A comprehensive approach to prediction of fractional flow reserve from deep-learning-augmented model.

The underuse of invasive fractional flow reserve (FFR) in clinical practice has motivated research towards non-invasive prediction of FFR. Although the non-invasive derivation of FFR (FFRCT) using computational fluid dynamics (CFD) principles has become a common practice, its clinical application has been limited due to the considerable time required for computation of resulting changes in haemodynamic conditions. An alternative to CFD technology is incorporating a neural network into the computational process to reduce the time necessary for running an effective model. In this study we propose a cascade of data-driven and physic-based neural networks (DP-NN) for predicting FFR (DL-FFRCT). The first network of cascade network DP-NN includes geometric features, and the second network includes physical features. We compare the differences between data-driven neural network (D-NN) and DP-NN for predicting FFR. The training and testing datasets were obtained by solving the three-dimensional incompressible Navier-Stokes equations. Coronary flow and geometric features were used as inputs to train D-NN. In DP-NN the training process involves first training a D-NN to output resting ΔP as one input feature to the DP-NN. Secondly, the physics-based microcirculatory resistance as another input feature to the DP-NN. Using clinically measured FFR as the "gold standard", we validated the computational accuracy of DL-FFRCT in 77 patients. Compared to D-NN, DP-NN improved the prediction of ΔP (R2 = 0.87 vs. R2 = 0.92). Statistical analysis demonstrated that the diagnostic accuracy of DL-FFRCT was not inferior to FFRCT (85.71 % vs. 88.3 %) and the computational time was reduced by a factor of approximately 3000 (4.26 s vs. 3.5 h). DP-NN represents a near real-time, interpretable, and highly accurate deep-learning network, which contributes to the development of high-performance computational methods for haemodynamics. We anticipate that DP-NN will enable near real-time prediction of DL-FFRCT in personalized narrow blood vessels and provide guidance for cardiovascular disease treatments.

A high-fidelity geometric multiscale hemodynamic model for predicting myocardial ischemia.

BACKGROUND AND OBJECTIVES: Coronary computed tomography angiography (CCTA) derived fractional flow reserve (CT-FFR) requires a maximal hyperemic state to be modeled by assuming the total coronary resistance decreased to a constant 0.24 of that under the resting state. However, this assumption neglects the vasodilator capacity of individual patients. Herein, we proposed a high-fidelity geometric multiscale model (HFMM) to characterize coronary pressure and flow under the resting state, seeking to better predict myocardial ischemia by using CCTA-derived instantaneous wave-free ratio (CT-iFR). METHODS: Fifty-seven patients (62 lesions) who had undergone CCTA and were then referred to invasive FFR were prospectively enrolled. The coronary microcirculation resistance hemodynamic model (RHM) under the resting condition was established on a patient-specific basis. Coupled with a closed-loop geometric multiscale model (CGM) of their individual coronary circulations, the HFMM model was established to non-invasively derive the CT-iFR from CCTA images. RESULTS: With the invasive FFR being the reference standard, accuracy of the obtained CT-iFR in identifying myocardial ischemia was greater than those of the CCTA and non-invasively derived CT-FFR (90.32% vs. 79.03% vs. 84.3%). The overall computational time of CT-iFR was 61 ± 6 min, faster than that of the CT-FFR (8 h). The sensitivity, specificity, positive predictive value, and negative predictive value of the CT-iFR in discriminating an invasive FFR > 0.8 were 78% (95% CI: 40-97%), 92% (95% CI: 82-98%), 64% (95% CI: 39-83%), and 96% (95% CI:88-99%), respectively. CONCLUSIONS: A high-fidelity geometric multiscale hemodynamic model was developed for rapid and accurate estimation of CT-iFR. Compared with CT-FFR, CT-iFR is of less computational cost and enables assessment of tandem lesions.

On inlet pressure boundary conditions for CT-based computation of fractional flow reserve: clinical measurement of aortic pressure.

