1247 TB

TB Causative Organism

Mycobacterium Tuberculosis
gram positive, acid fast bacillus

Why is there a resurgence of TB currently?

antibiotic resistant bacteria have developed and antibiotic treatemnt courses are lengthy and difficult

How is TB transmitted?

Ariborne droplets from coughing, speaking, sneezing, and singing

Pts can show TB symptoms _____________ after exposure, and so need to be tested several times

2-13 weeks

About Mycobacterium Tuberculosis
-______philic
-has an affinity for ______
-spreads via______ to ______, _____, _____, and _____

-aerophilic
-lungs
-spreads via lymphatic system to kidneys, bone epiphyses, cerebral cortex, and adrenal glands

How doe TB remain dormant? what is the name for dormant TB?

inflammatory response forms "wall" around organism along with macrophages & other cells to form granulomas, which inhibit replication and spread. Body has the ability to "wall it off" and prevent it from becoming active; eventually becomes calcified mass

What percentage of adults are able to fight off TB infection?

70%

What percentage of those with latent TB go on to develop active infection later?

5-10%

Does TB replicate slowly or quickly?

slowly

Once TB enters lungs, where does it lodge?

alveoli

How long can Mycobacterium nuclei remain airborne?

minutes to hours

Does a brief exposure to TB usually cause infection? How close do you need to be to acquire TB (typically)

No. Need frequent or prolonged exposure.
6 inches

How is TB not spread? (4)

touching
kissing
sharing utensils
other physical contact

TB initial signs and symptoms
-how soon develop?
-what are they? (5)

-develop 2-3 weeks after infection
1) fatigue
2) low-grade fever at night
3) anorexia
4) chest pain
5) bad cough (3 or more weeks)

TB late symptoms (2)
-r/t what?

1) hemoptysis
2) dyspnea
-r/t pleural effusion

TB: Factors that influence likelihood of infection (4)

1) Number of organisms expelled into air
2) concentration of organisms w/in a space
3) length of time of exposure
4) immune system of exposed person

Who is highest risk for developing TB?

HIV patients

How has HIV affected the spread of TB?

TB declined worldwide until mid-1980s when HIV emerged

Leading cause of death in patients with HIV

TB

TB infection vs disease

Infection: occurs when M. tuberculosis inhaled but an effective immune response renders the bacteria inactive
Disease: defined as active bacteria that multiply and cause clinically active disease

Why does TB disease occur rather than infection?

occurs if the initial immune response is inadequate

Is Latent TB Infection contagious?

No, but the active disease is.

Who else is at risk for TB, besides those with HIV? (7)

1) immunosuppressed
2) DM
3) IV drug users
4) homeless
5) foreign-born (especially asian)
6) previous TB
7) chronic disease

What is Primary TB?

when active disease develops within first 2 years of infection

Latent TB Infection (LTBI)
-symptomatic?
-skin test?
-CXR?
-Reactivation?
-Treatment?

-not symptomatic
-skin test can be positive
-CXR will be negative
-Reactivation possible if host defense mechanisms impaired
-Still needs to be treated b/c it could progress to transmissible disease

Triggers that can reactivate LTBI (7)

1) HIV (greatest risk)
2) immunosuppression
3) DM
4) poor nutrition
5) aging
6) pregnancy stress
7) chronic disease

Reactivation TB (define)

TB disease occurring 2 or more years after initial infection

TB: Nursing Interventions with the infected patient
-Precautions (5)
-Who must be notified

Precautions:
1) HEPA masks
2) airborne isolation room
3) teach patient to cover nose/mouth with tissue when coughing, sneezing
4) dispose of sputum by burning, trashing or flushing
5) always wash hands after handling sputum-soiled tissues
- MUST notify pu

Worst complications of TB (4)

1) PLEURAL EFFUSION
2) EMPYEMA
3) TB PNEUMONIA
4) MILIARY TB

What causes pleural effusion s/t to TB?

bacteria and exudate building up as inflammatory response in pleural space

What causes empyema s/t to TB?

large amounts of tubercular organisms in pleural space fill it with pus

What cuases pneumonia s/t to TB?

large amounts of discharged bacilli from granulomas in to the lungs or lymph nodes

Miliary TB: define
-caused by primary or reactivated TB?

