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ABIM Board Review: Pulmonary Medicine. Overview. Topics Respiratory Infections Airway Disease Restrictive Lung Diseases Pulmonary Vascular Disease Pleural Disease Sleep Potpourri. Hints. Stress certain topics ASTHMA, TB, SARCOID, ILD’s,PFT’s
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Overview • Topics • Respiratory Infections • Airway Disease • Restrictive Lung Diseases • Pulmonary Vascular Disease • Pleural Disease • Sleep • Potpourri
Hints • Stress certain topics • ASTHMA, TB, SARCOID, ILD’s,PFT’s • ‘Things marked with these things are pearls to remember’ • Disclaimer: A 3 year fellowship is difficult to condense into a 1 hour lecture…
Respiratory Infections • Community Acquired PNA (CAP) • HealthCare Assocoiated PNA • Hospital Acquired PNA (HAP) • Ventilator Associated PNA (VAP) • Nursing Home Associated PNA • TB
Types of Pneumonia • Community Acquired • Bacterial • Atypical • Hospital Acquired >72 hours after admission • Ventilator Associated • Aspiration Syndromes
Physical Signs of Pneumonia • Bronchial Breath sounds • Dullness to percussion • Egophony
Community Acquired Pneumonia Bugs • Strep pneumoniae • mycoplasma • viral • Chlamydia • H. influenzae • Staph aureus • Legionella • Anerobic?
Hospital Acquired PNA Bugs • Gram negative enterics • Staph aureus (MRSA) • H. influenzae • Strep pneumonia
Indicators of Severe Pneumonia • Multilobar • Advanced age • Elevated BUN • Elevated Respiratory rate • High or Low WBC • High or Low Temp. • Hypotension
Antibiotics • Outpatient younger than 60 • ATS • Macrolide or Tetracycline • IDSA • Macrolide or Fluoroquinolone or Doxycycline • Alternative: Oral second-generation cephalosporin or Augmentin • E-mycin does not cover H. flu (COPD)
Antibiotics Cont. • Outpatient older than 60 or with co-morbid conditions • ATS • Second generation cephalosporin, Bactrim, Augmentin with or without a macrolide • IDSA • Macrolide or Fluoroquinolone or Doxycycline • Alternative: Oral second-generation cephalosporin or Augmentin
Antibiotics Cont. • Inpatient Ward • ATS • Second or third generation cephalosporin or beta lactam/beta lactamase inhibitor with a macrolide • IDSA • Beta lactam with a macrolide or fluoroquinolone alone
Antibiotics Cont. • Inpatient Severe • ATS • Macrolide with antipseudomonal agent plus an aminoglycoside • IDSA • Cefotaxime, ceftriaxone, or Beta-lactam/ Beta-lactamase inhibitor with macrolide or fluoroquinolone
Follow-Up CXR • Fifty percent of pneumonias clear within 2 weeks and 75 percent clear with in 6 weeks • <5% of 20 year olds, 10-20% of 40 year olds, 30% of 60 year olds and 50% of 80 year olds will continue to have infiltrates at 12 weeks • Multilobar pneumonias are slower to resolve
Pneumovax • Persons older than the age of 50 • Persons with asplenia, high risk environments, immunosuppression and chronic illness. • Give vaccine if status is unknown • Repeat vaccination should be considered for patients at high risk and those vaccinated before 65 if not given with in 5 years.
TBFor Another Time… • Extra-Pulmonary Tuberculosis • Lungs> Kidneys> Bone> Brain • Mycobacterium Other Than Tuberculosis (MOTT) AKA Non-Tuberculous Mycobacteria (NTM)
AKA • Phthisis- “wasting”; chronic pulmonary tuberculosis • “Consumption” • “White Plague”
Nomenclature • Phthisiology- the study of tuberculosis of the lungs • Converter- patient who has experienced an increase of > 10mm of induration in PPD test size within a two-year period, regardless of age. • Reactor- a non-converter patient with a positive skin test. • LTBI- latent tuberculosis infection. “Treatment of Latent Tuberculosis Infection” has replaced “preventative therapy” and “chemoprophylaxis”.
Epidemiology • An estimated 1/3 of the world’s population is believed to be infected with M. Tuberculosis (roughly 2 billion people). • Because actual reporting is generally unreliable, several surrogate values have been used, including: • Average annual risk of MTB infection (ARTI) • Estimated incidence of smear positive MTB • Case Notifications • Estimated Case-Fatality rates.
Re-Emerging Scourge? • Although MTB experienced a resurgence in the mid-late 80’s, the incidence has actually continued to decline since 1993 and, as of 2005 was at an all-time low…
Location, Location, Location • In 1998 active TB reported in every state. • Seven states (CA, FL, GA, IL, NJ, NY and TX) accounted for 60% of all cases. • 40% of all cases in America’s 64 largest cities.
A Disease of Import • Incidence of MTB among Foreign-born persons varies by country of origin: • Latin America (57% from Mexico) • Philippines • Vietnam • South Korea • China
HIV: TB’s Not-So Silent Partner • HIV’s effect on cell-mediated immunity uniquely positions it as a dominant factor in susceptibility to MTB in SE Asia and Sub-Saharan Africa. • Rates of co-infection have increased as high as 45-fold between 1990 and 1994 (Thailand)
Where the Money is… • Active MTB cases: 1990-1999 • North America: 320,000 • Sub-Saharan Africa: 15,000,000 • Asia and the Sub-Continent: 55,000,000
High-Risk Groups: Infection • HIV+ • Foreign-born in endemic regions (4-6X) • Children of foreign-born from endemic regions • Homeless • Veterans • IV Drug users • Congregate living- Nursing homes, prisons, etc.
