经鼻导管高流量吸氧与经鼻气道正压通气在重症毛细支气管炎呼吸支持中的应用价值比较

目的：比较经鼻导管高流量吸氧（HFNC）与经鼻气道正压通气（nCPAP）在重症毛细支气管炎呼吸支持中的应用价值，为临床治疗方案的选择提供参考。方法：选取2016年12月至2018年12月我院儿科收治的重症毛细支气管炎患儿90例，采用随机数字表法分为观察组和对照组各45例。两组患儿入院后均给予常规综合治疗以保证呼吸道通畅，在此基础上观察组采用HFNC治疗，对照组采用nCPAP治疗，比较两组患儿治疗前和治疗24 h后呼吸频率、经皮血氧饱和度（TcSO2）、呼吸窘迫评分体系（CSS）评分、动脉血氧分压（PaO2）等呼吸相关指标及治疗前后临床症状体征改善情况。结果：两组患儿治疗24 h后呼吸频率、CSS评分均降低，且观察组降低程度更大，TcSO2、PaO2于治疗24 h后升高，观察组升高幅度较对照组明显；治疗后两组患儿咳嗽及肺部湿啰音、肺部炎症情况均改善，观察组症状体征消失时间早于对照组，差异均有统计学意义（P<0.05）。结论：重症毛细支气管炎患儿采用HFNC治疗可明显改善通气功能和临床症状，治疗效果优于nCPAP治疗，可扩大样本量进一步观察。     

Modern theatre design and usage: do joint replacements need laminar flow?

Since the introduction of laminar flow to theatre systems by Charnley, it has become a necessity in arthroplasty surgery. His initial work in the 1960s and 70s created improvements in terms of reducing overall rates of periprosthetic joint replacement, but it has been hard to ascertain if this stems from the laminar flow itself or improvements in asepsis and the utilization of perioperative antibiotics. The aim of this paper is therefore to establish if laminar flow is still a necessary addition to modern theatre design, particularly in joint replacement surgery, irrespective of other surgical factors. A wide variety of studies were utilized to form an objective analysis of whether laminar flow is essential to asepsis in theatre design. It explores a number of smaller earlier studies and ends with two large trials which provide evidence that laminar flow may in fact have a deleterious effect on the potential for peri-prosthetic joint infection (PJI). The article discusses potential reasons for these findings and seeks to explain them in context of overall asepsis during joint replacement surgery.     

Stress habituation,body shape and cardiovascular mortality

High cardiovascular mortality is well documented in lean phenotypes exhibiting visceral fat accumulation. In contrast, corpulent phenotypes with predominantly subcutaneous fat accumulation display a surprisingly low mortality. The term ‘obesity paradox’ reflects the difficulty in understanding the biological mechanisms underlying these clinical observations. The allostatic load model of chronic stress focuses on glucocorticoid dysregulation as part of a ‘network of allostasis’ involving autonomic, endocrine, metabolic, and immune mediators. Here, we expand upon the energetic demands of the brain and show that ‘habituators’ and ‘non-habituators’ develop divergent patterns of fat distribution. Central to this process is the recurrent rise in the cerebral energy need (arousal) that non-habituators experience during chronic stress. These neuroenergetic alterations promote visceral fat accumulation, subcutaneous fat loss, and atherogenesis with subsequent cardiovascular events. Habituators are more or less protected against such cardiovascular complications, but there is a metabolic trade-off that we shall discuss in the present paper.     

Perfusion pressure flow study in the upper urinary tract

Hydronephrosis with an undetermined pathology is a common condition detected in imaging studies. In urological clinical practice, it is a persistent dilemma to predict whether this condition will progress to result in the deterioration of renal function. Perfusion pressure flow study of the upper urinary tract, known as the Whitaker test, provides an alternative diagnostic tool for solving this condition. Perfusion pressure flow study has been criticized for its invasiveness, nonphysiological approach, and inconsistency in predicting outcomes. However, it continues to be used to evaluate difficult or equivocal cases and to provide an objective assessment of the upper urinary tract.     

