目的 评价基于临床流程为导向的急诊气道管理培训的培训效果。方法 选取急诊科一线值班医师，根据是否参加过基于临床流程为导向的急诊气道管理课程分为研究组和对照组。设置模拟临床情景分别进行考核。结果 40名临床医师入选，其中研究...目的 评价基于临床流程为导向的急诊气道管理培训的培训效果。方法 选取急诊科一线值班医师，根据是否参加过基于临床流程为导向的急诊气道管理课程分为研究组和对照组。设置模拟临床情景分别进行考核。结果 40名临床医师入选，其中研究组19人，对照组21人。研究组与对照组根据气道管理考核评分比较，在插管指征部分的通气条件得分（4.37±0.93 vs. 3.62±1.25），预防性插管得分（4.37±0.93 vs. 2.90±2.02），准备部分的患者气道评估得分（4.37±1.56 vs. 1.48±1.79），操作部分的预氧合得分（4.58±0.82 vs. 3.48±1.89），预治疗得分（4.42±1.27 vs. 2.67±2.38），总得分（84.84±11.63 vs. 76.67±11.52）均优于对照组（P＜0.05）。其他部分两组得分比较差异无统计学意义（P＞0.05）。结论 基于临床流程为导向的急诊气道管理课程不仅能够保证气管插管技能培训效果的同时，还能培养学员掌握合理临床流程, 更好地满足临床岗位胜任力的需求。展开更多
目的探讨血栓性血小板减少性紫癜(thrombotic thrombocytopenic purpura,TTP)的临床特点及预后因素。方法回顾性分析北京协和医院2012至2017年60例TTP患者的临床表现、实验室检查、诊断、治疗及转归,采用Logistic单因素及多因素回归分...目的探讨血栓性血小板减少性紫癜(thrombotic thrombocytopenic purpura,TTP)的临床特点及预后因素。方法回顾性分析北京协和医院2012至2017年60例TTP患者的临床表现、实验室检查、诊断、治疗及转归,采用Logistic单因素及多因素回归分析危险因素对预后的影响,采用K多个独立样本检验及Mann-Whitney U检验分析不同治疗方案对预后的影响。结果 60例患者中,男性17例(28.3%,17/60),女性43例(71.7%,43/60),平均年龄(41±15)岁。28例患者(46.7%,28/60)表现为发热、微血管病性溶血性贫血、血小板降低三联征,23例(38.3%,23/60)表现为发热、微血管病性溶血性贫血、血小板降低、肾功能不全、神经系统异常五联征,其余9例(15.0%,9/60)无典型三联征/五联征表现。28例患者接受血管性血友病因子裂解蛋白酶13(a disintegrin and metalloproteinase with a thrombospondin type 1motif,member 13,ADAMTS13)活性检测,其中23例ADAMTS13活性<10%,阳性率为82.1%(23/28);20例患者检测了ADAMTS13抑制物,阳性率为90.0%(18/20);20例同时行ADAMTS13活性及其抑制物检测,二者均为阳性者占90.0%(18/20)。根据是否有血源、患者经济条件等不同情况,采用血浆置换、糖皮质激素、利妥昔单抗、免疫抑制剂、注射用免疫球蛋白等不同治疗方案,42例患者(70.0%,42/60)病情缓解,18例(30.0%,18/60)死亡。在血浆置换及激素治疗的基础上加用免疫抑制治疗,可将缓解率由57.1%提高至85.2%(P=0.032)。未发现导致患者死亡率增高的危险因素。结论 TTP多表现为三联征或五联征,ADAMTS13活性降低及抑制物检测阳性率高,免疫抑制治疗可改善预后。展开更多
Objective:To study the stress distribution of the femoral hip prosthesis after the hip joint replacement.Methods:After the hip joint replacement,when the femur and prosthesis are considered as concentric cylinders wit...Objective:To study the stress distribution of the femoral hip prosthesis after the hip joint replacement.Methods:After the hip joint replacement,when the femur and prosthesis are considered as concentric cylinders with perfectly banded interface,a relatively perfect theoretical model of simulating the interfacial stress transfer is established.Results:The maximum interfacial shear stress occured at Z=0.At the cross-section of the femoral neck,interfacial shear stress decreased exponentially with the increases of the Z.Shear stress became very small at Z>0.1 m,which meant that the shear stress at the far end of the femoral hip prosthesis was very small.In order to avoid the stress concentration and femoral hip prosthesis sinking,interfacial stress must remain constant and balanced with the pressure load at Z=0.The radius of the femoral hip prosthesis changed with interfacial shear stress.The maximum value of the radius occured at Z=0,then it decreased at m.Specially,a=18.2 mm at Z=10 mm,a=5.36 mm at Z=98 mm,these are ideal radius.Conclusion:A theoretical model of simulating the interfacial stress is established when the femur and prosthesis are considered as concentric cylinders.The distributions of the interfacial shear and radial stresses with the axial positions are obtained.A theoretical reference for the design of the prosthesis is provided.展开更多
Objective:To model the stress transfer at the interface of the cemented prosthesis and femur,an axisymmetric model of the interfacial stress transfer was established.Methods: Assuming that the prosthesis,the cement an...Objective:To model the stress transfer at the interface of the cemented prosthesis and femur,an axisymmetric model of the interfacial stress transfer was established.Methods: Assuming that the prosthesis,the cement and the femur were concentric cylinders with linear elastic and isotropic properties,distributions of the axial stresses in the prosthesis,the cement and the femur as well as the interfacial shear stresses at the prosthesis/cement interface and the cement/femur interface in the axial direction were obtained from the established axisymmetric stress transfer model.Results: Interfacial failure was the main form for the prosthesis/cement/femur structure under external loads. Considering the residual thermal stresses,it was more likely to produce the mixed failure form than the pure shear failure form. Since the cement had a relatively high thermal expansion coefficient,the thermal