polyurethane and antiseptic-impregnated CVCs. Methods Each CVC was subjected to 120 hours of saline flow and analyzed at intervals over 24 hours. The analyses included energy-dispersive X-ray spectroscopy, scanning electron microscopy, and optical density after a Staphylococcus aureus incubation test. Results The weight percentage of silver in the CSS-CVCs significantly decreased to 56.18% (44.10% ± 3.32%) with 48-hour catheterization and to 18.88% (14.82% ± 1.33%) with 120-hour catheterization compared with the initial weight percentage (78.50% ± 6.32%). In the S. aureus incubation test, the antibacterial function of CSS-CVCs was lost after 48 hours [3 (N/D) of OD]. Similar results were observed in a pilot clinical study using 18 CSS-CVCs. Conclusions We found that the efficacy of CSS-CVCs decreased over time and that the antibacterial function was lost after 48 hours of simulated wear-out. Therefore, antibiotic-impregnated CVCs may be a better option when longer (>48 hours) indwelling is needed.

A Novel and Simple Method for Tracheal Intubation in a Swine Model: Preparing for the Era of Xenotransplantation.

OBJECTIVES: Organ transplant in humans is an established therapy for a variety of end-stage organ diseases. However, due to organ shortages and lack of donors, the need for xenotransplant has gradually increased. Xenotransplantation has great potential to solve many of the problems facing organ transplantation. Pigs are being developed as xenogeneic organ donors for use in humans. In this study, we propose a novel and simple method for tracheal intubation in a swine model using neuromuscular blocking agents and laryngeal mask airway. MATERIALS AND METHODS: Eight Yorkshire pigs were used for the 2 separate experiments, which were conducted 1 week apart. In the first experiment, an anesthesiologist with no previous comparable experience performed endotracheal intubation of pigs. One week later, using the same pig, a second experiment was performed by an experienced anesthesiologist. Anesthesia was induced with intramuscular injection of a mixture of 1 mg/kg xylazine (Rompun, Bayer Korea Ltd., Seoul, Korea) and 7 mg/kg Zoletil (a mixture of tiletamine hydrochloride and zolazepam hydro-chloride, Virbac Laboratory, Carros, France). The laryngeal mask was then placed, and 0.15 mg/kg vecuronium bromide was injected intravenously. Tracheal intubation was attempted after mask removal. The duration and number of intubation attempts were recorded, and the degree of intubation difficulty was scored. RESULTS: In all cases, the laryngeal mask was easily inserted, and endotracheal intubation was successfully completed. Oxygen saturation did not fall below 95%, and there were no hypoxemia episodes. Degree of intubation difficulty and duration were not significantly different between the 2 anesthesiologists. CONCLUSIONS: Tracheal intubation in our swine model was successfully performed using neuromuscular blocking agents and laryngeal masks without resulting in hypoxemia, with even anesthesiologists who are unfamiliar with endotracheal intubation of pigs easily able to do so using our protocol. Therefore, our protocol will enable all investigators to perform successful tracheal intubation in swine models.

The effect of fresh gas flow rate and type of anesthesia machine on time to reach target sevoflurane concentration.

BACKGROUND: Anesthesia machines have been developed by the application of new technology for rapid and easier control of anesthetic concentration. In this study, we used a test lung to investigate whether the time taken to reach the target sevoflurane concentration varies with the rate of fresh gas flow (FGF) and type of anesthesia machine (AM). METHODS: We measured the times taken to reach the target sevoflurane concentration (2 minimum alveolar concentration = 4%) at variable rates of FGF (0.5, 1, or 3 L/min) and different types of AM (Primus®, Perseus®, and Zeus® [Zeus®-F; Zeus® fresh gas mode, Zeus®-A; Zeus® auto-mode]). Concomitant ventilation was supplied using 100% O2. The AMs were connected to a test lung. A sevoflurane vaporizer setting of 6% was used in Primus®, Perseus®, and Zeus®-F; a target end-tidal setting of 4% was used in Zeus®-A (from a vaporizer setting of 0%). The time taken to reach the target concentration was measured in every group. RESULTS: When the same AM was used (Primus®, Perseus®, or Zeus®-F), the times to target concentration shortened as the FGF rate increased (P < 0.05). Conversely, when the same FGF rate was used, but with different AMs, the time to target concentration was shortest in Perseus®, followed by Primus®, and finally by Zeus®-F (P < 0.05). With regards to both modes of Zeus®, at FGF rates of 0.5 and 1 L/min, the time to target concentration was shorter in Zeus®-A than in Zeus®-F; however, the time was longer in Zeus®-A than in Zeus®-F at FGF rate of 3 L/min (P < 0.05). CONCLUSION: Shorter times taken to reach the target concentration were associated with high FGF rates, smaller internal volume of the AM, proximity of the fresh gas inlets to patients, absence of a decoupling system, and use of blower-driven ventilators in AM.