With the increasing requirements for fast charging and discharging,higher requirements have been put forward for the thermal management of power batteries.Therefore,there is an urgent need to develop efficient heat tr...With the increasing requirements for fast charging and discharging,higher requirements have been put forward for the thermal management of power batteries.Therefore,there is an urgent need to develop efficient heat transfer fluids.As a new type of heat transfer fluids,functional thermal fluids mainly includ-ing nanofluids(NFs)and phase change fluids(PCFs),have the advantages of high heat carrying density,high heat transfer rate,and broad operational temperature range.However,challenges that hinder their practical applications remain.In this paper,we firstly overview the classification,thermophysical prop-erties,drawbacks,and corresponding modifications of functional thermal fluids.For NFs,the high ther-mal conductivity and high convective heat transfer performance were mainly elaborated,while the stability and viscosity issues were also analyzed.And then for PCFs,the high heat carrying density was mainly elaborated,while the problems of supercooling,stability,and viscosity were also analyzed.On this basis,the composite fluids combined NFs and PCFs technology,has been summarized.Furthermore,the thermal properties of traditional fluids,NFs,PCFs,and composite fluids are compared,which proves that functional thermal fluids are a good choice to replace traditional fluids as coolants.Then,battery thermal management system(BTMS)based on functional thermal fluids is summarized in detail,and the thermal management effects and pump consumption are compared with that of water-based BTMS.Finally,the current technical challenges that parameters optimization of functional thermal fluids and structures optimization of BTMS systematically are presented.In the future,it is necessary to pay more attention to using machine learning to predict thermophysical properties of functional thermal fluids and their applications for BTMS under actual vehicle conditions.展开更多
Purpose: Central venous pressure (CVP) is considered to be unsuitable as preload parameter. Stroke volume variation (SVV) has recently been reported to be effective as a preload and fluid responsiveness parameter, and...Purpose: Central venous pressure (CVP) is considered to be unsuitable as preload parameter. Stroke volume variation (SVV) has recently been reported to be effective as a preload and fluid responsiveness parameter, and its usefulness for fluid management during living-donor liver transplantation (LDLT). However, use of SVV has not been reported in children. Our aim is to evaluate the use of SVV as a target parameter of circulating blood volume during pediatric LDLT. Methods: This retrospective study was conducted in 40 consecutive patients aged between 5 and 109 months who underwent elective LDLT. Twenty patients underwent LDLT without FloTrac? (C group) and the rest patients underwent LDLT with the FloTrac? monitoring (F group). As a fluid management target, CVP was maintained at 10 mmHg in the C group and SVV at 10% in the F group. We compared MAP and CVP at the times of the greatest decrease within 5 minutes after reperfusion. Results: MAP after reperfusion was significantly decreased in both groups (P < 0.01), with the magnitude of decrease significantly greater in the C group compared with the F group (P = 0.02). MAP before and after reperfusion did not significantly differ between the groups. After reperfusion, CVP was nearly the same in both groups, with that in the C group slightly decreased and nearly no change in the F group. SVV after reperfusion was significantly increased (P < 0.001). Conclusion: When used as a target parameter for fluid management during pediatric LDLT, hemodynamic changes was less when SVV was used as the parameter of circulating blood volume.展开更多
<strong>Introduction:</strong> The reported incidence of AKI with COVID-19 varies from 0.5% to 22%. Several mechanisms were postulated as a cause of AKI in patients infected with COVID-19. The appropriate ...<strong>Introduction:</strong> The reported incidence of AKI with COVID-19 varies from 0.5% to 22%. Several mechanisms were postulated as a cause of AKI in patients infected with COVID-19. The appropriate management of AKI in patients with COVID-19 remains unclear at this time. One point of absolute importance, is the consideration of volume status. Given the paucity of knowledge with regards to the role of different strategies for fluid management during an episode of AKI in patients with COVID-19, this retrospective study aims to compare renal outcome and overall prognosis in patients who received conservative versus liberal fluid management. <strong>Methods:</strong> This is a single-center retrospective observational cohort study at a community hospital in Westchester County, NY. All adult patients who tested positive for the COVID-19 infection by PCR testing of a nasopharyngeal swab and were hospitalized from March 22, 2020 to May 25, 2020 are eligible. Among those identified with AKI, patients were divided into two groups: conservative fluid administration versus liberal fluid administration. <strong>Results:</strong> Of