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.

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.

Effect of Institutional Case Volume on In-Hospital Mortality After Deceased Donor Liver Transplantation: A Nationwide Retrospective Cohort Study in Korea.

BACKGROUND: There is still controversy as to whether the case volume affects clinical outcomes after liver transplantation. This nationwide retrospective cohort study aimed to investigate the relationship between institutional case volume and post-transplant outcomes after deceased donor liver transplantation. MATERIAL AND METHODS: The data was extracted from the database of Korean National Healthcare Insurance Service. A total of 2648 adult deceased donor liver transplantations were performed at 54 centers in Korea from January 2007 to December 2016. Centers were divided into high-, medium-, and low-volume centers according to the average annual number of deceased donor liver transplantations as follows: < 10, 10-30, and >30. RESULTS: In-hospital mortality rates in high-, medium-, and low-volume centers were 10.3%, 14.3%, and 17.1%, respectively. Multivariable logistic regression analysis revealed that low-volume centers (adjusted odds ratio 1.953; 95% confidence interval, 1.461-2.611; P < .001) and medium-volume centers (adjusted odds ratio 1.480; 95% confidence interval, 1.098-1.994; P = .010) had a significantly higher in-hospital mortality compared to high-volume centers. Long-term mortality rates were also higher in low-volume centers (P = .007). CONCLUSION: Centers with higher volume showed better in-hospital mortality and long-term survival after deceased donor liver transplantation compared to centers with lower volume.

Radiographic and microsurgical characteristics of proximal (A1) segment aneurysms of the anterior cerebral artery.

BACKGROUND: Proximal A1 segment aneurysms of the anterior cerebral artery (ACA) radiologically resemble internal carotid artery bifurcation (ICBIF) aneurysms because of their anatomical proximity. However, proximal A1 aneurysms exhibit distinguishing features, relative to ICBIF aneurysms. We report our experience of managing proximal A1 aneurysms, then compare them to ICBIF aneurysms. METHODS: Among 2191 aneurysms treated between 2000 and 2016 in a single institution, we retrospectively reviewed 100 cases categorized as ICBIF or A1 aneurysms. We included aneurysms originating from the ICBIF and ACA, proximal to the anterior communicating artery (A1 segment) and divided them into two groups: proximal A1 (n = 32) and ICBIF (n = 50). If any portion of the aneurysm involved the ICBIF, it was classified as ICBIF. Aneurysms wholly located in the A1 segment were classified as proximal A1. Patient factors and angiographic factors were evaluated and compared. RESULTS: The proximal A1 group exhibited differences in aneurysm size (p = 0.013), posterior aneurysm direction (p = 0.001), and A1 perforators as incorporating vessels (p = 0.001). The proximal A1 group tended to rupture more frequently when the aneurysm was smaller (p = 0.046). One case of morbidity occurred in the proximal A1 group. CONCLUSION: Compared to ICBIF aneurysms, proximal A1 aneurysms were smaller and directed posteriorly, with incorporating perforators. Because of these characteristics, it may be difficult to perform clipping with 360° view in microsurgical field. Therefore, when planning to treat proximal A1 aneurysms, different treatment strategies may be necessary, relative to those used for ICBIF aneurysms.

Temperament and character traits in patients with tinnitus: a prospective case series with comparisons.

OBJECTIVE: To describe the personality traits of temperament and character in patients with tinnitus and to identify differences in these traits associated with the severity of tinnitus. STUDY DESIGN: Case series with comparisons. SETTING: Tertiary referral centre. PARTICIPANTS: From January to December 2014, one hundred and thirty-four adult patients with chronic subjective tinnitus completed psychoacoustic measurements of tinnitus and the Temperament and Character Inventory (TCI). MEASUREMENTS: Personality traits were assessed by the TCI. The TCI assesses seven dimensions of personality traits and four temperaments 'novelty seeking, harm avoidance, reward dependence, persistence', as well as three characters 'self-directedness, cooperativeness, self-transcendence'. MAIN OUTCOME MEASURES: The values of the TCI parameters in the tinnitus patients were compared with reference data from a non-institutional adult population, and associations between TCI parameter values and tinnitus severity were evaluated. RESULTS: In terms of temperament, tinnitus patients had higher scores for 'harm avoidance', whereas scores for 'novelty seeking', 'reward dependence' and 'persistence' were significantly lower than the reference. In terms of character, lower 'cooperativeness' and 'self-transcendence' were identified in the subjects with tinnitus. The 'novelty seeking' score was inversely related to tinnitus severity (r = -0.285, P = 0.001), while other temperament and character traits did not show significant correlations. CONCLUSIONS: There may be a connection between tinnitus and personality traits, especially in the case of 'novelty seeking', which is relatively constant over a lifetime. The TCI questionnaire may be useful in facilitating the application of personality traits to tailored counselling for tinnitus.

