Viva - Fungal Infections Flashcards

1
Q

Why are fungal infections important in critical illness

A

More immnocomprimised pts in ICU - chemo, HIV, transplant

Increasing use of invasive devices

Broad spec Abx usage

Increasing aggressvie medical/surgical intervention

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2
Q

What is an Invasive Fungal Infection

A

The presence of a fungaemia (in blood)

OR

Deep seated infection due to haematogenous spread

It distinguises systemic infection from colonisation of a non-sterile site with no evidence of infection, and sperficial (dermatitis, oesophagitis)

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3
Q

Name some important fungal pathogens in critical illnes

A

Candida albican accounts for 50% of fungal infections
Candida itself is the 6 to 10th commonest pathogen in European ICU

Rest are non-albican candida species and incidence is increasing, due to increased use of fluconazole

Aspergillus rises to 15%

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4
Q

Risk factors for fungal infection

A

Being in ITU - high rate of colonisation and transmission

High APACHE II score

Co-morbid - COPD, DM, liver failure

AKI on RRT

Immunosuppression

TPN

Presence of catheters, wonds, burns ETT

Abdominal surgery, hollow perf viscous

Colonisation of multiple sites

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5
Q

Criteria for fungal infection

A

Definitive criteria:

1) single positive blood culture (NEVER MISTAKE FOR A CONTAMINANT)
2) Positive culture from biopsy
3) Endopthalmitis
4) Burn wound invasion
5) positive ascitic fluid of CSF culture

Invasive - present of 3 colonised sites

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6
Q

What suspicious features lead to disseminated fungal infection

A

Immunocomp patiets - may show no features

Non specific inflam response and evidence of organ dysfunction.

Treat if there is:
Persistant fever despite Abx and negative micro
High grade funguria in UNCATHETERISED PATIENT
Fungiuria persisting AFTER catheter removal
Fungus culture from >2 sites
Confirmed visceral fungal lesions

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7
Q

How to investigate

A
Blood cultures - though only positive in 50%
Examine retinas for endopthalmititis
Urine for culture
Echo if endocarditis suspected
Tissue biopsies
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8
Q

How to manage suspected fungal infection

A

ABCDE and treat abnormalities

Start antifungals immediately

Do not wait for micro confirmation

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9
Q

If theres a candida isolate?

A

If candida isolate: often from resp secretions (true LRTI is rare)
Isolated growth from resp specimans should not prompt therapy in most patents

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10
Q

If asymptomatic candiduria

A

Change catheter

Treat IF candiurai persistss OR high risk patient

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11
Q

If candidaemia

A

Change line, send tip for MC&S
Early line removal –> better outcomes in non-immunocompromised

C.parapsilsos forms biofilms so if isolated - do not re-wire

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12
Q

Prognosis of candidaemia

A

Mortality 40-63%

Early tx - better prognosis

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13
Q

What is Aspergillus

A

Spore forming moulds found in soil

Only a few species are harmful

Aspergillus fumigatus, followed by aspergillus niger

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14
Q

Commonest site of infection for aspergillus

A

lung

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15
Q

What is an aspergilloma

A

a fungal ball,

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16
Q

How does asperigillus pneumonia present

A

Fever, cough, dypnoea, pleuritic pain, haemoptysis

PCR to detect fungal DNA
Galactomannan is present in the cell wall of aspergillus from blood and BAL

17
Q

Classifications of antifungals

A

Polyenes
Azoles
Echinocandins

18
Q

Example of polyene

A

Amphotericin B

19
Q

Example of Azole

A

Fluconazole
Itraconazole
Voriconazole

20
Q

Example of Echinocandins

A

Caspofungin

21
Q

How does amportercin work

A

Fungicide polyene
Binds ergosterol in fungal cell wall –> death

Dose limiting nephrotoxic
Broad spec
Fever chills and rigours common

22
Q

How does fluconazole work

A

Fungistatic azole (inhibits ergosterol synthesis)
Active against candida but NOT aspergillus
Some non-albicans species are resistant

100% bioavailabiltiy
Prolongs QT

23
Q

How does caspofungin work

A

Echinocandin

Inhibit cell wall glucan synthesis - fungicidal for candida, fungistatic for aspergilllus

IV only

Good side effect profile

Synergistic with polyenes (amph B)

24
Q

What is voriconazole active for

A

All candida species

First lone for invasive aspergillus

25
Q

Treatment of candidiasis

A

Fluconazole

26
Q

Non ablican candida

A

Amphotericin

27
Q

Aspergillus

A

Voriconazole
Amphortericin
Both

28
Q

Cryptococcus

A

Amphortericin and flucytosine

29
Q

PCP

A

Septrin and steroid
Petamidine

2nd line
Primaquine, atovaquone, clindamycin