Firstly, the hydrological and meteorological features of the upper reaches of the Yellow River above Tangnag are analyzed based on observation data, and effects of EI Nino and La Ni na events on the high and low flow ...Firstly, the hydrological and meteorological features of the upper reaches of the Yellow River above Tangnag are analyzed based on observation data, and effects of EI Nino and La Ni na events on the high and low flow in the upper Yellow River are discussed. The results show El Nino and La Nina events possess consanguineous relationship wi th runoff in the upper Yellow River. As a whole, the probability of low fl ow occurrence in the upper Yellow River is relatively great along wit h the occurrence of El Nino event. Moreover, the flood in the upper Yellow River occurs frequently with the occurrence of La Nina event. Besides, the results also show dissimilarity of El Nino event occurri ng time exerts greater impact on high flow and low flow in the uppe r Yellow River, that is, the probability of drought will be greater in the sam e year if El Nino event occurs in spring, the high-flow may happen in this y ear if El Nino occurs in summer or autumn; the longer the continuous period of El Nino is, the lower the runoff in the upper Yellow River is.展开更多
BACKGROUND: We sought to demonstrate the superiority of a targeted therapy strategy involving high-flow nasal cannula oxygen(HFNCO_(2)) therapy and noninvasive ventilation(NIV) using lung ultrasound score(LUS) in comp...BACKGROUND: We sought to demonstrate the superiority of a targeted therapy strategy involving high-flow nasal cannula oxygen(HFNCO_(2)) therapy and noninvasive ventilation(NIV) using lung ultrasound score(LUS) in comparison with standard care among patients in the intensive care unit(ICU) who undergo successful weaning to decrease the incidence of extubation failure at both 48 hours and seven days.METHODS: During the study period, 98 patients were enrolled in the study, including 49 in the control group and 49 in the treatment group. Patients in the control group and patients with an LUS score <14 points(at low risk of extubation failure) in the treatment group were extubated and received standard preventive care without NIV or HFNCO_(2). Patients with an LUS score ≥14 points(at high risk of extubation failure) in the treatment group were extubated with a second review of the therapeutic optimization to identify and address any persisting risk factors for postextubation respiratory distress;patients received HFNCO2 therapy combined with sessions of preventive NIV(4-8 hours per day for 4-8 sessions total) for the first 48 hours after extubation.RESULTS: In the control group, 13 patients had the LUS scores ≥14 points, while 36 patients had scores <14 points. In the treatment group, 16 patients had the LUS scores ≥14 points, while 33 patients had scores <14 points. Among patients with the LUS score ≥14 points, the extubation failure rate within 48 hours was 30.8% in the control group and 12.5% in the treatment group, constituting a statistically significant difference(P<0.05). Conversely, among patients with an LUS score <14 points, 13.9% in the control group and 9.1% in the treatment group experienced extubation failure(P=0.61). The length of ICU stay(9.4±3.1 days vs. 7.2±2.4 days) was significantly different and the re-intubation rate(at 48 hours: 18.4% vs. 10.2%;seven days: 22.4% vs. 12.2%) significantly varied between the two groups(P<0.05). There was no significant difference in the 28-day mortality r展开更多
Background Compared to conventional oxygen devices,high-flow oxygen treatment(HFOT)through the nasal cannulae has demonstrated clinical benefits.Limited data exist on whether such effects are also present in HFOT thro...Background Compared to conventional oxygen devices,high-flow oxygen treatment(HFOT)through the nasal cannulae has demonstrated clinical benefits.Limited data exist on whether such effects are also present in HFOT through tracheostomy.Hence,we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation.Methods A randomized,crossover,physiological study was conducted in our ICU between December 2020 and April 2021,in