Multiple Negative Differential Resistance Device by Using the Ambipolar Behavior of Tunneling Field Effect Transistor with Fast Switching Characteristics.

We propose a novel double-peak negative differential resistance (NDR) characteristic at the conventional single-peak MOS-NDR circuit by employing ambipolar behavior of TFET. The fluctuated voltage transfer curve (VTC) from ambipolar inverter is analyzed with simple model and successfully demonstrated with TFET, as a practical example, on the device simulation. We also verified that the fluctuated VTC generates additional peak and valleys on NDR characteristics by using circuit simulations. Moreover, by adjusting the threshold voltage of conventional MOSFET, ultra-high 1st and 2nd peak-to-valley current ratio (PVCR) over 10(7) is obtained with fully suppressed valley currents. The proposed double-peak NDR circuit expected to apply on faster switching and low power multi-functional applications.

Anti-obesity effects of gochujang products prepared using rice koji and soybean meju in rats.

The Korean traditional hot sauce gochujang has been reported to have biological activities. Different kinds of gochujang products were prepared based on combinations of a fungal rice koji with two kinds of bacterial soybean mejus. Diets that included gochujang products were fed to rats and anti-obesity effects were investigated. Gochujang products reduced body weight gains, epididymal fat weights, and triglyceride levels in the serum and the liver. Effects were exerted by the diet that included the non-fermented gochujang mixture, increased using a fungal rice koji, and further enhanced using a bacterial soybean meju. Dietary effects were apparently induced via inhibition of the lipogenic enzymes fatty acid synthase, malic enzyme, and lipoprotein lipase by gochujang products in epididymal adipose tissues, and inhibition of glucose-6-phosphate dehydrogenase in the liver. High levels of capsaicin and genistein in gochujang products are considered to contribute to anti-obesity effects.

Population-based epidemiology of primary biliary cirrhosis in South Korea.

BACKGROUND: As a rare disease, only a few population-based epidemiology studies of primary biliary cirrhosis (PBC) have been reported. AIMS: To elucidate the nationwide prevalence, incidence, complications, fatality and direct medical costs of PBC in South Korea. METHODS: The nationwide Health Insurance Review and Assessment Service claims data and Rare Intractable Disease registration data on PBC, identified with the International Classification of Diseases (ICD) 10 code of K74.3, were obtained from 2009 to 2013. Age- and gender-specific prevalence and incidence rates of PBC were calculated, and data on complications, comorbidities, prescribed drugs, therapeutic procedures and direct medical costs were analysed. RESULTS: A total of 2824 patients over 20 years old with PBC were identified in 2009-2013 (female-to-male ratio 6.2, median age 57 years old). The average age- and sex-adjusted incidence from 2011 to 2013 was 8.57 per million per year, and the average age- and sex-adjusted prevalence from 2009 to 2013 was 47.50 per million population. About 10% of patients presented with complications such as ascites (10.3%), variceal bleeding (5.8%) and/or hepatocellular carcinoma (HCC) (1.3%). Liver transplantation was undertaken in 71 patients (2.5%) for 5 years. Case fatality was 2.2% and the transplantation-free survival was 95.4% for 5 years. CONCLUSIONS: This is the first report on the nationwide epidemiology of primary biliary cirrhosis in South Korea, demonstrating lower incidence and prevalence rates than those of Western countries, but a considerable disease burden, representing at least 10% were complicated with decompensated cirrhosis or hepatocellular carcinoma requiring liver transplantation.

An IL-27/Lag3 axis enhances Foxp3+ regulatory T cell-suppressive function and therapeutic efficacy.

