Tuberculosis and pulmonary nodules

Question 1

Who is TB likely to affect and what is the effect of the bacille Calmette Guerin (BCG) vaccine

Answer 1

Recent immigrants, this vaccine has no effect on them and no effect on treatment recommendations for latent tuberculosis infection

Question 2

Who are at particular risk for TB

Answer 2

Recent immigrants, prisoners, healthcare workers, HIV people, steroid use, diabetes, and alcoholics

Question 3

What are common symptoms of TB

Answer 3

Fever, cough, sputum, weight loss, hemoptysis, and night sweats

Question 4

What is the best initial and most accurate TB test

Answer 4

Initial: CXR showing a cavity with scarring (white spot - pic page 153)

Best test: Pleural biopsy

Pearl: sputum stain and culture for acid fast bacilli must be done 3 times to fully exclude TB

Question 5

What is the treatment for TB

Answer 5

First check if smear if positive

If positive, begin rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE therapy) initially until sensitivity is obtained or for first two months. After two months, only continue rifampin and isoniazid for next 4 months, for a total of 6 months

Pearl: treat for 9 months if other problems, such as osteomyelitis, miliary tuberculosis, meningitis, or pregnancy

Question 6

The four drugs in tuberculosis are rifampin, isoniazid, pyrazinamide, and ethambutol. What are the side effects of each

Answer 6

1. ) Rifampin: Red color secretions
2. ) Isoniazid: Peripheral neuropathy - use pyridoxine to prevent
3. ) Pyrazinamide: Hyperuricemia, DO NOT GIVE IF PREGNANT
4. ) Ethambutol: Optic neuritis/color vision - decrease dose in renal failure

All cause hepatotoxicity, do not stop because of this unless transaminases rise to 3x-5x of normal

Question 7

What is the role of steroids in the treatment of TB

Answer 7

Should use them because they decrease the risk of constrictive pericarditis and the neurologic complication in TB meningitis

Question 8

When should PPD testing be done and when should it not be done

Answer 8

Do in high risk groups, not for everyone

But do not do if already symptomatic or abnormal chest X-ray, instead do sputum acid fast testing

Question 9

PPD criteria listed on page 155

Answer 9

YEAH!

Question 10

Why is two tests done for PPD

Answer 10

1. ) If they’ve never had a PPD skin test before, a second test must be done because the first test can be falsely negative. If second test negative, then truly negative. Otherwise if second positive test then first test was a false negative.
2. ) Once PPD positive, will always be positive in future
3. ) If first test positive, do not do second test

Question 11

What is the next steps after PPD test is positive

Answer 11

Go to chest x-ray, if negative then no active tuberculosis, but still have to receive 9 months of isoniazid

Question 12

Pulmonary nodules appear all the times and can be benign or malignant. What classifies a nodule as malignant

Answer 12

Over 40 years old, getting bigger, spiculated and over 2cm, person is a smoker, has eccentric calcification (vs. central in benign) and an abnormal PET scan - better to biopsy if malignant

Question 13

What is the first thing you must do if you discover a pulmonary nodule

Answer 13

Compare the nodule with previous x-rays

Question 14

If a pulmonary nodule does fit most of the malignant criteria, what must you do for management

Answer 14

Resect

Question 15

For intermediate probability nodules (some benign and malignant aspects) what are the options (four things)

Answer 15

1. ) Sputum cytology - if positive then highly specific and must resect
2. ) Bronchoscopy/Transthoracic needle biopsy - if central then do bronchoscopy, if peripheral then do TNB - side effect = pneumothorax for TNB
3. ) PET - can tell malignancy without biopsy by measuring glucose uptake
4. ) Video assiststed thoracic surgery - do this, get frozen section, and if malignant then can convert to open surgery - more accurate than all the previous tests