the 136 patients, 84 (61.76%) were admitted to the ICU, with 60% of patients under the conservative fluid strategy and 40% receiving liberal fluid management. On the other hand, 52 (38.23%) patients were admitted on the medical floors, with more patients (67.31%) receiving liberal fluid management. <strong>Discussion:</strong> In our cohort of 136 patients with COVID-19 respiratory illness and AKI, there was a significant difference in renal outcome, in terms of improvement of renal function in patients receiving liberal fluid management (55.07%) versus conservative fluid management (16.41%, p ≤ 0.001), with more patients in the liberal group having lower peak creatinine before levels improved. This, as well, was associated with improvement in oxygenation, characterized by improvement in respiratory status, facilitating weaning of oxygen supplementation (p < 0.001). On the other hand, there was no significant difference between the conservative and liberal groups in terms of undergoing renal replacement therapy. Twenty-one of the 136 patients with AKI required RRT and 19 (90%) of them were admitted to the ICU and mechanically ventilated. On the other hand, there was no statistical difference in mortality rate of patients who underwent renal replacement therapy, regardless of whether they were in the conservative or liberal strategy group. <strong>Conclusion:</strong> Our data report that liberal fluid management in COVID-19 patients with AKI, had better outcomes, in terms of renal function, oxygenation and mortality rate, as compared to patients in the conservative fluid management group. Once patients are started on renal replacement therapy, however, renal and lung outcomes and mortality rate become insignificant between the two groups.展开更多
Acute pancreatitis(AP) is a potentially life-threatening disease with a wide spectrum of severity. The overall mortality of AP is approximately 5%. According to the revised Atlanta classification system, AP can be cla...Acute pancreatitis(AP) is a potentially life-threatening disease with a wide spectrum of severity. The overall mortality of AP is approximately 5%. According to the revised Atlanta classification system, AP can be classified as mild, moderate, or severe. Severe AP often takes a clinical course with two phases, an early and a late phase, which should both be considered separately. In this review article, we first discuss general aspects of AP, including incidence, pathophysiology, etiology, and grading of severity, then focus on the assessment of patients with suspected AP, including diagnosis and risk stratification, followed by the management of AP during the early phase, with special emphasis on fluid therapy, pain management, nutrition, and antibiotic prophylaxis.展开更多
Diabetic ketoacidosis(DKA) is a complication seen in patients with both type 1 and type 2 diabetes. Due to its large, growing economic impact with associated morbidity, closer look at proper management is im-portant. ...Diabetic ketoacidosis(DKA) is a complication seen in patients with both type 1 and type 2 diabetes. Due to its large, growing economic impact with associated morbidity, closer look at proper management is im-portant. Factors involved in appropriate management involves fluid resuscitation, insulin regimen, and elec-trolyte replacement including types of fluid and insulin treatment. The caveat with generalized protocol is application to special populations such as renal or heart failure patients the sequelae of complications due to pathophysiology of the disease processes. This leads to complications and longer length of stay in the hospital, therefore, possibly increased cost and resource utilization during the hospitalization. This review takes a closer look at current guidelines of DKA management and resource utilization, the drawbacks of current management protocols and the cost associated with it. Therefore, a need for amendment to existing protocol or initiation of a newer guideline that properly manages DKA should incorporate special populations and appropriate regimen of fluid resuscitation, insulin therapy and electrolyte management.展开更多
Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste hea...Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste heat and heat flux to be dissipated to maintain the devices within a safe temperature range. However, both the total heat sinks aboard and the cooling capacity of currently utilized thermal control strategy are severely limited, which threatens the lifetime of the on-board equipment and even the entire flight system and shrink the vehicle’s flight time and range. Facing these thermal challenges, the USA proposed the program of "INVENT" to maximize utilities of the available heat sinks and enhance the cooling ability of thermal control strategies. Following the efforts done by the USA researchers, scientists in China fought their ways to develop thermal management technologies for Chinese advanced energy-optimized airplanes and spacecraft. This paper elaborates the available on-board heat sinks and aerospace thermal management systems using both active and passive technologies not confined to the technology in China. Subsequently, active thermal management technologies in China including fuel thermal management system, environment control system, non-fuel liquid cooling strategy are reviewed. At last, space thermal control technologies used in Chinese Space Station and Chang’e-3 and to be used in Chang’e-5 are introduced.Key issues to be solved are also identified, which could facilitate the development of aerospace thermal control techniques across the world.展开更多