BACKGROUND AND OBJECTIVES: A quick calculation approach of steady-state fractional flow reserve (FFRss) based on computed tomography angiography (CTA) images is a reliable non-invasive way of calculate FFR, the assumptions used in the research should be study further to increase forecast accuracy. The effect of inlet and outlet boundary conditions on FFRss was investigated. METHODS: 15 patients who had been diagnosed with coronary artery disease were enrolled in this study. We investigated the sensitivity of calculating FFR to boundary circumstances, using invasive FFR as a benchmark. There are two types of inlet: (1) aortic pressure based on clinically measured. (2) mean pressure calculated based on physiological formula; we further studied the outlet changes of FFRss under different coronary vasodilation responses (24%, 48%, 72%). RESULTS: According to the calculate FFR results of all patients, FFRSST (based on the clinical experiment) and FFRSSM (based on the physiological formula) {r = 0.99, [95% confidence interval (CI):0.0.94 to 1.14] (p < 0.001)}. Although the pressure difference between the two pressure boundary conditions is 15 mmHg, the calculated FFR result does not change significantly. The microcirculation resistance of the outlet gradually rose as the vasodilation state changed, and the computed FFR increased. CONCLUSIONS: A numerical analysis of the effects of proximal and distal boundary constraints of computational models on computed CT-FFR is presented. The findings revealed that distal boundary circumstances (hyperemic vasodilation response of coronary micro-vessels) have a significant impact on FFR, providing evidence to guide the development and application of a computational model for estimating FFR.

A computer model of the effect of venous-arterial-venous extracorporeal membrane oxygenation venous return of oxygenated blood on right atrial recirculation and tricuspid valve blood oxygen saturation.

OBJECTIVE: Venous-arterial venous extracorporeal membrane oxygenation (V-AV ECMO), as a new clinical application of ECMO, showed great clinical application potential in the treatment of patients with combined cardiopulmonary failure. Given the complicated cannulation strategy of V-AV ECMO, its influence on the hemodynamics of the human circulatory system remained unclear. METHODS: In this paper, a fluid-structure interaction was used to study the effect of V-AV ECMO oxygenated blood shunt ratio on right atrial recirculation and tricuspid valve (TV) blood oxygen saturation. In this study, the right atrium, superior vena cava supplying cannulae and inferior vena cava draining cannulae model of a specific patient was constructed. Seven cases with shunt ratio of 12.50%, 18.75%, 25.00%, 31.25%, 37.50%, 43.75% and 50.00% were designed. RESULTS: The streamline diagram and velocity contour of oxygenated blood, recirculation fraction (RF), correlation of three variables (shunt ratio, RF, and oxygen saturation), and the oxygen saturation of blood at the TV were extracted for the study. Study results showed that, first, as the shunt ratio increased, the RF of the seven cases was 14.64%, 29.87%, 33.85%, 40.12%, 40.40%, 40.02%, and 38.09%. Second, with the increase of the shunt ratio, oxygen saturation of blood at the TV in seven cases was 82.1%, 82.5%, 83.3%, 83.3%, 84.0%, 84.6%, and 85.3%. CONCLUSIONS: In this study, the shunt ratio had a strong correlation with the RF and oxygen saturation of blood at the TV. As the shunt ratio increased, the RF initially increased and then stabilized. However, oxygen saturation of blood at the TV would increase with the increase of the shunt ratio, but the degree of increase was small. This research provided useful information for surgeons and operators using V-AV ECMO.

Comparison of the Effects of Acute Appendicitis and Chronic Cholecystitis on Intestinal Mucosal Function During Surgery.

OBJECTIVE: The objective of this study is to explore the effect of acute appendicitis and chronic cholecystitis on inflammatory factors and intestinal mucosal function during operation. METHODS: This was a prospective cohort study. Forty-four patients including those who underwent elective cholecystectomy (Group A, n = 22) or emergency appendectomy (Group B, n = 22) were recruited. Before anesthesia and after surgery, arterial blood was collected for the measurement of plasma indices associated with inflammation or intestinal permeability. RESULTS:  Both the tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP) levels were higher in Group B than in Group A (P < 0.05). The preoperative IL-10 level was higher in Group A than in Group B (P = 0.036), while after surgery, the opposite relationship was observed (P = 0.020). There were no intergroup or intragroup differences for D-Lac. The postoperative lipopolysaccharide (LPS) and human syndecan-1 (Sdc-1) levels were lower than the corresponding preoperative value (P < 0.05) in the two groups. Both the preoperative Sdc-1 and fatty acid binding protein (FABP2) levels in Group A were higher than the corresponding levels in Group B (P < 0.05). CONCLUSIONS: The study suggested that chronic cholecystitis had more severe damage to intestinal mucosal function than acute appendicitis. It is necessary to strengthen the protection of intestinal mucosa during the perioperative period.

