This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter（IVAPC）. The fracture or migration of IVAPC occurred in 4 patients who were tr...This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter（IVAPC）. The fracture or migration of IVAPC occurred in 4 patients who were treated between May 2012 and January 2014 in Union Hospital,Wuhan,China. The port catheter leakage was found in 2 cases during drug infusion. Catheters that dislodged to the superior vena cava and right atrium were confirmed by port angiogram. The two dislodged catheters were successfully retrieved by interventional procedures. Catheter fracture occurred in two cases during port removal. One catheter was eventually removed from the subclavian vein through right clavicle osteotomy and subclavian venotomy,and the other removed by external jugular venotomy. Flushing the port in high pressure and injury of the totally implantable venous access port（TIVP） during implantation are usually responsible for catheter displacement. Interventional retrieval procedure can be used if the catheter dislodges to the vena cava and right atrium. Catheter fracture may occur during removal if clipping syndrome occurs or the catheter is sutured very tight during implantation.展开更多
Background: Elastomeric pumps (elastic balls into which analgesics or antibiotics can be inserted) push medicines through a catheter to a nerve or blood vessel. Since elastomeric pumps are small and need no power sour...Background: Elastomeric pumps (elastic balls into which analgesics or antibiotics can be inserted) push medicines through a catheter to a nerve or blood vessel. Since elastomeric pumps are small and need no power source, they fit easily into a pocket during infusion, allowing patient mobility. Elastomeric pumps are widely used and widely studied experimentally, but they have well-known problems, such as maintaining reliable flow rates and avoiding toxicity or other peak-and-trough effects. Objectives: Our research objective is to develop a realistic theoretical model of an elastomeric pump, analyze its flow rates, determine its toxicity conditions, and otherwise improve its operation. We believe this is the first such theoretical model of an elastomeric pump consisting of an elastic, medicine-filled ball attached to a horizontal catheter. Method: Our method is to model the system as a quasi-Poiseuille flow driven by the pressure drop generated by the elastic sphere. We construct an engineering model of the pressure exerted by an elastic sphere and match it to a solution of the one-dimensional radial Navier-Stokes equation that describes flow through a horizontal, cylindrical tube. Results: Our results are that the model accurately reproduces flow rates obtained in clinical studies. We also discover that the flow rate has an unavoidable maximum, which we call the “toxicity bump”, when the radius of the sphere approaches its terminal, unstretched value—an effect that has been observed experimentally. Conclusions: We conclude that by choosing the properties of an elastomeric pump, the toxicity bump can be restricted to less than 10% of the earlier, relatively constant flow rate. Our model also produces a relation between the length of time that the analgesic fluid infuses and the physical properties of the fluid, of the elastomeric sphere and the tube, and of the blood vessel into which the analgesic infuses. From these, we conclude that elastomeric pumps can be designed, using our simple model, to control infusion times while avoiding toxicity effects.展开更多
BACKGROUND Implanted intravenous infusion port(TIAP)is mainly used for patients who need central venous infusion and poor peripheral vascular conditions.With the advantages of easy to carry,long maintenance cycle,few ...BACKGROUND Implanted intravenous infusion port(TIAP)is mainly used for patients who need central venous infusion and poor peripheral vascular conditions.With the advantages of easy to carry,long maintenance cycle,few complications and excellent quality of life,it has been widely used in the fields of malignant tumor chemotherapy,parenteral nutrition support and repeated blood collection.Implanted intravenous infusion port(IVAP)dislocation can have significant complications if not recognised and reinstated immediately.CASE SUMMARY A 24-year-old man was treated with adjuvant chemotherapy for osteosarcoma.Severe displacement of IVAP catheter was found by chest X-ray examination.The IVAP cannot be used normally.Therefore,we conducted an emergency procedure to reset the catheter through double pigtail catheters,the operation was successful and the infusion port was restored.CONCLUSION When IVAP catheter displacement cannot be reset by conventional techniques,two pigtail catheters can be successfully used instead.展开更多
