N18.4 Chronic kidney disease, stage 4 (severe)

Name of the Condition

• Chronic Kidney Disease, Stage 4 (Severe)

Summary

Chronic Kidney Disease, Stage 4 (severe) is a progressive condition marked by significant loss of kidney function. At this stage, the estimated Glomerular Filtration Rate (eGFR) typically ranges between 15 and 29 mL/min/1.73m², indicating substantial impairment in the kidneys' ability to filter waste and excess fluids from the blood. Patients often experience symptoms and may require interventions to manage complications.

Causes

Chronic Kidney Disease, Stage 4 is usually the result of long-term damage to the kidneys from underlying conditions. Common causes include uncontrolled diabetes, high blood pressure, and glomerulonephritis. Other contributing factors may include polycystic kidney disease, recurrent kidney infections, or obstructive uropathy. In some cases, the exact cause may not be identifiable.

Risk Factors

• Uncontrolled diabetes or hypertension
• Family history of kidney disease
• Older age
• Ethnic background (African American, Hispanic, Asian, and Native American populations are at higher risk)
• Smoking and obesity
• Previous acute kidney injury

Symptoms

• Significant fatigue and weakness
• Noticeable swelling in the legs, feet, or ankles
• Changes in urination patterns (e.g., decreased output or dark urine)
• Persistent nausea or vomiting
• High blood pressure that is difficult to control
• Shortness of breath
• Itching or dry skin

Diagnosis

Diagnosis of Chronic Kidney Disease, Stage 4 involves blood tests to measure creatinine and calculate the estimated Glomerular Filtration Rate (eGFR), which confirms severe kidney function impairment. Urine tests check for protein or blood, and imaging studies such as ultrasounds may assess kidney structure. Additional tests may evaluate electrolyte levels or anemia.

Treatment Options

Treatment focuses on slowing disease progression and managing complications. This may include medications to control blood pressure, diabetes, or anemia. Dietary modifications, such as limiting sodium, potassium, and phosphorus, are often recommended. In some cases, dialysis or kidney transplantation may be necessary.

Prognosis and Follow-Up

Prognosis depends on the underlying cause, comorbidities, and adherence to treatment. Regular follow-up with a healthcare provider is essential to monitor kidney function, adjust medications, and address complications. Patients may require more frequent visits as the disease progresses.

Complications

• End-stage renal disease (ESRD)
• Cardiovascular disease
• Anemia
• Bone disease (e.g., renal osteodystrophy)
• Electrolyte imbalances
• Fluid overload
• Increased risk of infections

Lifestyle & Prevention

• Maintain blood pressure and blood sugar within target ranges
• Follow a kidney-friendly diet as advised by a healthcare provider
• Avoid smoking and limit alcohol consumption
• Stay physically active with guidance from a healthcare provider
• Attend regular check-ups to monitor kidney function

When to Seek Professional Help

Seek medical attention if you experience severe fatigue, uncontrolled swelling, persistent nausea, shortness of breath, or changes in urination. Prompt evaluation is important for managing symptoms and preventing further kidney damage.

Tips for Medical Coders

When coding for Chronic Kidney Disease, Stage 4 (N18.4), ensure documentation supports the severity of kidney function impairment. Verify that eGFR values or other clinical indicators align with the stage. Document any underlying causes or contributing factors to support accurate coding. Review clinical notes for evidence of complications or treatment plans to ensure comprehensive coding.