Hemodynamic monitoring and optimization improve postoperative outcome during high-risk surgery.However,hemodynamic management practices among Chinese anesthesiologists are largely unknown.This study sought to evaluate...Hemodynamic monitoring and optimization improve postoperative outcome during high-risk surgery.However,hemodynamic management practices among Chinese anesthesiologists are largely unknown.This study sought to evaluate the current intraoperative hemodynamic management practices for high-risk surgery patients in China.From September 2010 to November 2011,we surveyed anesthesiologists working in the operating rooms of 265 hospitals representing 28 Chinese provinces.All questionnaires were distributed to department chairs of anesthesiology or practicing anesthesiologists.Once completed,the 29-item questionnaires were collected and analyzed.Two hundred and 10 questionnaires from 265 hospitals in China were collected.We found that 91.4%of anesthesiologists monitored invasive arterial pressure,82.9%monitored central venous pressure（CVP）,13.3%monitored cardiac output（CO）,10.5%monitored mixed venous saturation,and less than 2%monitored pulse pressure variation（PPV） or systolic pressure variation（SPV） during high-risk surgery.The majority（88%） of anesthesiologists relied on clinical experience as an indicator for volume expansion and more than 80%relied on blood pressure,CVP and urine output.Anesthesiologists in China do not own enough attention on hemodynamic parameters such as PPV,SPV and CO during fluid management in high-risk surgical patients.The lack of CO monitoring may be attributed largely to the limited access to technologies,the cost of the devices and the lack of education on how to use them.There is a need for improving access to these technologies as well as an opportunity to create guidelines and education for hemodynamic optimization in China.展开更多
Liquid directional transport surfaces have the ability to control the movement of liquids in specific directions,making them highly applicable in various fields such as heat transfer,fluid management,microfluidics,and...Liquid directional transport surfaces have the ability to control the movement of liquids in specific directions,making them highly applicable in various fields such as heat transfer,fluid management,microfluidics,and chemical engineering.This review aims to summarize the research progress on liquid directional transport surfaces and spacecraft fluid management devices.Among the different liquid control technologies available,certain surface design methods based on principles of fluid dynamics under microgravity show remarkable potential for space fluid management.Precise fluid management is crucial for the in-orbit operation of spacecraft.Utilizing surface tension effects represents the most direct and effective approach to achieve directional liquid transport in space.The intrinsic flow characteristics of the two-dimensional plane of directional transport surfaces are advantageous for managing fluids in the confined spaces of spacecraft.By analyzing the functional characteristics of these liquid directional transport surfaces,we assess their feasibility for integration into spacecraft fluid management devices.Considering the features of the space environment,this review also provides design guidelines for liquid directional transport surfaces suitable for use in spacecraft fluid management devices,serving as a significant reference for future research.展开更多
BACKGROUND Intraoperative fluid management is an important aspect of anesthesia mana-gement in gastrointestinal surgery.Intraoperative goal-directed fluid therapy(GDFT)is a method for optimizing a patient's physio...BACKGROUND Intraoperative fluid management is an important aspect of anesthesia mana-gement in gastrointestinal surgery.Intraoperative goal-directed fluid therapy(GDFT)is a method for optimizing a patient's physiological state by monitoring and regulating fluid input in real-time.AIM To evaluate the efficacy of intraoperative GDFT in patients under anesthesia for gastrointestinal surgery.METHODS This study utilized a retrospective comparative study design and included 60 patients who underwent gastrointestinal surgery at a hospital.The experimental group(GDFT group)and the control group,each comprising 30 patients,received intraoperative GDFT and traditional fluid management strategies,respectively.The effect of GDFT was evaluated by comparing postoperative recovery,com-plication rates,hospitalization time,and other indicators between the two patient groups.RESULTS Intraoperative blood loss in the experimental and control groups was 296.64±46.71 mL and 470.05±73.26 mL(P<0.001),and urine volume was 415.13±96.72 mL and 239.15±94.69 mL(P<0.001),respectively.The postoperative recovery time was 