RESISTANCE TO FLUID-FLOW IN VEINS

We evaluated the resistance to fluid infusion in the veins of 118 adul t patients after intravenous catheter insertion prior to elective surg ery. Hydraulic resistance in veins was defined as the slope of the pre ssure-flow relationship obtained by measuring venous pressure at sever al fluid flow rates. A resistance unit (RU) was defined as 1 mmHg/L/hr . Resistance in veins ranged from -12.1 to 732 RU, with 50th and 95th percentiles being 22 and 198 RU, respectively. Venous resistance was n ot significantly affected by site of catheter insertion, tissue charac teristics at the insertion site, age, sex, patient anxiety, American S ociety of Anesthesiologists physical status, or catheter size. This re port provides a distribution of resistance to fluid infusion in arm ve ins of adult patients.