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
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. 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 three amazing children.
On Twitter, he is @precordialthump.
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