Foxp3-expressing regulatory T cells (Tregs) are central regulators of immune homeostasis and tolerance. As it has been suggested that proper Treg function is compromised under inflammatory conditions, seeking for a pathway that enhances or stabilizes Treg function is a subject of considerable interest. We report that interleukin (IL)-27, an IL-12 family cytokine known to have both pro- and anti-inflammatory roles in T cells, plays a pivotal role in enhancing Treg function to control T cell-induced colitis, a model for inflammatory bowel disease (IBD) in humans. Unlike wild-type (WT) Tregs capable of inhibiting colitogenic T-cell expansion and inflammatory cytokine expression, IL-27R-deficient Tregs were unable to downregulate inflammatory T-cell responses. Tregs stimulated with IL-27 expressed substantially improved suppressive function in vitro and in vivo. IL-27 stimulation of Tregs induced expression of Lag3, a surface molecule implicated in negatively regulating immune responses. Lag3 expression in Tregs was critical to mediate Treg function in suppressing colitogenic responses. Human Tregs also displayed enhanced suppressive function and Lag3 expression following IL-27 stimulation. Collectively, these results highlight a novel function for the IL-27/Lag3 axis in modulating Treg regulation of inflammatory responses in the intestine.

Impact of psychological characteristics in self-management in individuals with traumatic spinal cord injury.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: To examine the association between psychological characteristics in self-management and probable depression status in individuals with a traumatic spinal cord injury (SCI). SETTING: Community-dwelling individuals with traumatic SCI living across Canada. METHODS: Individuals with SCI were recruited by email via the Rick Hansen Institute as well as an outpatient hospital spinal clinic. Data were collected by self-report using an online survey. Standardized questionnaires were embedded within a larger survey and included the Hospital Anxiety and Depression Scale (HADS), the short version of the Patient Activation Measure (PAM), the Moorong Self-Efficacy Scale (MSES) and the Pearlin-Schooler Mastery Scale (PMS). RESULTS: Individuals with probable depression (n=25) had lower self-efficacy (67.9 vs 94.2, P<0.0001), mastery (18.9 vs 22.9, P<0.0001) and patient activation (60.4 vs 71.6, P<0.0001) as well as higher anxiety (9.0 vs 5.5, P<0.0001), compared with their non-depressed counterparts (n=75). A logistic regression determined that lower self-efficacy and mastery scores as well as less time since injury were associated with depression status (P=0.002; P=0.02 and P=0.02, respectively). Individuals with higher anxiety scores were almost 1.5 times more likely to be depressed, while older age was positively associated with depression status (P=0.016 and P=0.024, respectively). CONCLUSION: Interventions for depression in SCI, including a self-management program, should target factors such as self-efficacy and mastery, which could improve secondary medical complications and overall quality of life.

Retrospective Study of Association between Displacement of Maxillary Canine and Tooth Agenesis.

OBJECTIVE: The purpose of this study was to investigate the interrelationships between displacement of maxillary canine and tooth agenesis in age from 10 to 19 years. STUDY DESIGN: The panoramic radiographs of 128 subjects with displacement of maxillary canine and 600 subjects without displacement of maxillary canine were examined. The panoramic radiographs taken between 2003 and 2013 were used for diagnosis other related dental anomalies, including permanent tooth agenesis and small maxillary lateral incisor. RESULTS: Patients with maxillary canine displacement had a significantly higher prevalence rate of permanent tooth agenesis excluding of third molars (p < 0.05). Significant increase in occurrence of tooth agenesis of maxillary lateral incisor (p < 0.05), maxillary second premolar (p < 0.05) and small maxillary lateral incisor (p < 0.05). In contrast, the mandibular second premolar did not show any significant difference (p > 0.05). CONCLUSION: This study indicates that there is positive relationship between displacement of maxillary canine, small maxillary lateral incisor and permanent tooth agenesis. Especially, maxillary lateral incisor and maxillary second premolar have strong association with maxillary canine displacement. Consequently, permanent tooth agenesis and small maxillary lateral incisor can be a predictor of maxillary canine displacement.

A Protocol-Based Decision for Choosing a Proper Surgical Treatment Option for Carotid Artery Stenosis.

