What is the function of dwell time in a PD cycle?

What is the function of dwell time in a PD cycle?

• A. It is the time between exchanges when no dialysate is in the abdomen.
• B. It is the period the dialysate remains in the abdomen to allow diffusion of solutes and ultrafiltration.
• C. It is the time required to drain the dialysate from the abdomen.
• D. It is the time needed to prepare the dialysate solution.

Answer: (B)

In peritoneal dialysis, exchanges work by letting the dialysis fluid sit in the abdomen so waste products can move from blood into the solution and extra fluid can be drawn out. The time that the solution stays in the abdomen is called the dwell time. During this period, solutes such as urea and creatinine diffuse across the peritoneal membrane from higher to lower concentration, and water is pulled into the dialysate by the osmotic gradient created by glucose in the solution. The longer the dwell (within practical limits), the more time there is for diffusion and ultrafiltration, up to a point where the gradient levels off. That’s why the dwell time is defined as the period the dialysate remains in the abdomen to allow diffusion of solutes and ultrafiltration. The other described times refer to different parts of the process: a period with no dialysate in the abdomen, the draining phase, and the preparation of the dialysate solution.

In peritoneal dialysis, exchanges work by letting the dialysis fluid sit in the abdomen so waste products can move from blood into the solution and extra fluid can be drawn out. The time that the solution stays in the abdomen is called the dwell time. During this period, solutes such as urea and creatinine diffuse across the peritoneal membrane from higher to lower concentration, and water is pulled into the dialysate by the osmotic gradient created by glucose in the solution. The longer the dwell (within practical limits), the more time there is for diffusion and ultrafiltration, up to a point where the gradient levels off. That’s why the dwell time is defined as the period the dialysate remains in the abdomen to allow diffusion of solutes and ultrafiltration.

The other described times refer to different parts of the process: a period with no dialysate in the abdomen, the draining phase, and the preparation of the dialysate solution.