Chapter 22 - Pneumonia Flashcards Preview

Silverstein & Hopper (+ West) > Chapter 22 - Pneumonia > Flashcards

Flashcards in Chapter 22 - Pneumonia Deck (38)
Loading flashcards...
1
Q

The combination of respiratory signs, an inflammatory leukogram and pyrexia are sensitive and specific for pneumonia. True/False?

A

Neither sensitive nor specific

More than half of dogs and cats with bacterial pneumonia are afebrile

2
Q

What percentage of dogs with pneumonia have a concurrent predisposing disorder?

A

36-57%

3
Q

List 3 factors under each category that may predispose a dog or cat to pneumonia.

  1. impaired patient mobility
  2. upper airway disorders
  3. regurgitation syndromes
  4. other factors
A
  1. unconsciousness (natural/GA), mechanical ventilation, weakness/paresis/paralysis
  2. laryngeal mass/FB, laryngeal paralysis, laryngeal/pharyngeal surgery
  3. esophageal motility disorder, esophageal obstruction, megaesophagus
  4. bronchoesophageal fistula, cleft palate, crowded/unclean housing, forceful bottle feeding, gastric intubation, immune compromise, inadequate vaccinated, induced vomiting, seizures, tracheostomy
4
Q

List 3 common nonspecific systemic clinical features found in patients with pneumonia

A

lethargy, inappetence, weight loss

5
Q

Which of the following features are common (>90%) in adult dogs with pneumonia?

a) Pyrexia
b) Tachypnea
c) Increased respiratory effort
d) Loud breath sounds/crackles/wheezes on auscultation

A

d) Loud breath sounds/crackles/wheezes on auscultation

6
Q

Why are three view radiographs important when screening for pneumonia?

A

Asymmetric distribution is common, failure to take both laterals may lead to underdiagnosis if the dependent side is affected.

7
Q

Cytology and culture and sensitivity be performed on lower airway samples from every animal with suspected pneumonia. True/False? Why?

A

False. Should be strongly considered but only performed if safe and other diseases that could mimic pneumonia are ruled out (pulmonary hemorrhage due to coagulopathy, cardiogenic pulmonary edema).

8
Q

Transcutaneous fine-needle aspiration of lung tissue in suspected cases of infectious pneumonia may be (select all that apply):

a) high-yield and low-risk
b) low-yield and high-risk
c) lower risk of the patient is kept in lateral recumbency with aspirated side down for 5-10 minutes following procedure
d) better yield than endotracheal wash in cats with unexplained pulmonary parenchymal disease

A

b) low-yield and high-risk
d) better yield than endotracheal wash in cats with unexplained pulmonary parenchymal disease

for c), 5-10 is too short - lower risk if kept in lateral for 30-60 mins (15-20 if under GA)

9
Q

Abnormalities on arterial blood gas in dogs with pneumonia include (select all that apply):

a) hypoxemia
b) decreased oxygen saturation
c) decreased alveolar-arterial oxygen gradient
d) hypercapnia

A

a) hypoxemia
b) decreased oxygen saturation

c) should be increased not decreased

10
Q

What is the short formula for calculating A-a gradient?

A

Difference between calculated alveolar and measured arterial partial pressures of oxygen
= PAO2 - PaO2
= (150-PaCO2) - PaO2

11
Q

What is a normal A-a gradient?

A

<10mmHg

12
Q

In a dog with pneumonia, what factor may prevent measurement of an accurate A-a gradient, using the abbreviated formula?

A

Can only be accurately measured if the patient is breathing room air (FiO2 21mmHg); can be as high as 100-150mmHg if breathing 100% FiO2

13
Q

Inhaled particulate matter, including pathogens, are largely cleared by the upper respiratory tract. Below which size are they more likely to pass through to be deposited in the alveoli?

A

< 3um (micro-metres)

14
Q

Name 3 mechanisms of hypoxemia secondary to lower airway inflammation.

A
  1. low-ventilation to perfusion regions
  2. small airway and alveolar collapse (atelectasis)
  3. impaired diffusion
15
Q

List 3 effects of chronic or severe pneumonia that predisposes a patient to developing ALI/ARDS

A
  1. destruction of alveolar walls
  2. damage to type II pneumocytes
  3. increased pulmonary vascular permeability
16
Q

List 5 common isolates from TTW in adult dogs with pneumonia.

A
Pasteurella spp (22-28%)
Enterobacteriaceae such as E. coli (17-46%)
Staphylococcus ssp (14-21%)
Streptococcus spp (14-21%)
Mycoplasma spp (8% as sole organism, 62% in coinfections)
17
Q

What percentage of dogs and cats with pneumonia may have coinfections (based on multiple isolates cultured)?

A

dogs: 43-74%
cats: 38%

18
Q

Name the class, spectrum of activity and suggested dose rate for amikacin in pneumonia.

