Spontaneous bacterial peritonitis
See Peritoneal dialysis-associated peritonitis for PD peritonitis
Background
- Abreviation: SBP
- Develops in large, clinically obvious ascites secondary to cirrhosis
- Normal flora translocate across the bowel wall into the peritoneum
- 30% of ascitic pts will develop SBP in a given year
Clinical Features
- Fever (70%)
- Abdominal pain (diffuse) (60%)
- Altered mental status (55%)
- ~15% of patients have no signs/symptoms
Differential Diagnosis
Diffuse Abdominal pain
- Abdominal aortic aneurysm
- Acute gastroenteritis
- Aortoenteric fisulta
- Appendicitis (early)
- Bowel obstruction
- Bowel perforation
- Diabetic ketoacidosis
- Gastroparesis
- Hernia
- Hypercalcemia
- Inflammatory bowel disease
- Mesenteric ischemia
- Pancreatitis
- Peritonitis
- Sickle cell crisis
- Spontaneous bacterial peritonitis
- Volvulus
Diagnosis
Consider alternative diagnoses at the same time
SBP Work-Up of Ascitic Fluid via Paracentesis
- Cell count with differential
- Gram stain
- Culture (10cc in blood culture bottle)
- Glucose
- Protein
Consider
- Albumin and SERUM albumin
- LDH and SERUM LDH at same time
- Amylase
Specific circumstances
- TB smear and culture
- Cytology
- TG
- Billirubin
Diagnosis of SBP via Ascitic Fluid Analysis
Standard Evaluation
- Paracentesis results supporting a diagnosis of SBP:
- Absolute neutrophil count (PMNs) ≥250, pH <7.35, OR blood-ascites pH gradient >0.1[1]
- Bacteria on gram stain (single type)
- SAAG > 1.1
- Diagnostic of portal hypertension with 97% accuracy[2]
- SBP rarely develops in patients without portal hypertension
- Protein < 1, Glucose > 50 (otherwise concern for secondary bacterial peritonitis)
For bloody tap, subtract 1 WBC for every 250 RBC[3]
If on peritoneal dialysis
See Peritoneal dialysis-associated peritonitis
- Cell count >100/mm with >50% neutrophils most consistent with infection[4]
Spontaneous versus secondary bacterial peritonitis
- Importance of distinction
- Mortality of secondary bacterial peritonitis (eg. perforated appendicitis, cholecystitis) ~100% if treatment is only antibiotics without surgery
- Mortality of unnecessary surgery in patients with SBP ~80%
- Laboratory findings
- Secondary bacterial peritonitis strongly suggested by:
- Neutrocytic fluid (PMN ≥250) w/ two or more of the following:
- Total protein concentration >1 g/dL (10 g/L)
- Glucose concentration <50 mg/dL (2.8 mmol/L)
- LDH greater than upper limit of normal for serum
- Ascitic alk phos >240
- Gram stain
- Large numbers of different bacterial forms
- Neutrocytic fluid (PMN ≥250) w/ two or more of the following:
- Secondary bacterial peritonitis strongly suggested by:
- Imaging
- If evidence of secondary bacterial peritonitis obtain abdominal imaging
- If no evidence of free air or contrast extravasation then surgery is not indicated
- If evidence of secondary bacterial peritonitis obtain abdominal imaging
Treatment
Antibiotics
- SBP
- Broad-spectrum covering enterobacter (63%), pneumococcus (15%), entercocci (10%)
- Anaerobes causative agent <1%
- 3rd-generation cephalosporin is agent of choice:
- Cefotaxime 2g IV q8hr or Ceftriaxone 1-2g IV q12-24hr
- If beta-lactam allergy consider ciprofloxacin 400mg IV q12hr
- 3rd-generation cephalosporin is agent of choice:
- Secondary bacterial peritonitis
- 3rd-generation cephalosporin + metronidazole
- Surgery
Albumin
- Reduces renal failure and hospital mortality
- 1.5gm/kg at diagnosis; 1gm/kg on day 3
Disposition
- Can consider discharge w/ PO abx if pt has mild, uncomplicated disease and close f/u
See Also
References
- Paracentesis. N Engl J Med 2006; 355
- ↑ Wilkerson R, Sinert, R. The Use of Paracentesis in the Assessment of the Patient With Ascites. Ann Emerg Med 2009, 54(3): 465-68.
- ↑ Runyon BA, Montano AA, Akriviadis EA, et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites. Ann Intern Med 1992; 117:215.
- ↑ Hoefs JC "Increase in ascites white blood cell and protein concentrations during diuresis in patients with chronic liver disease."Hepatology. 1981;1(3):249. PMID 7286905
- ↑ ISPD GUIDELINES/RECOMMENDATIONS http://www.ispd.org/guidelines/articles/update/ispdperitonitis.pdf