History

• Had sudden onset RLQ pain starting about 1.5 hours prior to arrival
• Associated nausea but no vomiting
• No change in bowel movements
• No recent surgeries

PMH

• Stage IV pancreatic cancer
• Asthma
• Chronic back pain
• ETOH abuse (quit about 2 months prior)
• Chronic pancreatitis

Physical Exam 

VS - T: 98F, HR: 120, BP: 147/91, RR: 22, Ox: 93%

• General: appears uncomfortable, cannot sit still on stretcher
• HEENT: no scleral icterus
• CV: tachycardic
• Pulm: lungs CTA b/l
• Abdomen: distended, firm, epigastric and RLQ tenderness, voluntary guarding in RLQ, no rebound tenderness

Initial DDX

• SBO, acute perforation, appendicitis, pancreatitis, diverticulitis, mesenteric ischemia, cholecystitis, spontaneous bacterial peritonitis (SBP) 

Initial ED management 

• IV fluids, pain medication, anti-emetics
• Taken directly to CT scan

CT Scan abd/pelvis interpretatiion:

• “Increase in abdominal/pelvic ascites, with thickening and enhancement of peritoneal lining, which may be reactive versus represent changes of peritonitis; please correlate with physical examination.”

Further ED management and clinical course

• Broad spectrum antibiotics started including vancomycin, cefepime and metronidazole
• Repeat temperature 102.7 F 
• Diagnostic paracentesis performed: WBC in peritoneal fluid: >44,700
• Peritoneal fluid grows many gram-negative rods and many gram-positive cocci 

Spontaneous Bacterial Peritonitis Pearls

• Criteria for spontaneous bacterial paracentesis >250 PMN (for patients on peritoneal dialysis, cell count >100 with >50% neutrophils
• Initial antibiotic options can be third generation cephalosporins or ciprofloxacin 
• Supplemental treatment with albumin infusion 1.5 g/kg has been shown to decrease mortality (see this excellent review from Rebel EM here
• Disposition is usually admission for IV antibiotics and albumin therapy
• In patients with abdominal pain/fever/altered mental status and ascites, SBP should be on the differential and obtaining a diagnostic (not necessarily therapeutic) paracentesis in the ED should be part of the workup!!

Sources:

Koulaouzidis A, Bhat S, Karagiannidis A, Tan WC, Linaker BD. Spontaneous bacterial peritonitis. Postgrad Med J. 2007;83(980):379-383. doi:10.1136/pgmj.2006.056168

Tholey, D. (2021, December 14). Spontaneous bacterial peritonitis (SBP) - hepatic and biliary disorders. Merck Manuals Professional Edition. Retrieved December 20, 2021, from https://www.merckmanuals.com/professional/hepatic-and-biliary-disorders/...