Pulmonology E1: Infectious Diseases

Symptom onset of a URI is typically within _______ from exposure

24-72 hours

Symptoms of a URI may last ________

7-21 days

Most common symptoms of a URI

Rhinitis and nasal congestion

If you are suspicious of an URI, when is a CXR indicated?

If additional concern for a lower respiratory infection (PNA)

Are Abx recommended for a URI?

No

Who is not recommended to take cough medication?

Children under the age of 2

1st line treatment for URI

- Saline nasal irrigation
- Analgesics: acetaminophen & NSAIDs

2nd line treatment for URI

- Topical decongestants: Afrin (<3 days)
- Systemic decongestants: Sudafed (not for pts with HTN)
- Antihistamines: Benadryl

Acute infection of the pulmonary parenchyma acquired outside of the hospital

Community acquired pneumonia (CAP)

What is the most common infectious cause of death?

Community acquired pneumonia (CAP)

CXR finding for legionella pneumoniae

Bilateral lobar consolidation

CXR finding for mycoplasma pneumoniae

Diffuse lung infiltrates

Mycoplasma pneumoniae most commonly affects ______

College aged students

Unique associated symptoms of mycoplasma pneumoniae

Bullous myringitis (severe ear pain)

What type of CAP is associated with hotel AC systems?

Legionella pneumoniae

Associated symptoms of legionella pneumoniae

Hyponatremia, diarrhea, fevers, chills

Associated symptoms of chlamydia pneumoniae

Sore throat, hoarseness

Associated symptom of streptococcus pneumoniae

Rust colored sputum

What CAP is associated with rust colored sputum?

Streptococcus pneumoniae

What CAP is associated with a currant jelly sputum?

Klebsiella pneumoniae

What CAP has an increased tendency for abscess formation, cavitation, and empyema?

Klebsiella pneumoniae

Type of pneumonia commonly seen in: Alcoholics

Klebsiella

Type of pneumonia commonly seen in: COPD

H. Influenzae

Type of pneumonia commonly seen in: Cystic fibosis

Pseudomonas/Serratia/Burkolderia/Acinetobacter

Type of pneumonia commonly seen in: Healthy young adults/College students

Mycoplasma, Chlamydia

Type of pneumonia commonly seen in: AC/Recent water exposure

Legionella

Type of pneumonia commonly seen in: Patients < 1 y/o

RSV

Type of pneumonia commonly seen in: Pediatric patients > 2 y/o

Parainfluenza

What is the initial diagnostic study performed for suspected PNA?

CXR

What findings are expected on a CT with a patient who has PNA?

"Tree in bud" or "Ground glass"

What lab results are expected in a patient with PNA?

- Leukocytosis with leftward shift OR leukopenia

- Inc. ESR and CRP

- Inc. Procalcitonin

What is the curb-65 method used for?

To determine whether to admit a patient with PNA

What are the CURB-65 Criteria?

3 or more positive = ADMIT

Confusion

Uremia: BUN > 20

Respiration: RR > 30 BPM

BP: < 90/60

> 65 y/o

1st line treatment for typical and atypical CAP

Azithromycin

2nd line treatments for typical and atypical CAP

Clarithromycin or Doxy

Treatment for typical and atypical CAP if comorbidities or increased resistance to macrolides exists

FQ: Levofloxacin, Moxifloxacin

Pediatric treatment for typical CAP

Amoxicillin

Pediatric treatment for atypical CAP

Azithromycin

First line treatment for inpatient (non-ICU) CAP

Ceftriaxone OR Ceftaroline + Azithromycin

First line treatment for inpatient (non-ICU) CAP with suspicion for MRSA

Ceftriaxone OR Ceftaroline + Azithromycin PLUS Vanco or Linezolid

What can be done to prevent CAP?

Pneumococcal vaccine & Influenza vaccine

Pneumonia that occurs 48 hours or more after admission and did not appear to be incubating at the time of admission

Hospital Acquired Pneumonia (HAP)

Pneumonia that develops > 48 hours after endotracheal intubation

Ventilator Acquired Pneumonia (VAP)

What should you be suspicious of in patients with: new onset fever, purulent sputum, leukocytosis, and worsening hypoxemia

HAP/VAP

Causes of HAP/VAP

Aerobic gram negative bacilli & gram positive cocci

Pathogenesis of HAP/VAP

Microorganisms that have entered the lower respiratory tract

Micro aspiration of organisms that have colonized the oropharyngeal tract

How many blood cultures should be drawn?

2

What can be done to prevent HAP/VAP?

Elevate head of bed, minimize sedation, avoid intubation

What type of Influenza is most likely to have an antigenic shift? What does this mean?

Type A- able to get it more than once due to mutations

Complications of Influenza

Strep PNA, ARDS, mycocarditis

What is the most common cause of HIV associated PNA?