Non-Invasive Quantification of Fraction Flow Reserve Based on Steady-State Geometric Multiscale Models.

Background: The underuse of invasive fraction flow reserve (FFR) in clinical practice has motivated research towards its non-invasive prediction. The early attempts relied on solving the incompressible three-dimensional Navier-Stokes equations in segmented coronary arteries. However, transient boundary condition has a high resource intensity in terms of computational time. Herein, a method for calculating FFR based on steady-state geometric multiscale (FFRSS) is proposed. Methods: A total of 154 moderately stenotic vessels (40-80% diameter stenosis) from 136 patients with stable angina were included in this study to validate the clinical diagnostic performance of FFRSS. The method was based on the coronary artery model segmented from the patient's coronary CTA image. The average pressure was used as the boundary condition for the inlet, and the microcirculation resistance calculated by the coronary flow was used as the boundary condition for the outlet to calculate the patient-specific coronary hyperemia. Then, the flow velocity and pressure distribution and the FFRss of each coronary artery branch were calculated to evaluate the degree of myocardial ischemia caused by coronary stenosis. Also, the FFRSS and FFRCT of all patients were calculated, and the clinically measured FFR was used as the "gold standard" to verify the diagnostic performance of FFRSS and to compare the correlation between FFRSS and FFRCT. Results: According to the FFRSS calculation results of all patients, FFRSS and FFR have a good correlation (r = 0.68, p < 0.001). Similarly, the correlation of FFRSS and FFRCT demonstrated an r of 0.75 (95%CI: 0.67-0.72) (p < 0.001). On receiver-operating characteristic analysis, the optimal FFRSS cut point for FFR≤0.80 was 0.80 (AUC:0.85 [95% confidence interval: 0.79 to 0.90]; overall accuracy:88.3%). The overall sensitivity, specificity, PPV, and NPV for FFRSS ≤0.80 versus FFR ≤0.80 was 68.18% (95% CI: 52.4-81.4), 93.64% (95% CI: 87.3-97.4), 82.9%, and 91.1%, respectively. Conclusion: FFRSS is a reliable diagnostic index for myocardial ischemia. This method was similar to the closed-loop geometric multiscale calculation of FFR accuracy but improved the calculation efficiency. It also improved the clinical applicability of the non-invasive computational FFR model, helped the clinicians diagnose myocardial ischemia, and guided percutaneous coronary intervention.

Effect of the Coronary Arterial Diameter Derived From Coronary Computed Tomography Angiography on Fractional Flow Reserve.

BACKGROUND: Fractional flow reserve (FFR) is considered to be the criterion standard for the clinical diagnosis of functional myocardial ischemia. In this study, we explored the effect of the coronary arterial diameter derived from coronary computed tomography angiography on FFR. METHOD: We retrospectively reviewed the clinical information of 131 patients with moderate coronary artery stenosis. To compare the mean diameter of stenotic vessels, patients were divided into ischemic and nonischemic groups. According to the clinical statistics of the diameter of the ischemic group and the nonischemic group, we established 8 ideal models of coronary artery diameter of 4 mm (40%, 50%, 60%, and 70% stenosis) and diameter of 3 mm (40%, 50%, 60%, and 70% stenosis). Two sets of numerical simulation experiments were carried out: experiment 1 evaluated the variation rate of CT-based computation of non-invasive fractional flow reserve (FFRCT) with vessel diameters of 4 mm and 3 mm under different stenosis rates, and experiment 2 explored the variation of FFRCT with vessel diameters of 4 mm and 3 mm under different cardiac outputs. We simulated changes in the flow of narrow blood vessels by changes in cardiac output. RESULTS: According to clinical statistics, the mean ± SD diameter of stenotic vessels in the ischemic and nonischemic groups was 3.67 ± 0.77 mm and 3.31 ± 0.64 mm (P < 0.05 for difference), respectively. In experiment 1, the FFRCT of coronary with a diameter of 4 mm was 0.86, 0.80, 0.66, and 0.35, and that with a diameter of 3 mm was 0.90, 0.84, 0.71, and 0.50, respectively. In experiment 2, the FFRCT of the coronary vessel diameter of 4 mm was 0.84, 0.80, 0.76, and 0.72, respectively. The FFRCT coronary vessels with a diameter of 3 mm were 0.87, 0.84, 0.80, and 0.76, respectively. CONCLUSIONS: As the stenosis increases, compared with narrow blood vessel of small diameter, the narrow blood vessel with larger diameter is accompanied by faster flow rate changes and is more prone to ischemia.

