Trans-Thoracic Echocardiographic Aortic Blood Flow Peak Velocity Variation, Distance Minute, Aortic Velocity Time Integral and Postoperative Outcome in Pediatric Surgical Patients—An Observational Pilot Study Protocol

Background: A Randomized Controlled Trial (RCT) has been elaborated where goal directed fluid and hemodynamic therapy (GDFHT) will be realized with trans-thoracic echocardiographic aortic blood flow peak velocity variation (ΔVpeak) and distance minute (DM) to guide fluid therapy and hemodynamics in high risk pediatric surgical patients. This RCT will clarify the impact of GDFHT with ΔVpeak and DM on postoperative outcome in terms of morbidity, length of stay in the intensive care unit (LOSICU), length of mechanical ventilation (LMV) and length of hospital stay (LOS) in children. To determine values of ΔVpeak, DM and VTI predictive of these postoperative outcomes, an observational pilot study will be realized. This pilot study is described here. The primary objective of this study is to determine values of ΔVpeak, DM and ITV predictive of postoperative outcome in children in terms of morbidity. The secondary objectives are to determine values of ΔVpeak, DM and ITV predictive of LOSICU, LMV, LOS, intraoperative, postoperative fluid administration and vasoactive-inotropic therapy. Methods: 500 - 1000 children aged less than 18 years will be included prospectively. Statistic analysis will be realized with XLSTAT 2019.4.2 software or plus. Results and Conclusions: This trial protocol will determine values of ΔVpeak, DM and ITV with echocardiography predictive of postoperative outcome in children.

iFlow彩色血流编码成像技术在下肢动脉硬化闭塞症诊断中的应用价值

目的研究iFlow彩色血流编码成像技术在下肢动脉硬化闭塞症(LEASO)诊断中的应用价值。方法选择2022年3月至2023年10月期间确诊的106例LEASO患者作为本研究的LEASO组,以一般资料与LEASO组匹配且无动脉病变的80例志愿者作为对照组。两组受试者均进行数字减影血管造影(DSA)并采用iFlow彩色血流编码成像技术检测股骨头区域和踝关节区域达峰时间(TTP)、计算踝关节区域与股骨头区域TTP的差值,测量踝肱指数(ABI)。结果两组研究对象年龄、性别、体质量指数、吸烟史、高血压病史、糖尿病史、冠心病史、股骨头区域TTP的比较,差异无统计学意义(P>0.05);LEASO组踝关节区域TTP及TTP差值均高于对照组,差异有统计学意义(P<0.05);LEASO组中不同Rutherford分类患者股骨头区域TTP的比较以及左侧病变患者与右侧病变患者股骨头区域TTP、踝关节区域TTP、TTP差值的比较,差异无统计学意义(P>0.05),Rutherford分类越高,踝关节区域TTP及TTP差值越低(P<0.05);经Pearson检验,LEASO患者的踝关节区域TTP、TTP差值与ABI呈负相关(P<0.05);经受试者工作特征(ROC)曲线分析,踝关节区域TTP、TTP差值对LEASO具有诊断效能;经Delong检验,TTP差值诊断的ROC曲线下面积高于踝关节区域TTP(P<0.05)。结论iFlow彩色血流编码成像技术测定踝关节区TTP及TTP差值是诊断LEASO的量化指标。

Using Path Analysis to Identify the Influence of Climatic Factors on Spring Peak Flow Dominated by Snowmelt in an Alpine Watershed

