Accuracy and consistency of drop delivery in infusion pumps

Advances in intensive care medicine has made us more depend on infusion pumps to deliver accurate amounts of fluids to sick newborns, children and adults. When infusing rapid-acting critical drugs to patients, it is important not only to deliver accurate fluid-volume amounts over a specified time, but also to deliver the fluid at a constant rate with minimal fluctuation. The accuracy of drop delivery in four infusion pumps (IVAC 530, IVAC 560, IMED 922 and IMED 960) at different infusion rates were examined in a laboratory setting by using a photoelectric sensor and a computer. When it was not in its cassette-filling period, the IMED 960 was the most accurate at delivering fluid-drops, with a coefficient of variance (CV) of less than 10% at each flow rate. Yet, like other piston-cylinder cassette pumps, its cassette filling time and stabilizing period after cassette filling were longer at lower flow rates. Both the IVAC 530 and the IMED 922 delivered fluids irregularly with large coefficients of variance (CVs). IVAC 560 had the best results for consistency of drop-delivery over a 4-hour period.