A common call the nephrologist will receive when managing a peritoneal dialysis (PD) patient is that of poor flow. This problem is classically described as “one way” or “two way.”
One Way Obstruction: Classically defined as as slow or impeded drainage with normal dialysate instillation. The differential diagnosis is outlined in Table 1.
Table 1. Causes of one way obstruction in PD patients
The first treatment for a significant one-way or outflow obstruction is the aggressive use of laxatives. Studied agents include polyethylene glycol and dietary fiber. Should this fail, a KUB will help confirm the position of the catheter. If the KUB reveals a catheter in the cul-de-sac and no significant stool burden, manual removal of blood clot is attempted – if this is not productive, a catheter-gram should be pursued followed by laparoscopy if needed.
Two Way Obstruction: Defined as difficulty with both instillation and drainage of dialysate, typically an intraluminal problem with the catheter (Table 2).
Table 2. Causes of two way obstruction in PD patients
When a patient presents with two way obstruction, the first step in management is to evaluate the dialysis apparatus and tubing to make sure no clamps are inadvertently still in place and that tubing is intact at home. If the exterior of the tubing or the transfer set becomes wet overnight, this is a clue to a loss of patency. We then typically will palpate the tunnel to feel for sharp angles and changes in catheter position and aggressively flush/suction the catheter to aspirate any clot. If clot is retrieved the catheter can be flushed with alteplase. Should these attempts fail, laparoscopy is typically required to diagnose and treat the condition.
Post by: Ankur Shah, MD (@NephroShah)
Nephrologist, Brown University