Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, United States of America.
Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, United States of America.
PLoS One. 2020 Jul 30;15(7):e0236644. doi: 10.1371/journal.pone.0236644. eCollection 2020.
Gastrostomy tubes (G-tubes) are typically used when people cannot eat food by mouth. The connector section that allows G-tubes to connect to other devices, such as feeding sets or syringes, has been modified on some of the devices to reduce misconnections in hospital settings. The narrow internal diameter of the new connector, standardized under ISO 80369-3, has caused some users to express concern about a reduced flow rate. Previous studies performed on commercial devices determined that it was not conclusive how much the ISO 80369-3 connector contributed towards the reduced flow rate, because when manufacturers designed these new connector-based devices, they often changed other geometric variables (such as distal tube diameter, or length) at the same time. Thus, it became difficult isolating the effect of the connector from other geometric variables.
The key objective of this study was to investigate how different design variables impacted the flow rate through the G-tubes. 3D-printed devices were used to assess the geometric parameters in a systematic manner. Commercial diets and Newtonian analog fluids with matched viscosities were used for testing.
The flow path length of the "transition section" encompassing the standardized ISO 80369-3 connector in the new devices was found to cause reduced flow. Additionally, results showed that a shortened (≤ 10 mm) transition section, along with a 10% increase in the distal inner diameter of large bore devices (e.g., 24 Fr), can restore flow rates to levels consistent with the previous devices prior to the connector standardization.
The strategy for restoring flow rates to previous levels may help alleviate concerns raised by multiple stakeholders such as health care professionals, patients, caregivers and device manufacturers. In addition, the approach proposed here can be used as a tool for designing future G-tube devices.
当人们无法通过口腔进食时，通常会使用胃管（G-tube）。为了减少医院环境中的误连接，一些设备已对允许 G-tube 与其他设备（如喂养套件或注射器）连接的连接器部分进行了修改。新连接器的内部直径较窄，已根据 ISO 80369-3 进行了标准化，这导致一些用户对流量降低表示担忧。之前在商业设备上进行的研究表明，ISO 80369-3 连接器对流量降低的影响程度尚无定论，因为制造商在设计这些基于新连接器的设备时，通常会同时改变其他几何变量（如远端管直径或长度）。因此，很难将连接器的影响与其他几何变量隔离开来。
本研究的主要目的是研究不同设计变量如何影响 G-tube 的流量。使用 3D 打印设备系统地评估几何参数。使用商业饮食和具有匹配粘度的牛顿模拟流体进行测试。
发现新设备中标准化 ISO 80369-3 连接器的“过渡段”的流路长度导致流量降低。此外，结果表明，缩短（≤10mm）过渡段，同时将大口径设备（例如 24Fr）的远端内径增加 10%，可以将流量恢复到连接器标准化之前的先前设备的水平。
恢复到先前流量水平的策略可能有助于减轻多个利益相关者（如医疗保健专业人员、患者、护理人员和设备制造商）提出的担忧。此外，这里提出的方法可以用作设计未来 G-tube 设备的工具。
