What are the characteristics of Ascites, Spontaneous Bacterial Peritonitis, and Hepatorenal Syndrome?

Complications of Advanced Liver Disease: Matching Characteristics

Ascites is characterized by pathological intra-abdominal accumulation of sodium, water, and protein; Spontaneous Bacterial Peritonitis involves defects in host defense predisposing to infection in the peritoneal cavity; and Hepatorenal Syndrome is a dire complication with usually acute onset, progressive rising serum creatinine levels and oliguria. 1

Ascites: Pathological Fluid Accumulation

Ascites represents pathological intra-abdominal accumulation of sodium, water, and protein resulting from portal hypertension and renal sodium retention. 1

Key Pathophysiologic Features:

• Portal hypertension leads to increased sinusoidal hydrostatic pressure and lymph formation, driving fluid accumulation in the peritoneal cavity 1
• Splanchnic vasodilation causes arterial underfilling, activating vasoconstrictor systems (renin-angiotensin) and antidiuretic factors (arginine vasopressin), resulting in renal sodium and water retention 1, 2
• Plasma volume expansion occurs despite effective arterial underfilling, perpetuating the cycle of fluid accumulation 2

Clinical Impact:

• Ascites is the most common first decompensation event in cirrhosis, occurring in 5-10% of compensated patients annually 1
• Development of ascites reduces 5-year survival from 80% to 30% 1

Spontaneous Bacterial Peritonitis: Defective Host Defense

Spontaneous Bacterial Peritonitis develops from defects in host defense mechanisms that predispose to bacterial infection in the peritoneal cavity. 1

Pathophysiologic Mechanism:

• Increased gut permeability in portal hypertension allows bacterial translocation from the intestine to the peritoneal cavity 1, 3
• Impaired host defense mechanisms in cirrhotic patients fail to clear translocated bacteria from ascitic fluid 3, 4
• Low ascitic fluid protein concentration (<1.5 g/dL) indicates reduced opsonic activity and increased SBP risk 1

Diagnostic Criteria:

• SBP is diagnosed when ascitic fluid polymorphonuclear leukocyte count exceeds 250 cells/mm³ 5
• Diagnostic paracentesis must be performed in all cirrhotic patients with ascites who develop any clinical deterioration 1, 5

Hepatorenal Syndrome: Dire Renal Complication

Hepatorenal Syndrome is a dire, late complication of cirrhosis characterized by acute onset, progressive rising serum creatinine levels, and oliguria. 1

Clinical Characteristics:

• HRS typically presents with acute onset and rapid progression of renal dysfunction 1
• Progressive elevation in serum creatinine and oliguria occur without structural kidney damage initially 1
• HRS accounts for 3.2% of cirrhosis-related hospital discharges but carries approximately 46% inpatient mortality 1

Pathophysiologic Features:

• Severe arterial underfilling from splanchnic vasodilation leads to intense renal vasoconstriction and hypoperfusion 1, 2
• Activation of vasoconstrictor systems causes marked reduction in glomerular filtration rate despite absence of intrinsic kidney disease 2
• Renal hypoperfusion predisposes to additional hemodynamic renal injury, and structural kidney damage can follow severe or repeated episodes 1, 2

Clinical Significance:

• HRS represents a further decompensated stage of cirrhosis with extremely poor prognosis 4
• Patients developing HRS require urgent evaluation for liver transplantation 1