patients with tracheostomy and prolonged mechanical ventilation.The patients underwent a 30-min spontaneous breathing trial(SBT)and received oxygen either via T-piece or by HFOT through tracheostomy,followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner.At the start and end of each session,blood gasses,breathing frequency(f),and tidal volume(VT)via a Wright's spirometer were measured,along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction,which expressed the inspiratory muscle effort.Results Eleven patients were enrolled in whom 19 sessions were uneventfully completed;eight patients were studied twice on two different days with alternate sessions;and three patients were studied once.Patients were randomly assigned to start the SBT with a T-piece(n=10 sessions)or with HFOT(n=9 sessions).With HFOT,VT and minute ventilation(VE)significantly increased during SBT(from[465±119]mL to[549±134]mL,P<0.001 and from[12.4±4.3]L/min to[13.1±4.2]L/min,P<0.05,respectively),but they did not change significantly during SBT with T-piece(from[495±132]mL to[461±123]mL and from[12.8±4.4]mL to[12.0±4.4]mL,respectively);f/VT decreased during HFOT(from[64±31]breaths/(min∙L)to[49±24]breaths/(min∙L),P<0.001),but it did not change significantly during SBT with T-piece(from[59±28]breaths/(min∙L)to[64±33]breaths/(min∙L));partial pressure of a展开更多
Although standard oxygen face masks are first-line therapy for patients with acute hypoxemic respiratory failure,high-flow nasal cannula oxygen therapy has gained major popularity in intensive care units.The physiolog...Although standard oxygen face masks are first-line therapy for patients with acute hypoxemic respiratory failure,high-flow nasal cannula oxygen therapy has gained major popularity in intensive care units.The physiological effects of high-flow oxygen counterbalance the physiological consequences of acute hypoxemic respiratory failure by lessening the deleterious effects of intense and prolonged inspiratory efforts generated by patients.Its simplicity of application for physicians and nurses and its comfort for patients are other arguments for its use in this setting.Although clinical studies have reported a decreased risk of intubation with high-flow oxygen compared with standard oxygen,its survival benefit is uncertain.A more precise definition of acute hypoxemic respiratory failure,including a classification of severity based on oxygenation levels,is needed to better compare the efficiencies of different non-invasive oxygenation support methods(standard oxygen,high-flow oxygen,and non-invasive ventilation).Additionally,the respective role of each non-invasive oxygenation support method needs to be established through further clinical trials in acute hypoxemic respiratory failure,especially in severe forms.展开更多
Objective:To analyze the curative effect of humidified high-flow nasal oxygen therapy combined with alveolar lavage in patients with severe pneumonia and respiratory failure.Methods:120 patients with severe pneumonia ...Objective:To analyze the curative effect of humidified high-flow nasal oxygen therapy combined with alveolar lavage in patients with severe pneumonia and respiratory failure.Methods:120 patients with severe pneumonia complicated with respiratory failure admitted to the Third People’s Hospital of Xining from July 2021 to December 2022 were randomly divided into two groups:group A and group B.The patients in group A were given humidified high-flow nasal oxygen therapy combined with alveolar lavage,whereas those in group B were given humidified high-flow nasal oxygen therapy.The treatment efficacy,blood gas analysis results,and differences in inflammatory mediators were compared between the two groups.Results:The curative effect in group A(96.67%)was significantly higher than that in group B(81.67%),P<0.05;the partial pressure of carbon dioxide(PaCO2),partial pressure of oxygen(PaO2),oxygen saturation(SpO2),and Horowitz index(P/F)of group A were significantly better than group B,P<0.05;the interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),and C-reactive protein(CRP)levels,white blood cell(WBC)count,serum procalcitonin(PCT),and neutrophil(N)percentage of group A were significantly lower than those of group B,P<0.05.Conclusion:For patients with severe pneumonia complicated with respiratory failure,alveolar lavage,on the basis of humidified high-flow oxygen therapy,can inhibit local inflammation,improve blood gas analysis results,promote disease recovery,and improve the clinical treatment effect。展开更多