Spring snowmelt peak flow （SSPF） can cause serious damage. Precipitation as rainfall directly contributes to the SSPF and influences the characteristics of the SSPF, while temperature indirectly impacts the SSPF by shaping snowmelt rate and determining the soil frozen state which partitions snowmelt water into surface runoff and soil infiltration water in spring. It is necessary to identify the important and significant paths of climatic factors influencing the SSPF and provide estimates of the magnitude and significance of hypothesized causal connections between climatic factors and the SSPF. This study used path analysis with a selection of five factors - the antecedent precipitation index （API）, spring precipitation （SP）, winter precipitation as snowfall （WS）, 〈0℃ temperature accumulation in winter （[ATNI）, and average 〉0℃temperature accumulation in spring （AT） - to analyze their influences on the SSPF in the Kaidu River in Xinjiang, China. The results show that {ATN}, AT and WS have a significant correlation with the SSPF, while API and SP do not show a significant correlation. AT and WS directly influence the SSPF, while as the influence of[ATN] on SSPF is indirect through WS and AT. The indirect influence of [ATN[ on SSPF through WS accounts for 69% of the total influence of [ATN] on SSPF. Compared to the multiple linear regression method, path analysis provides additional valuable information, including influencing paths from independent variables to the dependent variable as well as direct and indirect impacts of external variables on the internal variable. This information can help improve the description of snow melt and spring runoff in hydrologic models as well as the planning and management of water resources.

The effects of rainfall regimes and rainfall characteristics on peak discharge in a small debris flow-prone catchment

Peak discharge plays an important role in triggering channelized debris flows.The rainfall regimes and rainfall characteristics have been demonstrated to have important influences on peak discharge.In order to explore the relationship between rainfall regimes and peak discharge,a measuring system was placed at the outlet of a small,debris flow-prone catchment.The facility consisted of an approximately rectangular stilling basin,ending with a sharp-crested weir.Six runoff events were recorded which provided a unique opportunity for characterizing the hydrological response of the debris flow-prone catchment.Then,a rainfall–runoff model was tested against the flow discharge measurements to have a deep understanding of hydrological response.Based on the calibrated rainfall-runoff model,twelve different artificially set rainfall patterns were regarded as the input parameters to investigate the effect of rainfall regimes on peak discharge.The results show that the rainfall patterns have a significant effect on peak discharge.The rainfall regimes which have higher peak rainfall intensity and peak rainfall point occur at the later part of rainfall process are easy to generate larger peak discharge in the condition of the same cumulative rainfall and duration.Then,in order to explore the relationship between rainfall characteristics and peak discharge under different cumulative precipitation and different duration,167 measured rainfall events were also collected.On the basis of rainfall depth,rainfall duration,and maximum hourly intensity,all the rainfall events were classified into four categories by using K-mean clustering.Rainfall regime 1 was composed of rainfall events with a moderate mean P(precipitation),a moderate D(duration),and a moderate I60(maximum hourly intensity).Rainfall regime 2 was the group of rainfall events with a high mean P,long D.Rainfall regime 3,however,had a low P and a long D.The characteristic of Rainfall regime 4 was high I60 and short duration with large P.The results show that the rainfall regime 2 and 4 are easier to generate peak discharge as the rainfall intensity plays an important role in generating peak discharge.The results in this study have implications for improving peak discharge prediction accuracy in debris flow gully.

Development of Upstream Data-Input Models to Estimate Downstream Peak Flow in Two Mediterranean River Basins of Chile

Accurate flood prediction is an important tool for risk management and hydraulic works design on a watershed scale. The objective of this study was to calibrate and validate 24 linear and non-linear regression models, using only upstream data to estimate real-time downstream flooding. Four critical downstream estimation points in the Mataquito and Maule river basins located in central Chile were selected to estimate peak flows using data from one, two, or three upstream stations. More than one thousand paper-based storm hydrographs were manually analyzed for rainfall events that occurred between 1999 and 2006, in order to determine the best models for predicting downstream peak flow. The Peak Flow Index (IQP) (defined as the quotient between upstream and downstream data) and the Transit Times (TT) between upstream and downstream points were also obtained and analyzed for each river basin. The Coefficients of Determination (R2), the Standard Error of the Estimate (SEE), and the Bland-Altman test (ACBA) were used to calibrate and validate the best selected model at each basin. Despite the high variability observed in peak flow data, the developed models were able to accurately estimate downstream peak flows using only upstream flow data.

