What is indicated by a blood alarm during dialysis?

A blood alarm during dialysis is primarily an indication that blood is not moving through the machine as intended, which typically points to a potential issue with the blood lines or the access site. This situation can arise due to various reasons, such as clots forming in the lines, a kink in the tubing, or issues related to the vascular access, such as inadequate blood flow or complications at the fistula or graft site.

Addressing this alarm promptly is crucial because it indicates that the patient may not be receiving effective dialysis treatment, which can lead to serious health risks if not resolved quickly. The alarm serves as a safety mechanism to alert the healthcare provider to investigate and rectify the issue to ensure that the patient continues to receive the necessary treatment without interruption.

In contrast, while altered vital signs, unexpected blood types, or insufficient saline levels are also important concerns in a dialysis setting, they do not specifically indicate the failure of blood movement through the machine like a blood alarm does. Hence, option C accurately captures the specific meaning of a blood alarm during dialysis.