5.44±1.1 days for the experimental group compared to 7.59±1.45 days(P<0.001)for the control group.Hospitalization time for the experimental group was 10.87±2.36 days vs 13.65±3 days for the control group(P<0.001).The visual analogue scale scores of the experimental and control groups at 24 h and 48 h INTRODUCTION Gastrointestinal surgery is one of the most common procedures in the field of general surgery[1],involving the stomach,intestines,liver,pancreas,spleen,and other internal abdominal organs[2,3].With advancements in surgical technology and anesthesia methods,the safety and success rates of surgery have significantly improved[4,5].However,intraop-erative fluid management remains a critical challenge[6].Traditional fluid management strategies often rely on experience and basic physiological parameters,which may lead to excessive or insufficient fluid input,thereby affecting postoperative recovery and complication rates.Intraoperative goal-directed fluid therapy(GDFT)is an emerging fluid management strategy that dynamically adjusts fluid input volume by monitoring the patient's hemodynamic parameters in real-time to optimize the patient's physiological state[7,8].GDFT has shown superiority in many surgical fields;however,its application in gastrointestinal surgery requires further research and verification[9,10].The application of intraoperative GDFT in clinical settings has gradually increased in recent years[11,12].Studies have demonstrated that GDFT can optimize tissue perfusion and oxygenation by precisely controlling fluid input and reducing the occurrence of postoperative complications[13,14].For example,in cardiac and major vascular surgeries,GDFT significantly reduced the incidence of postoperative acute kidney injury and cardiovascular events[15,16].Similarly,in abdominal surgery,GDFT effectively reduced postoperative infections and expedited recovery[17].However,studies on the utilization of GDFT in gastrointestinal surgery are relatively limited and they are confounded by contradictory findings[18].Traditional fluid management strategies typically rely on estimating fluid input volume based on the patient's weight,preoperative status,and basic physiological parameters[19].However,this method lacks real-time dynamic adjustment,which may result in either insufficient or excessive fluid input,consequently affecting postoperative recovery.Insufficient fluid input can lead to hypovolemia and inadequate tissue perfusion,whereas excessive fluid input can cause tissue edema and postoperative complications,such as pulmonary edema and heart failure.GDFT involves dynamically adjusting fluid input volume by monitoring the patient's hemodynamic parameters in real-time,such as cardiac output,pulse pressure variability,and central venous pressure.Commonly used monitoring equipment include esophageal Doppler and pulse wave profile analyzers[20].These devices provide real-time hemo-dynamic data to assist anesthesiologists in tailoring fluid therapy to a patient's specific condition.Firstly,the patient's volume responsiveness is assessed by preloading fluid;secondly,fluid input volume is dynamically adjusted based on real-time monitoring data;finally,vasoactive and inotropic drugs are administered in combination to further optimize the patient’s hemodynamic status.Through personalized fluid management,GDFT can more accurately maintain intraop-erative hemodynamic stability and reduce complications[21].Gastrointestinal surgery involves procedures on multiple organs,often requiring prolonged operative times and extensive tissue trauma,which presents challenges for intraop-erative fluid management.Surgical procedures can lead to significant bleeding and fluid loss,requiring prompt and effective fluid replenishment.In addition,the slow recovery of gastrointestinal function after surgery and susceptibility to complications such as intestinal obstruction and delayed gastric emptying elevate the necessity for postoperative fluid management.展开更多
目的 探讨限制性液体管理策略对重症脓毒症患者肠道微生态及临床结局的影响,并分析菌群变化与预后的相关性。方法 前瞻性纳入2024年4月-2025年4月入住本院ICU的80例重症脓毒症患者,分为限制性液体管理组(n=40)与常规液体管理组(n=40)。...目的 探讨限制性液体管理策略对重症脓毒症患者肠道微生态及临床结局的影响,并分析菌群变化与预后的相关性。方法 前瞻性纳入2024年4月-2025年4月入住本院ICU的80例重症脓毒症患者,分为限制性液体管理组(n=40)与常规液体管理组(n=40)。收集液体出入量、血流动力学指标及粪便样本行16S rRNA测序,比较多样性与菌群丰度,并记录住院病死率、机械通气时间、住院时间及并发症发生率,用Pearson相关分析菌群与结局关联。结果 限制性组第1、2 d液体入量显著低于常规组(2501.63±156.43 mL vs 3017.68±199.75 mL,t=19.24,P<0.01)、(1997.50±156.33 mL vs 2506.10±198.35 mL,t=17.85,P<0.01);累积平衡亦显著减少,第1 d(696.85±107.82) mL vs (1103.05±135.34) mL(t=23.89,P<0.01)。限制性组α多样性显著升高,Shannon指数3.48±0.31 vs 2.81±0.27(t=10.37,P<0.01);Simpson指数0.85±0.03 vs 0.75±0.04(t=11.96,P<0.01);Bifidobacterium、Lactobacillus相对丰度分别升至15.2%、12.3%,而Escherichia及Proteobacteria显著下降。临床结局方面,限制性组机械通气时间缩短2.76 d (7.45±1.31) d vs (10.21±1.49) d(t=8.823,P<0.01),住院时间缩短3.47 d(15.37±1.84) d vs (18.84±2.00) d(t=8.068,P<0.01);住院病死率、急性肾损伤、ARDS、MODS发生率均呈下降趋势(均P>0.05)。相关性分析结果可见,Lactobacillus与机械通气时间呈负相关(R=-0.478),Bacteroides与并发症发生率呈正相关(R=0.392)。结论 限制性液体管理可显著减少液体正平衡,改善肠道微生态多样性及有益菌丰度,进而缩短机械通气时间和住院时间。肠道菌群变化可能是限制性液体策略改善脓毒症预后的重要生物中介,为精准液体治疗提供了新的微生态靶点。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52271320)"Mechanics+"interdisciplinary innovation youth fund project of Ningbo University(LJ2023005).
