LRTIs Flashcards

1
Q

What is the pathogenesis of influenza?

A

Hemagglutinin binds host sialic acid to initiate infection,

Neuraminidase cleaves host cell contact to escape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacterial and Viral Causes of Acute Bronchitis

A

Respiratory syncytial virus, influenza virus, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordatella pertussis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

If patient presents with a cough persisting >3weeks, what should be suspected?

A

Bordatella pertussis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the most common LRTI in children <2yo?

A

Bronchiolitis -> RSV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 2 most common pathogens associated with pneumonia in neonates?

A

E. coli, S. agalactiae (GBS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What antibiotic is used to treat CAP as an outpatient vs inpatient?

A

Out: Amoxicillin (S. pneumo)
In: Ceftrixaone (Enterobacter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What antibiotic is used to treat M. pneumoniae?

A

Macrolides (e.g. azithro)

***M. pneumo does not have a cell wall, therefore beta-lactams will not work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What classes of antibiotics are used to treat Legionella infection?

A

1st line: macrolides, 2nd line: floroquinolones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Most common pathogen associated with ventilator-acquired-pneumonia and ABx to treat?

A

Pseudomonas aeruginosa

pipercillin-tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is empyema? What are the common culprits of empyema? Treatment?

A

Infected fluid in pleural space, typically by anaerobes. Drain fluid, administer ceftriaxone + metronidazole if chronic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most common culprit of chronic pneumonia in teenage CF patients?

A

Pseudomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

2 major viral causes of acute bronchitis

A
  1. Influenza

2. RSV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is hemagglutinin (H)?

A

Viral protein that binds sialic acid on epithelial cell surface to initiate infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is neuraminidase (N)?

A

A viral enzyme that cleaves viral progeny from the host cell to allow their escape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is antigenic drift?

A

Minor change in viral envelope glycoproteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is antigenic shift?

A

Major change in viral envelope glycoprotein that is associated with major epidemics and pandemics. The segmented genome allows reassortment in co-infected cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Clinical presentation of influenza

A

Illness begins with abrupt onset of fever, headache, myalgias, malaise along with sore throat, rhinorrhea and cough

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How long should uncomplicated influenza last?

A

2-5 days. Viral shedding stops after 6-7 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the most common complication of the flu?

A

Pneumonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Management of influenza

A
  1. Most cases are self-limiting
  2. Antiviral therapy for severely ill or those at risk of complications
  3. Those in (2) get Oseltamivir 75 mg PO BID. Must be given within 48 hours of symptom onset to be of benefit.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What precautions can be taken to prevent influenza transmission?

A
  1. Flu shot
  2. Droplet precautions
  3. Hand washing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List 3 bacterial causes of acute bronchitis

A
  1. Mycoplasma pneumoniae
  2. Chlamydophila pneumoniae
  3. Bordetella pertussis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Bronchitis without pneumonia is almost always caused by what?

A

A VIRUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When should you consider Whooping Cough?

A

In a patient with persistent cough for > 3 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is COPD?

A

Disease characterized by airflow limitation that is not fully reversible. This limitation is usually progressive and is associated with an inflammatory response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When is chronic bronchitis suspected?

A

Productive cough for at least 3 months/year for at least 2 consecutive years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the criteria for an acute exacerbation of chronic bronchitis?

A
  1. Increased sputum volume
  2. Increased sputum purulence
  3. Increased dyspnea
    (consider antibiotics if 2 or more present)
28
Q

What are the guidelines for antibiotic use in acute exacerbations of chronic bronchitis?

A
  1. Mild –> amoxicillin
  2. Moderate –> amoxicillin-clavulanate
  3. Severe –> levofloxacin
29
Q

What is the most common acute viral LRTI during the first 2 years of life?

A

Bronchiolitis

30
Q

What is the major cause of bronchiolitis?

A

RSV

31
Q

Clinical presentation of bronchiolitis

A
  1. Prominent cough, increased resp rate, lethargy, poor feeding
  2. Signs of increased work of breathing (retractions of chest wall, nasal flaring, grunting)
  3. Dehydration
32
Q

How long does bronchiolitis last?

A

Usually 3 to 7 days

33
Q

What can be done to Dx bronchiolitis?

A
  1. Naso-pharyngeal swab for viral Dx by PCR
34
Q

Tx and prevention of bronchiolitis

A
  1. Supportive care
  2. Maintain hydration
  3. Hand hygiene
35
Q

What is acute pneumonia?

A

An inflammatory condition of the lung primarily affecting the alveoli and usually caused by infection with viruses or bacteria

36
Q

What are 3 ways by which microbes can reach the lungs?

A
  1. Inhalation
  2. Aspiration
  3. The bloodstream
37
Q

What is the #1 cause of pneumonia in adults?

A

S. pneumoniae (pneumococcus)

38
Q

What conditions predispose someone to pneumonia?

A
  1. Alcoholism
  2. DM
  3. CHF
  4. COPD
  5. Smoking
  6. Aspiration
  7. Post influenza
  8. CF
39
Q

What investigations should be performed for suspected pneumonia?