目的探讨丙泊酚微量泵输注联合前锯肌平面阻滞对老年胃癌根治术患者麻醉药物用量、术后谵妄及躁动影响。方法前瞻性选取2021年1月至2023年12月临汾市人民医院收治的80例老年胃癌患者作为研究对象,按照抽签法分为观察组与对照组,每组各4...目的探讨丙泊酚微量泵输注联合前锯肌平面阻滞对老年胃癌根治术患者麻醉药物用量、术后谵妄及躁动影响。方法前瞻性选取2021年1月至2023年12月临汾市人民医院收治的80例老年胃癌患者作为研究对象,按照抽签法分为观察组与对照组,每组各40例。所有患者均择期实施胃癌根治术治疗,对照组患者实施单纯全身静脉麻醉,术中采取丙泊酚微量泵注维持麻醉,观察组在对照组基础上增加前锯肌平面阻滞。对比两组麻醉效果,麻醉前(T1)、麻醉后2 min(T2)、手术开始即刻(T3)及手术结束即刻(T4)平均动脉压、血氧饱和度及心率水平变化,对比两组麻醉药物总用量,术后1、6及12 h疼痛及镇静情况,最后对比其谵妄及躁动发生率。结果观察组麻醉效果Ⅰ级患者比率为65.00%,高于对照组(37.50%),观察组麻醉效果Ⅲ级患者比率为2.50%,低于对照组(15.00%),差异均有统计学意义(P<0.05)。观察组T2、T3、T4时MAP水平分别为(80.94±6.26)、(83.37±6.52)、(92.39±5.18)mmHg,均高于对照组[(74.33±4.85)、(76.21±4.42)、(83.72±11.22)mmHg],观察组T2、T3时血氧饱和度分别为(98.84±1.67)%、(98.95±1.56)%,均高于对照组[(93.52±2.52)%、(93.12±1.53)%],观察组T2时心率为(80.36±9.27)次/min,低于对照组[(86.28±7.22)次/min],差异均有统计学意义(P<0.05)。两组患者瑞芬太尼用量比较,差异无统计学意义(P>0.05),观察组患者舒芬太尼、丙泊酚用量分别为(43.32±5.12)μg、(251.63±42.52)mg,均明显低于对照组[(46.02±7.25)μg、(281.68±56.12)mg],差异均有统计学意义(P<0.05)。观察组术后1、6、12 h Ramsay评分(1.62±0.28)、(1.08±0.15)、(0.73±0.16)级,均低于对照组[(2.81±0.31)、(1.52±0.12)、(1.03±0.12)级];观察组术后1、6、12 h VAS评分(3.41±1.23)、(2.44±0.21)、(2.17±0.31)分,均低于对照组[(4.39±1.38)、(3.57±0.11)、(3.03±0.25)分],差异均有统计学意义(P<0.05)。观察组术后谵妄及躁动发生率分别为5.00%、2.50%,均明显低于对照组(22.50%、17.50%),差异均有统计学意义(P<0.05)。结论丙泊酚微量泵输注联合前锯肌平面阻滞可提升老年胃癌根治术患者麻醉效果,稳定术中生命体征,减少麻醉药物用量,同时可提升术后镇痛及镇静效果,降低躁动及谵妄发生率。展开更多
This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the in...This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.展开更多
文摘This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter（IVAPC）. The fracture or migration of IVAPC occurred in 4 patients who were treated between May 2012 and January 2014 in Union Hospital,Wuhan,China. The port catheter leakage was found in 2 cases during drug infusion. Catheters that dislodged to the superior vena cava and right atrium were confirmed by port angiogram. The two dislodged catheters were successfully retrieved by interventional procedures. Catheter fracture occurred in two cases during port removal. One catheter was eventually removed from the subclavian vein through right clavicle osteotomy and subclavian venotomy,and the other removed by external jugular venotomy. Flushing the port in high pressure and injury of the totally implantable venous access port（TIVP） during implantation are usually responsible for catheter displacement. Interventional retrieval procedure can be used if the catheter dislodges to the vena cava and right atrium. Catheter fracture may occur during removal if clipping syndrome occurs or the catheter is sutured very tight during implantation.
文摘Background: Elastomeric pumps (elastic balls into which analgesics or antibiotics can be inserted) push medicines through a catheter to a nerve or blood vessel. Since elastomeric pumps are small and need no power source, they fit easily into a pocket during infusion, allowing patient mobility. Elastomeric pumps are widely used and widely studied experimentally, but they have well-known problems, such as maintaining reliable flow rates and avoiding toxicity or other peak-and-trough effects. Objectives: Our research objective is to develop a realistic theoretical model of an elastomeric pump, analyze its flow rates, determine its toxicity conditions, and otherwise improve its operation. We believe this is the first such theoretical model of an elastomeric pump consisting of an elastic, medicine-filled ball attached to a horizontal catheter. Method: Our method is to model the system as a quasi-Poiseuille flow driven by the pressure drop generated by the elastic sphere. We construct an engineering model of the pressure exerted by an elastic sphere and match it to a solution of the one-dimensional radial Navier-Stokes equation that describes flow through a horizontal, cylindrical tube. Results: Our results are that the model accurately reproduces flow rates obtained in clinical studies. We also discover that the flow rate has an unavoidable maximum, which we call the “toxicity bump”, when the radius of the sphere approaches its terminal, unstretched value—an effect that has been observed experimentally. Conclusions: We conclude that by choosing the properties of an elastomeric pump, the toxicity bump can be restricted to less than 10% of the earlier, relatively constant flow rate. Our model also produces a relation between the length of time that the analgesic fluid infuses and the physical properties of the fluid, of the elastomeric sphere and the tube, and of the blood vessel into which the analgesic infuses. From these, we conclude that elastomeric pumps can be designed, using our simple model, to control infusion times while avoiding toxicity effects.
