Final answer:
To detect blood in the dialysate when a blood leak alarm goes off during dialysis, a blood leak test indicator should be used to test the dialysate.
Step-by-step explanation:
When a blood leak alarm occurs during dialysis, and no blood is visibly present in the effluent dialysate, the presence of blood can be verified by testing the dialysate with a blood leak test indicator. This is critical as during the dialysis process, a patient's blood runs through tubes within an artificial kidney machine, and the semipermeable membranes within these tubes should not allow larger blood components like red blood cells or white blood cells to pass through into the dialysate. If they do, it signifies a breach in the system. To detect this, lateral flow tests can be used where a test strip containing specific antibodies will bind to any blood antigens present in the dialysate, causing a change in color to indicate a positive result for blood presence.