Abstract
This study aimed to investigate the flow rate accuracy and bolus doses of four portable pumps with different mechanisms. We evaluated two electronic (COOPDECH Amy PCA [Amy] and CADD-Solis) and two elastomeric balloon-type pumps (COOPDECH Balloonjector and Rakurakufuser) under the following conditions: placement with an epidural catheter, operation on a shaking table, warming to 32 °C, and at room temperature (control, 25 °C). Amy maintained consistent flow rates across all conditions. The CADD-Solis also exhibited consistent flow rates, with minor yet statistically significant changes upon epidural catheter placement (- 5.0%, P = 0.005) and motion conditions (4.2%, P = 0.015). The Balloonjector and Rakurakufuser exhibited flow rate variations over time, and temperature increases significantly increased flow rates by 24.3% (P < 0.001) and 20.3% (P < 0.001), respectively. Bolus volume accuracy for the Amy, Balloonjector, and Rakurakufuser was not significantly affected under different conditions. The CADD-Solis showed a slight decrease in bolus volume with an epidural catheter (mean difference, 0.3 mL; P = 0.003). The electronic pumps maintained consistent flow rates across various conditions, whereas elastomeric balloon pumps exhibited variable rates influenced by time and temperature, increasing the risk of medication overdose. Bolus dosing accuracy was clinically satisfactory for all pump mechanisms.