Introduction

• Polysystemic toxic syndrome resulting from severe azotemia Azotemia due to decreased renal function. Azotemia is an increased concentration of non-protein nitrogenous compounds, eg urea and creatinine, in the blood.
• Cause: acute or chronic renal failure or prolonged urinary tract obstruction.
• Signs: vomiting, anorexia, lethargy/depression, anemia, weakness, hypothermia, oral ulcers, melena, muscle, tremors, seizures.
• Diagnosis: signs, blood biochemistry, urinalysis.
• Prognosis: depends on severity of renal damage.

Pathogenesis

Etiology

• Tubular failure due to dehydration, circulatory failure, hypovolemia (prerenal uremia).
• Toxins: aminoglycosides Therapeutics: antimicrobial drug , ethylene glycol Ethylene glycol poisoning , paraquat Paraquat poisoning , heavy metals, eg cisplatin.
• Vascular obstruction, ischemia.
• Hypercalcemia Blood biochemistry: total calcium.
• Acute interstitial nephritis Chronic interstitial nephritis.
• Glomerular failure due to infection, auto-immune disease or toxemia (pyometra/sepsis).
• Urinary tract obstruction Urinary obstruction (post-renal uremia).
• Trauma.
• Acute diffuse pyelonephritis Kidney: pyelonephritis.
• Decompensating chronic renal disease Kidney: chronic kidney disease (CKD).

• Congenital renal dysplasia Kidney: dysplasia or other juvenile renal diseases.
• Chronic interstitial nephritis Chronic interstitial nephritis.
• Glomerulonephritis Glomerulonephritis.
• Neoplasia Kidney: neoplasia.
• Pyelonephritis Kidney: pyelonephritis.
• Amyloidosis Amyloidosis.
• Hydronephrosis Hydronephrosis / hydroureter.

Predisposing factors

• Post-renal failure - urinary tract obstruction Urinary obstruction.

Specific

• Acute renal failure Kidney: acute kidney injury (AKI).
• Chronic renal failure Kidney: chronic kidney disease (CKD).

Pathophysiology

• Prerenal, renal or post-renal azotemia → decreased glomerular filtration → oliguria → retention of waste products → toxemia/uremia.

• Loss of functional nephrons → inability to concentrate urine → polyuria, polydipsia.
• Retention of waste products → toxemia → catabolism of body tisues → anorexia.
• Toxemia → increased erythrocyte fragility, bone marrow depression → anemia.
• Toxemia → oral and gastrointestinal ulceration → vomiting, diarrhea and anorexia.
• Loss of functional nephrons → decreased GFR → increased phosphorus → decreased calcium → increased PTH → normalizes calcium and phosphorus but causes renal secondary osteodystrophy.

Timecourse

• Acute or chronic.

Diagnosis

Treatment

Prevention

Outcomes