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 inf展开更多
镇痛泵是一种常用于术后镇痛的医疗设备,通过输送镇痛药物直接到患者体内,提供持续的镇痛效果。许多研究表明,镇痛泵在术后镇痛中具有一定的优势。首先,它可以提供更精确的药物输送,确保患者在术后期间得到恰当的镇痛效果。其次,镇痛泵...镇痛泵是一种常用于术后镇痛的医疗设备,通过输送镇痛药物直接到患者体内,提供持续的镇痛效果。许多研究表明,镇痛泵在术后镇痛中具有一定的优势。首先,它可以提供更精确的药物输送,确保患者在术后期间得到恰当的镇痛效果。其次,镇痛泵可以减少系统性副作用的发生,如恶心、呕吐和意识模糊等。这对于那些不能耐受口服镇痛药物的患者尤为重要。此外,镇痛泵还有助于提高患者的满意度,缓解疼痛并促进康复。本研究旨在对镇痛泵在术后镇痛中的应用进行全面评估,包括利与弊的综合分析,并提供数据支持。我们通过回顾相关文献和临床研究,总结了镇痛泵在术后镇痛中的关键优点和限制。利方面的数据支持显示,镇痛泵在术后镇痛中具有显著的效果。例如,一项针对腹部手术的研究发现,使用镇痛泵的患者在术后24h内的疼痛评分显著低于常规镇痛组(3.2 VS 5.8,P<0.001)。此外,镇痛泵组的患者还呈现较少的镇痛药物需要量(22.5 mg VS 47.6 mg,P<0.001)。另一项研究发现,镇痛泵在膝关节置换手术中的应用可以显著减少术后的镇痛药物副作用,如恶心和呕吐的发生率降低到5%以下。然而,弊端方面的数据也需要考虑。一些研究指出,使用镇痛泵可能存在并发症和风险,如感染、药物过量或药物误用。这需要医疗团队在使用镇痛泵时严密监测和管理,以减少潜在的风险。此外,使用镇痛泵也涉及到额外的成本和资源需求。一项经济评估研究发现,与传统的镇痛方法相比,镇痛泵的使用会增加术后镇痛的总费用。综合评估表明,镇痛泵在术后镇痛中具有明显的优势,但同时也伴随着一些限制。因此,在应用镇痛泵时,医疗团队应该充分考虑患者的情况和需要,并权衡其利与弊。同时,确保适当的监测和管理以减少并发症的风险,并进行合理的资源利用,将有助于确保镇痛泵展开更多
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 inf
文摘镇痛泵是一种常用于术后镇痛的医疗设备,通过输送镇痛药物直接到患者体内,提供持续的镇痛效果。许多研究表明,镇痛泵在术后镇痛中具有一定的优势。首先,它可以提供更精确的药物输送,确保患者在术后期间得到恰当的镇痛效果。其次,镇痛泵可以减少系统性副作用的发生,如恶心、呕吐和意识模糊等。这对于那些不能耐受口服镇痛药物的患者尤为重要。此外,镇痛泵还有助于提高患者的满意度,缓解疼痛并促进康复。本研究旨在对镇痛泵在术后镇痛中的应用进行全面评估,包括利与弊的综合分析,并提供数据支持。我们通过回顾相关文献和临床研究,总结了镇痛泵在术后镇痛中的关键优点和限制。利方面的数据支持显示,镇痛泵在术后镇痛中具有显著的效果。例如,一项针对腹部手术的研究发现,使用镇痛泵的患者在术后24h内的疼痛评分显著低于常规镇痛组(3.2 VS 5.8,P<0.001)。此外,镇痛泵组的患者还呈现较少的镇痛药物需要量(22.5 mg VS 47.6 mg,P<0.001)。另一项研究发现,镇痛泵在膝关节置换手术中的应用可以显著减少术后的镇痛药物副作用,如恶心和呕吐的发生率降低到5%以下。然而,弊端方面的数据也需要考虑。一些研究指出,使用镇痛泵可能存在并发症和风险,如感染、药物过量或药物误用。这需要医疗团队在使用镇痛泵时严密监测和管理,以减少潜在的风险。此外,使用镇痛泵也涉及到额外的成本和资源需求。一项经济评估研究发现,与传统的镇痛方法相比,镇痛泵的使用会增加术后镇痛的总费用。综合评估表明,镇痛泵在术后镇痛中具有明显的优势,但同时也伴随着一些限制。因此,在应用镇痛泵时,医疗团队应该充分考虑患者的情况和需要,并权衡其利与弊。同时,确保适当的监测和管理以减少并发症的风险,并进行合理的资源利用,将有助于确保镇痛泵
