Flow rate variability from electronic infusion devices.

During continuous drug administration to pediatric patients, unfavorable pharmacologic effects have occurred. These effects were attributed to variations in flow from electronic infusion devices (EIDs). The intent of this investigation was to evaluate the influence of microrate (0.1 to 99.9 ml/h) EID on the accuracy, continuity, and pattern of flow of continuously effused fluid. Using a factorial study design, iv fluid was effused through iv delivery systems using combinations of five microrate EIDs, three iv flow rates, and three sample-collection intervals. Serial weights were measured at the appropriate sample-collection time using a computerized gravimetric technique to determine accuracy, continuity, and pattern of flow. All the EIDs produced accurate flow within 5% of the desired rate of 5 and 10 ml/h. At 1 ml/h, the actual iv flow rate ranged from 65.1% to 91% of the desired rate. Each of the respective EIDs produced various levels of flow continuity; each flow pattern characterized the mechanism of pump operation for each device. Thus, alteration in response (e.g., increased toxicity or decreased efficacy) to a continuous drug infusion must not be attributed exclusively to the drug or clinical condition of the patient. Serious consideration should also be given to the method of drug delivery and, in particular, the continuity of flow that results from a particular EID.