From the Guidelines
Spontaneous bacterial peritonitis (SBP) is a serious infection that can occur in patients with nephrotic syndrome due to their immunocompromised state and low serum albumin levels, and treatment should begin immediately with broad-spectrum antibiotics, typically a third-generation cephalosporin like ceftriaxone or cefotaxime, as recommended by the most recent guidelines 1. The relationship between SBP and nephrotic syndrome (NS) is complex, with patients with NS being at increased risk of developing SBP due to their compromised immune system and low serum albumin levels.
- Key factors contributing to this relationship include:
- Immunocompromised state
- Low serum albumin levels
- Decreased complement levels
- Impaired opsonization
- The pathophysiology of SBP in NS involves bacterial translocation from the gut into ascitic fluid, facilitated by these factors, making patients particularly vulnerable to encapsulated organisms like Streptococcus pneumoniae and gram-negative enteric bacteria such as Escherichia coli.
- Diagnosis of SBP requires paracentesis with ascitic fluid analysis showing an elevated neutrophil count (>250 cells/mm³) without an obvious intraabdominal source of infection.
- Treatment should begin immediately with broad-spectrum antibiotics, and ceftriaxone (1-2g IV daily for 5-7 days) or cefotaxime (2g IV every 8 hours for 5-7 days) are recommended as first-line treatments 1.
- In patients with renal impairment, dose adjustments may be necessary, and albumin infusion (1.5g/kg on day 1, then 1g/kg on day 3) alongside antibiotics improves outcomes by enhancing intravascular volume and reducing inflammatory cytokines 1.
- Prophylaxis with norfloxacin (400mg daily) or trimethoprim-sulfamethoxazole (one double-strength tablet daily) should be considered for high-risk nephrotic patients with serum albumin <2.5g/dL, especially those with previous episodes of SBP 1.
From the Research
Relationship between Spontaneous Bacterial Peritonitis (SBP) and Nephrotic Syndrome (NS)
- SBP is a bacterial infection of ascitic fluid, commonly associated with decompensated cirrhosis, but can also occur in patients with nephrotic syndrome 2, 3.
- Nephrotic syndrome is characterized by heavy proteinuria, hypoalbuminemia, and edema, which can increase the risk of developing SBP 2, 3.
- The incidence of SBP in adult patients with nephrotic syndrome is rare, but it can be a life-threatening condition if not diagnosed and treated promptly 3.
- Studies have shown that patients with nephrotic syndrome, especially those with minimal change disease, are at a high risk of developing SBP, particularly if they have refractory ascites, severe hypoalbuminemia, and marked reduction in serum immunoglobulin G (IgG) 2.
- The diagnosis of SBP in patients with nephrotic syndrome can be challenging, and a high index of suspicion is necessary to initiate prompt treatment with antibiotics and supportive therapy 2, 3.
Risk Factors and Clinical Presentation
- Patients with nephrotic syndrome who develop SBP often present with abdominal pain, fever, and ascites, similar to those with cirrhotic ascites 2, 3.
- The ascitic fluid analysis is crucial in diagnosing SBP, and a high polymorphonuclear cell count is a sensitive indicator of infection 4.
- The use of immunosuppressive therapy, such as corticosteroids and cyclosporine, can increase the risk of developing SBP in patients with nephrotic syndrome 2.
- Renal dysfunction is a significant complication of SBP, and patients with nephrotic syndrome are at a higher risk of developing renal impairment after SBP 5.
Treatment and Management
- Empirical antibiotic therapy with cefotaxime or other broad-spectrum antibiotics is recommended for patients with suspected SBP, including those with nephrotic syndrome 2, 4.
- Supportive therapy, including intravenous albumin and fluid management, is essential in managing patients with SBP and nephrotic syndrome 2, 5.
- Close monitoring of renal function and prompt treatment of SBP are crucial in improving patient outcomes and reducing mortality 5.