Difference between revisions of "Tuberculosis"

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**Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
 
**Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
 
***PPD positive
 
***PPD positive
*Reactivation and active TB
+
*Reactivation Infection
 
**More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
 
**More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
 
+
*Check HIV in pts suspected of TB
 +
*Peds
 +
**More likely to progress early to active disease
 +
***Presentation more commonly that of primary TB
 +
**>5yr - classic symptoms
 +
**<5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that does not respond to abx
 +
**Children are usually not infectious due to their weak cough
 
==Diagnosis==
 
==Diagnosis==
 
===Clinical Features===
 
===Clinical Features===
Line 37: Line 43:
 
**Upper lobe or hilar nodules and fibrotic lesions
 
**Upper lobe or hilar nodules and fibrotic lesions
 
**Ghon foci, areas of scarring, calcification
 
**Ghon foci, areas of scarring, calcification
 
+
*HIV pts less likely to have classic lesions and may have normal CXR
==Treatment==
 
 
 
 
 
==Consequences==
 
 
 
 
 
 
 
- xmission influenced by source criteria- number of bacteria excreted and nature of encounter
 
 
 
- infc by 1- 5 bacteria in terminal alveolus
 
 
 
- primary tb usually mild and self limited- often undiagnosed- bacteria seed other organs for subsequent reactivation later
 
 
 
- most active tb is from latent reactivation buy and also be from infc by second strain of tb- esp if immune compromised or heavy exposure to new bacilli
 
 
 
- classic sxs- fvr, sweats, anorexia, wt loss, weakness
 
 
 
- organ specific sxs- pulm- cough, CP, hemoptysis
 
 
 
primary tb cxr shows infc in mid to lower lungs with lymphadenopathy- reactivation is upper lobe cavitations
 
 
 
- signs and sxs more vaied if hiv
 
 
 
- lung most common site, but also lymph nodes, pleura, bone, joints. also gu, cns, abd, pericardium
 
 
 
 
 
 
 
==Treatment==
 
==Treatment==
reportable in all states
+
===Active TB===
 
+
*Isoniazid + rifampin + pyrazinamide + ethambutol x8wk followed by INH/RIF x18wk
Anti TB Drugs
+
**2 drug continuation tx x 18-31wk
 
+
===Latent TB===
- 5 first line drugs
+
*Consider treatment for:
 
+
**Recent conversion to PPD-positive
- second line drugs are less effective or more toxic- only use if pt cannot tolerate first line or resis
+
**Persons in close contact w/ individual w/ active TB
 
+
**Isoniazid x9mo
 
 
 
==Adverse Effects==
 
 
 
 
 
INH- hepatitis, neuropathy, cns effects, elevated dilantin lvl, antabuse interaction, give with vit B6
 
 
 
Rif- fvr, low platelets, reduces blood levels of other drugs, caused orange urine
 
 
 
PZA- hyperuricemia
 
 
 
Ethambutol- color discrimination, visual acuity, optic neuritis
 
 
 
Strep- auditory and renal dysfnctn
 
 
 
 
 
 
==Current Recs==
 
 
 
 
 
- always use INH for duration of tx- effective, low cost, tolerable- if not mixed with rifampin- go 18 mo
 
 
 
- if double with INH/ rif- 9 mo for cure
 
 
 
- if triple with inh/ rif/ pza (pza for first 2 mo) shorten lenght to 6 mo
 
 
 
- try 3-4 meds initially and then 2 drugs afterwards
 
 
 
- consider local patterns of resis and schedule of administration likely to ensure adherance
 
 
 
- direct observation helps ensure compliance
 
 
 
- most common regimen- ihn/rif/pza for 8 wks, inh/rif for 16 wks with freq direct observation, and add ethambutol or streptomycin until susceptibility documented
 
 
 
- if cx ned, stop p 2 mo of inh/rif
 
 
 
- noncompliance not related to race, gender, education....cdc rec direct observation, and rewards
 
 
 
- get cxs- helps with resis
 
 
 
- baseline lfts, creatinine,cbc
 
 
 
- if use pza- check uric acid
 
 
 
- if use ethambutol- check vision and red/green color perception
 
 
 
- baseline cxr
 
 
 
- if cx neg, go by sxs and cxr at 3 mo
 
 
 
- sputum cx going from pos to neg - objective tx success- should change in 2 mo
 
 
 
- if longer than 3 mo, consider nonadherence, malabsorption, resis
 
 
 
- can also test urine for color in rif, urate in pza
 
 
 
- cx sputum at end of tx to document cure
 
 
 
 
 
 
==HIV Pts==
 
 
 
 
 
- hiv pt who adhere to standard tx do not have increased tx failure
 
 
 
- tx 6 mo- longer if slow response
 
 
 
- protease inhibitors and NNRT inhibitors mixed with rif cause rif toxicity and low levels of PI and NNRTI- avoid by using rifabutin
 
 
 
- do not use PI ritonivir or NNRTI delavirdine with rifabutin
 
 
 
 
 
 
==Extrapulm TB==
 
 
 
 
 
- since fewer bacilli in extrapulm site and good tissue penetration of drugs, tx should be no more difficult
 
 
 
- use regular 6 mo regimen
 
 
 
- 12 mo for meningitis in kids, bone/ joint or miliary tb
 
 
 
 
 
 
==Drug Resis==
 
 
 
 
 
- inh resis tx with rif, pza, ethambutol for 6 mo
 
 
 
- rif resis- inh, ethm for 18 mo or inh, pza, strep for 9 mo
 
 
 
- mulitidrug resis- resis to inh and rif- curable even in poor countries
 
 
 
 
 
 
==Management of Latent TB==
 
 
 
 
 
- test for tb only in high risk pt and those who will benefit from tx.
 