Pneumocystic jirovecii (PJP/PCP)

What symptoms are associated with HIV associated PNA?

Sxs evolve gradually over weeks to months:
- fever, progressive dyspnea, nonproductive cough, oral thrush common

CT finding is "Central ground glass opacifications in a perihilar distribution; septal thickening; thin walled cysts"

HIV associated PNA

Lab results associated with HIV associated PNA

Decreased CD4: < 200
+ LDH
+ Beta-D glucan

Treatment for HIV associated PNA

Bactrim + adjuvant corticosteroids

Prevention for HIV associated PNA

Vaccines & prophylactic Abx (Bactrim DS)

Pneumonia usually caused by aspiration of oropharyngeal secretions or gastric contents into the lower airways (foreign material in lung)

Anaerobic Pneumonia

Unique symptom associated with anaerobic pneumonia

Foul smelling purulent sputum

Presence of purulent pleural fluid

Empyema

Multiple cavitation within an area of consolidation

Necrotizing pneumonia

Thick walled solitary cavity surrounded by consolidation (usually has air-fluid level)

Abscess

Testing for anaerobic pneumonia & lung abscess

Transthoracic aspiration, thoracentesis, bronchoscopy with brushings

Treatment for anaerobic pneumonia & lung abscess for a patient with NKDA

Beta-lactam/Beta-lactamase inhibitor

Treatment for anaerobic pneumonia & lung abscess for a patient with beta-lactam allergy

Clindamycin

Clinical classification for chronic bronchitis

Lasts 3 months out of the year for 2 consecutive years

What is the most common cause of bronchitis?

Viral

Pathogenesis of bronchitis

Inflammation of the bronchi leading to mucosal thickening and basement membrane breakdown

What would a CXR be used for in bronchitis?

To exclude pneumonia

Symptoms associated with bronchitis

Persistent, productive cough that may last up to 4 weeks,
Costochondral tenderness

What is the most common cause of lower respiratory tract infections in children < 1 y/o?

RSV

Etiology of RSV

Paramyxovirus

Pathogenesis of RSV

Proliferation & necrosis of bronchiolar epithelium and increased mucus secretions

Prevention for RSV

SYNAGIS (Palivizumab)- monoclonal antibody

Most common cause of bronchiolitis

RSV

Chronic inflammation, concentric scarring, causing luminal obstruction, progressive clinical course unresponsive to steroids

Constrictive bronchiolitis

Lymphocytes, polyps, macrophages obstruct the bronchioles- when the exudate extends to alveoli it is termed bronchiolitis obliterans

Proliferative bronchiolitis

Risk factors for bronchiolitis

Premature infants
< 5 months old

Treatment for bronchiolitis

Supportive care

Life threatening condition that causes profound swelling of the upper airways

Epiglottitis

Most common cause of epiglottitis in children

H. influenzae type B

Most common cause of epiglottitis in adults

S. pneumoniae

Most common cause of epiglottitis in immunocompromised

Pseudomonas aeruginosa

What are the "3 Ds" of epiglottitis?

Dysphagia, Drooling, Distress

Condition associated with symptoms like: tripoding and muffled voice

Epiglottitis

What CXR finding is seen with epiglottitis?

Thumb print sign

What testing can you NOT perform with a patient who has epiglottitis?

Laryngoscopy- could cause a laryngospasm which leads to a loss of airway

Treatment for epiglottitis

Airway management
Corticosteroids
3rd gen cephalosporin + Vanco

Cause of pertussis (whopping cough)

Bordetella pertussis (gram negative coccobacillus)

What are the 3 phases of pertussis (whooping cough)?

1. Catarrhal stage
2. Paroxysmal stage
3. Convalescent stage

What stage of pertussis (whooping cough) is the most infectious?

Catarrhal stage

What stage of pertussis (whooping cough) displays the high pitched "whoop" or staccato cough?

Paroxysmal stage

When does the convalescent stage of pertussis (whooping cough) appear?

4 weeks after onset

What lab results are expected in a patient with pertussis (whooping cough)?

Leukocytosis with lymphocytosis

Prevention for pertussis (whooping cough)

- Vaccine DTaP in infancy and a booster of Tdap at 13 y/o

- Pregnant women receive a booster after 28 wks gestation

First line Abx treatment for pertussis (whooping cough)

Macrolides (azithro & clarithro)

What patients should avoid the use of macrolides?

< 4 weeks old

Second line Abx treatment for pertussis (whooping cough)

Bactrim DS

Postexposure prophylaxis with _______ is recommended for all household contacts of pertussis (whooping cough)

Macrolides (Azithro & Clarithro)

Respiratory illness of the trachea, larynx, and bronchi

Croup

Cause of croup

Parainfluenza virus type 1 & 2