1. 6/10/1999Mansfield, MA Approximate calculation of needed pump speed (PS) t = Kt/V * V/K * 1000 K = Kt/V *V/t*1000 t = 1.3 *40/300*1000 = 173 min K = 1.3 *40/240 *1000 = 217 K = 1.3 *50/240 *1000 = 270 Pump speed vs. clearance with F-80 dialyzer PS = 400; Blood Flow = 360; K = 270

2. 6/10/1999Mansfield, MA Approximate calculation of needed pump speed (PS) t = (Kt/V) * (V/K) * 1000 K = (Kt/V) *(V/t)*1000 t = 1.6 *(40/270)*1000 = 237 min K = 1.6 *(40/240) *1000 = 267 K = 1.6 *(50/240) *1000 = 333 Pump speed vs. clearance with F-80 dialyzer PS = 400; Blood Flow = 360; K = 270

3. 6/10/1999Mansfield, MA Blood flow through the catheter n Design – Length – Diameter – Cross section n Tip location n Tip occlusion – Fibrin sheath – Ball thrombus – Mural thrombus

4. 6/10/1999Mansfield, MA Catheter design Poiseuille’s equation Flow in catheters is directly proportional to the pressure difference and the 4th power of the lumen radius, and inversely proportional to the lumen length and the viscosity of fluid (blood) In lumens deviating from circular, resistance is higher (flow is lower at the same length and cross section)

5. 6/10/1999Mansfield, MA

6. 6/10/1999Mansfield, MA

7. 6/10/1999Mansfield, MA Tip location n The best tip location is at the superior vena cava/right atrium junction n Flows are usually worse with other locations

8. 6/10/1999Mansfield, MA Tip in right brachiocephalic vein

9. 6/10/1999Mansfield, MA Tip in right brachiocephalic vein

10. 6/10/1999Mansfield, MA Catheter tip in the mid-SVC

11. 6/10/1999Mansfield, MA Tip in right atrium

12. 6/10/1999Mansfield, MA Inflow in left brachicephalic vein Outflow in SVC against the wall

13. 6/10/1999Mansfield, MA Inflow against wall Outflow tip

14. 6/10/1999Mansfield, MA Tip low in atrium

15. 6/10/1999Mansfield, MA Tip in the mid right atrium

16. 6/10/1999Mansfield, MA Tip close to inferior vena cava Opti-Flow

17. 6/10/1999Mansfield, MA Tip in right ventricle

18. 6/10/1999Mansfield, MA Tip in right ventricle

19. 6/10/1999Mansfield, MA Tip occlusion n Fibrin sheath (sleeve) - probably on all catheters – Asymptomatic – Poor or no inflow when involving catheter tip n Ball thrombus – A large clot adherent to the catheter tip but not to the vessel wall. n Difficult to dissolve, can be stripped n Mural thrombus – A large clot adherent to both catheter and vessel wall and causing partial or complete occlusion of the vessel

20. 6/10/1999Mansfield, MA

21. 6/10/1999Mansfield, MA Inflow tip occluded

22. 6/10/1999Mansfield, MA Inflow tip occluded

23. 6/10/1999Mansfield, MA Both tips occluded

24. 6/10/1999Mansfield, MA Tip occlusion n Fibrin sheath (sleeve) - probably on all catheters – Asymptomatic – Poor or no inflow when involving catheter tip n Ball thrombus – A large clot adherent to the catheter tip but not to the vessel wall. n Difficult to dissolve, can be stripped n Mural thrombus – A large clot adherent to both catheter and vessel wall and causing partial or complete occlusion of the vessel

25. 6/10/1999Mansfield, MA Ball thrombus removed with catheter

26. 6/10/1999Mansfield, MA Ball thrombus, closer view