Suspected pleural infection - management algorithm

Antimicrobial therapy

• Unless absolutely impossible, send sample of fluid for culture before starting antimicrobial therapy
• If microbe known, follow advice of microbiologist / ID consultant
• Otherwise start empirical therapy while awaiting results of culture

Infection Control alerts

• Check for IC alert
• if IC alert not available, check previous 12 months of microbiology reports
• If MRSA present, treat as tagged for MRSA. See MRSA management
• if ESBL, MGNB, CARB present, treat as tagged for ESBL. See ESBL/MGNB/CARB management

Penicillin Allergy

• True penicillin allergy is rare
• Ask the patient and record what happened when they were given penicillin
• If any doubt about whether patient is truly allergic to penicillin, seek advice from a microbiologist or consultant in infectious diseases

Empirical antimicrobial regimen

• First line: Co-amoxiclav 1.2 g IV 8-hrly. Alternative (true penicillin allergy): Levofloxacin 500 mg IV by infusion 12-hrly plus metronidazole 500 mg IV by infusion/or 400 mg oral 8-hrly
  
  • if patient tagged for MRSA, add vancomycin IV by infusion (see Vancomycin guideline and calculator)
  • if MRSA proven (cultured in pleural fluid) or likely cause of empyema (e.g. recent relevant specimen other than pleural fluid positive for MRSA): Discuss use of additional antimicrobial (e.g. rifampicin) with microbiologist/ID Consultant

• Nutritional support in prolonged illness

Management of chest drain

• Ensure chest tube is draining freely and the tube is swinging at all times.
• If small bore (12-18 F) catheter is not draining freely, use the 3-way tap to flush with sodium chloride 0.9% 30 mL every 6-8 hrly
• No flushing required for larger bore drains

Removal of tube

• Remove chest drain when the patient better with:
• infection improving and
• CXR showing fluid drained almost completely

Oral antimicrobials

• Change to oral as soon as clinical improvement occurs and temperature normal for 24 hr
• providing there is no contra-indication to oral therapy and sensitivities allow
• Use oral antimicrobial to which microbe sensitive with good tissue penetration
• if not known or in doubt, discuss with microbiologist or consultant in infectious diseases

Duration of antimicrobials

• ≥3 weeks: continue antimicrobial therapy for a prolonged period of time 
• usually at least until all fluid has gone and drain has been removed
• Monitor patient closely for recurrence after stopping treatment

Calculating RAPID score

• Renal, age, purulence, infection source, dietary factors 
• For risk stratifying and inform discussions with patients regarding potential outcome from pleural infection
• Higher RAPID scores appear to indicate an increased risk of mortality and may indicate an increased length of hospital stay

Failure to respond to therapy

• Review by respiratory consultant/consultant in infectious diseases
• Repeat chest X-ray and thoracic ultrasound and if required, CT scan
• Check tube and fluid drainage
• Review antimicrobials when culture results become available and discuss with microbiology
• Discuss with respiratory to advise further management:
  
  • large bore chest tube if poor drainage despite presence of fluid
  • intrapleural tissue plasminogen activator (TPA) 10 mg diluted with sodium chloride 0.9% 30 mL twice daily (if risk of bleeding use 10 mg twice daily) plus DNase 5 mg diluted with sodium chloride 0.9% 30 mL twice daily for 3 days. Instil TPA, followed by DNase and then sodium chloride flush
  • clamp drain for 1 hr after each instillation
  • if TPA or DNase not suitable - intrapleural sodium chloride irrigation 
  • prolonged indwelling catheter
  • discussion with thoracic surgery for suitability for video assisted thoracic surgery (VATS) 

• Discharge when chest drains removed and clinical variables stable
• Continue antimicrobials for at least 3 weeks after initiation
• Follow all up patients in respiratory clinic with Chest X-ray about 3-4 weeks after discharge