What are the characteristics of ascites in spontaneous peritonitis?

Spontaneous bacterial peritonitis (SBP) is characterized by cloudy ascitic fluid, elevated white blood cell count in the ascites, positive bacterial culture of the ascitic fluid, systemic signs of infection, and frequent underlying liver disease. These features are key to differentiating infectious from non-infectious ascites. Patients with pre-existing liver disease who develop worsening abdominal distension accompanied by abdominal pain or fever should seek medical attention promptly.

1. Cloudy appearance of ascitic fluid: Normal or non-infectious ascites is typically clear. In contrast, infected ascites often appears pale yellow and purulent, slightly bloody, or milky white due to increased inflammatory cells and bacterial metabolic products, making its appearance distinctly different from typical ascites.

2. Elevated white blood cell count in ascites: Routine analysis of ascitic fluid shows an increased total white blood cell count, with neutrophils accounting for more than 50%. This is a key indicator of inflammation caused by infection in the ascitic fluid.

3. Positive bacterial culture of ascitic fluid: Bacterial cultures of the ascitic fluid may identify pathogenic organisms in some patients. Commonly isolated bacteria include enteric species such as *Escherichia coli* and *Klebsiella pneumoniae*. A positive culture directly confirms infection and helps guide antibiotic selection.

4. Systemic signs of infection: In addition to ascites-related symptoms, patients often present with low-grade or moderate fever. Some may experience chills, fatigue, and loss of appetite. In severe cases, signs of septic shock such as hypotension and altered mental status may occur.

5. Underlying liver disease: The majority of patients have pre-existing liver conditions such as cirrhosis or severe hepatitis. Impaired liver function leads to ascites formation, while reduced immune function facilitates bacterial translocation from the gut into the peritoneal cavity, resulting in infection.

In daily care, patients should follow medical advice regarding a low-salt diet. Monitor and record the degree of abdominal distension and changes in body temperature. Assist the patient in slowly changing positions to reduce discomfort, maintain skin cleanliness to prevent infection, cooperate with all necessary examinations, and promptly report any abnormalities to the physician.