 
 
- if test low risk population- will get too many false postives
 
 
 
- test hiv pt, immigrants, homeless, long term care residents, health workers
 
 
 
- those at risk for progression from latent to active dz are immune suppressed ore recently exposed to infectious tb- highest rate of progression is from pt with both hiv and tb- also dm, crf, CA, organ xplant, ivda,
 
 
 
- silicosis, abnormal cxr, too thin person also indication for testing
 
 
 
 
 
 
==TB Skin Test==
 
 
 
 
 
- PPD is gold standard for latent tb testing- intradermal not multipronged
 
 
 
- measure induration not redness 48- 72 hrs
 
 
 
- 5 mm- positve if pt with weak immune response- hiv, steroid use, recent exposure and body hasn't had time to mount immune response, abnormal cxr
 
 
 
- 15 mm- positive if low risk pt
 
 
 
- 10 mm- all other pts
 
 
 
- if long standing infc, may actually have neg test initially- if give second skin test will be positve since first test reinvigorated immune sys- so if pt needs serial testing- do second test in 2 wks- called 2 Step Testing- if second postive represents long standing infc not recent infection
 
 
 
- ppd will not cause 10 mm induration in uninfected pt ever
 
 
 
 
 
 
==BCG==
 
 
 
 
 
- not recommended in US but used elsewhere
 
 
 
- size and persistence of tb reaction p bcg vary with bcg dose and manufacturer
 
 
 
- CDC rec ignoring hx of bcg when giving and interpreting ppd test since bcg only givien in high risk populations in first place
 
 
 
- anergy testing not recommended in tb testing of hiv pt since results highly variable and not reproducible.
 
 
 
 
 
 
==Latent Tx/ PPD + Tx==
 
- 9 mo inh if no hiv and neg cxr. 12 mo better but less compliance and more cost
 
 
 
- 9 mo ihn if hiv + or pos cxr or age <18yr
 
 
 
- can also do 2 mo of rif and pza or 4 mo of rif alone
 
 
 
- baseline labs if hiv +, preg, etoh, liver dz
 
 
 
- if duration of tx interrupted, add on additional 3 mo of inh. If lapse is greater than 3 mo, restart whole tx
 
 
 
- if previously tx pt reexposed to tb, repeat tx not recommended
 
  
 +
==Disposition==
 +
*Discharge
 +
**Otherwise healthy
 +
***Contact public health services before discharge
 +
****Instructions for home isolation and f/u at appropriate clinic to receive meds
 +
***Do not start TB meds in ED unless specifically instructed by public health
 +
*Admit
 +
**Ill-appearing
 +
**Diagnosis is uncertain
 +
**Pt is noncompliant
  
 
[[Category:ID]]
 
[[Category:ID]]
 
[[Category:Pulm]]
 
[[Category:Pulm]]

Revision as of 02:59, 24 July 2011

Background

  • >1/3 of world's population is infected
  • Primary Infection
    • Usually contained by body via formation of tubercles
    • Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
      • PPD positive
  • Reactivation Infection
    • More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
  • Check HIV in pts suspected of TB
  • Peds
    • More likely to progress early to active disease
      • Presentation more commonly that of primary TB
    • >5yr - classic symptoms
    • <5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that does not respond to abx
    • Children are usually not infectious due to their weak cough

Diagnosis

Clinical Features

Primary Tuberculosis

  • Usually asymptomatic (only identified by positive PPD)
  • May be rapidly progressive and fatal in immunocompromised pts
    • Fever, malaise, wt loss, chest pain
  • Tuberculous pleural effusion may occur if subpleural node ruptures into the pleura
    • Pleuritic chest pain
    • Exudative fluid
      • Organisms may not be visible on acid-fast staining (need pleural biopsy)

Reactivation Tuberculosis

    • Pulmonary: Productive cough, hemoptysis, dyspnea, pleuritic chest pain
    • Systemic: Fever, night sweats, malaise, fatigue, wt loss
    • Extrapulmonary
      • Lymphadenopathy (painless)
      • Pericarditis
      • Meningitis
      • Adrenal insufficiency
      • Arthritis
      • Osteomyelitis

CXR

  • Primary infection
    • Infiltrates in any area of the lung
    • Isolated hilar or mediastinal adenopathy may be only finding
  • Reactivation infection
    • cavitary/noncavitary lesions in upper lobe or superior segment of lower lobe
  • Latent infection
    • Upper lobe or hilar nodules and fibrotic lesions
    • Ghon foci, areas of scarring, calcification
  • HIV pts less likely to have classic lesions and may have normal CXR

Treatment

Active TB

  • Isoniazid + rifampin + pyrazinamide + ethambutol x8wk followed by INH/RIF x18wk
    • 2 drug continuation tx x 18-31wk

Latent TB

  • Consider treatment for:
    • Recent conversion to PPD-positive
    • Persons in close contact w/ individual w/ active TB
    • Isoniazid x9mo

Disposition

  • Discharge
    • Otherwise healthy
      • Contact public health services before discharge
        • Instructions for home isolation and f/u at appropriate clinic to receive meds
      • Do not start TB meds in ED unless specifically instructed by public health
  • Admit
    • Ill-appearing
    • Diagnosis is uncertain
    • Pt is noncompliant