利用Flow-3D软件数值模拟堰塞坝溃决过程

利用Autodesk Civil3D软件,根据卫星遥感测绘获取的高程数据,建立唐家山堰塞坝三维数值模型,运用Flow-3D软件,模拟堰塞坝溃决过程,并通过与现场测量的溃口流量过程对比验证模型的合理性。堰塞坝漫顶冲蚀分3个阶段:快速溃口发展阶段、洪峰阶段、溃口发展减缓阶段。在溃决过程中,泄流渠中陡坎处的流速较快,泄流渠两岸冲蚀最深;唐家山堰塞坝溃决过程中,泄流渠有溯源侵蚀现象出现。参数敏感性分析表明:起溃水位对溃决过程影响显著;开挖泄流渠可有效降低堰塞坝溃决时的库水位,从而降低溃口的峰值流量,是控制危害损失的有效方案。

Combination of diaphragmatic breathing with therapeutic walking exercise to increase peak expiratory flow rate in asthma patients

Objective:This study aimed to determine the effect of combined diaphragmatic breathing and therapeutic walking exercise on peak expiratory flow in asthma patients.Methods:The research design used a quasi-experiment nonequivalent pretest and posttest design.The research sample contained 38 respondents divided into intervention and control groups,selected by simple random sampling.The control group received standard drug therapy,while the intervention group received standard drug therapy and a combination of diaphragmatic breathing and therapeutic walking exercise for 2 weeks.This exercise was carried out in the morning,6 times a week,with 5 diaphragmatic breathing and exhalations per exercise.After that,a 1-min break was followed by a therapeutic walking exercise of 5–15 min,with an increased duration.Both groups measured the peak expiratory flow before and after the intervention using a peak flow meter.The data analysis used central tendency and t-test.Results:The results showed that the mean peak expiratory flow in the intervention group was 306.84,while in the control group,it was 232.63,with the value of the t-test being-14.17(P<0.0001).Conclusions:Diaphragmatic breathing and therapeutic walking exercise significantly increased the peak expiratory flow in asthma patients.

森林结构差异对大兴安岭森林小流域径流情势和退水特征的影响

径流情势和流域退水是反映水文过程至关重要的指标,除气候因素外,主要受到下垫面和流域水文地质特征的影响。利用准配对流域法,对比大兴安岭地区森林结构不同的2个小流域(老爷岭流域、圣诞村流域),排除气候和地形地貌的干扰,探究森林结构变化对流域径流情势及退水过程的影响。结果表明:老爷岭流域的全年洪峰历时比圣诞村流域延长5 h、平均洪峰滞时推迟2 h,洪峰径流量、变异系数均无显著差异。随着森林平均蓄积量、树种组成、郁闭度等森林结构指标的提高,老爷岭流域(森林结构综合指数较高)较圣诞村流域(森林结构综合指数低)的枯水径流时间低4 h,平均枯水径流深提高0.65 mm(是圣诞村流域3倍),平均枯水径流变异系数低33%,且流域间差异均达到了极显著水平(P<0.01)。通过退水分析,结果表明:老爷岭流域和圣诞村流域退水系数(k)的均值分别为16.9、8.5 d,退水常数(α)均值分别为0.909 4、0.862 6,老爷岭流域的平均退水时间比圣诞村流域延缓了8.4 d。该地区流域水文特征受森林植被变化的影响明显,森林结构复杂、森林质量高的老爷岭流域枯水径流量高并且稳定,退水过程更慢,水源涵养功能更好。

