Dialysis is a medical treatment that filters waste products and excess fluid from the blood when kidneys fail. This process is essential to prevent harmful substances from building up in the bloodstream.
Understanding Kidney Function and Disease Stages
Healthy kidneys perform several important roles beyond filtering waste, including balancing fluids and electrolytes, producing hormones, and regulating blood pressure. When kidneys are damaged, their ability declines, leading to chronic kidney disease (CKD), a progressive condition.
Kidney function is primarily measured by the estimated Glomerular Filtration Rate (eGFR), which indicates how many milliliters of waste your kidneys can filter per minute. CKD is categorized into five stages based on eGFR levels. Stage 1 involves normal or high GFR (90 mL/min/1.73m² or greater) with signs of kidney damage, while Stage 2 shows a mild reduction (60-89 mL/min/1.73m²) alongside damage. Stages 3a and 3b indicate moderate impairment (45-59 mL/min/1.73m² and 30-44 mL/min/1.73m², respectively), often with accumulating waste.
Stage 4 signifies severe reduction in kidney function (15-29 mL/min/1.73m²), where symptoms may become more noticeable. The final stage, Stage 5, is characterized by an eGFR below 15 mL/min/1.73m², indicating End-Stage Renal Disease (ESRD). As kidney function declines, medical intervention becomes necessary.
The Point of Dialysis Initiation
Dialysis typically begins when kidney function reaches End-Stage Renal Disease (ESRD), or CKD Stage 5. This usually occurs when the estimated Glomerular Filtration Rate (eGFR) falls below 15 mL/min/1.73m². However, a specific GFR value is not the sole determinant for starting treatment.
The decision to initiate dialysis is heavily influenced by severe symptoms and complications from kidney failure, even if the GFR is slightly above the typical threshold. These include significant fluid overload, leading to shortness of breath, and dangerous electrolyte imbalances like high potassium levels affecting heart function. Uremic symptoms, caused by toxin buildup, also necessitate dialysis. These symptoms might manifest as severe fatigue, nausea, vomiting, loss of appetite, persistent itching, muscle cramps, and decreased mental sharpness or confusion.
Malnutrition is another serious complication that can prompt dialysis initiation. Doctors evaluate a combination of these clinical signs, laboratory test results, and the patient’s overall well-being to determine the most appropriate time to begin dialysis.
Individual Factors for Starting Dialysis
The decision to start dialysis is a highly individualized process. A person’s overall health and other medical conditions, such as heart disease or diabetes, play a significant role. These conditions affect how the body tolerates kidney failure and the potential benefits and risks of dialysis.
Age is another consideration; while older individuals might have a lower baseline GFR, their symptoms and quality of life are key factors in the decision-making process. Lifestyle and personal preferences are also important, as dialysis significantly impacts daily life. Some individuals may prioritize maintaining their current lifestyle, while others adapt to the treatment regimen.
The patient’s nutritional status is evaluated, as severe malnutrition can be a strong indicator for starting dialysis. The effectiveness of conservative treatments in managing symptoms and slowing disease progression is also assessed. The decision is ultimately made through shared decision-making between the patient and their healthcare team, ensuring that personal values and goals are considered alongside medical facts.
Getting Ready for Dialysis
Once the decision to start dialysis has been made, several preparatory steps are necessary before the first treatment session. This involves discussing the different types of dialysis to choose the most suitable option. The primary types are hemodialysis, which typically occurs at a center and involves a machine filtering blood, and peritoneal dialysis, which can often be done at home using the abdominal lining for filtration.
A critical part of preparing for hemodialysis is the creation of vascular access, a surgical procedure that provides a stable point for connecting to the dialysis machine. The preferred type is an arteriovenous (AV) fistula, which connects an artery and a vein, usually in the arm, and needs several weeks to months to mature before it can be used. If an AV fistula is not feasible or immediate dialysis is required, an AV graft (using a synthetic tube) or a central venous catheter (a temporary tube in a large vein) may be used. For peritoneal dialysis, a catheter is surgically placed into the abdomen.
Patient education and support are integral during this readiness phase. Patients learn about their chosen dialysis method, how to care for their access site, and how to manage potential side effects. This preparation ensures that individuals are as comfortable and informed as possible as they transition to regular dialysis treatment.