文摘With the increasing requirements for fast charging and discharging,higher requirements have been put forward for the thermal management of power batteries.Therefore,there is an urgent need to develop efficient heat transfer fluids.As a new type of heat transfer fluids,functional thermal fluids mainly includ-ing nanofluids(NFs)and phase change fluids(PCFs),have the advantages of high heat carrying density,high heat transfer rate,and broad operational temperature range.However,challenges that hinder their practical applications remain.In this paper,we firstly overview the classification,thermophysical prop-erties,drawbacks,and corresponding modifications of functional thermal fluids.For NFs,the high ther-mal conductivity and high convective heat transfer performance were mainly elaborated,while the stability and viscosity issues were also analyzed.And then for PCFs,the high heat carrying density was mainly elaborated,while the problems of supercooling,stability,and viscosity were also analyzed.On this basis,the composite fluids combined NFs and PCFs technology,has been summarized.Furthermore,the thermal properties of traditional fluids,NFs,PCFs,and composite fluids are compared,which proves that functional thermal fluids are a good choice to replace traditional fluids as coolants.Then,battery thermal management system(BTMS)based on functional thermal fluids is summarized in detail,and the thermal management effects and pump consumption are compared with that of water-based BTMS.Finally,the current technical challenges that parameters optimization of functional thermal fluids and structures optimization of BTMS systematically are presented.In the future,it is necessary to pay more attention to using machine learning to predict thermophysical properties of functional thermal fluids and their applications for BTMS under actual vehicle conditions.
文摘Purpose: Central venous pressure (CVP) is considered to be unsuitable as preload parameter. Stroke volume variation (SVV) has recently been reported to be effective as a preload and fluid responsiveness parameter, and its usefulness for fluid management during living-donor liver transplantation (LDLT). However, use of SVV has not been reported in children. Our aim is to evaluate the use of SVV as a target parameter of circulating blood volume during pediatric LDLT. Methods: This retrospective study was conducted in 40 consecutive patients aged between 5 and 109 months who underwent elective LDLT. Twenty patients underwent LDLT without FloTrac? (C group) and the rest patients underwent LDLT with the FloTrac? monitoring (F group). As a fluid management target, CVP was maintained at 10 mmHg in the C group and SVV at 10% in the F group. We compared MAP and CVP at the times of the greatest decrease within 5 minutes after reperfusion. Results: MAP after reperfusion was significantly decreased in both groups (P < 0.01), with the magnitude of decrease significantly greater in the C group compared with the F group (P = 0.02). MAP before and after reperfusion did not significantly differ between the groups. After reperfusion, CVP was nearly the same in both groups, with that in the C group slightly decreased and nearly no change in the F group. SVV after reperfusion was significantly increased (P < 0.001). Conclusion: When used as a target parameter for fluid management during pediatric LDLT, hemodynamic changes was less when SVV was used as the parameter of circulating blood volume.