经阴道彩色多普勒超声在子宫内膜病变患者中的应用价值

目的分析经阴道彩色多普勒超声在子宫内膜病变患者中的应用价值。方法选取2021年2月至2022年4月南昌大学第四附属医院收治的88例子宫内膜病变患者作为研究对象,所有患者均接受经阴道彩色多普勒超声及病理学检查,按照病理学检查结果将患者分为息肉组与癌变组,每组44例。比较两组二维超声子宫内膜情况、病灶血流动力学情况、经阴道彩色多普勒超声血流相关参数;以病理学检查结果为金标准,分析经阴道彩色多普勒超声对子宫内膜癌变的诊断效能。结果癌变组子宫内膜厚度厚于息肉组,内膜-肌层分界清晰、病灶回声均匀占比均低于息肉组,差异有统计学意义(P<0.05);癌变组血流丰富占比高于息肉组,差异有统计学意义(P<0.05);癌变组血流阻力指数(RI)、搏动指数(PI)均低于息肉组,时间平均峰值流速(TAP)慢于息肉组,差异有统计学意义(P<0.05);经阴道彩色多普勒超声对子宫内膜癌变的诊断灵敏度为86.36%,特异度为84.09%,准确度为85.23%;诊断息肉的灵敏度为84.09%,特异度为86.36%,准确度为85.23%。结论经阴道彩色多普勒超声对子宫内膜病变的诊断准确率较高,能通过血流动力学、RI、PI、TAP及影像学表现鉴别息肉或癌变。

床旁即时超声测量动脉峰流速呼吸变异度评价危重症患者容量反应性的临床价值

目的评估床旁即时超声(POCUS)测量动脉峰流速呼吸变异度(△Vpeak)评价危重症患者容量反应性的临床价值。方法回顾性选取川北医学院附属医院于2021年1月至2023年6月收治的100例危重症患者作为研究对象,所有患者均接受容量负荷(VE)试验,根据患者容量反应性分为有反应组[容量负荷后心脏每搏量(SV)增加≥15%,n=56]与无反应组(心脏指数增加<15%,n=44)。容量负荷前后均对患者实施床旁即时超声测量及中心静脉压(CVP)、脉压变异率(PPV)检测,比较两组容量负荷前后△Vpeak[主动脉血流峰流速(△Vpeak-AO)、颈总动脉血流峰流速(△Vpeak-CA)、肱动脉血流峰流速(△Vpeak-BA)、股动脉血流峰流速(△Vpeak-FA)]、CVP、PPV指标,并绘制受试者工作特征(ROC)曲线分析△Vpeak对危重症患者容量反应性的预测价值。结果容量负荷前,有反应组患者的△Vpeak-AO、△Vpeak-CA、△Vpeak-BA、△Vpeak-FA以及PPV分别为(15.42±4.24)%、(14.24±3.24)%、(13.29±2.54)%、(12.35±2.24)%、(13.32±2.53)%,均高于无反应组[(10.93±4.63)%、(10.48±3.16)%、(9.48±2.68)%、(7.84±2.16)%、(9.35±1.27)%],差异均有统计学意义(P<0.05),两组患者CVP比较差异无统计学意义(P>0.05);容量负荷后,有反应组与无反应组各项△Vpeak指标与PPV、CVP比较差异均无统计学意义(P>0.05)。△Vpeak-AO、△Vpeak-CA、△Vpeak-BA、△Vpeak-FA对危重症患者容量反应性敏感度、特异度及曲线下面积高于PPV。结论床旁即时超声测量△Vpeak能够有效预测危重症患者容量反应性,为临床诊断及治疗提供指导,具有较高临床价值。