Hemodynamics study on the relationship between the sigmoid sinus wall dehiscence and the blood flow pattern of the transverse sinus and sigmoid sinus junction.

Sigmoid sinus wall dehiscence (SSWD) is a common pathophysiology of patients with pulsatile tinnitus (PT). However, the pathological mechanism of SSWD is unclear. This study aimed to investigate the relationship between the position of the SSWD and blood flow pattern of the transverse sinus and sigmoid sinus (TS-SS) junction. The impact of the blood flow was hypothesized to be the pathological mechanism of SSWD. Twenty patients and two healthy volunteers were analyzed retrospectively, and transient computer fluid dynamics was used to verify this hypothesis. A 4D flow magnetic resonance imaging experiment was performed to validate the numerical simulation. The position of high-velocity blood flow impacting the vessel wall (17/20) was consistent with SSWD. In healthy volunteers, the temporal bone was thin where the blood flow impacted the blood vessel wall. The average wall shear stress (20/20) and pressure (18/20) of the SSWD area (peak) were higher than those of sigmoid sinus wall anomalies (the contact area between the vessel wall and the temporal bone at the TS-SS junction). The average wall pressure percentage differences of 16/20, 11/20, and 4/20 patients were more than 5%, 10%, and 20%, respectively. The average wall shear stress percentage differences of 20/20, 18/20, and 16/20 patients were more than 5%, 10%, and 20%, respectively. In brief, the blood flow of the TS-SS junction impacted the vessel wall and increased wall pressure, which might be an important pathological mechanism of SSWD. This study could serve as a basis for the diagnosis and SSWD resurfacing surgery of patients with PT induced by SSWD.

Hemodynamic mechanism of pulsatile tinnitus caused by venous diverticulum treated with coil embolization.

BACKGROUND AND OBJECTIVE: Coil embolization has become a new treatment method for pulsatile tinnitus (PT) caused by sigmoid sinus diverticulum (SSD). Although this therapy has achieved good results in clinical reports, the hemodynamic mechanism of coils in the treatment of PT in SSD remained unclear. METHODS: Finite element method (FEM) and computational fluid dynamics (CFD) were combined to explore the hemodynamic mechanism of coil embolization in SSD treatment. Three personalized geometric models of sigmoid sinus were established according to the CTA data of patients. Coil model were established by FEM, and the hemodynamic differences of SSD before and after coiling were compared by transient CFD method. RESULTS: Velocity streamlines disappeared in the SSD after coiling. At the peak time (t1 = 0.22 s), the SSD-average velocity decreased in every patient. The average value of the decreased in three patients was 0.154 ± 0.028 m/s (mean ± SD). Wall average pressure (Pavg) also showed a decline in every patient. Average of decrements of three patients was 17.69 ± 4.91 Pa (mean ± SD). Average WSS (WSSavg) was also reduced in every patient. The average value of WSS drop was 9.74 ± 3.02 Pa (mean ± SD). After coiling, the proportion of low-velocity region in the sigmoid sinus cortical plate dehiscence (SSCPD) area increased. Average of increments was 22.1 ± 5.36% (mean ± SD). CONCLUSIONS: A reduction in SSD-average velocity, wall pressure, and WSS were the short-term hemodynamic mechanism of coil embolization for PT. Coil embolization increased the proportion of low-velocity region in the SSCPD area, thereby creating a hemodynamic environment that easily produced thrombus and protects blood vessels from the impact of blood flow. This phenomenon was the long-term effect of coil embolization.