基金Supported by Shenzhen Key Medical Discipline Construction Fund,No.SZXK052。
文摘BACKGROUND Implanted intravenous infusion port(TIAP)is mainly used for patients who need central venous infusion and poor peripheral vascular conditions.With the advantages of easy to carry,long maintenance cycle,few complications and excellent quality of life,it has been widely used in the fields of malignant tumor chemotherapy,parenteral nutrition support and repeated blood collection.Implanted intravenous infusion port(IVAP)dislocation can have significant complications if not recognised and reinstated immediately.CASE SUMMARY A 24-year-old man was treated with adjuvant chemotherapy for osteosarcoma.Severe displacement of IVAP catheter was found by chest X-ray examination.The IVAP cannot be used normally.Therefore,we conducted an emergency procedure to reset the catheter through double pigtail catheters,the operation was successful and the infusion port was restored.CONCLUSION When IVAP catheter displacement cannot be reset by conventional techniques,two pigtail catheters can be successfully used instead.
文摘目的探讨丙泊酚微量泵输注联合前锯肌平面阻滞对老年胃癌根治术患者麻醉药物用量、术后谵妄及躁动影响。方法前瞻性选取2021年1月至2023年12月临汾市人民医院收治的80例老年胃癌患者作为研究对象,按照抽签法分为观察组与对照组,每组各40例。所有患者均择期实施胃癌根治术治疗,对照组患者实施单纯全身静脉麻醉,术中采取丙泊酚微量泵注维持麻醉,观察组在对照组基础上增加前锯肌平面阻滞。对比两组麻醉效果,麻醉前(T1)、麻醉后2 min(T2)、手术开始即刻(T3)及手术结束即刻(T4)平均动脉压、血氧饱和度及心率水平变化,对比两组麻醉药物总用量,术后1、6及12 h疼痛及镇静情况,最后对比其谵妄及躁动发生率。结果观察组麻醉效果Ⅰ级患者比率为65.00%,高于对照组(37.50%),观察组麻醉效果Ⅲ级患者比率为2.50%,低于对照组(15.00%),差异均有统计学意义(P<0.05)。观察组T2、T3、T4时MAP水平分别为(80.94±6.26)、(83.37±6.52)、(92.39±5.18)mmHg,均高于对照组[(74.33±4.85)、(76.21±4.42)、(83.72±11.22)mmHg],观察组T2、T3时血氧饱和度分别为(98.84±1.67)%、(98.95±1.56)%,均高于对照组[(93.52±2.52)%、(93.12±1.53)%],观察组T2时心率为(80.36±9.27)次/min,低于对照组[(86.28±7.22)次/min],差异均有统计学意义(P<0.05)。两组患者瑞芬太尼用量比较,差异无统计学意义(P>0.05),观察组患者舒芬太尼、丙泊酚用量分别为(43.32±5.12)μg、(251.63±42.52)mg,均明显低于对照组[(46.02±7.25)μg、(281.68±56.12)mg],差异均有统计学意义(P<0.05)。观察组术后1、6、12 h Ramsay评分(1.62±0.28)、(1.08±0.15)、(0.73±0.16)级,均低于对照组[(2.81±0.31)、(1.52±0.12)、(1.03±0.12)级];观察组术后1、6、12 h VAS评分(3.41±1.23)、(2.44±0.21)、(2.17±0.31)分,均低于对照组[(4.39±1.38)、(3.57±0.11)、(3.03±0.25)分],差异均有统计学意义(P<0.05)。观察组术后谵妄及躁动发生率分别为5.00%、2.50%,均明显低于对照组(22.50%、17.50%),差异均有统计学意义(P<0.05)。结论丙泊酚微量泵输注联合前锯肌平面阻滞可提升老年胃癌根治术患者麻醉效果,稳定术中生命体征,减少麻醉药物用量,同时可提升术后镇痛及镇静效果,降低躁动及谵妄发生率。
基金supported by the National High Technology Research and Development program of China (863 Program, Grant No. 2007AA02Z439)The Program for Outstanding Medical Academic Leader of Shanghai
文摘This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.
