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
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
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
This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient cond...This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.展开更多
This paper presents a high-efficiency charge pump circuit composed of cascaded cross-coupled voltage doublers implemented in an isolated bipolar-CMOS-DMOS（BCD） technology for implantable medical devices.Taking advan...This paper presents a high-efficiency charge pump circuit composed of cascaded cross-coupled voltage doublers implemented in an isolated bipolar-CMOS-DMOS（BCD） technology for implantable medical devices.Taking advantage of the transistor structures in the isolated BCD process, the leakage currents caused by the parasitic PNP transistors in the cross-coupled PMOS serial switches are eliminated by simply connecting the inside substrate terminal to the isolation terminal of each PMOS transistor. The simple circuit structure leads to small parasitic capacitance in the voltage doubler, which in turn ensures high efficiency of the overall charge pump. The proposed charge pump with 5 cascaded voltage doublers is fabricated in a 0.35-μm isolated BCD process. Measurement results with 2-V power supply, 1-MHz driving clock frequency and 40-μA current load show that an efficiency of 72.6% is achieved, and the output voltage can be pumped to about 11.5 V at zero load current. The chip area of the charge pump is 1.6 × 0.35 mm^2.展开更多
BACKGROUND Critically ill neonates and pediatric patients commonly require multiple low flow infusions.Volume limitations are imposed by small body habitus and comorbidities like cardiopulmonary disease,renal failure,...BACKGROUND Critically ill neonates and pediatric patients commonly require multiple low flow infusions.Volume limitations are imposed by small body habitus and comorbidities like cardiopulmonary disease,renal failure,or fluid overload.Vascular access is limited by diminutive veins.Maintenance fluids or parenteral nutrition in conjunction with actively titrated infusions such as insulin,fentanyl,prostaglandins,inotropes and vasopressors may necessitate simultaneous infusions using a single lumen to maintain vascular catheter patency.This requirement for multiple titratable infusions requires concentrated medications at low flows,rather than more dilute drugs at higher flows that in combination may volume overload small infants.AIM To determine whether carrier fluid reduces variability that variability of low flow drug infusions is proportional to syringe size in pediatric critical care.METHODS We assessed concentrations of orange“drug”in a 0.2 mL/h low flow clinical model with blue dyed carrier fluid at 5 mL/h,using 3-,10-,or 60-mL syringes.A graduated volumetric pipette was used to measure total flow.Mean time to target concentration was 30,21,and 46 min in 3-,10-,and 60-mL syringes,respectively(P=0.42).After achieving target concentration,more dilute drug was delivered by 60-mL(P<0.001)and 10-mL syringes(P=0.04)compared to 3-mL syringes.Drug overdoses were observed during the initial 45 min of infusion in 10-and 60-mL syringes.Total volumes infused after target concentration were less in the 60-mL condition compared to 3-mL(P<0.01)and 10-mL(P<0.001)syringes.RESULTS Linear mixed effects models demonstrated lesser delivered drug concentrations in the initial 30 min by 3-mL compared to 10-and 60-mL syringes(P=0.005 and P<0.001,respectively)but greater drug concentrations and total infused drug in the subsequent 30-60 and 60-90 min intervals with the 3-and 10-mL compared to 60-mL syringes.CONCLUSION With carrier fluid,larger syringes were associated with significantly less drug delivery,less total volume delivered,and other flow problems in our low flow drug model.Carrier fluid should not be used to compensate for inappropriately large syringes in critical low flow drug infusions.展开更多
BACKGROUND Implanted intravenous infusion port(IVAP)is indicated for patients undergoing chemotherapy,total parenteral nutrition and long-term antibiotic treatment.Among their complications,the rupture and migration o...BACKGROUND Implanted intravenous infusion port(IVAP)is indicated for patients undergoing chemotherapy,total parenteral nutrition and long-term antibiotic treatment.Among their complications,the rupture and migration of the catheter of an IVAP via internal jugular vein represents a very rare but potentially severe condition.CASE SUMMARY A 43-year-old woman was identified with a spontaneous fracture and migration of catheter of an IVAP via right internal jugular vein after adjuvant chemotherapy for left breast cancer.A computed tomography showed the fractured catheter of the IVAP in the pulmonary artery.Therefore,we conducted an emergency procedure to remove the catheter fragment by a pigtail catheter combined with a gooseneck trap.CONCLUSION When the fractured catheter of an IVAP was detected,the special shape of the pigtail catheter in combination with the gooseneck trap successfully facilitated the removal of the dislodged catheter.展开更多
Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pu...Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pumps, should be detected when an occlusion occurred. How-ever, infusion pumps’ occlusion pressure could not be tested and the performance of these pumps is not known to us. In order to test the occlusion pressure of infusion pump, a testing system has been put forward according to standards of IEC 60601-2-24:1998/ GB 9706.27- 2005. The system is comprised of sensor, acquisition card, three-way tap and so on;this system is controlled by a PC. At the same time, sampling rate could be changed if necessary and test time could be recorded. And then the characteristics of this system were studied, such as linear, effects of pump rates and different pumps. The system remained linear in a given environment. The higher is the pump rate, the faster is the time to reach occlusion condi-tion. The testing system has been proved to be effective in testing the occlusion pressure of infusion pumps and the accuracy error of pressure is content the demand of ±1% of range.展开更多
AIM: To evaluate pain control in chronic pancreatitis patients who underwent total pancreatectomy with islet cell transplantation or intrathecal narcotic pump infusion.METHODS: We recognized 13 patients who underwent ...AIM: To evaluate pain control in chronic pancreatitis patients who underwent total pancreatectomy with islet cell transplantation or intrathecal narcotic pump infusion.METHODS: We recognized 13 patients who underwent intrathecal narcotic pump(ITNP) infusion and 57 patients who underwent total pancreatectomy with autologous islet cell transplantation(TP + ICT) for chronic pancreatitis(CP) pain control between 1998 and 2008 at Indiana University Hospital. All patients had already failed multiple other modalities for pain control and the decision to proceed with either intervention was made at the discretion of the patients and their treating physicians. All patients were evaluated retrospectively using a questionnaire inquiring about their pain control(using a 0-10 pain scale), daily narcotic dose usage, and hospital admission days for pain control before each intervention and during their last follow-up. RESULTS: All 13 ITNP patients and 30 available TP + ICT patients were evaluated. The mean age was approximately 40 years in both groups. The median duration of pain before intervention was 6 years and 7 years in the ITNP and TP + ICT groups, respectively. The median pain score dropped from 8 to 2.5(on a scale of 0-10) in both groups on their last follow up. The median daily dose of narcotics also decreased from 393 mg equivalent of morphine sulfate to 8 mg in the ITNP group and from 300 mg to 40 mg in the TP + ICT group. No patient had diabetes mellitus(DM) before either procedure whereas 85% of those who underwent pancreatectomy were insulin dependent on their last evaluation despite ICT. CONCLUSION: ITNP and TP + ICT are comparable for pain control in patients with CP however with high incidence of DM among those who underwent TP + ICT. Prospective comparative studies and longer follow up are needed to better define treatment outcomes.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
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 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%.
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This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.
基金Project supported by the National Natural Science Foundation of China(No.61474092)
文摘This paper presents a high-efficiency charge pump circuit composed of cascaded cross-coupled voltage doublers implemented in an isolated bipolar-CMOS-DMOS（BCD） technology for implantable medical devices.Taking advantage of the transistor structures in the isolated BCD process, the leakage currents caused by the parasitic PNP transistors in the cross-coupled PMOS serial switches are eliminated by simply connecting the inside substrate terminal to the isolation terminal of each PMOS transistor. The simple circuit structure leads to small parasitic capacitance in the voltage doubler, which in turn ensures high efficiency of the overall charge pump. The proposed charge pump with 5 cascaded voltage doublers is fabricated in a 0.35-μm isolated BCD process. Measurement results with 2-V power supply, 1-MHz driving clock frequency and 40-μA current load show that an efficiency of 72.6% is achieved, and the output voltage can be pumped to about 11.5 V at zero load current. The chip area of the charge pump is 1.6 × 0.35 mm^2.
基金Supported by NIH National Center for Advancing Translational Sciences(NCATS)UCLA CTSI,No.UL1TR001881.