The Median Effective Concentration (EC50) of Epidural Ropivacaine With Different Doses of Oxycodone During Limb Surgery in Elderly Patients.

BACKGROUND: Oxycodone can be used both intravenously and epidurally in elderly patients because of its strong analgesic effect and more slight respiratory inhibition compared with other opioids at the same effect. In this study, we determined the median effective concentration (EC50) of epidural ropivacaine required for great saphenous vein surgery in elderly patients in order to describe its pharmacodynamic interaction with oxycodone. METHODS: One hundred forty-one elderly patients scheduled for high ligation and stripping of the great saphenous vein surgery were allocated into three groups in a randomized, double-blinded manner as follows: Q2.5 group (2.5 mg oxycodone), Q5.0 group (5.0 mg oxycodone), and C group (normal saline). Anesthesia, was achieved with epidural ropivacaine and oxycodone. The EC50 of ropivacaine for surgery with different doses of oxycodone was adjusted by using an up-and-down sequential methods with an adjacent concentration gradient at a factor of 0.9 to inhibit analgesia. Anesthesia associated adverse events and recovery, characteristics were also recorded. RESULTS: The EC50 of ropivacaine for the great saphenous vein surgery in elderly patients was 0.399% (95% CI, 0.371-0.430%) in the Q2.5 group, 0.396% (95% CI, 0.355-0.441%) in the Q5.0 group, and 0.487% (95% CI, 0.510-0.465%) in the C group, respectively (P < 0.05). Specially, the EC50 of ropivacaine in the Q2.5 and Q5.0 groups was lower than that in the C group (P < 0.01), But the difference between the Q2.5 group and the Q5.0 group was not significant (P > 0.05). There was no significant difference in the Bromage score from the motor block examination, heart rate (HR) or mean arterial pressure (MAP) at each observation time point after epidural administration among the three groups (P > 0.05). No serious adverse reactions occurred in any of the three groups. CONCLUSION: Oxycodone combined with ropivacaine epidural anesthesia can reduce the EC50 of ropivacaine required for elderly patients undergoing the great saphenous vein surgery. There was no significant difference in anesthesia associated adverse events among the three groups. The recommended dose of oxycodone is 2.5 mg.

Highly-efficient red-to-yellow/green upconversion sensitized by phthalocyanine palladium with high triplet energy-level.

Soluble 3,7,11,15-tetra(tert-butyl)phthalocyanine palladium (TBPcPd) and 3,7,11,15-tetra(pentyloxy)phthalocyanine palladium (POPcPd) were synthesized and employed as sensitizers in expectation of achieving red-to-yellow/green upconversion (UC), doped with rubrene (Rub) and 9,10-bis(phenylethynyl)anthracene (BPEA), respectively. Under excitation of a 655 nm diode laser (∼1.5 W cm-2), a maximum red-to-green UC efficiency of 0.07% and a maximum red-to-yellow UC efficiency of 8.03% were obtained and the latter can drive a Si-photodiode to generate obvious photocurrent. The results showed that although a large triplet energy-level difference (ΔE = 3 E sen. - 3 E anni.) of the sensitizer (3 E sen.)/annihilator (3 E anni.) pair helps to improve the upconversion, the sensitizer/annihilator pair with a ΔE value less than zero still works. However, when the ΔE ≤ -0.05 eV, this bicomponent pair is not valid anymore. Thus, a comparison of the ΔE value can predict whether the sensitizer/annihilator pair is useful, which presents a quantitatively evaluated approach for exploring new-type upconversion systems for the first time.

Hemodynamic study of the therapeutic effects of the different degrees of sigmoid sinus diverticulum reconstruction on patients.