High-flow hydraulic one-way valves in water pipes are typically used to mitigate conditions,which would otherwise cause vibration and cavitation erosion after long-term operation.To prevent cavitation and enhance the ...High-flow hydraulic one-way valves in water pipes are typically used to mitigate conditions,which would otherwise cause vibration and cavitation erosion after long-term operation.To prevent cavitation and enhance the performance of hydraulic one-way valves,in the present work a dedicated experimental study has been conducted.The structural parameters relating to the pilot valve core,the main valve core,and the through-flow section of the considered flow channel have been changed to analyse reverse impact,and cavitation,characteristics.The results show that the control pressure has a weak effect on the cavitation characteristics,while changes in the structural parameters can significantly affect them.In particular,the cavitation index,representing the extent of cavitation,has been found to display a linear correlation with the inlet pressure,but,not with the inlet flow rate.Most importantly,a stepped throttling structure can reduce the pressure oscillation,improve the response speed,enhance the impact characteristics,and decrease the likelihood and severity of cavitation.The larger the flow passage area,the shorter the unloading time.Cavitation mainly occurs when the pilot valve core is fully opened.The stepped main valve core throttling structure has been found to be an optimal option.展开更多
目的探讨新型高流量湿化氧疗对老年卒中相关性肺炎(SAP)病人的治疗效果。方法选取2017年9月至2019年9月我院神经内科ICU收治的70例老年急性缺血性脑卒中(AIS)血管内介入治疗术后并发SAP病人,按照随机数字表将其分为研究组和对照组,每组...目的探讨新型高流量湿化氧疗对老年卒中相关性肺炎(SAP)病人的治疗效果。方法选取2017年9月至2019年9月我院神经内科ICU收治的70例老年急性缺血性脑卒中(AIS)血管内介入治疗术后并发SAP病人,按照随机数字表将其分为研究组和对照组,每组各35例。2组均给予抗炎、祛痰、止咳等基础疗法,研究组使用经鼻高流量呼吸湿化氧疗,对照组采用传统鼻导管或面罩氧疗方式进行治疗。比较2组治疗前后的临床肺部感染评分(CPIS)及动脉血气分析指标、WBC、hs-CRP水平。统计并比较2组病人的住院时间。结果2组治疗前及治疗后24 h CPIS评分差异均无统计学意义(P>0.05);2组治疗后36 h、7 d,CPIS评分均较治疗前明显下降,且研究组下降更显著,差异均有统计学意义(P<0.05)。2组治疗后pH值、PaO2、PaCO2、WBC、hs-CRP水平均较治疗前显著改善(P<0.05),且研究组pH值显著高于对照组(P<0.05);但2组PaO2、PaCO2、WBC、hs-CRP水平差异均无统计学意义(P>0.05)。研究组的平均住院时间显著短于对照组(P<0.001)。结论新型高流量湿化氧疗能显著改善老年SAP病人的血气水平及肺部感染情况,缩短住院时间。展开更多
Operating principle of water three-way valve with high flow for individual hydraulic prop in coal was presented in this paper, its strict and precise mathematical model was established, its flow field was simulated nu...Operating principle of water three-way valve with high flow for individual hydraulic prop in coal was presented in this paper, its strict and precise mathematical model was established, its flow field was simulated numerically by software Fluent, and its dynamic characteristics were analyzed during the work process such as raising leg, loading and overflow, the influence of the related parameters on high-flow water three-way valve was determined. The results as follows： during the raising leg stage and early raising leg stage, when the damping ratio increases, the overshoot of system decreases and the setting time reduces, and the dynamic response performance has a significant improvement. During the loading stage and the overflow stage, the pressure in plunger chamber of single hydraulic prop, the output flow and the displacement of the high-flow water three-way valve decrease with the decreasing of the external load. The spring stiffness of the safety valve directs the flow and the spool＇s displacement of the safety valve, and it can be used to control the high-flow three-way valve＇s sensitivity.展开更多
Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to inve...Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to investigate what types of nursing support are offered to such patients. Methods: We examined one patient each for NPPV and NHF. Polysomnography (PSG), review of the patient charts, and semi-structured interviews were used to collect the data for analysis. Results: Patients treated with NPPV or NHF demonstrated a noticeable reduction in deep sleep, with most of their sleep being shallow. Their sleep patterns varied greatly from those of healthy individuals. These results suggest that, in addition to experiencing extremely fragmented sleep, sleep in these patients was more likely to be interrupted by nursing interventions, such as during auscultation of breath sounds. Furthermore, it was revealed that “anxiety or discomfort that accompanies the mask or air pressure” in patients treated with NPPV and “discomfort that accompanies the nasal cannula or NHF circuit” in patients treated with NHF may be primary causes of disrupted sleep. Our results suggest a need for nursing care aimed at improving sleep quality in patients treated with NPPV or NHF.展开更多
In intensive care units(ICUs),the decision to extubate is a critical one because mortality is particularly high in case of reintubation.Around 15%of patients ready to be weaned offa ventilator experience extubation fa...In intensive care units(ICUs),the decision to extubate is a critical one because mortality is particularly high in case of reintubation.Around 15%of patients ready to be weaned offa ventilator experience extubation failure leading to reintubation.The use of high-flow nasal oxygen and non-invasive ventilation are two alternatives of standard oxygen supplementation that may help to prevent reintubation.High-flow nasal oxygen and non-invasive ventilation,may be used to prevent reintubation in patients with low(e.g.,patients without comorbidities and with short durations of mechanical ventilation)and high risk(e.g.,patients>65 years and those with underlying cardiac disease,chronic respiratory disorders,and/or hypercapnia at the time of extubation)of reintubation,respectively.However,non-invasive ventilation used as a rescue therapy to treat established post-extubation respiratory failure could increase mortality by delaying reintubation,and should therefore be used very carefully in this setting.The oxygenation strategy to be applied in postoperative patients is different from the patients who are extubated in the ICUs.Standard oxygen after a surgical procedure is adequate,even following major abdominal or cardio-thoracic surgery,but should probably be switched to high-flow nasal oxygen in patients with hypoxemic.Unlike in patients experiencing post-extubation respiratory failure in ICUs wherein non-invasive ventilation may have deleterious effects,it may actually improve the outcomes in postoperative patients with respiratory failure.This review discusses the different clinical situations with the aim of choosing the most effective oxygenation strategy to prevent post-extubation respiratory failure and to avoid reintubation.展开更多
基金Knowledge Innovation Project of Cold and Arid Regions Environmental and Engineering Research Institute of CAS, No.210100, No.210016 Knowledge Innovation Project of CAS, No.KZCX1-10-03National Natural Science Foundation of China, No.4
文摘Firstly, the hydrological and meteorological features of the upper reaches of the Yellow River above Tangnag are analyzed based on observation data, and effects of EI Nino and La Ni na events on the high and low flow in the upper Yellow River are discussed. The results show El Nino and La Nina events possess consanguineous relationship wi th runoff in the upper Yellow River. As a whole, the probability of low fl ow occurrence in the upper Yellow River is relatively great along wit h the occurrence of El Nino event. Moreover, the flood in the upper Yellow River occurs frequently with the occurrence of La Nina event. Besides, the results also show dissimilarity of El Nino event occurri ng time exerts greater impact on high flow and low flow in the uppe r Yellow River, that is, the probability of drought will be greater in the sam e year if El Nino event occurs in spring, the high-flow may happen in this y ear if El Nino occurs in summer or autumn; the longer the continuous period of El Nino is, the lower the runoff in the upper Yellow River is.
