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
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
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
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
目的探究胰岛素泵长期持续皮下胰岛素输注(CSII)治疗儿童1型糖尿病(T1DM)效果的影响因素。方法选取2021年1月至2022年12月在泉州市妇幼保健院·儿童医院接受CSII治疗的130例T1DM患儿作为研究对象,依据病历系统记录6个月后的空腹血糖...目的探究胰岛素泵长期持续皮下胰岛素输注(CSII)治疗儿童1型糖尿病(T1DM)效果的影响因素。方法选取2021年1月至2022年12月在泉州市妇幼保健院·儿童医院接受CSII治疗的130例T1DM患儿作为研究对象,依据病历系统记录6个月后的空腹血糖(FPG)、餐后2 h血糖(2 h PBG)及糖化血红蛋白(HbA1c)达标情况分为对照组(达标组,100例)、观察组(未达标组,30例),收集比较患儿相关资料,使用多因素logistic回归分析,分析胰岛素泵长期CSII治疗儿童T1DM效果的影响因素。结果两组患儿父母文化程度、家庭月收入、服药情况、胰岛素β细胞分泌指数(Homa-β)、胰岛素抵抗指数(Homa-IR)比较,差异有统计学意义(P<0.05)。多因素logistic回归分析结果显示,父母文化程度(β=1.159,OR=3.188,95%CI:1.372~7.403)、家庭月收入(β=1.286,OR=3.619,95%CI:1.544~8.480)、服药情况(β=1.168,OR=1.632,95%CI:1.017~3.711)为CISS对T1DM患儿治疗效果的危险因素(OR>1,P<0.05),Homa-β(β=-2.383,OR=0.092,95%CI:0.015~0.552)、Homa-IR(β=-3.402,OR=0.033,95%CI:0.003~0.387)为CSII对T1DM患儿治疗效果的保护因素(OR<1,P<0.05)。结论T1DM患儿长期CSII疗效的影响因素包含父母文化程度、家庭月收入、服药情况、Homa-β、Homa-IR,临床应对以上因素保持关注。展开更多
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.
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.
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。
文摘目的探究胰岛素泵长期持续皮下胰岛素输注(CSII)治疗儿童1型糖尿病(T1DM)效果的影响因素。方法选取2021年1月至2022年12月在泉州市妇幼保健院·儿童医院接受CSII治疗的130例T1DM患儿作为研究对象,依据病历系统记录6个月后的空腹血糖(FPG)、餐后2 h血糖(2 h PBG)及糖化血红蛋白(HbA1c)达标情况分为对照组(达标组,100例)、观察组(未达标组,30例),收集比较患儿相关资料,使用多因素logistic回归分析,分析胰岛素泵长期CSII治疗儿童T1DM效果的影响因素。结果两组患儿父母文化程度、家庭月收入、服药情况、胰岛素β细胞分泌指数(Homa-β)、胰岛素抵抗指数(Homa-IR)比较,差异有统计学意义(P<0.05)。多因素logistic回归分析结果显示,父母文化程度(β=1.159,OR=3.188,95%CI:1.372~7.403)、家庭月收入(β=1.286,OR=3.619,95%CI:1.544~8.480)、服药情况(β=1.168,OR=1.632,95%CI:1.017~3.711)为CISS对T1DM患儿治疗效果的危险因素(OR>1,P<0.05),Homa-β(β=-2.383,OR=0.092,95%CI:0.015~0.552)、Homa-IR(β=-3.402,OR=0.033,95%CI:0.003~0.387)为CSII对T1DM患儿治疗效果的保护因素(OR<1,P<0.05)。结论T1DM患儿长期CSII疗效的影响因素包含父母文化程度、家庭月收入、服药情况、Homa-β、Homa-IR,临床应对以上因素保持关注。