Sigmoid sinus diverticulum (SSD) is a common pathophysiology of pulsatile tinnitus (PT) and mainly treated by SSD reconstruction surgery. The degree of reconstruction is an important indicator of SSD reconstruction surgery, but its impact on the effect of SSD reconstruction is unclear. This study aimed to clarify the effect of the degree of SSD reconstruction on diverticulum reconstruction surgical treatment. One patient-specific case (control subject) was reconstructed based on the computed tomography angiography (CTA) images of patients with PT. The SSD reconstruction degree was used as a new index in this study. And the case of 30% (case 1), 60% (case 2), and 100% (case 3) of the diverticulum reconstruction degree of control subject were constructed. Transient-state computational fluid dynamics was performed. Wall pressure distribution, wall average pressure (Pavg) of SSD, flow pattern (velocity streamlines and velocity vector), wall shear stress (WSS) and averaged WSS (WSSavg) were calculated and used in evaluating the hemodynamic differences among the DRD cases. Results demonstrated that change in SSD pressure was not linear with increase in DRD. The DRD that reached 60% of the original diverticulum was effective. At the peak point of the inlet boundary condition (T1 = 0.22s), the Pavg of SSD had a nonlinear change (control subject, 126.967 Pa vs. case 1, 126.274 Pa vs. case 2, 106.897 Pa vs. case 3, 94.116 Pa). Flow vorticity decreased gradually, and the smoothness of the streamlines increased with DRD. WSSavg slightly changed with increasing DRD. The high-speed flow blood hit the diverticulum entrance and then swirled to hit the area of the sigmoid sinus wall abnormal. It was concluded that flow patterns related to PT differ with DRD. In diverticulum reconstruction surgery, there is a threshold value, and only when the DRD exceeds this value (60% or 70% or 80%), it will have a noticeable effect. In this study, DRD should at least reach 60% of the original diverticulum. When DRD is insufficient, hemodynamic change in the diverticulum is small, and the PT may have remained. SSD may be caused by high-speed blood flow.

New species and new synonyms of Macromotettixoides (Orthoptera: Tetrigidae) with an updated key.

The genus Macromotettixoides Zheng, Wei Jiang, 2005 is reviewed. Four new species of the genus, M. daiyunshanensis Deng, sp. nov., M. curvicarina Deng, sp. nov., M. convexa Deng, sp. nov. and M. shengtangshanensis Deng, sp. nov. are described with detailed illustrations of external morphology. Two new synonyms are established: M. jinggangshanensis, syn. nov. is synonymized with M. jiuwanshanensis Zheng, Wei Jiang, 2005; M. parvula Zha Wen, 2017, syn. nov. is synonymized with M. undulatifemura Deng, Zheng Yang, 2012. Additionally, an updated key to species of the genus is given.

A stimuli responsive triplet-triplet annihilation upconversion system and its application as a ratiometric sensor for Fe3+ ions.

A ratiometric fluorescent sensor for the detection of Fe3+ ions is achieved based on triplet-triplet annihilation upconversion (TTA-UC) luminescence. A new anthracene derivative (named as DHTPA) is designed and synthesized and reveals similar optical properties to 9,10-diphenylanthracene (DPA) and is used as a stimuli responsive annihilator in a TTA-UC system due to its complexation ability. As a result, the UC emission can be significantly quenched by Fe3+ ions, while the phosphorescence (PL) emission of sensitizer palladium(ii) octaetylporphyrin (PdOEP) remains nearly constant, which makes the PL signal an appropriate internal reference for the UC signal. The UC and ratio signals (I UC/I PL) both reveal a good linear relationship with Fe3+ ion concentration, which for the first time makes the TTA-UC system a perfect ratiometric sensor for Fe3+ ion detection. This sensing method will open a novel avenue to achieve ratiometric sensors in chemical and biological fields.

Can Dexmedetomidine Improve Arterial Oxygenation and Intrapulmonary Shunt during One-lung Ventilation in Adults Undergoing Thoracic Surgery? A Meta-analysis of Randomized, Placebo-controlled Trials.