Definition: systemic TB, involves many organs simultaneously infected with TB
-can occur as result of primary TB or reactivation of latent TB.

Standard method to screen for TB infection
-what is the name of the test?
-what is the material used?
-How much?
-Process
-When is it read?

Name: tuberculin skin test (TST or Mantoux)
Uses: purified protein derivative (PPD)
How much: 0.1 mL of PPD
Process: injected ID to produce 6 mm wheal on dorsal forearm
Read: 48-72 hours later

What is induration?

the hard, white raised area

What does a positive TB skin test indicate?

positive only means person exposed and antibodies have developed--no differentiation between active or latent infection

What is not induration?

erythema

How many mm induration considered positive in low-risk person?

15 mm induration

How many mm induration considered positive in moderate risk persons

10 mm induration

How many mm induration considered positive in high risk persons?

5 mm induration

What risk level is a healthcare worker considered to be for TST test?

moderate risk

Who is considered to be high risk for TB when doing TST?

immunocompromised cancer or HIV patients

TST: What can cause a false positive reaction? (2)

1) may have received the BCG vaccine (live)
2) may have a NON-tuberculosis mycobacterium infection

TST: What can cause a false negative reaction? (7)

1) recent TB infection (antibodies develop 2-12 weeks after initial exposure)
2) very young (< 6 months old)
3) previously infected but with waning immune response
4) anergy (lack of immune response)
5) OVERWHELMING TB infection
6) very old TB infection (

Does positive reaction to PPD mean person has TB?

No, just exposed--requires sputum culture to confirm; cannot tell if dormant or active just by PPD reaction

Who needs to get the two step TST? Why?

Who: recommended INITIAL testing for health care workers and others who will need repeated tests in the future
Why: a negative 2-step prevents misinterpretation in future tests, since later tests that are positive indicate new infections

Two-step TST: why might second test result be different from first?

previously-infected person may have negative first test d/t waning immune response, but positive second test d/t the "boost" effect of first test

Two step TST: what does two consecutive negatives mean?

two consecutive negatives confirm no present or PREVIOUS infection

If the skin test is positive, what is the next step to confirm dx?

Sputum culture if patient has symptoms

If a person has TB-like symptoms but a negative skin test, then the HCP would likely order what?

sputum culture; or a CXR if unable to get culture

Diagnostic studies needed to positively diagnose TB disease

1) 3 sputum cultures obtained on 2-3 consecutive days; culture all specimens, even if smear is negative.

TB sputum culture can take up to _____________ due to _________

8 weeks, slow growing organism

TB Blood serology SCREENING test (aka)

QuantiFERON-TB (QFT) test

QFT test: process

Blood is obtained from patient and placed in container with mycobacterial antigens. If the patient is infected with TB, the lymphocytes in the blood will recognize these antigens and secrete interferon, a cytokine produced by lymphocytes.

QFT test results are available in _________ and are not affected by _______________

a few hours, the BCG vaccination.

TB: Can a chest x-ray diagnose?

No, can only tell us if there is a shadow in lung

TB: Treatment Approach
-Aggressive or Conservative?
-2 Phases

-Aggressive
-Phases: Initial and Continuation

Initial TB Tx:
-How long?
-Drugs (4)
-Pregnant or Liver Disease?

How Long: 2-month
Drugs: 1. isoniazid (INH), 2. rifampin, 3. pyrazinamide (PZA), 4. ethambutol
Pregnant or Liver Disease: no PZA

Continuation TB Tx:
-How long (normal, pregnant, liver disease)
-Continue until?

How long: normal - 18 weeks; pregnant or liver disease - 31 weeks
Continue until: monthly cutlures come back negative

LTBI: Does patient get treated? With What? For how long? Why?

YES. Must treat to prevent possibility of becoming active. Only Isoniazid (INH) for 6-9 months as fewer bacteria make treatment easier

TB Nursing Care: Goals (4)

1) compliance with therapy
2) have no recurrence
3) normal pulmonary function
4) prevent spread through appropriate measures

isoniazid (INH)
-Side Effects (3)

SE:
1) noninfectious hepatitis
2) peripheral neuropathy
3) hypersensitivity.