OBJECTIVE: There are two established surgical treatment options for carotid artery stenosis. Carotid endarterectomy (CEA) has been accepted as a gold standard for surgical treatment while carotid artery stenting (CAS) has recently become an alternative option. Each treatment option has advantages and disadvantages for the treatment outcomes. We propose a protocol for selection of a proper surgical treatment option for carotid artery stenosis. MATERIALS AND METHODS: A total of 192 published articles on management of carotid artery stenosis were reviewed. Preoperatively considerable factors which had been repeatedly noted in those articles for the risk/benefits of CEA or CAS were selected. According to those factors, a protocol with four categories was established. RESULTS: CEA or CAS is indicated when the patient has a symptomatic stenosis ≥ 50%, or when the patient has an asymptomatic stenosis ≥ 80%. Each treatment option has absolute indications and favorable indications. Each absolute indication is scored with three points, and each favorable indication, one point. Based on the highest scores, a proper treatment option (CEA or CAS) is selected. CONCLUSION: We have been treating patients according to this protocol and evaluating the outcomes of our protocol-based decision because this protocol might be helpful in assessment of risk/benefit for selection of a proper surgical treatment option in patients with carotid artery stenosis.

Clinical Risk Factors Affecting Procedure-Related Major Neurological Complications in Unruptured Intracranial Aneurysms.

PURPOSE: The operative risk and natural history rupture risk for the treatment of unruptured intracranial aneurysms (UIAs) should be evaluated. The purpose of this study was to report our experience with treating UIAs and to outline clinical risk factors associated with procedure-related major neurological complications. MATERIALS AND METHODS: We treated 1158 UIAs in 998 patients over the last 14 years. All patients underwent operation performed by a single microvascular surgeon and two interventionists at a single institution. Patient factors, aneurysm factors, and clinical outcomes were analyzed in relation to procedure-related complications. RESULTS: The total complication rate was 22 (2.2%) out of 998 patients. Among them, complications developed in 14 (2.3%) out of 612 patients who underwent microsurgery and in 8 (2.1%) out of 386 patients who underwent endovascular procedures. One patient died due to intraoperative rupture during an endovascular procedure. The procedure-related complication was highly correlated with age (p=0.004), hypertension (p=0.002), and history of ischemic stroke (p<0.001) in univariate analysis. The multivariate analysis revealed previous history of ischemic stroke (p=0.001) to be strongly correlated with procedure-related complications. CONCLUSION: A history of ischemic stroke was strongly correlated with procedure-related major neurological complications when treating UIAs. Accordingly, patients with UIAs who have a previous history of ischemic stroke might be at risk of procedure-related major neurological complications.

Clinical utility of serum beta-2-microglobulin as a predictor of diabetic complications in patients with type 2 diabetes without renal impairment.

AIM: As serum beta-2-microglobulin (B2M) levels are usually elevated in patients with renal failure, they have been suggested as a surrogate marker of cardiovascular mortality for patients with chronic kidney disease. Glycation of B2M is cytotoxic and may contribute to the risk of diabetic complications in patients with diabetes. Our objective was to evaluate the relationship between B2M and diabetic complications in patients with type 2 diabetes (T2D) and normal kidney function. METHODS: A total of 366 patients with T2D and preserved renal function with no clinical evidence of cardiovascular disease were enrolled consecutively into this study. High B2M was defined as a median serum B2M level ≥ 1.8 mg/L. Subclinical atherosclerosis was defined as a carotid artery intima-media thickness (C-IMT) ≥ 0.9 mm or the presence of carotid plaque. The definition of diabetic nephropathy was based on the presence of albuminuria (≥ 30 mg/g creatinine). RESULTS: Patients with high B2M were older, and had diabetes of longer duration, higher serum creatinine, microalbuminuria, and increased vascular stiffness and C-IMT compared with patients with low B2M. B2M levels were positively correlated with C-IMT and vascular stiffness, and these associations remained constant after adjusting for age. In addition, after adjusting for age, gender, body mass index, serum creatinine, hypertension, smoking and alcohol consumption, the adjusted odds ratio (OR) for atherosclerosis was 2.01 [95% confidence interval (CI): 1.02-3.94] per 1mg/L increase in B2M. The prevalences of diabetic retinopathy and nephropathy were significantly higher with a high B2M than with a low B2M. The multiple adjusted OR for diabetic nephropathy was 2.29 (95% CI: 1.11-4.72) per 1mg/L increase of B2M. CONCLUSION: Higher serum B2M was an independent risk factor for subclinical atherosclerosis and diabetic nephropathy in patients with T2D without renal impairment.

