Pulmonary Infections Flashcards
What is the most common cause of CAP?
strep pnemoniae
Best initial test for CAP?
CXR
After confirming diagnosis of CAP, what is the best next step?
Assess severity
CURB-65 tool + clinical judgment
- tells severity
1. confusion
2. uremia (BUN > 19mg/dl)
3. Respiratory distress (RR > 30/min)
4. BP low (SBP <90mmghg)
5. > 65 y.o - 0 to 1 = home
- > 2 = hospital
- SOB, hypotension, confusion = no perfusion = hospital
No comorbidities, no previous antibiotics CAP tx
Macrolides (azithromycin, clarithromycin, erythromycin) or Doxycycline x 5 days
- do not stop until afebrile for 48 hrs
Comorbidities, treated with abx in past 3 months CAP tc
Respiratory FQ (levofloxacin 750mg, moxifloxacin, gemifloxacin) or Beta-Lactam (high dose of amoxicillin, amoxicillin/clavulanate, cefuroxime) + Macrolide or Doxycycline
Intermediate Risk - PPSV 23 vaccine
- younger adults (<65 y/o) with comorbid condition:
1. cigarette smokers
2. chronic heart disease
3. chronic lung disease
4. asthma
5. DM
6. chronic liver disease
7. alcoholism
High Risk - PCV13 followed by PPSV23
- adults >65 y/o
- immunocompromising conditions (HIV, cancer, anatomic asplenia, CSF leak)
TB bacteria facts
- Mycobacterium tuberculosis
- transmitted through droplets
Increased risk for TB
- recent (<5 yr) immigrant from developing countries
- HIV positive
- prisoners
- Homeless/urban poor/ IVDU
- healthcare workers
- impaired cell immunity (DM, organ transplant, cancer)
2 risk factors fro TB
- immunosuppressed
- living in crowded conditions
Latent TB
- infected but body is successful in containing org
- NOT INFECTIOUS
- NO SYMPTOMS
- ppd
- 10% risk of reactivation
Secondary (Reactivated) Infection
- caused by stress on immune system
- INFECTIOUS
- symptomatic
Diagnostic Tests for ACTIVE TB
- CXR/ CT chest: SUGGESTIVE but not diagnostic»_space; isolate
- Sputum acid-fast stain: Not very sensitive or specific. Makes PRESUMED dx and reflects high infectivity»_space; initiate treatment pending culture
- Sputum culture: “Gold standard”, takes 4-6 weeks, required for confirmation of the diagnosis and for drug susceptibility testing
- PPD or IGRA: For screening of asymptomatic individuals at risk, not for dx symptomatic patients
Tx : TB
RIPE ( at least 6 months): • Rifampin ( RIF) • Isoniazid ( INH) • Pyrazinamide ( PZA) • Ethambutol ( ETM)
- Can start Tx based on positive acid fast stain
Side effects of TB medication
RIF: red color of secretion, causes contraceptive fx
INH: peripheral neuropathy (give pyridoxine - B6), washes out B6 -
PZA: Hepatotoxic
ETM: optic neuritis/color vision
all medications are hepatotoxic
When is PPD indicated?
• To screen asymptomatic patients at risk for latent TB: Recent immigrants ( 5 years) Immunosuppressed Prisoners Health care workers (done every year to detect recent infection) Homeless Nursing home residents Alcoholics Close contact with TB patients
When do you read a PPD
48 hours
PPD: When is it positive?
> 5 mm induration • HIV • Organ transplant recipients • Steroid users • Close contact of those w/ ACTIVE TB > 10 mm induration • Recent immigrants Prisoners • Health care workers • Homeless • Nursing home residents • Alcoholics > 15 mm induration No risk factors (should not be screened)
Positive PPD: What is the next best step?
CXR to r/o TB
Recommended tx for latent TB (PPD positive, CXR neg, no symptoms)
- INH for 9 months (especially for patients who have converted from negative to positive within 2 years)
- No need to repeat PPD test in patients with positive PPD
PPD
Skin test
Two visits
May cross react w/ BCG (depends on time when BCG given)
IGRA
Blood test
One visit ( compliance, comfort)
More specific. Do not cross react w. BCG
Not approved in children < 5 y
Pertussis (clinical findings)
paroxysmal cough and posttussive vomiting
Pertussis (Dx test)
no sensitive tests at time of symptoms
Pertussis: Important facts
- Gram-negative bacteria Bordetella pertussis
- spread via respiratory droplets
Pertussis: natural history
Early ( catarrhal) phase (6 days) - non-specific sx. Dx tests are most specific in this period!
Paroxysmal phase (6 weeks) – In children- cough paroxysms, a vigorous inspiration causes the "whooping" sound, post-tussive vomiting. In adolescents or adults - just prolonged cough, +/- posttussive vomiting.
Convalescent phase (6 weeks)
Diagnostic tests for pertussis
- CXR: Usually negative. Done to r/o pneumonia
- Culture: Requires specific medium. 7-10 days, sensitivity declines after 2 weeks, w/ recent abx use
- NAAT (by PCR): Sensitivity declines after 4 weeks and with recent abx use.
- Serology: Not useful in acute period
best initial therapy for pertussis
Azithromycin ( Z-pack) – for 5 days
Reduces spread!
Treat close contacts
Who should be vaccinated against pertussis?
- 19 and older: Tdap as a single booster regardless of timing of Td
- pregnant women every pregnancy
