9/11- Pulmonary Infections Flashcards Preview

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Flashcards in 9/11- Pulmonary Infections Deck (43)
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What are high risk groups for TB? What is considered positive on a tuberculin skin test (TST)?

- HIV or immunosuppressed

- Close contact of TB pt

- Abnormal CXR

Positive > 5mm


What are moderate risk groups for TB? What is considered positive on a tuberculin skin test (TST)?

- Recently infected (under 2 yrs) = recent converter

- High risk medical conditions: DM, cancer of head/neck, lung, organ transplant

Positive > 10 mm


What are low risk groups for TB? What is considered positive on a tuberculin skin test (TST)?

None of the other conditions (HIV/immunosuppressed, close contact, abnromal CXR, high risk medical conditions like DM, cancer, organ transplant...)

Positive > 15 mm


What is the natural history/course of LTBI in an HIV negative pt?

- No further problem with no evidence of active disease (90%)

- Primary infection is not well contained and active disease develops within 2 years (lower lobe, hilar, pleural) (5%)

- "Reactivation of previously contained, dormant TB (usually > 2 years after primary infection (5%)


What is the natural history/course of LTBI in an HIV pt?

Risk for active TB: 7-10% per year


Treatment of LTBI?

- Standard therapy: 4 first line drugs

---- Intensive phase = RIPE (Rifampin, Isoniazid, Pyrazinamide, Ethambutol) for 2 mo

----- Continuation phase = RI for 4 mo

- Provide safest, most effective therapy in shortest time: decrease infectivity, morbidity mortality

- Adherence to therapy- DOT, in all

- Major determinant of outcome is adherence and completion

- Children treated same as adults

- Extrapulmonary TB treated the same

- Contact investigation = key to dz prevention (pic 2)


What are risks for active TB?

- Previously untreated TB (stable, fibrotic pulmonary lesion)


- Silicosis

- Use of anti-TNF, chronic steroids

- Malignancy – head and neck, lung

- Chronic renal failure

- Diabetes mellitus

- Alcoholism

- Active smoker

- Malnutrition

- Post gastrectomy


Characteristics of primary TB (pathologically/anatomically)?

- Lower lobe involvement

- Pneumonic pattern

- Hilar LAD

- Pleural effusion


Characteristics of reactivation TB (who gets it, sites, anatomy)

- Majority of pts with active TB

- Endogenous reactivation of latent infection

- Occurs in sites that were disseminated during the primary infection

- Most common site = apical posterior segment of lung (80%)


What clinical features aid in the diagnosis of TB?

- Risk factors for exposure

- Signs and symptoms: usually chronic (wks - mos) and non-specific

Pulmonary Sx:

- Persistant cough

- Hemoptysis

- Dyspnea

Systemic Sx:

- Malaise, fatigue

- Fever

- Weight loss, anorexia

- Night sweats


How can the microbiologic diagnosis be made for TB?

Acid fast stain: Ziehl Neelsen or auramine fluorescence

- Three sputum specimens ~50% positive

- Culture: 2-6 weeks

- Drug susceptibility: 1-2 weeks

Molecular technology

- Nucleic acid amplification – PCR based

- Drug susceptibility – detect gene mutation


How can therapy be monitored?

Monthly sputum culture until negative

- 80% are culture negative in 2 months

- If positive > 2 months, repeat susceptibility

Serial CXR are not recommended

- End of treatment CXR – future comparison

Clinical evaluation monthly

- Adverse reactions and adherence to therapy

Treat co-morbidity – DM, COPD, HIV

Supportive environment



- Emerging threats to global TB control

- Treatment of LTBI – important role in TB elimination

- Clinical presentation of TB is varied

- Close clinical follow up and partnership with public health department – ensure completion of treatment

- Clinical manifestations of pneumonia are non-specific

- Epidemiologic factors are useful in narrowing the possible etiologic agents

- Treatment should be directed to the most likely pathogen(s) and initiated without delay

- Clinical features that predict mortality help guide decision for hospitalization