text: The present invention relates generally to treatment of patients using continuous ambulatory peritoneal dialysis (CAPD). More specifically, the present invention relates to a portable pump apparatus for CAPD and a method for providing CAPD to a patient.
  It is known to use dialysis to support a patient whose renal function has decreased to the point where the kidneys no longer sufficiently function. Two principal dialysis methods are utilized: hemodialysis; and peritoneal dialysis.
  In hemodialysis, the patient's blood is passed through an artificial kidney dialysis machine. A membrane in the machine acts as an artificial kidney for cleansing the blood. Because it is an extracorporeal treatment that requires special machinery, there are certain inherent disadvantages with hemodialysis.
  To overcome the disadvantages associated with hemodialysis, peritoneal dialysis was developed. Peritoneal dialysis utilizes the patient's own peritoneum as a semi-permeable membrane. The peritoneum is a membranous lining of the abdominal body cavity that due to a large number of blood vessels and capillaries is capable of acting as a natural semi-permeable membrane.
  In continuous ambulatory peritoneal dialysis, a dialysis solution is introduced into the peritoneal cavity utilizing a catheter. Solutes (e.g., urea, creatinine, etc.) diffuse from the blood into the dialysate due to the presence of a diffusion gradient. Similarly, the presence of an osmotic gradient between the peritoneal cavity and the blood causes fluid to be removed from the body into the dialysate which is then drained through the catheter. These processes allow the proper chemical and fluid balance to be returned to the body.
  After a sufficient period of time, an exchange of solutes between the dialysate and the blood is achieved. Fluid removal is achieved by providing a suitable osmotic gradient from the blood to the dialysate to permit water out flow from the blood. This allows the proper acid-base, electrolyte and fluid balance to be returned to the blood, and the dialysis solution is simply drained from the body cavity through the catheter.
  Peritoneal dialysis raises a number of issues including: the danger of peritonitis; a lower efficiency and therefore increased duration of dialysis hours compared to hemodialysis; and cost issues when automated equipment is utilized.
  A number of variations on peritoneal dialysis have been explored. One such variation is reciprocating, recirculating, or semi-continuous peritoneal dialysis. In such systems, dialysis solution is infused into the peritoneal cavity and then, typically, on a continuous process basis a portion of the dialysis solution is sequentially drained, cleansed, and reinfused.
  Currently, a CAPD patient drains the peritoneal cavity by means of gravity alone. This however is rather time consuming. For example, the drainage takes about fifteen minutes on the average, depending on the patient's body position. As such, CAPD is relatively inconvenient for the patient.
  Certain attempts have been made to improve the process of draining fluid from a patient. For example, U.S. Pat. No. 4,710,165 to McNeil et al. discloses a wearable, variable rate suction and collection device for the withdrawal and collection of fluid from a patient. Also, U.S. Pat. No. 4,316,466 to Babb discloses a body fluid drainage device which may be mounted externally on the body of a patient and may be driven by a portable source of power. In addition, recycled effluent systems are currently used but are not portable.
  Therefore, a need has arisen for a portable drainage pump apparatus to assist flow and to improve CAPD drainage times.