文摘BACKGROUND Critically ill neonates and pediatric patients commonly require multiple low flow infusions.Volume limitations are imposed by small body habitus and comorbidities like cardiopulmonary disease,renal failure,or fluid overload.Vascular access is limited by diminutive veins.Maintenance fluids or parenteral nutrition in conjunction with actively titrated infusions such as insulin,fentanyl,prostaglandins,inotropes and vasopressors may necessitate simultaneous infusions using a single lumen to maintain vascular catheter patency.This requirement for multiple titratable infusions requires concentrated medications at low flows,rather than more dilute drugs at higher flows that in combination may volume overload small infants.AIM To determine whether carrier fluid reduces variability that variability of low flow drug infusions is proportional to syringe size in pediatric critical care.METHODS We assessed concentrations of orange“drug”in a 0.2 mL/h low flow clinical model with blue dyed carrier fluid at 5 mL/h,using 3-,10-,or 60-mL syringes.A graduated volumetric pipette was used to measure total flow.Mean time to target concentration was 30,21,and 46 min in 3-,10-,and 60-mL syringes,respectively(P=0.42).After achieving target concentration,more dilute drug was delivered by 60-mL(P<0.001)and 10-mL syringes(P=0.04)compared to 3-mL syringes.Drug overdoses were observed during the initial 45 min of infusion in 10-and 60-mL syringes.Total volumes infused after target concentration were less in the 60-mL condition compared to 3-mL(P<0.01)and 10-mL(P<0.001)syringes.RESULTS Linear mixed effects models demonstrated lesser delivered drug concentrations in the initial 30 min by 3-mL compared to 10-and 60-mL syringes(P=0.005 and P<0.001,respectively)but greater drug concentrations and total infused drug in the subsequent 30-60 and 60-90 min intervals with the 3-and 10-mL compared to 60-mL syringes.CONCLUSION With carrier fluid,larger syringes were associated with significantly less drug delivery,less total volume delivered,and other flow problems in our low flow drug model.Carrier fluid should not be used to compensate for inappropriately large syringes in critical low flow drug infusions.
文摘BACKGROUND Implanted intravenous infusion port(IVAP)is indicated for patients undergoing chemotherapy,total parenteral nutrition and long-term antibiotic treatment.Among their complications,the rupture and migration of the catheter of an IVAP via internal jugular vein represents a very rare but potentially severe condition.CASE SUMMARY A 43-year-old woman was identified with a spontaneous fracture and migration of catheter of an IVAP via right internal jugular vein after adjuvant chemotherapy for left breast cancer.A computed tomography showed the fractured catheter of the IVAP in the pulmonary artery.Therefore,we conducted an emergency procedure to remove the catheter fragment by a pigtail catheter combined with a gooseneck trap.CONCLUSION When the fractured catheter of an IVAP was detected,the special shape of the pigtail catheter in combination with the gooseneck trap successfully facilitated the removal of the dislodged catheter.
文摘Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pumps, should be detected when an occlusion occurred. How-ever, infusion pumps’ occlusion pressure could not be tested and the performance of these pumps is not known to us. In order to test the occlusion pressure of infusion pump, a testing system has been put forward according to standards of IEC 60601-2-24:1998/ GB 9706.27- 2005. The system is comprised of sensor, acquisition card, three-way tap and so on;this system is controlled by a PC. At the same time, sampling rate could be changed if necessary and test time could be recorded. And then the characteristics of this system were studied, such as linear, effects of pump rates and different pumps. The system remained linear in a given environment. The higher is the pump rate, the faster is the time to reach occlusion condi-tion. The testing system has been proved to be effective in testing the occlusion pressure of infusion pumps and the accuracy error of pressure is content the demand of ±1% of range.
文摘AIM: To evaluate pain control in chronic pancreatitis patients who underwent total pancreatectomy with islet cell transplantation or intrathecal narcotic pump infusion.METHODS: We recognized 13 patients who underwent intrathecal narcotic pump(ITNP) infusion and 57 patients who underwent total pancreatectomy with autologous islet cell transplantation(TP + ICT) for chronic pancreatitis(CP) pain control between 1998 and 2008 at Indiana University Hospital. All patients had already failed multiple other modalities for pain control and the decision to proceed with either intervention was made at the discretion of the patients and their treating physicians. All patients were evaluated retrospectively using a questionnaire inquiring about their pain control(using a 0-10 pain scale), daily narcotic dose usage, and hospital admission days for pain control before each intervention and during their last follow-up. RESULTS: All 13 ITNP patients and 30 available TP + ICT patients were evaluated. The mean age was approximately 40 years in both groups. The median duration of pain before intervention was 6 years and 7 years in the ITNP and TP + ICT groups, respectively. The median pain score dropped from 8 to 2.5(on a scale of 0-10) in both groups on their last follow up. The median daily dose of narcotics also decreased from 393 mg equivalent of morphine sulfate to 8 mg in the ITNP group and from 300 mg to 40 mg in the TP + ICT group. No patient had diabetes mellitus(DM) before either procedure whereas 85% of those who underwent pancreatectomy were insulin dependent on their last evaluation despite ICT. CONCLUSION: ITNP and TP + ICT are comparable for pain control in patients with CP however with high incidence of DM among those who underwent TP + ICT. Prospective comparative studies and longer follow up are needed to better define treatment outcomes.
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。