文摘<strong>Introduction:</strong> The reported incidence of AKI with COVID-19 varies from 0.5% to 22%. Several mechanisms were postulated as a cause of AKI in patients infected with COVID-19. The appropriate management of AKI in patients with COVID-19 remains unclear at this time. One point of absolute importance, is the consideration of volume status. Given the paucity of knowledge with regards to the role of different strategies for fluid management during an episode of AKI in patients with COVID-19, this retrospective study aims to compare renal outcome and overall prognosis in patients who received conservative versus liberal fluid management. <strong>Methods:</strong> This is a single-center retrospective observational cohort study at a community hospital in Westchester County, NY. All adult patients who tested positive for the COVID-19 infection by PCR testing of a nasopharyngeal swab and were hospitalized from March 22, 2020 to May 25, 2020 are eligible. Among those identified with AKI, patients were divided into two groups: conservative fluid administration versus liberal fluid administration. <strong>Results:</strong> Of the 136 patients, 84 (61.76%) were admitted to the ICU, with 60% of patients under the conservative fluid strategy and 40% receiving liberal fluid management. On the other hand, 52 (38.23%) patients were admitted on the medical floors, with more patients (67.31%) receiving liberal fluid management. <strong>Discussion:</strong> In our cohort of 136 patients with COVID-19 respiratory illness and AKI, there was a significant difference in renal outcome, in terms of improvement of renal function in patients receiving liberal fluid management (55.07%) versus conservative fluid management (16.41%, p ≤ 0.001), with more patients in the liberal group having lower peak creatinine before levels improved. This, as well, was associated with improvement in oxygenation, characterized by improvement in respiratory status, facilitating weaning of oxygen supplementation (p < 0.001). On the other hand, there was no significant difference between the conservative and liberal groups in terms of undergoing renal replacement therapy. Twenty-one of the 136 patients with AKI required RRT and 19 (90%) of them were admitted to the ICU and mechanically ventilated. On the other hand, there was no statistical difference in mortality rate of patients who underwent renal replacement therapy, regardless of whether they were in the conservative or liberal strategy group. <strong>Conclusion:</strong> Our data report that liberal fluid management in COVID-19 patients with AKI, had better outcomes, in terms of renal function, oxygenation and mortality rate, as compared to patients in the conservative fluid management group. Once patients are started on renal replacement therapy, however, renal and lung outcomes and mortality rate become insignificant between the two groups.
文摘Acute pancreatitis(AP) is a potentially life-threatening disease with a wide spectrum of severity. The overall mortality of AP is approximately 5%. According to the revised Atlanta classification system, AP can be classified as mild, moderate, or severe. Severe AP often takes a clinical course with two phases, an early and a late phase, which should both be considered separately. In this review article, we first discuss general aspects of AP, including incidence, pathophysiology, etiology, and grading of severity, then focus on the assessment of patients with suspected AP, including diagnosis and risk stratification, followed by the management of AP during the early phase, with special emphasis on fluid therapy, pain management, nutrition, and antibiotic prophylaxis.
文摘Diabetic ketoacidosis(DKA) is a complication seen in patients with both type 1 and type 2 diabetes. Due to its large, growing economic impact with associated morbidity, closer look at proper management is im-portant. Factors involved in appropriate management involves fluid resuscitation, insulin regimen, and elec-trolyte replacement including types of fluid and insulin treatment. The caveat with generalized protocol is application to special populations such as renal or heart failure patients the sequelae of complications due to pathophysiology of the disease processes. This leads to complications and longer length of stay in the hospital, therefore, possibly increased cost and resource utilization during the hospitalization. This review takes a closer look at current guidelines of DKA management and resource utilization, the drawbacks of current management protocols and the cost associated with it. Therefore, a need for amendment to existing protocol or initiation of a newer guideline that properly manages DKA should incorporate special populations and appropriate regimen of fluid resuscitation, insulin therapy and electrolyte management.
基金supported by the Starting Foundation for Young Researchers in Yangzhou Universityfunded by the Chinese Postdoctoral Science Foundation (No. 2020M671618)。
文摘Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste heat and heat flux to be dissipated to maintain the devices within a safe temperature range. However, both the total heat sinks aboard and the cooling capacity of currently utilized thermal control strategy are severely limited, which threatens the lifetime of the on-board equipment and even the entire flight system and shrink the vehicle’s flight time and range. Facing these thermal challenges, the USA proposed the program of "INVENT" to maximize utilities of the available heat sinks and enhance the cooling ability of thermal control strategies. Following the efforts done by the USA researchers, scientists in China fought their ways to develop thermal management technologies for Chinese advanced energy-optimized airplanes and spacecraft. This paper elaborates the available on-board heat sinks and aerospace thermal management systems using both active and passive technologies not confined to the technology in China. Subsequently, active thermal management technologies in China including fuel thermal management system, environment control system, non-fuel liquid cooling strategy are reviewed. At last, space thermal control technologies used in Chinese Space Station and Chang’e-3 and to be used in Chang’e-5 are introduced.Key issues to be solved are also identified, which could facilitate the development of aerospace thermal control techniques across the world.