A

Aminoglycoside

gram -ve

15mg/kg (dog), 10mg/kg (cat) IV q24h
Only in euvolemic animals with normal renal function, monitor urine for casts throughout therapy.

19
Q

Name the class, spectrum of activity and suggested dose rate for ampicillin in pneumonia.

A

Aminopenicillin

gram +ve, some gram -ve (certain E.coli, Klebsiella strains), some anaerobes (Clostridia)

22mg/kg IV q6-8h

20
Q

Name the class, spectrum of activity and suggested dose rate for azithromycin in pneumonia.

A

Macrolide

gram +ve, gram -ve, Mycoplasma

5-10mg/kg IV q24h

21
Q

Name the class, spectrum of activity and suggested dose rate for cefoxitin in pneumonia.

A

2nd generation cephalosporin

some gram +ve, some anaerobes

30mg/kg IV q6-8h

22
Q

Name the class, spectrum of activity and suggested dose rate for clindamycin in pneumonia.

A

Lincosamide

gram +ve, Mycoplasma, Toxoplasma, anaerobes

20mg/kg IV q8-12h

23
Q

Name the class, spectrum of activity and suggested dose rate for enrofloxacin in pneumonia.

A

Fluoroquinolone

gram -ve, Mycoplasma

dogs: 5-10mg/kg IV q12h or 12.5-20mg/kg IV q24h
cats: maximum 5mg/kg q24h
Dilute 1:1 with saline

24
Q

Name the class, spectrum of activity and suggested dose rate for gentamicin in pneumonia.

A

Aminoglycoside

gram -ve

dog: 10mg/kg IV q24h
cat: 6mg/kg IV q24h
Only in euvolemic animals with normal renal function, monitor serum creatinine and urine for casts throughout therapy.

25
Q

Name the class, spectrum of activity and suggested dose rate for metronidazole in pneumonia.

A

Nitroimidazole

anaerobes

10mg/kg slow IV q12h

26
Q

Name the class, spectrum of activity and suggested dose rate for ticarcillin/clavulanate in pneumonia.

A

Extended spectrum penicillin + beta-lactamase inhibitor

gram +ve, gram -ve, anaerobes

40-50mg/kg slow IV q6h

27
Q

Name the class, spectrum of activity and suggested dose rate for trimethoprim-sulfamethoxazole in pneumonia.

A

Potentiated sulfonamide

some gram +ve, some gram -ve

15-30mg/kg IV q12h

28
Q

What is the most common isolate in pneumonia in puppies?

A

Bordetella bronchisepta (49%)

29
Q

In general, how long should antibiotics be continued after radiograph resolution of pneumonia?

A

2 weeks minimum.

30
Q

List 3 potential benefits and 3 potential deleterious effects of bronchodilator use in pneumonia.

A

Benefits:

  1. increased airflow
  2. improved ciliary activity
  3. more serous nature of respiratory secretions

Deleterious effects:

  1. suppression of cough reflex
  2. worse V/Q mismatch
  3. exudate within affected lung may spread to unaffected portions
31
Q

Methylxanthine bronchodilators such as aminophylline have 2 additional benefits. List.

A
  1. inhibition of mast cell degranulation

2. decreased microvascular permeability and leak

32
Q

Mucolytics such as N-acetylcysteine are (select all that apply):

a) proven to be beneficial in veterinary patients
b) uncommonly employed
c) safe and efficacious if given intravenously
d) safe and efficacious if given by aerosolization

A

All wrong:

a) no proof of benefit in veterinary patients
b) commonly employed
c) commonly given IV, effects on respiratory system unknown
d) not recommended to be given by aerosolization due to reflex bronchoconstriction (directly irritant)

33
Q

N-acetylcysteine is commonly used for its free radical scavenging effect (glutathione precursor). How does it work as a mucolytic?

A

Breaks down disulphide bonds in thick airway mucus.

34
Q

Why are vaporisers and humidifiers ineffective in delivering particulate saline droplets to the lower airways?

A

Particle size generally >3um, cleared by upper respiratory tract, need to nebulise.

35
Q

List 3 contraindications to coupage.

A
  1. coagulopathy
  2. frequently regurgitating
  3. painful in the chest region
  4. fractious
    (5. relatively contraindicated in animals that are coughing spontaneously and frequently)
36
Q

Pneumonia-causing bacteria are not generally contagious. True/False?

A

True

37
Q

List 3 potentially zoonotic organisms.

A
Mycobacteria spp
Yersinia pestis (plague)
Francisella tularensis (tularemia)
38
Q

What bacteria causes acute, fulminant, hemorrhagic pneumonia (seen most commonly in shelter dogs)?

A

Streptococcos equi subsp. zooepidemicus

Decks in Silverstein & Hopper (+ West) Class (84):