Application progress of point-of-care ultrasound monitoring inferior vena cava in volume management of critically ill patients / 中华危重病急救医学

Determining whether patients have volume-responsiveness is one of the frequently asked questions in the intensive care unit, especially in shock patients. Evaluating the volume status and volume responsiveness can help clinical medical staff accurately grasp the patient's cardiac preload, guide reasonable volume management, and help improve patient prognosis. Therefore, many non-invasive and invasive methods have been proposed to evaluate volume responsiveness. Inferior vena cava ultrasound has been widely used to guide the fluid management of critically ill patients due to its simplicity, non-invasiveness, and good repeatability. This article reviews the clinical applications of inferior vena cava ultrasound in fluid management of critically ill patients, so as to provide a reference for circulatory management of critically ill patients.

Resolvin D1 attenuates lipopolysaccharide induced acute lung injury through CXCL-12/CXCR4 pathway.

BACKGROUND: The recruitment of neutrophils plays an important role in the progress of acute lung injury (ALI). Excessive neutrophils released from bone marrow accumulate in lung, release proinflammatory factors, and cause tissue damage. CXCL-12/CXCR4 is an important signaling pathway, which regulates the migration of bone marrow hematopoietic cells out of bone marrow and involves in neutrophil accumulation and retention in the inflammatory site. Resolvin D1 (RvD1) is a kind of lipid mediators, which can alleviate many inflammatory diseases. We hypothesized that RvD1 can alleviate lipopolysaccharide (LPS)-induced ALI through regulating CXCL-12/CXCR4 pathway. METHODS: We randomized mice into five groups: control group, RvD1 group, LPS group, LPS plus RvD1 group, and LPS plus AMD3100 group. ALI was established by intratracheal instillation of LPS. After 24 and 72 h, mice were sacrificed, and lung tissues were harvested for histologic analysis, wet-to-dry ratio, myeloperoxidase activity, and CXCL-12 expression. Bronchoalveolar fluid was collected for protein analysis, cytokines assay, and flow cytometry analysis. RESULTS: Histologic findings as well as wet-to-dry ratio, protein concentration, cytokines assay, neutrophil number, and myeloperoxidase activity confirmed that RvD1 and AMD3100 alleviated LPS-induced ALI. RvD1 decreased CXCL-12 messenger RNA expression in lung. However, RvD1 promoted CXCR4 expression in neutrophils in the initial stage of inflammation and reduced its level in the later stage. CONCLUSIONS: RvD1 protects LPS-induced ALI partially through regulating CXCL-12/CXCR4 pathway.

Effect of α-lipoic acid on cognitive function after cardiopulmonary bypass in diabetic rats / 中华麻醉学杂志

Objective To evaluate the effect of α-lipoic acid on the cognitive function after cardiopulmonary bypass (CPB) in diabetic rats.Methods Health adult male Sprague-Dawley rats,weighing 400-500 g,aged 16-22 weeks,were used in this study.Diabetes mellitus was induced by intraperitoneal streptozocin 60 mg/kg and confirmed by blood glucose≥ 16.7 mmol/L.Thirty-two diabetic rats were randomly divided into 2 groups (n =16 each):diabetes mellitus group (group D) and α-lipoi cacid group (group L).In group L,α-lipoic acid 30 mg/kg was intraperitoneally injected once a day for 7 consecutive days starting from 6th week after induction of diabetes mellitus.While the equal volume of normal saline was given instead in group D.The two groups underwent CPB after the last administration.Before induction of diabetes mellitus,on 5th week after induction of diabetes mellitus,before CPB,at the end of CPB,and on 3 and 5 days after termination of CPB,10 rats were chosen from each group and venous blood samples were collected for determination of plasma TNF-α and IL-10 concentrations.Ten rats in each group were chosen for detection of cognitive function before induction of diabetes mellitus,before CPB and 5 days after termination of CPB.The rats were then sacrificed and hippocampi were isolated for measurement of NF-κB activity.Results Compare with group D,the plasma TNF-α concentration,times of electric shock and activity of NF-κB in hippocampal tissues were significantly decreased and the plasma IL-10 concentration was increased in group L (P ＜ 0.05 or 0.01).Conclusion α-lipoic acid can improve the cognitive function after CPB in diabetic rats and inhibition of activation of NF-κB in hippocampal neurons is involved in the mechanism.