文摘Hemodynamic monitoring and optimization improve postoperative outcome during high-risk surgery.However,hemodynamic management practices among Chinese anesthesiologists are largely unknown.This study sought to evaluate the current intraoperative hemodynamic management practices for high-risk surgery patients in China.From September 2010 to November 2011,we surveyed anesthesiologists working in the operating rooms of 265 hospitals representing 28 Chinese provinces.All questionnaires were distributed to department chairs of anesthesiology or practicing anesthesiologists.Once completed,the 29-item questionnaires were collected and analyzed.Two hundred and 10 questionnaires from 265 hospitals in China were collected.We found that 91.4%of anesthesiologists monitored invasive arterial pressure,82.9%monitored central venous pressure（CVP）,13.3%monitored cardiac output（CO）,10.5%monitored mixed venous saturation,and less than 2%monitored pulse pressure variation（PPV） or systolic pressure variation（SPV） during high-risk surgery.The majority（88%） of anesthesiologists relied on clinical experience as an indicator for volume expansion and more than 80%relied on blood pressure,CVP and urine output.Anesthesiologists in China do not own enough attention on hemodynamic parameters such as PPV,SPV and CO during fluid management in high-risk surgical patients.The lack of CO monitoring may be attributed largely to the limited access to technologies,the cost of the devices and the lack of education on how to use them.There is a need for improving access to these technologies as well as an opportunity to create guidelines and education for hemodynamic optimization in China.
基金National Key R&D Programof China,Grant/Award Numbers:2022YFF0503500,2023YFB4603700Strategic Priority Research Programof the Chinese Academy of Sciences,Grant/Award Number:XDB0910300。
文摘Liquid directional transport surfaces have the ability to control the movement of liquids in specific directions,making them highly applicable in various fields such as heat transfer,fluid management,microfluidics,and chemical engineering.This review aims to summarize the research progress on liquid directional transport surfaces and spacecraft fluid management devices.Among the different liquid control technologies available,certain surface design methods based on principles of fluid dynamics under microgravity show remarkable potential for space fluid management.Precise fluid management is crucial for the in-orbit operation of spacecraft.Utilizing surface tension effects represents the most direct and effective approach to achieve directional liquid transport in space.The intrinsic flow characteristics of the two-dimensional plane of directional transport surfaces are advantageous for managing fluids in the confined spaces of spacecraft.By analyzing the functional characteristics of these liquid directional transport surfaces,we assess their feasibility for integration into spacecraft fluid management devices.Considering the features of the space environment,this review also provides design guidelines for liquid directional transport surfaces suitable for use in spacecraft fluid management devices,serving as a significant reference for future research.
文摘BACKGROUND Intraoperative fluid management is an important aspect of anesthesia mana-gement in gastrointestinal surgery.Intraoperative goal-directed fluid therapy(GDFT)is a method for optimizing a patient's physiological state by monitoring and regulating fluid input in real-time.AIM To evaluate the efficacy of intraoperative GDFT in patients under anesthesia for gastrointestinal surgery.METHODS This study utilized a retrospective comparative study design and included 60 patients who underwent gastrointestinal surgery at a hospital.The experimental group(GDFT group)and the control group,each comprising 30 patients,received intraoperative GDFT and traditional fluid management strategies,respectively.The effect of GDFT was evaluated by comparing postoperative recovery,com-plication rates,hospitalization time,and other indicators between the two patient groups.RESULTS Intraoperative blood loss in the experimental and control groups was 296.64±46.71 mL and 470.05±73.26 mL(P<0.001),and urine volume was 415.13±96.72 mL and 239.15±94.69 mL(P<0.001),respectively.The postoperative recovery time was 5.44±1.1 days for the experimental group compared to 7.59±1.45 days(P<0.001)for the control group.Hospitalization time for the experimental group was 10.87±2.36 days vs 13.65±3 days for the control group(P<0.001).The visual analogue scale scores of the experimental and control groups at 24 h and 48 h INTRODUCTION