Alterations in response to pharmacological agents have been attributed to flow rate variation produced by intravenous infusion devices during drug delivery. A wide range of variation has been shown to occur with large-volume infusion devices. The intent of this investigation was to examine flow variation resulting from the use of selected small-volume syringe and mobile infusion devices and determine whether these devices have greater flow continuity than large-volume infusion pumps. Each syringe and mobile infusion device delivered iv fluid at three flow rates (1, 5, and 10 ml/h). The effusate was collected in a tared beaker and serial weights were measured every ten seconds using a computerized, gravimetric technique. Accuracy, continuity, and pattern of flow were determined for each of the syringe and mobile infusion devices. All of the devices produced accurate flow, within ± 10 percent of the desired 5 and 10 ml/h rates. However, the actual iv flow rate ranged from 53 to 93 percent for the 1 ml/h rate. Continuity and pattern of flow resulting from each device were diverse. When compared with large-volume, microrate infusion devices, no significant differences could be observed. Therefore, no clear advantage to delivering drug solutions on a continuous basis can be expected from the use of small-volume devices. Specific infusion devices may be preferable for certain clinical applications; flow continuity data may be valuable when selecting an infusion device.