机械性吸呼仪参数设置对模拟肺呼气峰流速、呼气容量的影响研究

目的:探讨使用机械性吸呼仪(mechanical in-exsufflation,MIE)治疗中的吸气压力设置参数(set inspiratory pressure,SIP)、呼气压力设置参数(set expiratory pressure,SEP)及SIP/SEP对模拟肺呼气峰流速(peak expiratory flow,PEF)和呼气容量(expiratory volume,EV)的影响,以为临床治疗中增强气道廓清的效果提供参考。方法:将MIE与模拟肺连接,在模拟肺无自主呼吸状态下分别针对健康成人、肺部感染成人、慢性阻塞性肺疾病成人、急性呼吸窘迫综合征成人设置气道阻力及肺顺应性。MIE压差(SIP与SEP的差值)分别设置为60、40、30 cmH_(2)O(1 cmH_(2)O=98.06 Pa),在固定压差下,SIP/SEP设置为1∶1、1∶2、2∶3。在每种参数设置状态下,MIE均工作5个周期,记录PEF、EV的平均值。分析MIE治疗中PEF的出现时间,对比不同参数设置下PEF、EV的平均值,并分析SIP及SEP分别与PEF、EV的相关性。采用SPSS 20.0统计学软件进行数据分析。结果:模拟肺在不同生理条件下,MIE治疗中的PEF均出现在呼气初始,当压力释放的瞬间产生最大的PEF。MIE设置的压差越大,产生的PEF、EV越大;在压差相同情况下,SIP/SEP为1∶1时产生的PEF、EV最大。SIP与PEF、EV的斯皮尔曼相关系数为0.919、0.990,SEP与PEF、EV的斯皮尔曼相关系数为-0.737、-0.674,SIP与PEF、EV的相关性高于SEP与PEF、EV的相关性。结论:MIE治疗中设置压差越大,产生的气道廓清效果越好;在压差相同情况下,将SIP/SEP设置为1∶1,能够产生咳嗽效应的最大化,从而增强气道廓清的效果。

稻田控制排水对高邮灌区河道洪水过程的影响

以高邮灌区为例,采用水文-水动力模型,研究稻田控制排水措施对河道洪峰流量、水位和洪水过程的影响。结果表明,雨前通过控制灌溉适当降低田间水位可减轻稻田出流峰值,随着稻田控制水位的增加,稻田径流峰值逐渐降低。通过稻田控制排水,可降低田间出口峰值流量,改变灌区河道洪水过程,降低河道洪峰流量和水位,减轻灌区内部以及附近河道的防洪压力。

高风电渗透率下液流电池储能系统调峰优化控制策略

【目的】在“双碳”目标背景下,解决高风电渗透率系统建设带来的调峰安全性和经济性问题。【方法】采用电池储能系统削峰填谷的解决方案,提出了一种兼顾技术及经济性的锌溴液流电池(zinc-bromine flow battery,ZBB)储能的调峰优化控制方法。根据实际电池装置,对ZBB储能进行结构解析及数学模型构建。考虑调峰技术性效果,以调峰后的负荷曲线标准差最小为目标函数,提出一种考虑调峰效果的储能双向寻优控制策略。在此基础上,依据电网分时(time of use,TOU)电价政策,以技术性及经济性最优为目标函数,提出一种基于TOU电价机制的储能调峰经济模型,得出储能优化功率时序结果。最后,以东北某地区负荷及风电数据为例,对比验证所提策略的有效性。【结果】所提策略相较于原负荷,在日均负荷峰谷差、峰谷差率指标上分别降低了35.973%和34.205%,在调峰经济性优化方面提高了5.582%,且合并缓解了电网弃风消纳问题。【结论】所提策略在达到一定调峰效果的同时,在其全寿命周期内仍保持较好的调峰经济性。

结构参数对闭口体系新型激波吹灰器工作特性的影响研究

锅炉吹灰器可以有效实现清除锅炉内部的积灰,提高锅炉运行效率,对锅炉安全运行具有重要意义。SPG型激波吹灰器是在传统激波吹灰器基础上发展而来的闭口体系新型高性能吹灰器,使用数值方法对该装置的可行性进行验证,并分析工作特性,可以为实际应用与改进提供参考。基于CFD技术,将SPG型激波吹灰器作为研究对象,使用动网格技术对设备内活塞的真实运动过程进行仿真模拟,利用Fluent软件模拟计算SPG型激波吹灰器内部流场的连续变化这一动态过程,并通过调整喷管、燃烧室以及压力蓄能器的结构参数,在出口处监测得到各部件结构参数变化对排气特性的影响规律,获取其工作特性。结果表明:喷管的长径比从2增加到4时,出口参数峰值出现滞后现象,但压力峰值与速度峰值获得显著提升,且喷管的扩张段改为直管可以降低膨胀损失,适当增加喷管长径比并直接连接直管是一种较好的方案;燃烧室径向和轴向壁面之间的间距缩短均可使出口压力峰值提高,但轴向距离缩短压力峰值增加幅度更大;在压力蓄能器中,去除阻尼装置压力提升较少,且无法减缓活塞复位,使排出气体减少,去除限位器后喷管出口压力大幅提高,但其峰值持续时间变短。