High-Risk Groups: Infectioncon’t • Close contacts of individuals known, or suspected, to have active MTB. • Health care workers (i.e. you)
High Risk Groups: Disease • HIV+ (100X) • Diabetes Mellitus (3X) • Post-Gastrectomy or Intestinal Bypass • Silicosis (30X) • Certain Cancers- Leukemia, Lymphomas, HEENT(16X) • Pharmacologically Immunosuppressed • Post-chemotherapy, DMARD, Steroids • Post solid-organ transplant (20-74X) • Recent infection (within 2 years)
High-Risk Groups: Disease con’t • CXR consistent with prior disease without adequate treatment. • ESRD (10-25X) • Chronic malabsorption syndromes • Low Body Weight (<10% below ideal) (2X)
Clinical Pathogenesis • Although one organism per 12,000 cu ft has been shown to produce infection, only up to 1/3 of individuals in close contact with patient with active MTB develop infection. • Most infected aerosolized droplets are cleared by upper airway mechanisms. • Those less than 5 microns reach the alveolus, and are phagocytosed by macrophages (MTB infection).
Bacilli multiply at this primary site of infection and within 2 weeks are transported to lymphatics to establish secondary site. • Within 4 weeks delayed-type hypersensitivity develops leading to granuloma formation and subsequent decrease in bacterial burden. • However, sterilization rarely occurs, even though host displays acquired immunity, rapidly clearing subsequent exposures.
THEORETICALLY, as the host begins to control MTB through the primary response, the normally aerophilic bacilli downshifts into a non-replicating stage as surrounding oxygen tension drops. • This non-replicating, or latent, stage allows organisms to avoid the anti-microbial effects of MTB regimens.
The goal of treating latent tuberculosis infection (LTBI) is prolonged courses of therapy so effective drug levels are persistent for months as latent organisms reactivate, rendering themselves susceptible.
By the Numbers… • Once infected with MTB 3-5% of immunocompetent hosts develop active disease within one year. A further 3-5% will develop active disease within their lifetime. • Said another way: Once primarily infected, lifetime risk of active MTB is 10%; half of those within the following year.
More Numbers • For immunosuppressed, risk of developing active MTB is 7-10% annually.
Diagnosis: Symptoms • Pulmonary • Prolonged productive cough • Hemoptysis • Chest pain • Systemic • Fevers/Chills • Drenching Night Sweats • Anorexia/Weight loss • Easy Fatigability
Diagnosis: H&P • After considering diagnosis of MTB (and putting a mask on you or patient), focus history on risk factors for MTB infection or disease (see previous) as well as past exposure and treatment history. • Don’t forget to perform adequate review of systems as only 73% of pulmonary MTB cases are exclusively pulmonary.
Diagnosis: The Laboratory • The gold standard for diagnosis, the sputum smear, is neither sensitive nor specific. • >10,000 organisms/ml are required for detection, leaving the smear positive in only 50% of active MTB cases • Any acid-fast bacilli present will cause the test to be positive.
The Sputum • Early AM specimens on three consecutive days are ideal. Induced sputum with inhaled saline may be required in patients unable to provide adequate lower airway samples. • Alternatives • Bronchoscopy (choose wisely) • Early AM Gastric aspiration
Sensitivities • All initially positive MTB cultures must be tested for sensitivities to guide anti-microbiologic treatment and identify Multi-Drug Resistant-TB (MDRTB). • Sensitivities should be repeated if patient experiences clinical treatment failure or cultures remain positive despite two months of treatment.
Purified Protein Derivative • First recognized as potential tool for diagnosis by Sir Arthur Conan Doyle. • Later perfected by Mantoux. • Though fairly accurate for diagnosing infection (not disease), limited by false positive rate around 10% and false negative rates around 20-30% (higher in immunocompromised).
PPD con’t • A PPD may take up to 10 weeks to turn positive after initial infection. • The PPD is the only way to diagnose MTB infection prior to MTB disease. • Role of Interferon-Gamma…
The PPD Itself • 0.1 ml of PPD tuberculin containing 5 TU is injected intradermally on the inner surface of the forearm producing a 6-10 mm wheal. • A reading 48-72 hours from PPD placement should be obtained: • Positive readings may be obtained up to one week after placement. • Failure to obtain reading within 72 hours indicates need for repeat testing
More PPD • The area of induration (not erythema) is measured in millimeters perpendicular to the long-axis of the forearm. • “Conversion”- defined as an increase of >10mm within a 2-year period.
A Positive PPD • >5 mm • HIV+ • Recent contacts of active MTB case • CXR consistent with healed MTB • Patients with organ transplants or immunosuppression > 15mg/day of prednisone > 1 month
>10 mm • Recent arrivals (<5 years) from endemic regions. • IVDU • Residents/Employees of: • Prisons/jails • Nursing home/shelters • Hospitals, including mycobacterial labs • High-Risk of Progressing to MTB disease • Children <4 yo
> 15mm • No known risk factors for MTB.
PPD: False Positives • MOTT • BCG vaccination