文摘BACKGROUND: We sought to demonstrate the superiority of a targeted therapy strategy involving high-flow nasal cannula oxygen(HFNCO_(2)) therapy and noninvasive ventilation(NIV) using lung ultrasound score(LUS) in comparison with standard care among patients in the intensive care unit(ICU) who undergo successful weaning to decrease the incidence of extubation failure at both 48 hours and seven days.METHODS: During the study period, 98 patients were enrolled in the study, including 49 in the control group and 49 in the treatment group. Patients in the control group and patients with an LUS score <14 points(at low risk of extubation failure) in the treatment group were extubated and received standard preventive care without NIV or HFNCO_(2). Patients with an LUS score ≥14 points(at high risk of extubation failure) in the treatment group were extubated with a second review of the therapeutic optimization to identify and address any persisting risk factors for postextubation respiratory distress;patients received HFNCO2 therapy combined with sessions of preventive NIV(4-8 hours per day for 4-8 sessions total) for the first 48 hours after extubation.RESULTS: In the control group, 13 patients had the LUS scores ≥14 points, while 36 patients had scores <14 points. In the treatment group, 16 patients had the LUS scores ≥14 points, while 33 patients had scores <14 points. Among patients with the LUS score ≥14 points, the extubation failure rate within 48 hours was 30.8% in the control group and 12.5% in the treatment group, constituting a statistically significant difference(P<0.05). Conversely, among patients with an LUS score <14 points, 13.9% in the control group and 9.1% in the treatment group experienced extubation failure(P=0.61). The length of ICU stay(9.4±3.1 days vs. 7.2±2.4 days) was significantly different and the re-intubation rate(at 48 hours: 18.4% vs. 10.2%;seven days: 22.4% vs. 12.2%) significantly varied between the two groups(P<0.05). There was no significant difference in the 28-day mortality r
基金The study protocol was approved by the Evangelismos Hospital Ethics Committee(reference number:771/2019)This study was registered in ClinicalTrials.gov(NCT04758910).
文摘Background Compared to conventional oxygen devices,high-flow oxygen treatment(HFOT)through the nasal cannulae has demonstrated clinical benefits.Limited data exist on whether such effects are also present in HFOT through tracheostomy.Hence,we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation.Methods A randomized,crossover,physiological study was conducted in our ICU between December 2020 and April 2021,in patients with tracheostomy and prolonged mechanical ventilation.The patients underwent a 30-min spontaneous breathing trial(SBT)and received oxygen either via T-piece or by HFOT through tracheostomy,followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner.At the start and end of each session,blood gasses,breathing frequency(f),and tidal volume(VT)via a Wright's spirometer were measured,along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction,which expressed the inspiratory muscle effort.Results Eleven patients were enrolled in whom 19 sessions were uneventfully completed;eight patients were studied twice on two different days with alternate sessions;and three patients were studied once.Patients were randomly assigned to start the SBT with a T-piece(n=10 sessions)or with HFOT(n=9 sessions).With HFOT,VT and minute ventilation(VE)significantly increased during SBT(from[465±119]mL to[549±134]mL,P<0.001 and from[12.4±4.3]L/min to[13.1±4.2]L/min,P<0.05,respectively),but they did not change significantly during SBT with T-piece(from[495±132]mL to[461±123]mL and from[12.8±4.4]mL to[12.0±4.4]mL,respectively);f/VT decreased during HFOT(from[64±31]breaths/(min∙L)to[49±24]breaths/(min∙L),P<0.001),but it did not change significantly during SBT with T-piece(from[59±28]breaths/(min∙L)to[64±33]breaths/(min∙L));partial pressure of a
文摘Although standard oxygen face masks are first-line therapy for patients with acute hypoxemic respiratory failure,high-flow nasal cannula oxygen therapy has gained major popularity in intensive care units.The physiological effects of high-flow oxygen counterbalance the physiological consequences of acute hypoxemic respiratory failure by lessening the deleterious effects of intense and prolonged inspiratory efforts generated by patients.Its simplicity of application for physicians and nurses and its comfort for patients are other arguments for its use in this setting.Although clinical studies have reported a decreased risk of intubation with high-flow oxygen compared with standard oxygen,its survival benefit is uncertain.A more precise definition of acute hypoxemic respiratory failure,including a classification of severity based on oxygenation levels,is needed to better compare the efficiencies of different non-invasive oxygenation support methods(standard oxygen,high-flow oxygen,and non-invasive ventilation).Additionally,the respective role of each non-invasive oxygenation support method needs to be established through further clinical trials in acute hypoxemic respiratory failure,especially in severe forms.
