Timed Controlled Repeated Rotation of the CAR-170-C NXSTAGE Chronic Cartridge Hemodialysis Filter: A Novel Approach to Enabling Heparin-Free Frequent Daily Home Hemodialysis

Abstract

Heparin-free hemodialysis is often warranted in postoperative states, bleeding diathesis, and critically ill patients. Conventionally, this is achieved through normal saline flushes or regional citrate anticoagulation. An 87-year-old white man with end-stage renal disease and atrial fibrillation, who was taking warfarin and using maintenance home hemodialysis (HHD) with an NxStage machine, underwent laparoscopic appendicectomy. The procedure was complicated by intra-abdominal abscess, sepsis, and tamponade from a bloody pericardial effusion. He needed emergent therapeutic pericardiocentesis. Warfarin was promptly discontinued. He was discharged home with heparin-free HHD. Prior heparin anticoagulation for HHD was an initial bolus of 4000 units of heparin. He continued to clot his extracorporeal system with resultant very high venous pressures and compromised HHD. Heparin anticoagulation was still contraindicated. Flushes with 250-500 mL normal saline, delivered in aliquots every 15-30 minutes, failed to prevent the frequent clotting. The first author, our HD Senior Technician, had astutely observed that the horizontally placed hemodialysis filter exhibited early "clot" formation at the 12-o'clock position, despite the saline flushes. Through trial and error, he discovered that rotating the horizontally placed hemodialysis filter along its long axis, 60 degrees clockwise for 15 minutes, return to the neutral position for 15 minutes, rotating the filter another 60 degrees counterclockwise for 15 minutes, with this repeated cycle of rotations "did the trick." It promptly and consistently resolved the clotting problem. The lines stopped clotting, and he has not needed saline flushes for smooth heparin-free HHD for more than 7 months. To our knowledge, this is the first such report. Further study is justified. We have hypothesized a mechanism and have named this the "Locke-Onuigbo Maneuver."

Keywords: ECMO, extracorporeal membrane oxygenation; HHD, home hemodialysis.

Figure 1

Composite showing pictures of the horizontally aligned NxSTAGE CAR-170-C cartridge (A) in the neutral position, (B) rotated clockwise to the 2-o’clock position, (C) rotated back to the neutral position, and (D) rotated counterclockwise to the 10-o’clock position. This “Locke-Onuigbo Maneuver” is repeated throughout the home hemodialysis treatment.

Figure 2

Home hemodialysis dialysis daily diary notations by patient’s wife for the months of (A) December 2019 and (B) January 2020, 1 month before and 1 month after the initiation of the “Locke-Onuigbo Maneuver.”