BACKGROUND: One-lung ventilation (OLV) is a common ventilation technology during thoracic surgery that can cause serious clinical problems. We aimed to conduct a meta-analysis to compare oxygenation and intrapulmonary shunt during OLV in adults undergoing thoracic surgery with dexmedetomidine (Dex) versus placebo to assess the influence and safety of using Dex. METHODS: Randomized controlled trials comparing lung protection in patients who underwent thoracic surgery with Dex or a placebo were retrieved from PubMed, EMBASE, MEDLINE, Cochrane Library, and China CNKI database. The following information was extracted from the paper: arterial oxygen partial pressure (PaO2), PaO2/inspired oxygen concentration (PaO2/FiO2, oxygenation index [OI]), intrapulmonary shunt (calculated as Qs/Qt), mean arterial pressure (MAP), heart rate (HR), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, superoxide dismutase (SOD), and malondialdehyde (MDA). RESULTS: Fourteen randomized controlled trials were included containing a total of 625 patients. Compared with placebo group, Dex significantly increased PaO2/FiO2(standard mean difference [SMD] = 0.98, 95% confidence interval [CI] [0.72, 1.23], P < 0.00001). Besides, Qs/Qt (SMD= -1.22, 95% CI [-2.20, -0.23], P = 0.020), HR (SMD= -0.69, 95% CI [-1.20, 0.17], P = 0.009), MAP (SMD= -0.44, 95% CI [-0.84, 0.04], P = 0.030), the concentrations of TNF-α (SMD = -1.55, 95% CI [-2.16, -0.95], P <0.001), and IL-6 (SMD = -1.53, 95% CI [-2.37, -0.70], P = 0.0003) were decreased in the treated group, when compared to placebo group. No significant difference was found in MDA (SMD = -1.14, 95% CI [-3.48, 1.20], P = 0.340) and SOD (SMD = 0.41, 95% CI [-0.29, 1.10], P = 0.250) between the Dex group and the placebo group. Funnel plots did not detect any significant publication bias. CONCLUSIONS: Dex may improve OI and reduce intrapulmonary shunt during OLV in adults undergoing thoracic surgery. However, this conclusion might be weakened by the limited number of pooled studies and patients.

Cancer survival in China, 2003-2005: a population-based study.

Limited population-based cancer registry data available in China until now has hampered efforts to inform cancer control policy. Following extensive efforts to improve the systematic cancer surveillance in this country, we report on the largest pooled analysis of cancer survival data in China to date. Of 21 population-based cancer registries, data from 17 registries (n = 138,852 cancer records) were included in the final analysis. Cases were diagnosed in 2003-2005 and followed until the end of 2010. Age-standardized relative survival was calculated using region-specific life tables for all cancers combined and 26 individual cancers. Estimates were further stratified by sex and geographical area. The age-standardized 5-year relative survival for all cancers was 30.9% (95% confidence intervals: 30.6%-31.2%). Female breast cancer had high survival (73.0%) followed by cancers of the colorectum (47.2%), stomach (27.4%), esophagus (20.9%), with lung and liver cancer having poor survival (16.1% and 10.1%), respectively. Survival for women was generally higher than for men. Survival for rural patients was about half that of their urban counterparts for all cancers combined (21.8% vs. 39.5%); the pattern was similar for individual major cancers except esophageal cancer. The poor population survival rates in China emphasize the urgent need for government policy changes and investment to improve health services. While the causes for the striking urban-rural disparities observed are not fully understood, increasing access of health service in rural areas and providing basic health-care to the disadvantaged populations will be essential for reducing this disparity in the future.

The influence of the severity of chronic virus-related liver disease on propofol requirements during propofol-remifentanil anesthesia.

PURPOSE: The purpose of this study was to investigate the influence of chronic virus- related liver disease severity on propofol requirements. MATERIALS AND METHODS: In this study, 48 male patients with chronic hepatitis B infection were divided into three groups according to Child-Turcotte-Pugh classification of liver function (groups A, B, and C with mild, moderate and severe liver disease, respectively). After intubation, propofol concentration was adjusted by ± 0.3 µg/mL increments to maintain bispectral index in the range of 40-60. Target propofol concentrations at anesthesia initiation, pre-intubation and pre-incision were recorded. RESULTS: The initial concentration used in group C was significantly lower than that used in group A or B (p<0.05), whereas no difference was observed between groups A and B. At pre-intubation, the actual required concentration of propofol increased significantly (3.2 µg/mL) in group A (p<0.05), which lead to significant differences between the groups (p<0.05). At pre-incision, the requirements for propofol decreased significantly in both groups A and B (3.0 µg/mL and 2.7 µg/mL, respectively) compared with those at pre-intubation (p<0.05), and were significantly different for all three groups (p<0.05), with group C demonstrating the lowest requirement (2.2 µg/mL). The required concentrations of propofol at pre-incision were similar to those at induction. CONCLUSION: In this study, propofol requirements administered by target-controlled infusion to maintain similar depths of hypnosis were shown to depend on the severity of chronic virus-related liver dysfunction. In other words, patients with the most severe liver dysfunction required the least amount of propofol.

