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 eval uated methods to deliver AC more accurately and consistently at a 11:1 ratio on the Fenwal CS 3000 Plus. Two modifications (shortened AC tub ing, shortened AC tubing with modified drip chamber) and two unmodifie d methods (unmodified right-hand string, unmodified double string) wer e compared (n = 20 platelet apheresis procedures each), resulting in a verage 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 o f ratios within +/- 10% of 11:1 using the modified methods, 90% and 10 0%, versus the unmodified methods, 50% and 55%, respectively. Comparis on of 36 plateletapheresis (each) using 15-, 30-, and 90-minute interv als in AC drip rate monitoring revealed no significant difference. How ever, the 30-minute interval had a better ratio, 11.4 +/- 1.0 versus 1 1.6 +/- 0.8 or 11.7 +/- 1.1, and higher frequency of 11 +/- 10%:1 at 8 1% versus 75% and 72% and was more practical to use than 15-minute int erval; the 90-minute interval did require adjustments in 8% of the pro cedures. The use of a spring scale versus AC bag graduations (n = 75 p lateletapheresis) to measure AC volume was significantly superior in m easuring 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 m ore accurate and consistent AC delivery with the Fenwal CS 3000 Plus, we recommend three courses of action: 1) Shorten the AC line and modif y 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 spri ng scale rather than AC bag graduations to obtain more accurate measur ement of AC volume used. (C) 1995 Wiley-Liss, Inc.