Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• Updates in spontaneous bacterial pleuritis: diagnosis and care

  Spontaneous bacterial pleuritis, sometimes called spontaneous bacterial empyema, describes infection of a pre-existing pleural effusion without preceding surgery or penetrating trauma. It most often arises in patients with hepatic hydrothorax, though immunocompromised hosts and those with community-acquired pneumonia can also develop the condition. Recent evidence has shifted several long-held practices around empirical antibiotics, drainage thresholds, and adjunctive therapy.

  Clinicians across Australian tertiary centres, from Royal Prince Alfred in Sydney to The Alfred in Melbourne, are seeing growing numbers of cirrhotic patients who develop this complication. Local data from the Australasian Society for Infectious Diseases and TSANZ working groups have helped standardise initial work-up, yet management still varies between urban teaching hospitals and remote outreach services supported by the Royal Flying Doctor Service.

  Pathophysiology and clinical recognition

  The infection begins when bacteria translocate across an inflamed visceral pleura or seed a hydrothorax via haematogenous spread. Cirrhosis-associated immune dysfunction, low pleural fluid opsonins, and impaired lymphatic drainage create a permissive environment. Patients typically present with worsening dyspnoea, pleuritic chest pain, fever, or unexplained encephalopathy in advanced liver disease.

  A high index of suspicion is warranted because signs can be subtle, particularly in patients with hepatic encephalopathy who cannot reliably report symptoms. In Australia, where many cirrhotic patients are managed through outreach hepatology clinics, a sudden drop in oxygen saturation or new confusion should prompt immediate pleural imaging, even when the initial complaint seems unrelated.

  Diagnostic criteria and imaging

  Diagnosis rests on pleural fluid analysis. The traditional threshold of pH below 7.2, glucose under 3.4 mmol/L, or positive Gram stain and culture remains the cornerstone. LDH above 1000 IU/L and fluid loculations on ultrasound support a diagnosis of complicated parapneumonic effusion or frank empyema. Thoracic ultrasound at the bedside has largely replaced blind aspiration in Australian emergency departments because it reduces iatrogenic pneumothorax and characterises septations.

  Chest CT is reserved for suspected underlying malignancy, when drainage fails to improve, or when bronchopleural fistula is a concern. At institutions such as Royal Adelaide Hospital and the Prince Charles in Brisbane, point-of-care ultrasound is now part of the standard pleural protocol for any new effusion in a septic patient.

  Microbiological patterns

  Organisms vary by underlying disease. In cirrhotic patients, Escherichia coli, Klebsiella species, and Enterococcus dominate, while Streptococcus pneumoniae, Staphylococcus aureus, and anaerobes are more typical after community-acquired pneumonia. Australia has relatively low rates of methicillin-resistant S. aureus compared with North American cohorts, yet community-associated MRSA remains prevalent in the tropical north and among some Indigenous communities.

  Blood and pleural fluid cultures should be drawn before antibiotics whenever feasible. Broader molecular testing, including 16S PCR and targeted pneumococcal antigen, is increasingly available through reference laboratories such as the Doherty Institute in Melbourne. Antibiogram guidance differs between metropolitan and regional services, so clinicians should consult their local stewardship team before adjusting empirical cover.

  Empirical antibiotic selection

  Empirical therapy should cover gram-positive, gram-negative, and anaerobic organisms while awaiting culture data. A third-generation cephalosporin such as ceftriaxone combined with metronidazole remains appropriate in most Australian settings. For patients with recent hospitalisation, healthcare exposure, or known MRSA colonisation, vancomycin or linezolid should be added until nasal swabs and susceptibilities return.

  In regions with higher rates of extended-spectrum beta-lactamase organisms, particularly in tropical Queensland, piperacillin-tazobactam may be preferred over ceftriaxone. Antibiotic duration is typically four to six weeks, guided by clinical response, inflammatory markers, and imaging. Outpatient parenteral antibiotic therapy programs, well established through Hospital in the Home services in New South Wales and Victoria, allow many patients to complete treatment without prolonged inpatient stays.

  Pleural drainage and fibrinolytics

  Chest tube drainage is recommended when fluid is frankly purulent, pH is below 7.2, or loculations cause persistent sepsis. Small-bore catheters (12 to 14 French) inserted under ultrasound guidance have largely replaced larger surgical tubes in most Australian centres, with comparable success and lower patient discomfort. Daily saline flushes help maintain patency, especially when fibrinous debris is present.

  Intrapleural fibrinolytic therapy with tissue plasminogen activator plus DNase has transformed the management of complicated effusions. The MIST-2 regimen, given as 10 mg tPA and 5 mg DNase twice daily for three doses, is now standard practice at tertiary centres. Surgery remains an option when drainage fails, but the need for decortication has fallen significantly since the adoption of fibrinolytics.

  Considerations for remote and Indigenous populations

  Aboriginal and Torres Strait Islander peoples experience higher rates of chronic respiratory disease, and pleural infection may coexist with bronchiectasis or post-tuberculous scarring. Culturally safe communication, often involving Aboriginal health workers, supports earlier presentation and adherence to follow-up. In the Northern Territory and parts of Western Australia, where patients may live hundreds of kilometres from the nearest centre, transfer via the Royal Flying Doctor Service requires careful coordination with receiving hospitals.

  Telehealth follow-up, expanded under Medicare since 2020, allows remote review of drains and wound sites, reducing the need for repeated long-distance travel. Localised protocols that account for weather, road access, and seasonal infections are essential when planning outpatient antibiotic and drainage management in these communities.

  Recovery and prevention

  Patients who recover should be reviewed at four to six weeks with repeat imaging to confirm pleural resolution. Persistent thickening or trapped lung warrants thoracic surgery referral. Underlying drivers, including cirrhosis management, alcohol reduction, vaccination against pneumococcus and influenza, and optimisation of chronic lung disease, should be addressed to reduce recurrence.

  Smoking cessation support, available through Quitline and Aboriginal quit programs, is a core part of secondary prevention. Where alcohol-related liver disease contributes, integration with hepatology, addiction medicine, and social work improves long-term outcomes and lowers the risk of recurrent pleural infection.

  Practical recommendations for the bedside clinician

  • Obtain pleural fluid analysis early, including pH, glucose, LDH, cell count, Gram stain, and culture, before empirical antibiotics whenever possible.
  • Use bedside thoracic ultrasound for both diagnosis and guided drainage to minimise complications and characterise loculations.
  • Choose empirical antibiotics based on local resistance patterns and host factors, adjusting promptly when cultures return.
  • Insert small-bore chest drains under ultrasound guidance for complicated effusions, with daily flushes to maintain patency.
  • Offer intrapleural tPA plus DNase early when septations are present, before considering surgical referral.
  • Coordinate with outreach services such as the Royal Flying Doctor Service and Aboriginal health workers when managing remote patients.
  • Plan follow-up imaging, vaccination, and chronic disease optimisation to prevent recurrence.

  Discussions at the APSR 2022 congress explore these themes in depth, including workshops on pleural ultrasound and case-based panels on complex infections. Respiratory trainees and established specialists can review the streamed sessions through the official portal once they are released. The next concrete step for any clinician managing suspected pleural infection is to verify that their local protocol includes bedside ultrasound, contemporary antibiotic stewardship, and access to intrapleural fibrinolytics, so the team is ready when the next case presents.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)