Method and apparatus for ultrafiltration utilizing a peripheral access dual lumen venous cannula

Abstract

Method and apparatus for the extracorporeal treatment of blood by utilizing a peripherally inserted dual lumen catheter assembly for the continuous removal and return of blood for renal replacement treatment, in particularly, treatment of congestive heart failure and fluid overload by ultrafiltration. A catheter is inserted in a peripheral vein and maneuvered upward through the vascular system to access the reservoir of blood in the large or great veins for continuous blood withdrawal and treatment. Air-tight connectors are incorporated in the catheter assembly to overcome the untoward effects of negative pressure in blood withdrawal.

1 . A dual lumen catheter for withdrawing blood and returning treated blood through a peripheral vein of a patient, said catheter comprising: 
 a catheter tube having an insertable length of at least 10 cm, wherein said insertable length further comprises a proximal dual lumen section having a withdrawal lumen and an infusion lumen, and wherein said withdrawal lumen continues as a single lumen distal to the dual lumen section.    
   
   
       2 . A catheter as in  claim 1  wherein the catheter has a substantially uniform cross-sectional periphery along the insertable length.  
   
   
       3 . A catheter as in  claim 1  wherein the catheter is formed of 90 to 110 Shore A polyurethane.  
   
   
       4 . A catheter as in  claim 1  further comprising a fluid withdrawal inlet opening within two cm of a distal tip of the withdrawal lumen.  
   
   
       5 . A catheter as in  claim 4  wherein fluid return is performed through a lumen outlet opening at least 10 cm proximal to the withdrawal lumen inlet opening.  
   
   
       6 . A catheter as in  claim 1  wherein an internal cross sectional area of the fluid withdrawal lumen is substantially larger in the single lumen portion of the catheter than in the double lumen portion.  
   
   
       7 . A catheter as in  claim 1  wherein the single lumen portion is at least 10 cm.  
   
   
       8 . A catheter as in  claim 1  wherein an internal cross sectional area of the fluid withdrawal lumen transitions over a length of 1 to 3 mm from a small area to a larger area in a section of the catheter proximal to a transition from the dual lumen to single lumen sections.  
   
   
       9 . A catheter as in  claim 1  wherein the transition of the fluid withdrawal lumen cross section forms an angle of no greater than 45°.  
   
   
       10 . A catheter as in  claim 1  wherein a cross-section of a fluid withdrawal lumen is 100% to 175% larger in a distal portion of the catheter than in a proximal dual lumen portion of the catheter.  
   
   
       11 . A catheter as in  claim 1  wherein a fluid withdrawal lumen distal opening has at least one opening in a sidewall of the catheter with a combined opening cross sectional area of at least as great as a cross section of withdrawal lumen adjacent the distal opening.  
   
   
       12 . A catheter as in  claim 1  wherein the fluid withdrawal lumen includes an inlet opening at a catheter tip and a plurality of sidewall inlet openings in a side wall of the lumen, wherein the sidewall inlet openings are within two cm of the catheter tip.  
   
   
       13 . A catheter as in  claim 1  wherein the withdrawal lumen further comprises a tapered tip having at least one opening in a tapered side wall.  
   
   
       14 . A catheter as in  claim 1  wherein a blood pump applies a negative pressure to an inlet of the withdrawal lumen in a range of negative 100 to negative 300 millimeters of mercury.  
   
   
       15 . A catheter as in  claim 1  wherein a blood pump applies a negative pressure to an inlet of the withdrawal lumen in a range of negative 150 to negative 200 millimeters of mercury.  
   
   
       16 . A dual lumen catheter for withdrawing blood and returning treated blood through a peripheral vein of a patient, said catheter comprising: 
 a catheter tube having an insertable portion adapted to be inserted into the peripheral vein;    an infusion lumen within said catheter extending through a portion of the insertable portion of the catheter tube;    a withdrawal lumen within said catheter tube further comprising a first withdrawal section extending parallel to said infusion lumen and a second withdrawal section contiguous with the first withdrawal section, wherein said second withdrawal section extends distally beyond said infusion lumen.    
   
   
       17 . A dual lumen catheter as in  claim 16  wherein said catheter tube has a constant outside diameter section extending along its insertable length to a distal tip portion of the catheter.  
   
   
       18 . A dual lumen catheter as in  claim 17  wherein the distal tip portion is tapered and has a decreasing cross-sectional area.  
   
   
       19 . A dual lumen catheter as in  claim 16  wherein said infusion lumen and first withdrawal section are separated by a septum wall that terminates at a transition between the first withdrawal section and the section withdrawal section.  
   
   
       20 . A dual lumen catheter as in  claim 19  wherein the septum wall is helical at least at a distal section of the wall.  
   
   
       21 . A dual lumen catheter as in  claim 16  wherein the infusion lumen further comprises a first infusion opening and a second infusion opening angularly offset from the first infusion opening.  
   
   
       22 . A dual lumen catheter as in  claim 21  wherein the angular offset is at least 60 degrees.  
   
   
       23 . A dual lumen catheter as in  claim 16  further comprising a tube reinforcing member in a section of tube wall at least adjacent the infusion lumen.  
   
   
       24 . A dual lumen catheter as in  claim 23  wherein said reinforcing member further comprises an gap aligned with an infusion opening in said infusion lumen.  
   
   
       25 . A dual lumen catheter as in  claim 23  wherein said reinforcing member comprises a coil embedded in said tube wall adjacent an infusion opening in said infusion lumen.  
   
   
       26 . A dual lumen catheter as in  claim 25  wherein said coil includes at least one incomplete winding between opposite complete windings extending completely around said tube wall, and wherein said at least one incomplete winding is aligned with the infusion opening.  
   
   
       27 . A dual lumen catheter as in  claim 25  wherein said coil further comprises a first coil and a second coil, embedded in said tube wall on opposite sides of the infusion opening.  
   
   
       28 . A dual lumen catheter as in  claim 23  wherein said reinforcing member comprises an increase of the durometer of the catheter tube at a tube section including the infusion opening.  
   
   
       29 . A dual lumen catheter as in  claim 28  wherein said durometer increase is to a durometer of 55 to 75 shore D.  
   
   
       30 . A dual lumen catheter as in  claim 28  wherein the tube section extends a distance no more than 1.5 cm from either end of the infusion opening.  
   
   
       31 . A dual lumen catheter as in  claim 23  wherein said reinforcing member comprises a ridged tubing section along a tube section including the infusion opening.  
   
   
       32 . A dual lumen catheter as in  claim 22  wherein the tube section extends a distance no more than 1.5 cm from either end of the infusion opening.  
   
   
       33 . A dual lumen catheter as in  claim 16  where said insertable length is at least 20 cm and said infusion lumen has an insertable length of less than 10 cm.  
   
   
       34 . A dual lumen catheter as in  claim 16  further comprising a large diameter section of said catheter tube including both said infusion lumen and said withdrawal lumen, wherein said large diameter section is proximal to said insertable portion, and said insertable portion is smaller in diameter than is said large diameter section.  
   
   
       35 . A dual lumen catheter as in  claim 34  wherein a cross-sectional area of said withdrawal lumen contracts at an interface between the large diameter section of the catheter tube and the first withdrawal section, and expands at an area between the first withdrawal section and the second withdrawal section.  
   
   
       36 . A dual lumen catheter as in  claim 16  further comprising a distal withdrawal opening at a distal end of the second withdrawal section, proximal withdrawal opening in the first withdrawal section, and an infusion opening at a distal end of the infusion lumen.  
   
   
       37 . A dual lumen catheter as in  claim 36  wherein said proximal withdrawal opening is adjacent the infusion opening.