Do the lungs contribute to propofol elimination in patients during orthotopic liver transplantation without veno-venous bypass?

BACKGROUND: The clearance of propofol is very rapid, and its transformation takes place mainly in the liver. Some reports indicated extrahepatic clearance of the drug and that the lungs are the likely place where the process occurs. This study was undertaken to compare the plasma concentrations of propofol both in the pulmonary and radial arteries after constant infusion during the dissection, anhepatic and reperfusion phases of orthotopic liver transplantation (OLT) without veno-venous bypass, attempting to investigate extrahepatic clearance and to determine whether the human lungs take part in the elimination of propofol. METHODS: Fifteen patients undergoing OLT without veno-venous bypass were enrolled in the study, and propofol was infused via a forearm vein at a rate of 2 mg x kg-1 x h-1. Blood samples were simultaneously collected from pulmonary and radial arteries at the end of the first hepatic portal dissection (T0), at the clamping of the portal vein (T1), 30, and 60 minutes after the beginning of the anhepatic phase (T2, T3), and 30, 60, and 120 minutes after the unclamping of the new liver (T4, T5, T6). Plasma propofol concentrations were measured using a reversed-phase, high-performance liquid chromatographic method with fluorescence detection. RESULTS: The concentrations of plasma propofol in the pulmonary and radial arteries at T2 and T3 rose significantly compared with T0 and T1 (P<0.01) respectively. After reperfusion, the drug concentrations at T4, T5 and T6 decreased significantly compared with T2, T3 (P<0.01) respectively. There were no significant differences in plasma propofol concentrations between the pulmonary and radial arteries at any time points. CONCLUSIONS: Propofol is eliminated mainly by the liver, and also by extrahepatic organs. The lungs seem to be not a major site contributing to the extrahepatic metabolism of propofol in humans.

Plasma levels of tumor necrotic factor-alpha and interleukin-6, -8 during orthotopic liver transplantation and their relations to postoperative pulmonary complications.

BACKGROUND: Pulmonary complications after orthotopic liver transplantation (OLT) include high morbidity and mortality. Experimental data have suggested hepatic ischemia and reperfusion are induced by pro-inflammatory cytokines. The high level of inflammatory cytokines might additionally influence pulmonary capillary fluid filtration. The objectives of this study were to measure the concentrations of tumor necrotic factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) during OLT and to investigate the relationship between these cytokines and postoperative pulmonary complications. METHODS: Twenty-two patients undergoing OLT were divided into two groups according to whether they had postoperative pulmonary complications: group A consisting of 8 patients with postoperative pulmonary complications, and group B consisting of 14 patients without postoperative pulmonary complications. Enzyme-linked immunoassay (ELISA) was used to determine serum TNF-alpha, IL-6 and IL-8. Blood samples were taken at the beginning of operation (T0), clamping and cross-clamping of the inferior cava and portal vein (T1, T2), 90 minutes and 3 hours after reperfusion (T3, T4) and 24 hours after operation (T5). RESULTS: The level of PaO2/FiO2 in group A was lower than that in group B (P<0.05). The concentrations of TNF-alpha, IL-6 and IL-8 in the two groups increased rapidly at T2, peaked at T3, decreased rapidly after T3 until 24 hours after operation. The concentrations of TNF-alpha, IL-6 and IL-8 in group A were higher than those in group B at T2, T3, and T4 (P<0.05). CONCLUSION: After un-clamping of the inferior cava and portal vein, the serum concentrations of TNF-alpha, IL-6 and IL-8 increased may be related to pulmonary injury after hepatic ischemic reperfusion.