When a doctor recommends dialysis for a patient, the first question that comes to the family’s mind is whether the kidneys are completely damaged. The answer isn’t always “yes.” Dialysis is a medical treatment that helps the body when the kidneys can no longer adequately remove waste products and excess fluid from the blood. This condition can occur in the late stages of chronic kidney disease, but sudden acute kidney injury may also require dialysis for a period of time. Therefore, starting dialysis is not the same as complete kidney failure.
According to the NIH, both kidneys continuously filter the body’s blood. These kidneys remove waste products, such as impurities and excess fluid, such as water, and also help maintain the body’s balance of sodium, potassium, calcium, and other minerals. The kidneys also play a role in removing acids and regulating blood pressure.
When the kidneys are unable to perform this function adequately, impurities and excess fluid accumulate in the blood. In such cases, dialysis helps take over some of the kidneys’ essential functions, either temporarily or long-term. The most common methods of dialysis are hemodialysis and peritoneal dialysis. In hemodialysis, blood is passed through a special filter, called a dialyzer, outside the body, and then the clean blood is returned to the body. In peritoneal dialysis, the inner lining of the abdomen, called the peritoneum, is used as a filter.
According to the NIH, when the kidneys’ filtering capacity is significantly reduced, several changes can occur in the body. Urea and other waste products increase in the blood. Excess fluid can accumulate in the body, causing swelling in the legs or face, weight gain, and, in some cases, difficulty breathing. Poor kidney function can also affect potassium and acid-base balance. Hyperkalemia, in particular, can be a serious condition, as it can affect heart rhythm.
Does starting dialysis mean the kidneys have completely stopped working? Not necessarily. This is one of the biggest misconceptions about dialysis. According to the NCBI, if a person has long-term chronic kidney disease and their kidney function has declined so much that it becomes difficult to maintain the balance of waste, fluid, and electrolytes in the body, long-term dialysis may be required. Kidney failure is usually defined when kidney function falls below approximately 15 percent of normal.
But this does not mean that the kidneys have no function at all. Dialysis takes over some of the kidney’s functions externally, while the remaining kidney function may continue to function to some extent.
Acute kidney injury, according to the National Kidney Foundation, is a condition in which kidney function suddenly deteriorates over a period of hours or days. This can be due to a variety of reasons, such as severe infection, excessive fluid loss, certain medications, or conditions that damage the kidneys.
Dialysis can be a life-saving treatment for severe kidney failure, but the initiation of dialysis does not always indicate complete kidney failure. Chronic kidney dialysis may require long-term treatment, while many patients with acute kidney injury require dialysis for a short period of time and can be discontinued once kidney function improves.
Therefore, the nephrologist makes the decision about the need for dialysis based not only on the creatinine level, but also on the patient’s overall clinical condition, kidney function, urine output, electrolytes, fluid balance, and the underlying cause of the disease.