A
  1. Hx and physical
  2. Sputum sample
  3. Possible invasive procedures (i.e. bronchoscopy, lung biopsy)
  4. Labs: CBC, procalcitonin, blood cultures, serology, urine Ag
40
Q

Things to look for in CXR with regards to pneumonia

A
  1. Location and nature of infiltrates
  2. Cavitation
  3. Volume loss
  4. Pleural fluid
  5. Mediastinal adenopathy
41
Q

What is used for outpatient Tx of CAP?

A
  1. Amoxicillin 1 g PO TID

2. Co-morbidities/atypical pathogen –> ADD Doxycycline, OR Clarithromycin

42
Q

What is used for in-patient Tx of CAP?

A
  1. Ceftriaxone IV

2. If atypical pathogen –> Doxycycline OR Clarithromycin

43
Q

What comorbidities are associated with pneumonia?

A

Asthma, alcoholism, DM, CHF, COPD, smoking, lung CA, chronic renal or liver failure, chronic corticosteroid use, malnutrition.

44
Q

What are 3 atypical pathogens that cause pneumonia?

A
  1. Mycoplasma pneumoniae
  2. Chlamydophila pneumoniae
  3. Legionella pneumophila
45
Q

M. pneumoniae is Gram +ve, T or F?

A

FALSE. It has NO cell wall, so it does not Gram stain at all!

46
Q

M. pneumoniae is a common cause of pneumonia in young people, how is it treated?

A
  1. Macrolides
47
Q

Mycoplasmas are highly susceptible to all beta-lactams, T or F?

A

FALSE. They have no cell wall - so beta-lactams have NO effect!

48
Q

When should you consider Legionella pneumophila as a cause of someones pneumonia?

A
  1. When they aren’t responding to beta-lactams
  2. If they are at risk (COPD, old, transplant recipients, pts on anti-TNF)
  3. Those exposed to aerosols (i.e. A/C, hot tubs, resp therapy equipment, fountains, etc.)
49
Q

How can the Dx of Legionella pneumonia be made?

A
  1. Urine Ag test

2. Culture/PCR of bronchoscopy specimens

50
Q

What do you Tx Legionella pneumonia with?

A
  1. Quinolones (levo or moxi)

2. OR macrolides (azi or clari)

51
Q

How do you Tx CAP in the nursing home patient?

A
  1. Amoxicillin-Clavulanate
52
Q

What are the usual causes of HAP and what is the empiric Tx?

A
  1. Enterobacteriaceae and S. aureus

2. Ceftriaxone

53
Q

What is a major cause of ventilator acquired pneumonia and what is the empiric Tx?

A
  1. P. aeruginosa

2. Pipercillin-tazobactam

54
Q

What is important when managing someone with pleural effusion or empyema?

A
  1. Drain the pleural space!

2. Obtain a sample for Gram stain and C/S

55
Q

Tx for empyema

A
  1. Ceftriaxone IV

2. If chronic ADD Metronidazole

56
Q

How do you get a lung abscess?

A

Results from microbial infection that causes necrosis of the lung parenchyma to produce one or more cavities

57
Q

Tx of a lung abscess

A
  1. Clindamycin
  2. OR penicillin and Metronidazole
  3. Consider TB/fungi/cancer if cavitation without air fluid level
58
Q

Some general characteristics of Mycobacterium

A
  1. Acid fast bacilli
  2. Strictly aerobic
  3. Grow slow (2-6 weeks)
59
Q

How is TB transmitted?

A

It is carried in airborne particles that are then inhaled by a susceptible person

60
Q

What happens once TB enters a new host?

A

The TB is engulfed by alveolar macrophages, and may be transported by lymphatics.

61
Q

TB natural Hx

A
  1. Inhalation followed by: Immediate clearance or, Primary active disease, or Latent infection with chance of reactivation.
62
Q

TB reactivation is associated with…

A

Immunosuppression

  1. HIV
  2. Declining cell-mediated immunity with age
  3. Corticosteroids
  4. TNF inhibitors
  5. DM
  6. Renal disease
  7. Cancer or chemo
63
Q

Usual TB presentation

A

Pulmonary infection

  1. Cough
  2. Hemoptysis
  3. Weight loss
  4. Night sweats
  5. Low grade fever
  6. Dyspnea
  7. Chest pain
64
Q

What are some extrapulmonary manifestations of TB?

A
  1. Cervical lymphadenitis
  2. Pleuritis
  3. Pericarditis
  4. Meningitis
  5. SSTI (joints, bones, and internal organs)
65
Q

Who might have a +ve TST?

A
  1. Someone with active TB
  2. Those previously exposed to TB
  3. Those exposed to another Mycobacterium
  4. Those who had the BCG vaccine
66
Q

What are the 3 clinical signs of acute exacerbated chronic bronchitis? Also, who is at greatest risk of contracting AECB?

A

Increased sputum production, purulent sputum, dyspnea

Smokers