Clinico-radiological Characteristics of Spontaneous Basal Ganglia Hemorrhage, According to Regional Classification.

OBJECTIVE: The clinico-radiologic features of the spontaneous basal ganglia hemorrhage (BGH) may often differ one from another, according to its regional location. Therefore, we attempted to classify the BGH into regional subgroups, and to extrapolate the distinct characteristics of each group of BGH. MATERIALS AND METHODS: A total of 103 BGHs were analyzed by retrospective review of medical records. BGH was classified according to four subgroups; anterior BGH; posterior BGH; lateral BGH; massive BGH. RESULTS: The most common BGH was the posterior BGH (56, 54.4%), followed by the lateral BGH (26, 25.2%), the massive BGH (12, 11.7%), and the anterior BGH (9, 8.7%). The shape of hemorrhage tended to be round in anterior, irregular in posterior, and ovoid in lateral BGH. A layered density of hematoma on initial computed tomography showed correlation with hematoma expansion (p = 0.016), which was observed more often in the postero-lateral group of BGH than in the anterior BGH group. Relatively better recovery from the initial insult was observed in the lateral BGH group than in the other regional BGH groups. The proportion of poor outcome (modified Rankin scale 4, 5, 6) was 100% in the massive, 41.1% in the posterior, 34.6% in the lateral, and 0% in the anterior BGH group. CONCLUSION: We observed that BGH can be grouped according to its regional location and each group may have distinct characteristics. Thus, a more sophisticated clinical strategy tailored to each group of BGHs can be implemented.

Dual specific oral tolerance induction using interferon gamma for IgE-mediated anaphylactic food allergy and the dissociation of local skin allergy and systemic oral allergy: tolerance or desensitization?

BACKGROUND: Specific oral tolerance induction (SOTI) for IgE-mediated food allergy (IFA) can be successfully achieved using interfero gamma (classic SOTI). OBJECTIVE: In this study, a tolerable dose was introduced during tolerance induction with interferon gamma (dual SOTI), and its effectiveness was evaluated. METHODS: The study population comprised 25 IFA patients. Blood samples were taken for analysis, including complete blood count with differential counts of eosinophils, serum total IgE levels, and specific IgE for allergenic foods. Skin prick tests were conducted with the allergens. Oral food challenges were performed to diagnose IFA. Ten patients received dual SOTI, 5 received classic SOTI, 5 received SOTI without interferon gamma (original SOTI), and 5 were not treated (controls). RESULTS: Patients treated with dual SOTI and classic SOTI using interferon gamma became tolerant to the allergenic food. The tolerable dose was introduced successfully in dual SOTI. It was difficult to proceed with the same dosing protocol used for classic SOTI in cases treated with original SOTI. Following dual SOTI, the systemic reaction to oral intake subsided, but the local skin reaction to contact with the allergenic food persisted. CONCLUSIONS: Dual SOTI is an improved protocol for SOTI using interferon gamma for IFA.The local skin reaction and systemic reaction to oral intake were dissociated following dual SOTI. In cases of food allergy, tolerance appears to result from desensitization to allergens.

Higher levels of small dense low-density lipoprotein (LDL) are associated with cardiac autonomic neuropathy in patients with type 2 diabetes.

