Renal Disease and K/DOQI Classification

• Presentations of renal disease can be accidental, present with trivial or life-threatening symptoms.
• The presentation may be related to the underlying cause of renal impairment or loss of renal excretory function.

Acute Renal Disease

• Acute renal disease often presents as part of a severe illness with a clear cause, such as sepsis, post-surgical complications, or trauma.

Chronic Renal Disease

• Chronic renal disease is insidious and may present with no symptoms or with non-specific symptoms.

K/DOQI Classification of Renal Disease

• Stage 1: Normal GFR is greater than 90 ml/min/1.73m2 with persistent albuminuria; This affects 3.3% which is 9,900,000 people.

• Stage 2: GFR is 60-89 ml/min/1.73m2 with persistent albuminuria; This affects 3.0% which is 9,000,000 people.

• Stage 3: GFR is 30-59 ml/min/1.73m2; This affects 4.3% which is 12,900,000 people.

• Stage 4: GFR is 15-29 ml/min/1.73m2; This affects 0.2% which is 600,000 people.

• Stage 5: GFR is less than 15 ml/min/1.73m2 or ESRD; This affects 0.2% which is 600,000 people.

• Most renal disease has no symptoms

• Kidney disease can be detected incidentally by urinalysis, for well-person checks, employment, life insurance, etc.

• Kidney disease may be manifest as microscopic hematuria, proteinuria, or both.

• Kidney disease may be found when blood is tested for other reasons, such as diabetes or hypertension.

• The presentation of kidney disease ranges from asymptomatic individuals with proteinuria, hematuria, or low eGFR detected on routine examination to patients with fulminant disease and acute renal failure with life-threatening extrarenal disease.

• Dramatic symptomatic presentations of renal disease are uncommon.

• Asymptomatic presentations are more common but less specific.

• Asymptomatic urinary abnormalities indicate a wide range of other urinary tract diseases.

• Patients >45 years require cystoscopy as first investigation

Microscopic Hematuria

• Microscopic hematuria is very common, with a prevalence up to 22% in some screened populations, and may be due to various causes.
• The likelihood of glomerular disease increases if microhematuria is associated with proteinuria and/or hypertension.
• Renal biopsy not mandatory

Macroscopic Hematuria

• With glomerular disease is often brown or smoky in color rather than red, and clots are very unusual.
• Must distinguish from other causes of red or brown urine: haemoglobinuria, myoglobinuria, or food dyes.
• Episodic macroscopic hematuria associated is often brown or smoky and clots are very unusual
• Is usually painless, commonest glomerular cause is IgA nephropathy, macroscopic haematuria typically occurs within 24 hours of upper respiratory infection..
• Usually requires urological workup unless characteristic history of glomerular haematuria

Isolated Asymptomatic Proteinuria

• Normal urine protein excretion is less than 150 mg/24 hours (10-30 mg albumin)
• Microalbuminuria is defined as 30-300 mg albuminuria/24 hours.
• Non-nephrotic proteinuria is defined as protein excretion of less than 3.5 g/24 hours.
• May be associated with conditions other than glomerulonephritis

Nephrotic Syndrome

• Has the classic triad of findings - Proteinuria (usually >3.5g/24 hours), Hypoalbuminaemia, Oedema + hyperlipidaemia.
• Is pathognomonic of glomerular disease
• Requires renal biopsy for diagnosis

Nephritic Syndrome

• Can include: Rapid onset, oliguria, hypertension, generalized edema or haematuria with smoky brown urine
• Can include, variable renal impairment and urine containing blood protein and red cell casts
• Some glomerulonephritides causes either nephritic or nephrotic syndrome
• Renal biopsy is typically required for diagnosis

Post-Streptococcal Glomerulonephritis

Chronic Renal Failure

• The natural history of many forms of kidney disease is slowly progressive renal impairment
• If no clinical event brings attention early, patients may present with renal impairment, hypertension, microscopic hematuria and protienuria
• Often associated with small, smooth shrunken kidneys

Symptoms of Chronic Renal Failure

• Usually none until eGFR <30 mls/min
• Because renal disease progresses slowly, patients don't realize they are slowly reducing physical performance
• Non-specific symptoms can include tiredness, lethargy, loss of appetite, nausea, weight loss, shortness of breath (anaemia, fluid retention), nocturia, pruritis, and restless legs.
• A Biopsy is hazardous and unlikely to provide diagnostic material.

Uraemic Emergency

• Is life threatening if left untreated
• Consists of Hyperkalaemia and Pulmonary oedema
• Consists of Metabolic acidosis, Hypertensive encephalopathy and Uraemic encephalopathy
• Can include Pericarditis, and Pericardial tamponade