Term
You suspect a patient has TB and you run an acid-fast stain that comes back positive.
How do you confirm? |
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Definition
Remember, CLINICAL SUSPICION IS KEY
1) Traditional TB culture (4-6 weeks in special lab with >90% sensitivity and gold standard for specificity) followed by Niacin test to confirm.
2) Automated Liquid Culture- 9-10 days for + specimens and 16 days for - specimens and susceptibilities (confirm with DNA probe).
3) Direct PCR is easier to do (2 hours) and is extremely quick, but is WEAK for SMEAR - specimens. |
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Term
| What is the standard treatment regimen for TB? |
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Definition
6 Month total: 4 drugs (avoid resistance) given for 2 months, then INH + RIF for 4 more months.
1) Isoniazid (INH)
2) Rifampin (RIF)
3) Ethambutal (ETH)- cover against resistance
4) Pyrazinamide (PZA)- bactericidal |
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Term
| What is the most common reason for treatment failure for TB? |
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Definition
| Failure to complete 6 month, 4 drug regiment. |
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Term
| Which Drug against TB is most prone to resistance? |
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Definition
ETH.
INH and STR about the same
RIF is least susceptible. |
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Term
| Why is Directly Observed Therapy critical for TB treatment? |
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Definition
TB often occurs in people with socioeconomic factors, addictions, language barriers, ect. that make them less likely to be compliant with 4 drug treatment.
COMPLIANCE IS THE ISSUE. |
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Term
| Why is it important to track liver enzyme levels during TB treatment? |
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Definition
Anti-TB drug-induced Hepatotxicity (PZA>INH>RIF)
- 20% of patients have asymptomatic increases is ALT/AST
- 1-2% develop hepatotoxicity (ALT>5x UNL or >3X UNL with symptoms) |
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Term
| Which drugs are most likely to cause Hepatotoxicity in TB treatment? |
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Definition
| Pyrazinamide> Isoniazid> Rifampin |
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Term
| What are the primary risk factors associated with drug-induced TB hepatotoxicity? |
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Definition
Older females who are immunocompromised, alcoholics or who are slow acetylators of INH
1) Older age
2) Female
3) HIV/AIDS
4) Alcohol use
5) Slow acetylator of INH |
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Term
| How do you manage a patient with mostly treated TB if there are hepatotoxicity issues? |
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Definition
1) Stop the hepatotoxic drugs (PZA/IMH/RIF)
2) Can stop ETH/ add 2 non-hepatotoxic drugs (i.e. Cipro and Amikacin)
3) If liver gets better, might consider re-starting Rifampin, then perhaps INH. |
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Term
| If an older patient with a history of alcohol use presents with cachexia, pleural effusion and dyspnea, how might you proceed initially? |
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Definition
Sounds like TB so get an X-ray/CT
- If it looks like TB in the lungs, get an Acid-Fast stain
- Cell wall of mycobacteria is waxy and will take up dye but not de-colarize under acid wash.
WONT GIVE YOU SPECIES. |
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Term
| What is the general course a presenting TB case will take in a hospital? |
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Definition
1) See a patient with risk factors (Diabetes, COPD, Silicsis, Chronic renal failure, ect) that is cachexic and experiencing dyspnea
2) Get an X-ray and CT and look for lung infiltrates
3) Get an Acid-Fast mycobacteria test
4) Confirm with Automated liquid culture or PCR
5) Treat with PZA/INH/RIF/ETH for 2 months and then INH/RIF for 4 months
6) Check for hepatotoxicity, and if you see it, replace PZA/INH/RIF with Amikicin/Cipro for a while. |
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Term
| What should you do with a patient with expected TB FIRST? |
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Definition
| Get them in negative-pressure isolation under droplet precaution. |
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Term
| Where does primary TB take place? |
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Definition
| Large airborne droplets containing bacilli bypass protective cilia in respiratory tract and end up in alveoli of upper lobe (often asymptomatic). |
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