Pneumonia in the Immunocompromised

OVERVIEW

  • the numbers of immunocompromised patients is increasing c/o improved solid-organ and haemopoietic transplants and the expanded use of immunomodulatory therapies.
  • pulmonary infections = most frequent complication with high mortality

HISTORY

  • < 30 days post transplant – bacteria, fungi, HSV, respiratory viruses
  • 2-6 months post transplant – bacteria, fungi, CMV, EBV, Pneumocystis carinii, Listeria
  • > 6 months post transplant – community viruses and bacteria, opportunistic infections

EXAMINATION

  • signs may be not as fulminant due to obtunded immunological response

INVESTIGATIONS

CXR

Local Infiltrates

  • gram –ve rods
  • staph aureus
  • aspergillus
  • malignancy
  • Cryptococcus
  • nocardia
  • mucomycosis
  • pneumocystis carinii
  • Tb
  • legionella
  • radiation pneumonitis

Diffuse Infiltrates

  • CMV
  • HSV
  • PCP
  • drug reaction
  • non-specific pneumonitis
  • advanced aspergillus
  • malignancy
  • TRALI

To see list of pathogens associated with the different types of immunodeficiency see “Infectious Diseases – Specific Infections and Causative Organisms”

Sputum

  • low sensitivity
  • indicated as upper respiratory tract organisms likely to be causing pneumonia

Bronchoscopy

  • consider early in management once infiltrate appears
  • provides diagnosis in 50-80% of cases
  • BAL is very reliable technique

Open Lung Biopsy

  • rare, but diagnostic yield high

CT Chest

  • important in the diagnosis of invasive pulmonary aspergillosis: halo sign (haemorrhage pulmonary nodule), air-crescent sign (cavitation)
  • if CXR looks normal -> get CT

MANAGEMENT

  • Bacterial infection
    –> cefuroxime + erythromycin -> imipenem
  • CMV
    –> focarnet, ganciclovir
  • Pneumocysttis jiroveci (carinii) –
    > trimethoprim-sulphamethoxazole
    + corticosteroids should be used in those with HIV + hypoxia: prednisone 1mg/kg Q12hrly for 5 days
  • Invasive Pulmonary Aspergillous
    — neutropenic = most susceptible
    — can perform surveillance with galacto-mannan (polysaccharide antigen of A. fumigatus)
    -> voriconazole or amphortericin B or itraconazole
    Candida
    — only truly pathogenic if fungaemia or lung tissue invasion demonstrated
    -> caspofungin (acts against Aspergillous too)
    Cryptococcus neoformans
    -> amphortericin B +/- flucytosine

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health, a Clinical Adjunct Associate Professor at Monash University, and the Chair of the Australian and New Zealand Intensive Care Society (ANZICS) Education Committee. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.