Chronic kidney diseases (CKD)

Chronic Kidney Disease (CKD) is defined as structural or functional kidney damage persisting for more than 3 months, with or without reduction in glomerular filtration rate (GFR).

CKD represents a progressive and irreversible decline in renal function leading to accumulation of metabolic waste, electrolyte imbalance, cardiovascular complications, and eventual end-stage kidney disease (ESKD) requiring renal replacement therapy.

Important Notes

• CKD may remain completely asymptomatic in early stages.

• Early detection significantly slows disease progression and improves survival.

• Individuals with diabetes mellitus, hypertension, or cardiovascular disease should undergo routine screening.

• Adults with CKD stages 1–3 may be managed at primary care level once diagnosis and care plan are established.

• All children require specialist referral.

CKD Classification (Based on GFR)

Risk Factors

Common Causes

• Hypertension

• Diabetes mellitus

• Glomerular diseases

Additional Risk Factors

• Cardiovascular disease

• Advanced age

• Obesity

• Smoking

• Family history of kidney disease

• Recurrent urinary tract infections

• Obstructive uropathy

• Long-term nephrotoxic drug use (NSAIDs)

• Autoimmune diseases

• Polycystic kidney disease

Pathophysiology

Progressive nephron loss results in:

• Compensatory hyperfiltration of remaining nephrons

• Glomerular hypertension

• Proteinuria

• Tubulointerstitial fibrosis

• Progressive decline in GFR

CKD also promotes systemic complications including:

• Anaemia

• Bone mineral disease

• Cardiovascular morbidity

• Fluid overload

Signs and Symptoms

Clinical features depend on disease stage.

Early CKD

Often asymptomatic.

Possible findings:

• Mild hypertension

• Nocturia

• Fatigue

Advanced CKD

• Anorexia

• Malaise

• Nausea and vomiting

• Oliguria or anuria

• Peripheral oedema

• Pruritus

• Muscle cramps

• Shortness of breath

• Cognitive impairment

Diagnostic Criteria

Diagnosis requires ≥3 months of one or more:

• Reduced GFR (<60 mL/min/1.73 m²)

• Persistent proteinuria

• Structural kidney abnormality

• Persistent haematuria of renal origin

Advanced disease may present with:

• Anorexia

• Malaise

• Vomiting

• Oliguria/anuria

Investigations

Laboratory Tests

• Serum creatinine and urea

• Estimated GFR (eGFR)

• Full blood count (anaemia assessment)

• Serum electrolytes

• Calcium and phosphate levels

• Lipid profile

• Blood glucose / HbA1c

Urine Tests

• Urinalysis

• Proteinuria assessment

• Albumin–creatinine ratio (ACR)

• Urine protein–creatinine ratio

Significant proteinuria:

• PCR >0.1 g/mmolOR

• ACR >100 mg/mmol(confirmed on ≥2 occasions)

Imaging

• Renal ultrasound(kidney size, obstruction, structural disease)

Management

Management goals:

1. Treat reversible causes

2. Slow disease progression

3. Manage complications

4. Reduce cardiovascular risk

5. Prepare for renal replacement therapy

Pharmacological Management

1. Renoprotective Therapy

ACE Inhibitor

• Enalapril 10–20 mg orally every 12 hours

Benefits:

• Reduces proteinuria

• Slows CKD progression

• Controls blood pressure

Start low dose and titrate gradually.

Contraindications

• Hyperkalaemia

• ACE-inhibitor allergy

• Severe renal artery stenosis

Monitor:

• Creatinine

• Potassium

• Blood pressure

2. Hypertension Management

Treat according to hypertension guidelines.

Target:

• General CKD: standard BP targets

• CKD with albuminuria: <130/80 mmHg

3. Diabetes Management

• Optimize glycaemic control.

• Avoid oral hypoglycaemics when GFR <60 mL/min due to:

  • Metformin → lactic acidosis risk

  • Sulphonylureas → prolonged hypoglycaemia

4. Fluid Overload

Adults:

• Furosemide 40–80 mg PO or slow IV every 12 hours

If inadequate response:

• Repeat after 1 hour.

Do NOT administer IV fluid infusions unnecessarily.

Exclude heart failure in persistent oedema.

5. Hyperlipidaemia

Manage according to cardiovascular risk reduction guidelines.

Non-Pharmacological Management

Dietary Measures

• Reduce salt intake

• Protein restriction (Stage 4–5):

  • ≤1 g/kg/day

• Control fluid intake if overloaded

• Avoid high potassium foods when indicated

Lifestyle Modification

• Smoking cessation

• Weight control

• Regular physical activity

• Cardiovascular risk reduction

Proteinuria Control

ACE inhibitors recommended even without hypertension if proteinuria present.

Ensure:

• Adequate hydration before initiation

• Regular monitoring of renal function

Referral to Nephrologist

Refer urgently if:

• CKD stages 3–5

• All children

• Persistent haematuria

• Significant proteinuria

• Raised urea or creatinine

• Uncontrolled hypertension

• Fluid overload

• CKD with hyperlipidaemia

• Failure of ACE-I therapy

• Suspected hereditary kidney disease

Early referral recommended when:

GFR <30 mL/min/1.73 m²

to allow dialysis or transplant preparation.

Complications of CKD

• End-stage kidney disease

• Anaemia of chronic disease

• Mineral and bone disorder

• Hyperkalaemia

• Metabolic acidosis

• Fluid overload

• Cardiovascular disease

• Uraemia

Cardiovascular disease remains the leading cause of death in CKD patients.

Renal Replacement Therapy

Indicated in advanced CKD:

• Haemodialysis

• Peritoneal dialysis

• Kidney transplantation

Preparation should begin early.

Prevention

• Early detection in high-risk populations

• Tight blood pressure control

• Optimal diabetes management

• Avoid nephrotoxic drugs

• Treat urinary obstruction early

• Lifestyle modification

• Routine kidney screening in hypertensive and diabetic patients

Prognosis

Disease progression varies depending on:

• Underlying cause

• Blood pressure control

• Proteinuria level

• Treatment adherence

Early intervention significantly delays progression to kidney failure.