AIM: To investigate the relationship between small dense LDL cholesterol and cardiac autonomic neuropathy among patients with Type 2 diabetes. METHODS: A total of 175 patients who had not taken lipid-lowering agents previously were enrolled consecutively in this study. Small dense LDL cholesterol level was measured using polyacrylamide tube gel electrophoresis, which fractionates LDL cholesterol into seven components according to particle size and charge. We analysed the mean LDL cholesterol particle size and the proportion of small dense LDL cholesterol. RESULTS: The mean (± sd) patient age was 56 (± 14) years, the mean (± sd) duration of diabetes was 10.3 (± 8.3) years, the mean (± sd) proportion of small dense LDL cholesterol was 21.3 (± 17.6)% and the mean (± sd) LDL cholesterol size was 26.33 (± 0.8) nm. Men with cardiac autonomic neuropathy had a longer duration of diabetes compared with those without cardiac autonomic neuropathy. Women with cardiac autonomic neuropathy had a larger waist circumference, higher plasma triglyceride levels, smaller mean (± sd) LDL cholesterol size [26.8 (± 4.3) nm vs 26.4 (± 6.9) nm; P < 0.01] and larger mean (± sd) proportion of small dense LDL cholesterol [10.1 (± 9.9)% vs 19.1 (± 16.8)%; P < 0.01] compared with those without cardiac autonomic neuropathy. After adjusting for other confounding risk factors, the triglyceride/ HDL cholesterol ratio (odds ratio = 1.698, 95% CI: 1.07-2.69; P = 0.025) and mean LDL cholesterol size (odds ratio = 0.873, 95% CI: 0.77-0.99; P = 0.038) remained as independent risk factors for cardiac autonomic neuropathy in women. CONCLUSIONS: A more atherogenic lipid profile such as the triglyceride: HDL cholesterol ratio and a smaller mean LDL cholesterol particle size were related to the prevalence of cardiac autonomic neuropathy in women with Type 2 diabetes.

Haemodynamics and cerebral oxygenation during arthroscopic shoulder surgery in beach chair position under general anaesthesia.

BACKGROUND: Patients undergoing surgery in beach chair position (BCP) are at risk of cerebral ischaemia. We determined the prevalence and risk factors of jugular venous bulb oxygen desaturation (SjvO(2) < 50%) in BCP. It was also examined whether regional cerebral tissue oxygen saturation (SctO(2) ) measured by near-infrared spectroscopy and SjvO(2) are interchangeable for assessment of cerebral oxygenation. METHODS: Fifty-six consecutive patients undergoing arthroscopic shoulder surgery in BCP were studied. Anaesthesia was intravenous with propofol and remifentanil (P/R) or inhalational with sevoflurane and 50% nitrous oxide (S/N) depending on provider choice. Mean arterial pressure (MAP), heart rate (HR), SjvO(2) , and SctO(2) were measured before (baseline; post-induction in supine position) and after the patients assumed BCP. Bland-Altman analysis was performed to measure the agreement between SctO(2) and SjvO(2) . RESULTS: SjvO(2) , SctO(2) , MAP, and HR decreased significantly when patients were raised into BCP. Jugular desaturation occurred in 41% of patients (56% with P/R vs. 21% with S/N anaesthesia, P = 0.0077). Risk factors for the desaturation included P/R anaesthesia [adjusted odds ratio (aOR) 4.76, 95% confidence interval (CI) 1.34-16.95, P = 0.016] and MAP < 50 mmHg (aOR 3.85, 95% CI 1.21-12.25, P = 0.023). Bland-Altman analysis showed a mean difference of -8.9% with 95% limit of agreement between -40.0% and 23.0%. The percentage error [1.96 standard deviation/mean of the reference method] was 48.5%. CONCLUSIONS: The incidence of jugular desaturation in BCP was 41%, and P/R anaesthesia and hypotension were associated with its occurrence while undergoing surgery under general anaesthesia. SctO(2) may not replace SjvO(2) for the determination of cerebral oxygenation.

Live cell-imaging perfusion culture system of liver sinusoidal endothelial cells to mimic stem cell engraftment in liver.

Hepatocyte and various hepatic stem cell transplantations have been studied as alternative therapies to orthotopic liver transplantation for liver injury. The engraftment of transplanted cells into the parenchyma requires transmigration through sinusoidal endothelial cells (SECs), the only cellular barrier. In this study, we constructed a SEC-imaging perfusion culture system that mimics sinusoids with respect to hemorheologic properties. SECs were successfully maintained for 24 hours. Human liver stem cells (HLSCs) were used as a model of transplanted cells for in vitro engraftment to SECs under perfusion culture conditions. Conditions of high shear stress perfusion with 0.34 dyne/cm(2) significantly reduced cell adhesion in contrast to lower shear stress conditions of 0.1 and 0.03 dyne/cm(2). Among the biologic perfusion fluids, namely, fetal bovine serum (FBS), pig plasma, and 5% human albumin solution, HLSCs showed significantly greater attachment to SECs when perfused with FBS, which is well known to contain abundant amounts of adhesion molecules. This biomimetic SEC perfusion culture system may provide a useful tool to study engraftment mechanisms and to evaluate the effects of various enhancers as an alternative to animal models.