Kidney failure

Disease Description (Causes and Symptoms)

• Definition: Renal failure is a condition in which the kidneys lose the ability to remove waste products and excess water from the blood and maintain fluid, electrolyte, and acid–base homeostasis. It is classified as acute (occurring over a short period and potentially reversible), chronic (gradual decline in kidney function, which may progress irreversibly), and end-stage renal disease (ESRD; requiring dialysis or transplantation).
• Main causes: Diabetic nephropathy, glomerulonephritis, hypertensive nephropathy (impaired renal blood flow), polycystic kidney disease (hereditary), systemic lupus erythematosus, drug-induced causes (nephrotoxic drugs, contrast agents, etc.), preeclampsia, and others.
• Pathophysiology summary: Damage to the renal tubules and glomeruli causes a decrease in the number of functional nephrons → decreased glomerular filtration rate (GFR) → accumulation of waste products (uremic toxins), water, potassium, phosphorus, and others → systemic complications such as metabolic acidosis, anemia (decreased erythropoietin), and abnormalities of bone metabolism (hyperphosphatemia and secondary hyperparathyroidism).
• Main symptoms: Generalized edema (face and legs), shortness of breath (pulmonary edema), decreased or changed urine output, fatigue and weakness, nausea and vomiting, loss of appetite, itching (pruritus), and confusion or decreased orientation (in severe uremia). Decreased skin elasticity and other findings may also be observed.

Treatment Methods and Precautions

• Basic principles for acute kidney injury (AKI): Identify and correct the cause (correct reduced blood flow, treat infection, remove toxic substances), monitor and correct fluid, electrolyte, and acid–base status, and discontinue or replace nephrotoxic drugs. Renal replacement therapy (dialysis) is performed when necessary.
• Goals of chronic kidney disease (CKD) management: Suppress progression, prevent and treat complications, and determine the timing of dialysis or transplantation.
  • Treatment of underlying diseases: Strict blood pressure control (RAAS blockers, such as an ACE inhibitor or ARB, are generally considered first when proteinuria is present), and diabetes control (individualize blood glucose targets).
  • Drug therapy: Diuretics (edema management), RAAS blockers (to reduce proteinuria and suppress progression), corrective medications for hyperkalemia, hyperphosphatemia, and acidosis, respectively (potassium restriction, phosphate binders, bicarbonate, etc.), and iron and erythropoietin (EPO) treatment for anemia (depending on the indication).
  • Renal replacement therapy: Dialysis (hemodialysis or peritoneal dialysis)—examples of indications for starting dialysis include uncontrollable hyperkalemia, severe metabolic acidosis, and pulmonary edema (based on clinical judgment; refer to the AEIOU criteria). Kidney transplantation may improve prognosis and quality of life as a long-term treatment.
  • Lifestyle management: A low-salt diet (sodium restriction), adjustment of protein intake (according to the stage of kidney function), regulation of potassium and phosphorus intake, management of fluid intake, regular monitoring of blood pressure, weight, and urine output, and smoking cessation, weight management, and exercise are recommended.
• Precautions:
  • Use caution with nephrotoxic drugs (nonsteroidal anti-inflammatory drugs (NSAIDs), some antibiotics and anticancer drugs, contrast agents, etc.).
  • Drug doses need to be adjusted according to GFR—kidney function must be checked before prescribing.
  • Strict infection prevention (vaccination is recommended) and management of the dialysis access site (such as an arteriovenous fistula) are necessary.
• Risk of complications: Cardiovascular disease (the main cause of death), arrhythmia caused by hyperkalemia, metabolic acidosis, anemia, abnormalities of bone metabolism, uremic neuropathy and gastrointestinal symptoms, and others.

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Items/information to bring:
  • A list of all medications currently being taken (including prescriptions, OTC drugs, herbal medicines, and supplements)
  • Recent test results (paper or electronic): Blood tests (creatinine, eGFR, electrolytes, calcium, phosphorus, PTH, Hb), urinalysis (urine protein, urine albumin/creatinine ratio), and recent imaging or electrocardiogram results (if available)
  • Records of changes in blood pressure, weight, and urine output (preferably for several days)
  • A symptom diary (the onset and course of edema, shortness of breath, changes in urination, fatigue, vomiting, etc.)
  • Allergy information (medications and food)
  • Dialysis patients: Information about the dialysis schedule and the condition of the access site (fistula or catheter)
• Show the doctor during the outpatient visit:
  • Medication list, recent test results, and blood pressure and weight records
• Example questions (sentences for patients to write down in advance):
  • "What was my eGFR (or creatinine) in my recent test?"
  • "If the edema and weight gain continue, when should I come to the hospital?"

General Example Questions to Ask the Doctor

• "What stage is my current kidney function (e.g., eGFR) at, and how fast is it progressing?"
• "Do any of the medications I am taking (or that are being prescribed) have kidney-related side effects, or do their doses need to be adjusted?"
• "What are the criteria for deciding when to start dialysis? Which is more suitable for me, hemodialysis or peritoneal dialysis?"
• "What should I change first in my lifestyle or diet to protect my kidneys?"

Examples of Disease-Specific Questions

• If diabetes-related renal failure is suspected: "How should my blood glucose and HbA1c targets be set, and is it possible for my kidney function to improve with blood glucose control?"
• For patients considering dialysis or transplantation: "Could I be a candidate for a kidney transplant? What are the requirements for registering on the transplant waiting list, and what is the expected waiting time?"

(Note: The information above is guidance compiled based on general medical knowledge. Decisions about treatment, tests, and medications for an individual condition should be made in consultation with the treating doctor.)