Pulmonary OI Flashcards
When is immediate empirical PCP therapy not indicated?
If CD4<200 effort should be made to confirm a specific diagnosis
Predictive factors for PCP
90% of cases if CD4 <200 or <14%
Not on ART
Not adherent to prophylaxis
Oral candidiasis
OHL
Weight loss
Recurrent bacterial pneumonia
Previous PCP
High plasma HIV VL
Presentation of PCP
Exertional dyspnoea progressing over several weeks
Malaise
Dry cough
Inability to take a deep breath
Fever
Physical exam findings in PCP
Tachyonoea
Normal breath sounds of end exp crackles (less common)
What should be considered if HIV positive individual has spontaneous or infection induced pneumothorax?
PCP
CXR findings in PCP
Perihilar haze, interstitial infiltrates sparing apices and costophrenic angles, pneumatoceles, pneumothoraces
Normal in up to 39%
How to diagnose PCP?
Microbiological investigations required to confirm
Induced sputum if available send 50-90%
If not, negative or inconclusive assess for BAL sensitivity >90%
Open lung biopsy more sensitive but reserved for occasional patient with negative initial tests and no improvement
When should lung biopsy be considered in PCP?
Occasional patients with negative initial test and not improving on empirical treatment
Can spontaneously expectorated sputum be used in PCP diagnosis?
No, not an adequate alveolar sample
How is pneumocystis jirovercii diagnosed from samples?
Can’t be cultured in vitro
Visualisation of organism using silver stains or immunoflourescent stains
NAAT increased sensitivity but decreased specificity compared to stains
How long after starting PCP therapy can adequate pulmonary samples for PCP be gained?
7-10 days
Criteria for mild PCP
Dyspnoea on exertion +/- cough and sweats
PaO2 > 11
Sats at rest on air >96
Normal or minor perihilar shadowing on CXR
Criteria for moderate PCR
Dyspnoea on minimal exertion and occasionally at rest, cough and fever +/- sweats
PaO2 8.1-11.0
Sats 91-96
Cxr - diffuse interstitial shadowing
Criteria for severe PCP
Dyspnoea and tachypnoea at rest, fever and cough
PaO2 <8
Sats <91
Cxr - extensive interstitial shadowing with or without diffuse alveolar shadowing
Treatment categories for PCP
Mod-severe - PaO2 <9.3
Mild >9.3
How effective is septrin for PCP?
70% in more severe cases
90% in mild disease
Treatment for moderate/severe PCP
PaO2 <9.3
Septrin 120mg/kg/day for 3/7
Reduce to 90mg/kg/day for 18/7
IV preferred for severe disease
Reducing dose reduces risks of adverse effects
Treatment for mild PCP
Either oral septrin 1920mg TDS or 90mg/kg/day tds
Or IV regime as per severe (120mg/kg/day 3/7 and 90/mg/kg/day 18/7)
Use of prednisone in PCP
PaO2 <9.3 or sats <92 reducing course
Day 1-5 40mg BD
6-10 40mg OD
11-21 20mg OD
If unable to take orally methylpred at 75% of dose
Start within 72hrs of anti PCP tx
Resistance to Sulphamethoxazole
DHPS mutations associated with long term septrin prophylaxis
Decreasing now we have ARVs and therefore less use of prophylaxis
Salvage treatment for severe PCP
Failure occurs after at least 5/7
Occurs in up to 1/3
Severe - clindamycin 600-900mg qds/tds iv or 300-450mg qds/tds PO and primaquine 15-30mg od PO or pentamidine 4mg/kg od iv for 21/7
Clindamycin less toxicity than pentamidine
Mild-mod - if septrin not tolerated trimethoprim 20mg/kg/day and dapsone 109mg OD PO for 21/7 or atovaquone liquid 750mg BD for 21/7
What to do in mild-mod disease if septrin not tolerated
trimethoprim 20mg/kg/day and dapsone 109mg OD PO for 21/7 or atovaquone liquid 750mg BD for 21/7
When should G6PD levels be checked in context of PCP?
Before or as soon after starting tx with dapsone, primaquine, High dose sulphamethoxazole
Treatment shouldn’t be delayed while awaiting result.
Who is at risk of G6PD deficiency?
Classified by level of RBC enzyme activity
Common in patients of African origin
Also some Mediterranean populations, Sephardic Jews, certain Chinese population
Which drugs trigger harmony saus in G6PD deficient patients?
Oxidant drugs - dapsone, primaquine, high level sulphamethoxazole
Options for deteriorating PCP patient?
Early ITU review
CPAP early if hypoxic but not hypercapnic
Mechanical ventilation if needed for those who deteriorate early in tx or have good premorbid state
Who should have PCP prophylaxis?
All HIV patients with CD4 <200 or <14%, or oral candidiasis, or previous aids defining illness