Grant: Project Grant

In patients with advanced chronic kidney disease (CKD), the decision to initiate dialysis is based on the degree of kidney dysfunction as well as the presence of any acute indications including high acid levels, high potassium and fluid overload. In patients without any acute indications, the decision to initiate dialysis is subjective and based on a constellation of "uremic" symptoms, nutrition, and physical factors. Examples of "uremic" symptoms include anxiety, depression, difficulty sleeping, nausea and vomiting, poor appetite, fatigue, itchiness and restless legs. These symptoms are thought to be due to the accumulation of "uremic toxins" normally cleared by the kidney which may or may not be removed by dialysis. How individual uremic symptoms respond to dialysis is unknown. If clinicians were able toaccurately predict which uremic symptoms are responsive to dialysis, this could improve decision-making regarding starting long term dialysis. Patients with uremic symptoms responsive to dialysis might be able to start dialysis earlier with improved quality of life and patients with uremic symptoms unresponsive to dialysis might be able to continue to defer dialysis and avoid its potential harms (e.g. infection, heart problems). Our study will evaluate the trajectory of uremic symptoms in adults with advanced CKD followed by kidney doctors in ten or more clinics across Canada. It will identify which symptoms are responsive to dialysis as well as determine which specific uremic toxins are responsible for individual symptoms including restless legs, mood, itchiness, fatigue and nausea/vomiting. The study will be used to inform dialysis decision-making based on uremic symptoms and help us understand why some symptoms occur in some patients while other do not.