What signifies poor needle placement during dialysis?

Rising venous pressures during dialysis can indicate poor needle placement. This occurs when the blood flow in the venous circuit is obstructed, often due to improper placement of the needle in the access site. When the needle is not correctly positioned, resistance increases, leading to elevated pressures in the venous line. This can result in various complications, such as inadequate dialysis or even damage to the access site if not addressed promptly.

In contrast, low arterial pressures might suggest issues with the blood flow into the dialyzer or may be influenced by other factors, but they do not directly indicate needle placement quality. Normal transmembrane pressure (TMP) indicates that the dialyzer is functioning well, which does not relate to the placement of the needles. Lastly, a calm patient demeanor is not indicative of needle placement; the patient's comfort depends on multiple factors unrelated to the technical aspects of needle insertion. Therefore, rising venous pressures is a clear and significant sign of potential issues related to needle placement during dialysis.