effect accelerated the interface failure and thus aggravated the stress shielding effect. Due to a relatively high thermal residual temperature difference,the interfacial debonding and femur failure was more likely to occur for the cobalt-chromium alloy prosthesis material than the Ti-6Al-4V alloy prosthesis material.Conclusion: Assuming that the prosthesis,the cement and the femur are concentric cylinders with linear elastic and isotropic properties,distributions of the axial stresses in the prosthesis,the cement and the femur as well as the interfacial shear stresses at the prosthesis/cement interface and the cement/femur interface in the axial direction was obtained using the basic equations of axisymmetric elastic mechanics when the prosthesis bears the compressive stresses. Interface failure is the main failure form for the prosthesis/cement/femur structure under external loads. The thermal effects accelerate the failure of the prosthesis/cement interface and the cement/femur interface and the relaxation of the prosthesis,and then aggravates the stress shielding effect of the femur. Also,the thermal effects decrease the efficiencies of the interfacial stress transfer to some extent since it alleviates the failure of the interface and the femur,which was confirmed by the clinical results.展开更多
Objective: The biomechanical characters of the bone fracture of the man femoral hip joint under impact loads are explored. Methods:A biosystem model of the man femoral hip joint by using the GE (General Electric) ligh...Objective: The biomechanical characters of the bone fracture of the man femoral hip joint under impact loads are explored. Methods:A biosystem model of the man femoral hip joint by using the GE (General Electric) lightspeed multi-lay spiral CT is conducted. A 3D finite element model is established by employing the finite element software ANSYS. The FE analysis mainly concentrates on the effects of the impact directions arising from intense movements and the parenchyma on the femoral hip joint on the stress distributions of the proximal femur. Results:The parenchyma on the hip joint has relatively large relaxation effect on the impact loads. Conclusion:Effects of the angle δ of the impact load to the anterior direction and the angle γ of the impact load to the femur shaft on the bone fracture are given;δ has larger effect on the stress and strain distributions than the angle γ, which mainly represents the fracture of the upper femur including the femoral neck fracture when the posterolateral femur is impacted, consistent with the clinical results.展开更多
文摘目的 评价基于临床流程为导向的急诊气道管理培训的培训效果。方法 选取急诊科一线值班医师，根据是否参加过基于临床流程为导向的急诊气道管理课程分为研究组和对照组。设置模拟临床情景分别进行考核。结果 40名临床医师入选，其中研究组19人，对照组21人。研究组与对照组根据气道管理考核评分比较，在插管指征部分的通气条件得分（4.37±0.93 vs. 3.62±1.25），预防性插管得分（4.37±0.93 vs. 2.90±2.02），准备部分的患者气道评估得分（4.37±1.56 vs. 1.48±1.79），操作部分的预氧合得分（4.58±0.82 vs. 3.48±1.89），预治疗得分（4.42±1.27 vs. 2.67±2.38），总得分（84.84±11.63 vs. 76.67±11.52）均优于对照组（P＜0.05）。其他部分两组得分比较差异无统计学意义（P＞0.05）。结论 基于临床流程为导向的急诊气道管理课程不仅能够保证气管插管技能培训效果的同时，还能培养学员掌握合理临床流程, 更好地满足临床岗位胜任力的需求。
文摘目的探讨血栓性血小板减少性紫癜(thrombotic thrombocytopenic purpura,TTP)的临床特点及预后因素。方法回顾性分析北京协和医院2012至2017年60例TTP患者的临床表现、实验室检查、诊断、治疗及转归,采用Logistic单因素及多因素回归分析危险因素对预后的影响,采用K多个独立样本检验及Mann-Whitney U检验分析不同治疗方案对预后的影响。结果 60例患者中,男性17例(28.3%,17/60),女性43例(71.7%,43/60),平均年龄(41±15)岁。28例患者(46.7%,28/60)表现为发热、微血管病性溶血性贫血、血小板降低三联征,23例(38.3%,23/60)表现为发热、微血管病性溶血性贫血、血小板降低、肾功能不全、神经系统异常五联征,其余9例(15.0%,9/60)无典型三联征/五联征表现。28例患者接受血管性血友病因子裂解蛋白酶13(a disintegrin and metalloproteinase with a thrombospondin type 1motif,member 13,ADAMTS13)活性检测,其中23例ADAMTS13活性<10%,阳性率为82.1%(23/28);20例患者检测了ADAMTS13抑制物,阳性率为90.0%(18/20);20例同时行ADAMTS13活性及其抑制物检测,二者均为阳性者占90.0%(18/20)。根据是否有血源、患者经济条件等不同情况,采用血浆置换、糖皮质激素、利妥昔单抗、免疫抑制剂、注射用免疫球蛋白等不同治疗方案,42例患者(70.0%,42/60)病情缓解,18例(30.0%,18/60)死亡。在血浆置换及激素治疗的基础上加用免疫抑制治疗,可将缓解率由57.1%提高至85.2%(P=0.032)。未发现导致患者死亡率增高的危险因素。结论 TTP多表现为三联征或五联征,ADAMTS13活性降低及抑制物检测阳性率高,免疫抑制治疗可改善预后。