文摘Objective:To analyze the curative effect of humidified high-flow nasal oxygen therapy combined with alveolar lavage in patients with severe pneumonia and respiratory failure.Methods:120 patients with severe pneumonia complicated with respiratory failure admitted to the Third People’s Hospital of Xining from July 2021 to December 2022 were randomly divided into two groups:group A and group B.The patients in group A were given humidified high-flow nasal oxygen therapy combined with alveolar lavage,whereas those in group B were given humidified high-flow nasal oxygen therapy.The treatment efficacy,blood gas analysis results,and differences in inflammatory mediators were compared between the two groups.Results:The curative effect in group A(96.67%)was significantly higher than that in group B(81.67%),P<0.05;the partial pressure of carbon dioxide(PaCO2),partial pressure of oxygen(PaO2),oxygen saturation(SpO2),and Horowitz index(P/F)of group A were significantly better than group B,P<0.05;the interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),and C-reactive protein(CRP)levels,white blood cell(WBC)count,serum procalcitonin(PCT),and neutrophil(N)percentage of group A were significantly lower than those of group B,P<0.05.Conclusion:For patients with severe pneumonia complicated with respiratory failure,alveolar lavage,on the basis of humidified high-flow oxygen therapy,can inhibit local inflammation,improve blood gas analysis results,promote disease recovery,and improve the clinical treatment effect。
基金supported by the University Natural Science Research Programme of Jiangsu Province(grant numbers 18KJB460028)the Natural Science Foundation of Jiangsu Province(grant numbers BK20180177)+1 种基金the Major Programme from the Natural Science Foundation for Colleges and Universities of Jiangsu Province(grant numbers 18KJA460008)the Project of Xuzhou Applied and Basic Research(grant numbers KH17012).
文摘High-flow hydraulic one-way valves in water pipes are typically used to mitigate conditions,which would otherwise cause vibration and cavitation erosion after long-term operation.To prevent cavitation and enhance the performance of hydraulic one-way valves,in the present work a dedicated experimental study has been conducted.The structural parameters relating to the pilot valve core,the main valve core,and the through-flow section of the considered flow channel have been changed to analyse reverse impact,and cavitation,characteristics.The results show that the control pressure has a weak effect on the cavitation characteristics,while changes in the structural parameters can significantly affect them.In particular,the cavitation index,representing the extent of cavitation,has been found to display a linear correlation with the inlet pressure,but,not with the inlet flow rate.Most importantly,a stepped throttling structure can reduce the pressure oscillation,improve the response speed,enhance the impact characteristics,and decrease the likelihood and severity of cavitation.The larger the flow passage area,the shorter the unloading time.Cavitation mainly occurs when the pilot valve core is fully opened.The stepped main valve core throttling structure has been found to be an optimal option.
