Modifications to increase accuracy and consistency of anticoagulant delivery using the Fenwal CS3000 plus

Consistent and accurate delivery of anticoagulant (AC) with the Fenwal CS3000 Plus has been difficult to maintain. We have modified and evaluated methods to deliver AC more accurately and consistently at a 11:1 ratio on the Fenwal CS 3000 Plus. Two modifications (shortened AC tubing, shortened AC tubing with modified drip chamber) and two unmodified methods (unmodified right-hand string, unmodified double string) were compared (n = 20 platelet apheresis procedures each), resulting in average AC ratios of 11.4 +/- 0.5, 11.2 +/- 0.4, 11.6 +/- 1.3, and 12.1 +/- 0.7:1, respectively. There was a significantly higher incidence of ratios within +/- 10% of 11:1 using the modified methods, 90% and 100%, versus the unmodified methods, 50% and 55%, respectively. Comparison of 36 plateletapheresis (each) using 15-, 30-, and 90-minute intervals in AC drip rate monitoring revealed no significant difference. However, the 30-minute interval had a better ratio, 11.4 +/- 1.0 versus 11.6 +/- 0.8 or 11.7 +/- 1.1, and higher frequency of 11 +/- 10%: versus 75% and 72% and was more practical to use than 15-minute interval; the 90-minute interval did require adjustments in 8% of the procedures. The use of a spring scale versus AC bag graduations (n = 75 plateletapheresis) to measure AC volume was significantly superior in measuring volume (343 +/- 64 versus 373 +/- 72 ml), ratio (11.2 +/- 1.5 versus 10.2 +/- 1.6), and ratios 11 +/- 10%:1 (71% versus 52%). For more accurate and consistent AC delivery with the Fenwal CS 3000 Plus, we recommend three courses of action: 1) Shorten the AC line and modify the AC drip chamber, 2) use a 30-minute interval to monitor AC drip rate and adjust only if off by more than 3 drops/15 sec, 3) use a spring scale rather than AC bag graduations to obtain more accurate measurement of AC volume used.