人工气道患者咳嗽强度评估及应用的研究进展

咳嗽是机体的防御性神经反射,对清除呼吸道分泌物和有害因子有重要作用。人工气道患者咳嗽强度评估与气道廓清、误吸预防、机械通气脱机及气管导管拔除等结局密切相关,如何根据患者病情和临床特征进行个性化、科学的咳嗽强度评估是实施精准干预及疗效评价的基础。本文对目前国内外常见咳嗽强度评估工具的评估方式、特点及其应用现状进行综述,评估工具主要包括咳嗽呼气峰值流速、白卡试验、简化咳嗽试验、半定量咳嗽强度评分、反射性咳嗽强度分级、膈肌移动度、气囊压力变化值、腹内压变化值及胃内压变化值等,以期为人工气道患者咳嗽强度评估工具的开发和应用提供借鉴,为科学评估咳嗽强度、制订个性化干预措施提供依据。

甘肃省庆城县极端暴雨下水保措施抵御暴洪灾害的能力

[目的]最大洪峰流量是导致暴洪灾害的决定性因素。研究小流域降水频率、治理程度与洪峰流量、暴洪灾害损失的关联性,为水土保持减灾防灾工作提供科学依据。[方法]采用回归分析、对比分析等方法,对甘肃省庆阳市庆城县蔡家庙、野狐沟两条相邻流域1981—2022年水保措施的调水效益以及降水因子、水保措施对洪峰流量的影响进行分析。[结果](1)小流域水保措施调水效益随治理程度的提高而增加,随降水频率的提高而减少。(2)年最大日降水量对洪峰流量变化具有极显著的正向影响(p<0.01),贡献率系数为0.707;治理程度对洪峰流量呈负影响,贡献率系数为-0.237。(3)30 a一遇洪峰流量(频率为3%)与50 a一遇洪峰流量(频率为2%)灾害损失强度分别达到1.74×10^(5),3.13×10^(6)元/km^(2),后者比前者增长了16.95倍。[结论]影响洪峰流量变化的主要因素是年最大日降水量。水保措施对削减洪峰流量具有显著的影响。流域治理程度越高,削减洪峰流量的效果越明显,减少暴洪灾害经济损失的能力越大。

不同粒组含量下堰塞坝溃决过程的试验研究

【目的】堰塞坝结构松散、颗粒级配范围宽,易发生漫顶溃决,严重威胁上下游人民的生命财产安全。为进一步探究相同粒径范围内不同粒组含量条件下堰塞坝的溃决过程,【方法】以“11.3”金沙江白格堰塞坝为参考原型,开展了溃决模型水槽试验。【结果】结果显示,堰塞坝的溃决过程可以划分为渗流与过流、溯源侵蚀、溃口发展及衰减平衡四个阶段。溃口流速与溃决流量均呈现先增大后减小的过程,但峰值流量滞后于峰值流速。另外,溃决水流冲击力在溃口发展阶段持续增大,在衰减平衡阶段开始下降,而水流重度在溃口发展阶段表现出一定范围内的波动。随着中值粒径的增大,溃决流量峰值减小、峰现时间延迟、溃决水流冲击力峰值减小,下游泥沙淤积区长度变短、厚度变大。【结论】研究结果进一步揭示了相同粒径范围内的不同粒组含量对堰塞坝稳定性、溃决过程和溃决参数的影响,可为堰塞坝灾害的风险评估和应急处置提供参考。