文摘目的探讨新型高流量湿化氧疗对老年卒中相关性肺炎(SAP)病人的治疗效果。方法选取2017年9月至2019年9月我院神经内科ICU收治的70例老年急性缺血性脑卒中(AIS)血管内介入治疗术后并发SAP病人,按照随机数字表将其分为研究组和对照组,每组各35例。2组均给予抗炎、祛痰、止咳等基础疗法,研究组使用经鼻高流量呼吸湿化氧疗,对照组采用传统鼻导管或面罩氧疗方式进行治疗。比较2组治疗前后的临床肺部感染评分(CPIS)及动脉血气分析指标、WBC、hs-CRP水平。统计并比较2组病人的住院时间。结果2组治疗前及治疗后24 h CPIS评分差异均无统计学意义(P>0.05);2组治疗后36 h、7 d,CPIS评分均较治疗前明显下降,且研究组下降更显著,差异均有统计学意义(P<0.05)。2组治疗后pH值、PaO2、PaCO2、WBC、hs-CRP水平均较治疗前显著改善(P<0.05),且研究组pH值显著高于对照组(P<0.05);但2组PaO2、PaCO2、WBC、hs-CRP水平差异均无统计学意义(P>0.05)。研究组的平均住院时间显著短于对照组(P<0.001)。结论新型高流量湿化氧疗能显著改善老年SAP病人的血气水平及肺部感染情况,缩短住院时间。
基金Supported by the National Natural Science Foundation of China （51075001） the Nature Science Research Project of Anhui Province （KJ2009A020）
文摘Operating principle of water three-way valve with high flow for individual hydraulic prop in coal was presented in this paper, its strict and precise mathematical model was established, its flow field was simulated numerically by software Fluent, and its dynamic characteristics were analyzed during the work process such as raising leg, loading and overflow, the influence of the related parameters on high-flow water three-way valve was determined. The results as follows： during the raising leg stage and early raising leg stage, when the damping ratio increases, the overshoot of system decreases and the setting time reduces, and the dynamic response performance has a significant improvement. During the loading stage and the overflow stage, the pressure in plunger chamber of single hydraulic prop, the output flow and the displacement of the high-flow water three-way valve decrease with the decreasing of the external load. The spring stiffness of the safety valve directs the flow and the spool＇s displacement of the safety valve, and it can be used to control the high-flow three-way valve＇s sensitivity.
文摘Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to investigate what types of nursing support are offered to such patients. Methods: We examined one patient each for NPPV and NHF. Polysomnography (PSG), review of the patient charts, and semi-structured interviews were used to collect the data for analysis. Results: Patients treated with NPPV or NHF demonstrated a noticeable reduction in deep sleep, with most of their sleep being shallow. Their sleep patterns varied greatly from those of healthy individuals. These results suggest that, in addition to experiencing extremely fragmented sleep, sleep in these patients was more likely to be interrupted by nursing interventions, such as during auscultation of breath sounds. Furthermore, it was revealed that “anxiety or discomfort that accompanies the mask or air pressure” in patients treated with NPPV and “discomfort that accompanies the nasal cannula or NHF circuit” in patients treated with NHF may be primary causes of disrupted sleep. Our results suggest a need for nursing care aimed at improving sleep quality in patients treated with NPPV or NHF.
文摘In intensive care units(ICUs),the decision to extubate is a critical one because mortality is particularly high in case of reintubation.Around 15%of patients ready to be weaned offa ventilator experience extubation failure leading to reintubation.The use of high-flow nasal oxygen and non-invasive ventilation are two alternatives of standard oxygen supplementation that may help to prevent reintubation.High-flow nasal oxygen and non-invasive ventilation,may be used to prevent reintubation in patients with low(e.g.,patients without comorbidities and with short durations of mechanical ventilation)and high risk(e.g.,patients>65 years and those with underlying cardiac disease,chronic respiratory disorders,and/or hypercapnia at the time of extubation)of reintubation,respectively.However,non-invasive ventilation used as a rescue therapy to treat established post-extubation respiratory failure could increase mortality by delaying reintubation,and should therefore be used very carefully in this setting.The oxygenation strategy to be applied in postoperative patients is different from the patients who are extubated in the ICUs.Standard oxygen after a surgical procedure is adequate,even following major abdominal or cardio-thoracic surgery,but should probably be switched to high-flow nasal oxygen in patients with hypoxemic.Unlike in patients experiencing post-extubation respiratory failure in ICUs wherein non-invasive ventilation may have deleterious effects,it may actually improve the outcomes in postoperative patients with respiratory failure.This review discusses the different clinical situations with the aim of choosing the most effective oxygenation strategy to prevent post-extubation respiratory failure and to avoid reintubation.