Gastrointestinal surgery is one of the most common procedures in the field of general surgery[1],involving the stomach,intestines,liver,pancreas,spleen,and other internal abdominal organs[2,3].With advancements in surgical technology and anesthesia methods,the safety and success rates of surgery have significantly improved[4,5].However,intraop-erative fluid management remains a critical challenge[6].Traditional fluid management strategies often rely on experience and basic physiological parameters,which may lead to excessive or insufficient fluid input,thereby affecting postoperative recovery and complication rates.Intraoperative goal-directed fluid therapy(GDFT)is an emerging fluid management strategy that dynamically adjusts fluid input volume by monitoring the patient's hemodynamic parameters in real-time to optimize the patient's physiological state[7,8].GDFT has shown superiority in many surgical fields;however,its application in gastrointestinal surgery requires further research and verification[9,10].The application of intraoperative GDFT in clinical settings has gradually increased in recent years[11,12].Studies have demonstrated that GDFT can optimize tissue perfusion and oxygenation by precisely controlling fluid input and reducing the occurrence of postoperative complications[13,14].For example,in cardiac and major vascular surgeries,GDFT significantly reduced the incidence of postoperative acute kidney injury and cardiovascular events[15,16].Similarly,in abdominal surgery,GDFT effectively reduced postoperative infections and expedited recovery[17].However,studies on the utilization of GDFT in gastrointestinal surgery are relatively limited and they are confounded by contradictory findings[18].Traditional fluid management strategies typically rely on estimating fluid input volume based on the patient's weight,preoperative status,and basic physiological parameters[19].However,this method lacks real-time dynamic adjustment,which may result in either insufficient or excessive fluid input,consequently affecting postoperative recovery.Insufficient fluid input can lead to hypovolemia and inadequate tissue perfusion,whereas excessive fluid input can cause tissue edema and postoperative complications,such as pulmonary edema and heart failure.GDFT involves dynamically adjusting fluid input volume by monitoring the patient's hemodynamic parameters in real-time,such as cardiac output,pulse pressure variability,and central venous pressure.Commonly used monitoring equipment include esophageal Doppler and pulse wave profile analyzers[20].These devices provide real-time hemo-dynamic data to assist anesthesiologists in tailoring fluid therapy to a patient's specific condition.Firstly,the patient's volume responsiveness is assessed by preloading fluid;secondly,fluid input volume is dynamically adjusted based on real-time monitoring data;finally,vasoactive and inotropic drugs are administered in combination to further optimize the patient’s hemodynamic status.Through personalized fluid management,GDFT can more accurately maintain intraop-erative hemodynamic stability and reduce complications[21].Gastrointestinal surgery involves procedures on multiple organs,often requiring prolonged operative times and extensive tissue trauma,which presents challenges for intraop-erative fluid management.Surgical procedures can lead to significant bleeding and fluid loss,requiring prompt and effective fluid replenishment.In addition,the slow recovery of gastrointestinal function after surgery and susceptibility to complications such as intestinal obstruction and delayed gastric emptying elevate the necessity for postoperative fluid management.
文摘目的 探讨限制性液体管理策略对重症脓毒症患者肠道微生态及临床结局的影响,并分析菌群变化与预后的相关性。方法 前瞻性纳入2024年4月-2025年4月入住本院ICU的80例重症脓毒症患者,分为限制性液体管理组(n=40)与常规液体管理组(n=40)。收集液体出入量、血流动力学指标及粪便样本行16S rRNA测序,比较多样性与菌群丰度,并记录住院病死率、机械通气时间、住院时间及并发症发生率,用Pearson相关分析菌群与结局关联。结果 限制性组第1、2 d液体入量显著低于常规组(2501.63±156.43 mL vs 3017.68±199.75 mL,t=19.24,P<0.01)、(1997.50±156.33 mL vs 2506.10±198.35 mL,t=17.85,P<0.01);累积平衡亦显著减少,第1 d(696.85±107.82) mL vs (1103.05±135.34) mL(t=23.89,P<0.01)。限制性组α多样性显著升高,Shannon指数3.48±0.31 vs 2.81±0.27(t=10.37,P<0.01);Simpson指数0.85±0.03 vs 0.75±0.04(t=11.96,P<0.01);Bifidobacterium、Lactobacillus相对丰度分别升至15.2%、12.3%,而Escherichia及Proteobacteria显著下降。临床结局方面,限制性组机械通气时间缩短2.76 d (7.45±1.31) d vs (10.21±1.49) d(t=8.823,P<0.01),住院时间缩短3.47 d(15.37±1.84) d vs (18.84±2.00) d(t=8.068,P<0.01);住院病死率、急性肾损伤、ARDS、MODS发生率均呈下降趋势(均P>0.05)。相关性分析结果可见,Lactobacillus与机械通气时间呈负相关(R=-0.478),Bacteroides与并发症发生率呈正相关(R=0.392)。结论 限制性液体管理可显著减少液体正平衡,改善肠道微生态多样性及有益菌丰度,进而缩短机械通气时间和住院时间。肠道菌群变化可能是限制性液体策略改善脓毒症预后的重要生物中介,为精准液体治疗提供了新的微生态靶点。