滤筒除尘器喷吹孔孔径的优化

【目的】为控制各个喷吹管气流量的均匀性,对喷吹管上的喷吹孔径进行优化,提高滤筒除尘器清灰效果。【方法】自制高压脉冲喷吹气流量测量装置对现有喷吹管气流量进行测定,采用光纤传感分析仪测试除尘器滤筒各部分的侧壁压力峰值,分析各滤筒清灰效果不均匀的原因;以滤筒各部位侧壁压力峰值作为清灰均匀性效果评估指标,优化喷吹孔径。【结果】优化前4个喷吹孔径均为19 mm,喷吹孔的气流量依次为13.69、 14.78、 16.03、 16.93 L,对应4个滤筒上、中、下部侧壁压力峰值的最小值分别为最大值的37%、 26%、 20%,气流量均匀度标准差为1.41;优化后4个喷吹孔径分别为23、 20、 18、 17 mm,喷吹气流量依次为14.05、 15.08、 15.87、 16.13 L,对应4个滤筒上、中、下部测壁压力峰值的最小值为最大值的56%、 56%、 53%,气流量均匀度标准差降为0.93。【结论】优化后的喷吹管气流量均匀化程度提高,可实现滤筒除尘器的均匀清灰。

不同暴雨条件下扇形和羽形流域的洪水规律

为了探讨降雨过程时空分布不均匀性对河道径流的影响,以沂河、沭河流域为例,利用瞬时单位线法和马斯京根法计算重现期为10、 20、 50 a的3 d特征暴雨和2019年台风“利奇马”暴雨在2个流域中的洪水流量,得出各防洪控制站在不同暴雨条件下的洪水规律。结果表明:扇形流域内洪水汇流较集中,容易发生洪灾;羽形流域内各支流洪水交错汇入干流,近水先去,远水后去,洪水较缓和,沂河的防汛压力大于沭河的防汛压力;在相同降雨量条件下,沂沭河流域内临沂站在从北向南的降雨过程中更易形成大洪峰,斜午站、石拉渊站和重沟站在从南向北的降雨过程中更易形成大洪峰;莒县站位于沭河上游,控制流域包含多个支流和3个水库,流域形状为属于羽形流域的沭河流域中的扇形流域,具有洪水汇流集中的特点,沭河莒县站的防汛压力大于沭河其他防洪控制站的防汛压力,而且当沭河流域出现大范围同步降雨过程时,莒县站更易形成大洪峰。

全髋关节置换患者间歇性充气加压装置单次最佳使用时长的临床试验研究

目的探讨全髋关节置换术(total hip arthroplasty,THA)患者间歇性充气加压装置(intermittent pneumatic compression,IPC)单次最佳使用时长。方法便利抽取2021年11月-2022年6月在我院行全髋关节置换的患者120例,术后24~48 h内无时间上限地让患者持续接受IPC治疗,直到患者因任意原因要求停止。在开始前静息状态(基线)、每隔30 min、结束时测量患者术侧股总静脉峰值流速(peak velocity,PV)和心理接受度1次;基线、每隔1 h、结束时观察伤口渗血量各1次。对时长和血峰值流速进行相关性分析。结果120例患者IPC平均耐受时长为(80.42±3.31)min,87.5%的患者可耐受60 min,96例(71.1%)患者因影响翻身和其他活动是患者要求停止;IPC任意时长时的PV与静息的PV相比,差异有统计学意义(P均<0.05);耐受IPC 30 min与60 min、90 min、120 min、150 min、180 min时PV相比,差异有统计学意义(P均<0.001);耐受IPC 60 min与90 min、120 min、150 min、180 min时PV相比,差异有统计学意义(P<0.001、P<0.001、P=0.003、P=0.031);其他各耐受时长间PV差异无统计学意义(P>0.05)。IPC不同使用IPC同时一定要做踝泵运动,使用时长均未额外增加伤口渗血。结论对于意识清醒患者,兼顾考虑患者耐受性和对静脉血液流速的促进作用,建议单次使用IPC的时长为60~90 min,可增加每日的使用的频次或使用间歇期间进行踝泵运动。对于意识障碍患者可考虑指南中建议的每天18 h的时长。