TB Flashcards
TB pathogen
Mycobacterium tuberculosis
anaerobic bacillus
how many resistant strains are there for TB?
2
Multidrug-resistant (MDR)
Extensively drug-resistant (XDR)
Top 4 TB countries
china, inida, philippines, vietnam
how is TB transmitted?
inhaling aeroslized droplets containg it
TB presentation
fever, night sweats, cough, HEMOPTYSIS, WT LOSS, sometimes pleuritic chest pain
similar to cancer
How long does it take for TB to come out of hiding in macrophages and trigger an immune response
same amnt of time to wait for (+) test
2-12 wks
How to Dx TB
PPD skin welt test
purified protein derivative
do you measure the redness or bump for TB skin test?
BUMP
Single positive PPD is not helpful diagnostically. Must have _____to confirm diagnosis.
CXR
Rx for TB
- RIPE =
- Rifampin
- Isoniazid (INH)
- Pyrazinamide (PZA)
- Ethambutol (EMB)
ALL 3 TIMES A WEEK FOR 6 MONTHS
FORCE PPL TO COME IN AND TAKE MEDS IN FRONT OF US
Does a (-) PPD rule out acute TB?
NOOOOOOO
gold standard for dx of active disease?
Sputum for AFB stains
acid-fast bacillus
Work up for TB
- PPD skin test for latent dz
- CXR will likely be norm in latent dz
- Sputum for AFB (gold standard)
Criteria of a (+) PPD skin test?
5mm -> if HIV
10mm -> if high-risk grp
15mm -> if low risk
read 72 hrs later
Will CXR show anything if not showing symptoms?
likely not. more used as a dx criteria for symptomatic pts
TB CXR looks like what?
Apical cavitation with calcification and hilar lymphadenopathy
What does TB look like when its healed?
Pt has Hx of TB and their CXR shows bullae. What’s happening
Reactivation of TB
Rx CAUTIONS
RIPE
Rifampin: Red urine, jaundice
Ethmabutol: Eye, vision loss, photosensitivity
Isoniazid (INH): Hepatitis, neuropathy (take B6 to prevent neuropathy)
Pyrazinamide: Hepatitis
TB Trmnt for immunocomp (HIV)
9 months total therapy =
- 2 months RIPE daily until smear negative and sensitivity confirmed
- then INH and rifampin qid for 7 months
Continue all treatment at least 3 months following conversion to negative cultures
Trmnt for latent TB or asymp contact prevention
WU: (+) skin test, (-) CXR and/or sputum
highest risk in immunocomp (think HIV)
3 trmnt opts (choose one):
- 9 mo INH
- 4 mo Rifampin
- 3 mo INH + Rifampin
Billman updated trmnt options after test 1
Trmnt for ACTIVE TB
WU: (+) skin test AND (+)CXR or Sputum required
Norm: RIPE 3x a week for 6 months
Immunocomp: RIPE 4x a day for 2 months, then when CXR (-) -> INH + Rifampin for 7 months
FU for TB
- Will have visits 3 times a week for witnessed medication taking x 6 months
- At 2 to 4 weeks, sputum culture, assess for lack of recent fevers
- At 2-3 months confirm chest x-ray regression
Pts predisposed to neuropathy (ex. alcoholics, DM, uremia, malnutrition, and HIV) taking Isoniazid (INH) should also be taking _____
Pyridoxine (Vit B6) supplements
TB is a ____ mediated immune response
T-Cell
TB Pathophysiology
Aersolized droplets inhaled -> macrophages try to phagocytose mycobacterium -> forms into caseating granuloma (cheese center) -> macrophages get stuck in hilar lymph nodes (hilar lymphadenopathy on CXR) -> cavitates into lung -> eventually breaks free from granuloma and runs wild in your body -> body finally recognizes the foreign antingens -> immune response -> symptoms show -> (+) skin test
whole thing can take about 12 weeks long
is TB caseating or non-caseating?
Caseating granuloma (cheese curd center of yuck)
Pleural effusions in TB are exudative or transudative?
exudative bc infection