文摘Objective:To study the stress distribution of the femoral hip prosthesis after the hip joint replacement.Methods:After the hip joint replacement,when the femur and prosthesis are considered as concentric cylinders with perfectly banded interface,a relatively perfect theoretical model of simulating the interfacial stress transfer is established.Results:The maximum interfacial shear stress occured at Z=0.At the cross-section of the femoral neck,interfacial shear stress decreased exponentially with the increases of the Z.Shear stress became very small at Z>0.1 m,which meant that the shear stress at the far end of the femoral hip prosthesis was very small.In order to avoid the stress concentration and femoral hip prosthesis sinking,interfacial stress must remain constant and balanced with the pressure load at Z=0.The radius of the femoral hip prosthesis changed with interfacial shear stress.The maximum value of the radius occured at Z=0,then it decreased at m.Specially,a=18.2 mm at Z=10 mm,a=5.36 mm at Z=98 mm,these are ideal radius.Conclusion:A theoretical model of simulating the interfacial stress is established when the femur and prosthesis are considered as concentric cylinders.The distributions of the interfacial shear and radial stresses with the axial positions are obtained.A theoretical reference for the design of the prosthesis is provided.
文摘Objective:To model the stress transfer at the interface of the cemented prosthesis and femur,an axisymmetric model of the interfacial stress transfer was established.Methods: Assuming that the prosthesis,the cement and the femur were concentric cylinders with linear elastic and isotropic properties,distributions of the axial stresses in the prosthesis,the cement and the femur as well as the interfacial shear stresses at the prosthesis/cement interface and the cement/femur interface in the axial direction were obtained from the established axisymmetric stress transfer model.Results: Interfacial failure was the main form for the prosthesis/cement/femur structure under external loads. Considering the residual thermal stresses,it was more likely to produce the mixed failure form than the pure shear failure form. Since the cement had a relatively high thermal expansion coefficient,the thermal effect accelerated the interface failure and thus aggravated the stress shielding effect. Due to a relatively high thermal residual temperature difference,the interfacial debonding and femur failure was more likely to occur for the cobalt-chromium alloy prosthesis material than the Ti-6Al-4V alloy prosthesis material.Conclusion: Assuming that the prosthesis,the cement and the femur are concentric cylinders with linear elastic and isotropic properties,distributions of the axial stresses in the prosthesis,the cement and the femur as well as the interfacial shear stresses at the prosthesis/cement interface and the cement/femur interface in the axial direction was obtained using the basic equations of axisymmetric elastic mechanics when the prosthesis bears the compressive stresses. Interface failure is the main failure form for the prosthesis/cement/femur structure under external loads. The thermal effects accelerate the failure of the prosthesis/cement interface and the cement/femur interface and the relaxation of the prosthesis,and then aggravates the stress shielding effect of the femur. Also,the thermal effects decrease the efficiencies of the interfacial stress transfer to some extent since it alleviates the failure of the interface and the femur,which was confirmed by the clinical results.
文摘Objective: The biomechanical characters of the bone fracture of the man femoral hip joint under impact loads are explored. Methods:A biosystem model of the man femoral hip joint by using the GE (General Electric) lightspeed multi-lay spiral CT is conducted. A 3D finite element model is established by employing the finite element software ANSYS. The FE analysis mainly concentrates on the effects of the impact directions arising from intense movements and the parenchyma on the femoral hip joint on the stress distributions of the proximal femur. Results:The parenchyma on the hip joint has relatively large relaxation effect on the impact loads. Conclusion:Effects of the angle δ of the impact load to the anterior direction and the angle γ of the impact load to the femur shaft on the bone fracture are given;δ has larger effect on the stress and strain distributions than the angle γ, which mainly represents the fracture of the upper femur including the femoral neck fracture when the posterolateral femur is impacted, consistent with the clinical results.
