Anderson Hemodialysis for Nurses and Dialysis Personnel (HEMOTECH21) Continuing Education (CE) Practice Test

The removal of a poison during dialysis is significantly influenced by its physical and chemical characteristics. For effective removal, a poison should ideally be water soluble and low in molecular weight.

When a substance is water soluble, it can easily dissolve in the dialysate used during the dialysis process. This solubility enables the poison to diffuse across the semi-permeable membrane of the dialysis machine and be efficiently removed from the patient's blood. Low molecular weight is equally important because larger molecules tend to be retained in the bloodstream and are less likely to pass through the dialysis membrane. Compounds that meet both of these criteria are more readily cleared from circulation during the dialysis process, resulting in effective detoxification.

In contrast, characteristics such as high protein binding and large volume of distribution can hinder the removal of a substance during dialysis, as they prevent the poison from being effectively filtered. High molecular weight and low water solubility also impede the diffusion across the dialyzer membrane, limiting clearance. Therefore, the combination of water solubility and low molecular weight is essential for maximizing the effectiveness of dialysis in removing poisons.