Pneumocystis jirovecii pneumonia: Difference between revisions

Revision as of 22:34, 28 November 2011

Background

Most common opportunistic infection among AIDS pts
Most common identifiable cause of death
Risk factors:
- CD4 < 200
- Immunosuppressive medications
- Cancer
- Primary immunodeficiencies
- Severe malnutrition

Clinical Features

Fever (62%)
Dry cough
Shortness of breath (progressive from exertion only to at rest)

Diagnosis

Imaging
- CXR
  - Normal in 25% of cases
  - Diffuse, interstitial infiltrates
- CT Chest
  - Sn 100%, Sp 89%
  - May see ground glass infiltrative pattern
Labs
- LDH
  - Low Sn, Sp
- ABG
  - Hypoxemia, increased A-a gradient

Work-Up

CBC
Chemistry
LDH
ABG
CD4 count
CXR
A-a gradient
- P(A-a)O2 = 145 – PaCO2 – PaO2 (normal is <10 in young, healthy pts)

DDX

Dyspnea (SOB)

Treatment

Abx
- TMP-SMX PO or IV
  - Consider IV for:
    - Severe respiratory distress
    - A-a gradient > 45mmHg OR PaO2 < 60mmHg
  - 2 DS tabs PO TID OR 15-20mg TMP IV in divided doses q6-8hr
Steroids
- Indicated for:
  - A-a gradient >35mmHg
  - PaO2 <70mmHg
- Prednisone 40 mg PO BID x5d followed by 21d taper

Disposition

Symptoms usually worsen 2-3d after start of treatment
Pts w/ disease severe enough to warrant IV therapy or steroids should be admitted

Source

Uptodate
Rosen
Tintinalli

Authors:

@@ Line 1: / Line 1: @@
 == Background ==
-*Thought to be caused by opportunistic protozoan vs. fungal infection seen most commonly in immunocompromised patients
+*Most common opportunistic infection among AIDS pts
-**Risk factors: CD4 count < 200, immunosuppressive medications, cancer, primary immunodeficiencies, severe malnutrition
+*Most common identifiable cause of death
+*Risk factors:
+**CD4 < 200
+**Immunosuppressive medications
+**Cancer
+**Primary immunodeficiencies
+**Severe malnutrition
 == Clinical Features ==
-*Non-HIV infected patients tend to present with fever, dry cough, and respiratory failure
+*Fever (62%)
-*HIV infected patients commonly present with dry cough, weakness, and chest pain lasting > 2 weeks
+*Dry cough
-*Fever - 62%
+*Shortness of breath (progressive from exertion only to at rest)
-*Crackles - 50%
-*High percentage of normal physical exams
 == Diagnosis ==
-*Chest X-ray
+*Imaging
-**Can be normal in 25% of cases
+**CXR
-**May see asymmetry, cysts, nodules, bullae, or pleural effusions
+***Normal in 25% of cases
-*CT Chest
+***Diffuse, interstitial infiltrates
-**High sensitivity ~ 100%
+**CT Chest
-**Specificity 89%
+***Sn 100%, Sp 89%
-**May see ground glass infiltrative pattern
+***May see ground glass infiltrative pattern
-*Lactate dehydrogenase level
+*Labs
-**Suggestive of PCP
+**LDH
-**may be used as prognostic indicator
+***Low Sn, Sp
-*Immunofluorescent antibody staining
+**ABG
-**Staining of sputum samples yields 100% specificity, but 50-90% sensitivity
+***Hypoxemia, increased A-a gradient
-**Staining of bronchoalveolar lavage samples has 97% diagnostic yield
 == Work-Up ==
 *CBC
-*Complete Metabolic Panel
+*Chemistry
-*Lactate dehydrogenase
+*LDH
-*Arterial blood gas
+*ABG
-*CD 4 count
+*CD4 count
-*Chest x-ray
+*CXR
-*Alveolar-arterial gradient
+*A-a gradient
 **P(A-a)O2 = 145 – PaCO2 – PaO2 (normal is <10 in young, healthy pts)
 == DDX ==
-*See [[Dyspnea (SOB)]]
+*[[Dyspnea (SOB)]]
 == Treatment ==
-*Trimethoprim-Sulfamethoxazole
+*Abx
-**Oral/intravenous regimen: Trimethoprim 20 mg/kg/day + Sulfamethoxazole 75 mg/kg/day divided bid-tid x21 days
+**TMP-SMX PO or IV
-***Average adult - Bactrim DS 2 tabs PO q8hrs
+***Consider IV for:
-**Consider intravenous regimen for:
+****Severe respiratory distress
-***Severe respiratory distress
+****A-a gradient > 45mmHg OR PaO2 < 60mmHg
-***A-a gradient above 45 mm Hg
+***2 DS tabs PO TID OR 15-20mg TMP IV in divided doses q6-8hr
-***PaO2 < 60 mm Hg
 *Steroids
-**Oral regimen: Prednisone 40 mg PO BID x5 days with taper
 **Indicated for:
-***A-a gradient above 35 mm Hg
+***A-a gradient >35mmHg
-***PaO2 < 70 mm Hg
+***PaO2 <70mmHg
-*Other regimens
+**Prednisone 40 mg PO BID x5d followed by 21d taper
-**Pentamidine (IV)
-***Side effects: renal failure, hypoglycemia, hypotension, induction of diabetes
-**Clindamycin + primaquine (IV/PO)
-***Caution when using primaquine in patients with G6P deficiency
-**Atovaquone (PO)
-***Indicated only in mild cases of PCP
-**Dapsone + TMP (PO)
-***Caution when using dapsone in patients with G6P deficiency
 == Disposition ==
-*Symptoms usually worsen after 2-3 days of treatment
+*Symptoms usually worsen 2-3d after start of treatment
-*Patients with disease severe enough to warrant IV therapy or corticosteroids should be admitted for close monitoring
+*Pts w/ disease severe enough to warrant IV therapy or steroids should be admitted
 == Source ==
 *Uptodate
 *Rosen
+*Tintinalli
 [[Category:ID]]