颈内静脉内径呼吸变异度和血流速度在椎管内麻醉后容量预测中的价值

目的探究超声测量颈内静脉内径呼吸变异度和血流速度在椎管内麻醉后血容量判断中的价值。方法选择我院2017年2月至2019年2月择期手术的椎管内麻醉患者120例,男64例,女56例,年龄为34～66岁,ASAⅠ或Ⅱ级。记录麻醉前、麻醉后5、15、25 min左侧颈内静脉最大直径(Dmax)、最小直径(Dmin)、内径呼吸变异度(RVI)、中心静脉压(CVP)、血流速度最大值(BVmax)、血流速度最小值(BVmin)和血流速度变异度(BVI),取CVP=6 mmHg作为预测值,并通过绘制ROC曲线来评估Dmax、Dmin、RVI、BVmax、BVmin和BVI的预测效能。结果与麻醉前比较,麻醉后5 min时Dmax、Dmin和BVI明显降低(P0.05),RVI明显升高(P0.05);与麻醉后5和15 min比较,麻醉后25 min,Dmax、Dmin和BVI明显升高(P0.05),RVI明显降低(P0.05)。麻醉前BVmin的AUC值最大为0.958,临界值6.86,敏感性82.6%,特异性95.2%;麻醉后5 min,Dmin的AUC值最大为0.944,临界值0.74,敏感性98.4%,特异性84.3%;麻醉后15 min,Dmin和BVmax的AUC值最大分别为0.949和0.945,临界值分别为0.72和7.99,敏感性分别为96.5%和89.8%,特异性分别为82.4%和82.1%;麻醉后25 min,BVmax的AUC值最大为0.981,临界值8.98,敏感性92.0%,特异性90.5%。结论超声测量患者颈内静脉的内径变异度和血流速度可作为预测椎管内麻醉后血容量的方式。     

Assessment of extracellular vesicles using IFC for application in transfusion medicine

Extracellular vesicles (EVs) have been shown to be involved in various physiological and pathophysiological processes. With respect to Transfusion Medicine, the accumulation of EVs in blood products during hypothermic storage is an indicator of the storage lesion and reportedly correlates with adverse effects after transfusion, including but not limited to immunomodulation, activation of coagulation, endothelial activation, and others. To optimally reduce such an impact on blood product quality degradation and improve post-transfusion outcomes, better methods for detection, enumeration, characterisation by size and phenotype, and functional involvement of EVs in different pathophysiological and physiological processes are required. Currently, Imaging Flow Cytometry (IFC) technology provides the most comprehensive assessment of EV subsets in different body fluids. The unique ability of IFC to detect EVs of 20 nm size by registration of a single pixel of fluorescence signal makes this approach highly promising for comprehensive studies of EVs. In this review, we will focus on the recent breakthrough and advantages of using the ImageStream^X MKII IFC platform for the detection and characterisation of EVs and its future prospects for routine application of IFC in Transfusion Medicine.     

Packed red blood cell transfusion (PRBC) attenuates intestinal blood flow responses to feedings in pre-term neonates with normalization at 24 hours

Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.

Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion.     

Distribution of temperature changes and neurovascular coupling in rat brain following 3,4‐methylenedioxymethamphetamine (MDMA, “ecstasy”) exposure

(+/?)3,4‐methylenedioxymethamphetamine (MDMA, “ecstasy”) is an abused psychostimulant that produces strong monoaminergic stimulation and whole‐body hyperthermia. MDMA‐induced thermogenesis involves activation of uncoupling proteins (UCPs), primarily a type specific to skeletal muscle (UCP‐3) and absent from the brain, although other UCP types are expressed in the brain (e.g. thalamus) and might contribute to thermogenesis. Since neuroimaging of brain temperature could provide insights into MDMA action, we measured spatial distributions of systemically administered MDMA‐induced temperature changes and dynamics in rat cortex and subcortex using a novel magnetic resonance method, Biosensor Imaging of Redundant Deviation in Shifts (BIRDS), with an exogenous temperature‐sensitive probe (thulium ion and macrocyclic chelate 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetramethyl‐1,4,7,10‐tetraacetate (DOTMA^4?)). The MDMA‐induced temperature rise was greater in the cortex than in the subcortex (1.6 ± 0.4 °C versus 1.3 ± 0.4 °C) and occurred more rapidly (2.0 ± 0.2 °C/h versus 1.5 ± 0.2 °C/h). MDMA‐induced temperature changes and dynamics in the cortex and body were correlated, although the body temperature exceeded the cortex temperature before and after MDMA. Temperature, neuronal activity, and blood flow (CBF) were measured simultaneously in the cortex and subcortex (i.e. thalamus) to investigate possible differences of MDMA‐induced warming across brain regions. MDMA‐induced warming correlated with increases in neuronal activity and blood flow in the cortex, suggesting that the normal neurovascular response to increased neural activity was maintained. In contrast to the cortex, a biphasic relationship was seen in the subcortex (i.e. thalamus), with a decline in CBF as temperature and neural activity rose, transitioning to a rise in CBF for temperature above 37 °C, suggesting that MDMA affected CBF and neurovascular coupling differently in subcortical regions. Considering that MDMA effects on CBF and heat dissipation (as well as potential heat generation) may vary regionally, neuroprotection may require different cooling strategies. Copyright © 2015 John Wiley & Sons, Ltd.