Effects of mechanical stretch on expression of pentraxin-3 mRNA and protein in A549 cells / 中华麻醉学杂志

Objective To evaluate the effects of mechanical stretch on pentraxin-3(PTX-3)mRNA and protein expression in human alveolar epithelial cells (A549 cells).Methods The human lung epithelial adenocarcinoma cells A549(A549 cells)were purchased from cell biology laboratory,Tongji Medical College,Huazhong University of Science and Technology.The cultured A549 cells were inoculated on collagen Ⅰ BioFlex plates and divided into 5 groups(n=3 wells each):group Ⅰ normal control;groupⅡsham mechanical stretch;group Ⅲ mechanical stretch;groupⅣsiRNA and groupⅤ siRNA+mechanical stretch.In group Ⅲ the cells underwent square cyclic mechanical stretch for 4 h using the Flexercell Systcm.In group Ⅳ the cells were transfected with chemosynthetic PTX-3 specific siRNA by RNAi technique.In group Ⅴ at 24 h after being transfected with PTX-3 siRNA the cells underwent mechanical stretch for 4 h.In groupⅡ mechanical stretch of the cells were prevented by Flexstep.The expression of PTX-3 mRNA in the cells was detected by real-time PCR and the expression of PTX-3 protein in the culture media was determined by Western blotting.Apoptosis of the cells was measured bv flow cytometry(Beeten-Dickinson,USA).Results PTX-3 mRNA and protein expression was signlficantly up-regulated by mechanical stretch in groupⅢand decreased by transfection with siRNA in group Ⅳand Ⅴ as compared with group Ⅰ andⅡ(P＜0.05 or 0.01).The apoptosis ratio was significantly higher in group Ⅲ and Ⅴ than in groupⅡ and was significantly lower in group Ⅴ thanin group Ⅲ(P＜0.01).Conclusion Mechanical stretch can up-regulate PTX-3 mRNA expression in A549 cells.

Effects of mechanical stretch on the expression of human beta-defensin-3 in alveolar epithelial cells elicited by interferon- gamma / 中华急诊医学杂志

Objective To study the effect of mechanical stretch on the expression of human beta-defensin-3 (HBD-3) in alveolar epithelial cells(A549 cells) elicited by interferon-gamma(IFN-γ) and to investigate the role of HBD-3 in the pathogenesis of ventilator-associated pneumonia (VAP) . Method A549 cells cultured in vitro were treated with mechanical stretch (group S), 10 ng/ml IFN-γ (group I) ,and 10 ng/ml IFN-γ with mechanical stretch (group IS), respectively. Cells without treatment served as controls (group C). Cells were stretched by 20% amplitude of stretch at 30 cycles/mm by Flexercell-4000[TM]Unit for 2 h, 4 h, and 6 hours. The HBD-3 mRNA expression was determined by real-time RT-PCR after treatment. After 6 hours, treatment, cells were cultured for 24 hours and the expression of HBD-3 was examined by laser scanning confocal microscope. The experimental data were statistically analyzed by using one-way ANOVA analysis and q-test. Results The expression of HBD-3 mRNA in A549 cells could not significantly be changed by mechanical stretch alone. Compared with group C,the HBD-3 mRNA expression after treatment with 10 ng/ml IFN-γ for 2 hours,4 hours and 6 hours increased significantly by (2.63 C,the HBD-3 mRNA expression after treatment with 10 ng/ml IFN-γ and mechanical stretch for 2 hours,4 hours and 6 hours increased by (1.54 were significantly lower than those in group I (P < 0.01). The HBD-3 expression in group IS after mechanical stretch for 6 significantly different from than in group C. Conclusions Mechanical stretch can significantly suppress the up-regulation of HBD-3 in alveolar epithelial cells elicited by IFN-γ, and this may be one of the explaina-tions that patients under mechanical ventilatiori(MV) have a higher risk of VAP.

Pharmacokinetics of different concentration of ropivacaine following lumbar plexus combined with sciatic nerve block / 中华麻醉学杂志

Objective To evaluate the pharmacokinetics of ropivacaine following lumbar plexus combined with sciatic nerve block for knee arthroscopy. Methods After obtaining written informed consent 16 ASAⅠorⅡpatients of both sexes (8 males ,8 females) scheduled for unilateral knee arthroscopy under lumbar plexus combined with sciatic nerve block with ropivacaine were randomly divided into 2 groups (n = 8 each) : group A received 0.5% ropivacaine 30 ml (15.0 mg) and group B received 0.75% ropivacaine 30 ml (22.5 mg) . Blood samples were taken from radial artery immediately after and at 5, 10, 15, 30, 45, 60, 120 and 180 min after drug administration for determination of plasma ropivacaine concentration by HPLC. The pharmacokinetic parameters were calculated using 3p97 computer program. Results The two groups were comparable with respect to sex ratio (M/F), age, body weight, height, duration of operation and amount of fluid infused. The main pharmacokinetic parameters in group A and B were: Cmax(1.4?0.3) mg?L-1 and (2.7?0.9) mg?L-1;AUC (3.88?0.28) mg?L-1?h-1 and (7.13?0.65) mg?L-1?h-1;t1/2?(0.44?0.19)h and (0.60?0.34)h; t1/2?(3.4?0.4)h and (2.4?0.5)h. The Cmax in group B was significantly higher than that in group A. The Cmax of ropivacaine reached 3.57 mg?L-1 in group B. No patient developed central nervous system or cardiac toxicity.Conclusion The plasma concentration versus time curve is fitted to two-compartment pharmacokinetic model. Lumbar plexus combined with sciatic nerve block with 0.5% ropivacaine 30 ml is safer.