USE OF DOUBLE-LUMEN DIALYSIS CATHETERS - LOADING WITH LOCKED HEPARIN

Improvement in double-lumen catheter usage could provide lasting, user friendly angioaccess for patients on hemodialysis (HD), especially th ose on home HD. These catheters are routinely locked with concentrated heparin at the end of an HD session, in a volume corresponding to the lumen capacity. At the start of the next HD session, this heparin is aspirated with a small amount of blood and discarded. The cumulative b lood loss over a long period becomes significant. The authors aimed to study whether a predetermined loading dose of heparin could be used t o lock the catheter, and be administered as such during the next HD se ssion. Thirteen patients were evaluated during four HD sessions (Rx 1 through 4; Rx 4 followed a weekend). Prior to the first study HD (Rx 1 ), the catheter was locked with 10,000 units heparin per lumen, as per our standard practice. Therefore, Rx 1 was considered the standard fo r the purpose of the study. On study HD (Rx 1 through 4), the catheter was locked with the patient's loading dose (half per lumen). The hepa rin loading dose was given as follows: Rx 1 and 2 = fresh heparin; Rx 3 and 4 = locked heparin. Again, activated clotting time (ACT) was mea sured periodically and heparin was given according to an ACT-based sli ding scale. The first ACT and heparin level (drawn after the loading d ose) were compared for Rx 1 rs Rx 2, 3, and 4. The mean (+/- SEM) valu es were as follows: Rx 1 - first ACT = 299.2 +/- 16.5 sec, heparin lev el = 1.25 +/- 0.15 IU/ml; Rx 2 - first ACT = 305 +/- 20 sec, heparin l evel = 1.1 +/- 0.09 IU/ml; Rx 4 - first ACT = 293 +/- 18.5 sec, hepari n level = 1.1 +/- 0.19 IU/ml; and Rx 4 - first ACT = 288 +/- 24.1 sec, heparin level = 1.07 +/- 0.16 IU/ml. The mean of the differences betw een Rw 1 and Rx 2, 3, and 4, were not significantly different for all of the analyzed parameters. No catheter was lost during the study peri od. The results suggest that locked heparin can be effectively used as the loading dose. Advantages of this method include decreased blood w astage, heparin cost savings corresponding to the cost of concentrated heparin (approximately $156.00 per patient year for HD three time wee kly), and at least one less connection per catheter lumen. The latter would possibly reduce the risk of transluminal catheter related infect ions.