How to manage a patient with a high count of Polymorphonuclear Neutrophils (PMNs)?

Management of High Polymorphonuclear Neutrophil (PMN) Count

Patients with elevated PMN counts ≥250 cells/mm³ in ascitic fluid should receive immediate empiric antibiotic therapy with intravenous cefotaxime 2g every 8 hours plus albumin infusion to reduce mortality. 1

Diagnostic Approach

When faced with a high PMN count, the first step is to determine the source and clinical context:

1. Ascitic fluid evaluation:

   • Perform diagnostic paracentesis for all patients with cirrhosis and ascites with suspected infection
   • PMN count ≥250 cells/mm³ in ascitic fluid indicates spontaneous bacterial peritonitis (SBP) even with negative cultures 2
   • Culture ascitic fluid in blood culture bottles at bedside to increase yield 1

2. Rule out secondary causes:

   • Consider secondary peritonitis if ascitic fluid shows:
     • Multiple organisms on culture
     • Total protein >1 g/dL
     • LDH higher than serum upper limit
     • Glucose <50 mg/dL 2, 1
   • Other causes of elevated PMN count: hemorrhagic ascites, peritoneal carcinomatosis, pancreatitis, peritoneal tuberculosis 2

Treatment Algorithm

For SBP (PMN count ≥250 cells/mm³ in ascitic fluid):

1. Immediate antibiotic therapy:

   • First-line: IV cefotaxime 2g every 8 hours 2, 1
   • Alternative (for stable patients): Oral ofloxacin 400mg twice daily if:
     • No vomiting
     • No shock
     • No grade II or higher hepatic encephalopathy
     • Serum creatinine <3 mg/dL
     • No prior quinolone prophylaxis 2, 1

2. Albumin administration:

   • 1.5 g/kg body weight within 6 hours of diagnosis
   • Follow with 1.0 g/kg on day 3
   • Reduces mortality from 29% to 10% 1

3. Duration of treatment:

   • 5 days is as effective as 10 days for uncomplicated SBP 2, 1

4. Follow-up paracentesis:

   • Not needed in typical cases with good clinical response
   • Perform if clinical response is inadequate or atypical presentation 2

Special Considerations:

• Alcoholic hepatitis patients may present with fever, leukocytosis, and abdominal pain mimicking SBP

  • Empiric antibiotics can be discontinued after 48 hours if cultures are negative 2

• Culture-negative neutrocytic ascites should be treated the same as culture-positive SBP if PMN count ≥250 cells/mm³ 2, 1

• Patients with signs/symptoms of infection (fever, abdominal pain, encephalopathy) should receive empiric antibiotics regardless of PMN count while awaiting culture results 2

Prevention of Recurrence

• Consider long-term antibiotic prophylaxis with norfloxacin or trimethoprim/sulfamethoxazole in patients with prior SBP 1
• Refer appropriate candidates for liver transplantation evaluation 1

Common Pitfalls to Avoid

1. Delaying treatment while awaiting culture results may result in death from overwhelming infection 1
2. Inadequate albumin administration may lead to increased mortality 1
3. Missing secondary peritonitis if there is inadequate response to antibiotics 2, 1
4. Relying on clinical diagnosis without paracentesis is inadequate 2
5. Failing to recognize that PMNs are critical immune cells that, while protective against infection, can also contribute to tissue damage when dysregulated 3, 4

Remember that PMNs are the most abundant circulating immune cells and represent the first line of defense against infection 4. However, their powerful inflammatory effects must be properly managed to prevent collateral damage to host tissues.