For peritonitis associated with dialysis refer to: Edinburgh Renal Unit Antimicrobial Guidance.

Required investigations

  • Blood cultures prior to administering antibiotics.
  • Paracentesis should be carried out without delay. Diagnosis confirmed by:
    • WCC > 500 X 106/L
    • Positive ascitic fluid culture with clinical signs of infection

Antibiotic recommendations

Piperacillin-tazobactam 4.5g every 8 hours IV

Known MRSA carriage:

Piperacillin-tazobactam 4.5g every 8 hours IV

PLUS

Vancomycin IV (use NHS Lothian Calculator located on AMT intranet page)- target trough level 15-20mg/L

Penicillin allergy:

Vancomycin IV (use NHS Lothian Calculator located on AMT intranet page) - target trough level 15-20mg/L

PLUS

Ciprofloxacin 500mg every 12 hours orally (or 400mg every 12 hours IV)

See MHRA fluoroquinolone guidance here.

Piperacillin-tazobactam and ciprofloxacin are associated with C.diff infection. See here for risk factors for C.diff infection.

IV to oral switch

Recommended total duration: 5 days (total duration = IV + oral)

  • Review patient in 48 hours. If clinically improving, consider IV to oral switch
  • This should be based on culture results when available. Otherwise empirical cover as below:

Preferred:

Co-trimoxazole 960mg every 12 hours orally (suitable in penicillin allergy)

Alternative:

Co-amoxiclav 625mg every 8 hours orally

Suitable for those ≤ 65 years old. See prevention of Cdiff infection.

Notes

  • Likely organisms: Gram positive cocci and/or Gram negative coliforms.
  • Culture results may be negative in patients taking prophylactic antibiotics