Labs (3) and S&S (4)to monitor with INH treatment. How often?

Labs: Liver enzymes, BUN, Creatinine
S&S: of hepatitis: jaundice, dark urine, clay colored stools, pruritus
Monthly

Should INH be taken with meals

No. Take on empty stomach.

Supplement to give with INH. Why?

Give B6 pyridoxine as prophylactic against peripheral neuropathy

Foods to avoid when taking INH. Why?

Foods that contain tyramine and histamine: tuna, aged cheese, red wine, soy sauce, yeast extracts
Causes flushing

rifampin (aka)

Rifadin

rifampin:
Side Effects (4)

SE:
1) hepatitis
2) GI disturbances
3) Orange discoloration of body fluids (sputum, urine, sweat, tears)
4) increased metabolism of other meds and makes them ineffective (e.g., cardiac meds and steroids)

Pt. education about rifampin (3)

1) orange discoloration of fluids/ urine.
2) Discolor contact lenses
3) drink lots of water

PZA (aka)

pyrazinamide

PZA: Side Effects (4)

1) Hepatoxicity
2) polyarthritis
3) Skin rash
4) hyperuricemia

PZA: monitoring
-Labs: (1)
-S&S: (5)

Labs: uric acid levels
S&S: of hepatitis (jaundice, yellow skin, dark urine, clay colored stools, pruritus).

Major SE of INH, rifampin and PZA

nonviral hepatitis--always monitor liver function

ethambutol (aka)

Myambutol

ethambutol: Side Effects (2)

1) Retrobulbar neuritis (decreased red-green color discrimination
2) skin rash

ethambutol: tests to monitor
-Baseline? (1)
-Monthly?

Baseline: Snellen vision
Monthly: color discrimination monthly when on high doses

Pt. teaching for ethambutol (2)

1) ADVISE pt. that driving may be an issue
2) stay out of light

If the M. tuberculosis is susceptible to all of the 4 main drugs, which drug is dropped?
When?

ethambutol
When: Pt. will get all four meds for at least 8 weeks; after 8 weeks if treatment is shown effective, ethambutol can be dropped

Can a patient with a positive TB culture go home?

Yes, IF contacts in the home have previously been exposed.

Home instructions for TB patients: (5)

1) Room s/b well ventilated
2) sleep alone
3) spend time outside
4) restrict visitors
5) avoid public transport and places

When can home restrictions be eased for a TB patient?

Can remove most restrictions once sputums are negative.

Who must the nurse notify when d/c a TB patient home? Why?

public health department, so PHN can f/u

How long is patient with sputum smear-positive TB considered infectious after starting treatment?

First 2 weeks.

Are most people with TB treated as inpatients or outpatients?

Outpatient

How many neg sputum cultures needed to confirm TB tx success?

3 different

TB Drug Therapy: Teaching
-lifestyle
-Adeherence

Lifestyle: no alcohol d/t hepatotoxicity, no smoking, no acetaminophen
Adherence: esp., the right dose at the right time for entire course

What percentage of TB disease patients relapse?

5%

MDR-TB (aka)

Multi Drug Resistant TB

DOT (aka)

Direct Observation Therapy

If no response to treatment after 3 months (positive culture or persistent symptoms), what is next step?

reevaluate for MDR-TB or nonadherence to drug tx

What is done if it is MDR-TB?

fluoroquinolones "oxacin

What is done for noncompliance?

consider DOT

DOT: what is it

Provide drugs directly to the patient and watch patient swallow drugs.

What is done if pt refuses DOT?

may have to put involuntarily in treatment facility to protect the community

Classification System for TB
0
1
2
3
4
5

O-no exposure or history
1 - history of exposure but negative on skin test
2 - positive reaction to skin test, negative bacteriologic studies and no clinical or radiographic evidence of active infection
3 - clinical, bacteriological, or radiographic evide

What is POTS disease?

TB in the spine

How do you obtain a sputum specimen for TB testing?

1st thing in AM.
Take 3 deep breaths, hack deep cough
Tell Pt not to brush teeth, drink anything, etc.
Use sterile cup.

TB vaccine: name

Bacille Calmette-Guerin (BCG)

IS TB vaccine used in US?

Not usually, except for very select individuals