L36 - Infectious causes of upper airway obstruction Flashcards

1
Q

List 5 common oropharynx infections?

A

Acute epiglottitis

Corynebacterium diphtheriae

Bilateral peritonsillar abcess

Deep fascial space infections

EBV mononucleosis

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2
Q

Name one common larynx URTI?

A

Laryngotracheobronchitis (croup)

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3
Q

Epidemiology, clinical features, pathogen and diagnosis of acute epiglottitis?

A

children of 2-4 years old (but can also occur in adults)

Fever (6-12 hours), Severe sore throat, Dysphonia, drooling oral secretions**, stridor

Haemophilus influenzae type B

“cherry-red” epiglottis*** by laryngoscopy

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4
Q

Investigation techniques, management of acute epiglottitis?

A
  • XR neck: “thumb” sign (DO NOT wait for XR!)
  • Blood culture
  • Laryngoscopy
  • AIRWAY PROTECTION!
  • Antibiotic e.g. amoxcillin-clavulanate
  • Rifampicin prophylaxis if unvaccinated contact ≤4 years in household
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5
Q

Gram- stain, morphology, classification of the most common bacteria causing acute epiglottitis? Growth requirements?

A

Haemophilus influenzae

  • Gram-negative, coccobacilli
  • Classified into six types (a to f) or nontypeable
  • Growth requires both X (hemin) & V (NAD) factors
  • Produce beta-lactamases
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6
Q

Epidemiology, clinical features, pathogen of Peritonsillar abscess (quinsy)?

A

adolescents and young adults usually

  • Severe sore throat
  • Low grade fever
  • Dysphagia
  • Inflammation of peritonsillar area with medial displacement of tonsil**
  • Bilateral airway obstruction → stridor
  • Group A streptococcus (Streptococcus pyogenes)
  • Mixed (oropharyngeal organisms: viridans Streptococcus, anaerobes)
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7
Q

Management of peritonsillar abscess (quinsy)?

A

AIRWAY PROTECTION!

Antibiotic

Drainage of abscess

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8
Q

Compare Strep. pyogenes to viridans Streptococcus? What URTI do they commonly cause?

A

Peritonsillar abscess (quinsy)

Streptococcus pyogenes:

  • β-hemolytic streptococci
  • Lancefield group A, bile soluble
  • sensitive to bacitracin

viridans Streptococcus:

  • α-hemolytic streptococci
  • bile insoluble
  • resistant to optochin
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9
Q

List the three major deep spaces involved in deep fascial space infections?

A
  • submandibular & sublingual space (Ludwig’s angina)
  • lateral pharyngeal/parapharyngeal space
  • retropharyngeal space
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10
Q

Underlying cause, clinical features, pathogen in Submandibular and sublingual space infection?

A

Dental root abscess 50-90%**

  • Board-like swelling** involving bilateral submandibular and sublingual spaces
  • High fever, systemic toxicity
  • Mouth held open
  • Dysphagia

mixed oral flora

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11
Q

Management of submandibular and sublingual space infections?

A
  • AIRWAY PROTECTION!
  • Antibiotic
  • Soft tissue decompression
  • Dental assessment
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12
Q

Underlying cause, clinical features, complications and pathogen in Lateral pharyngeal/ parapharyngeal space infection?

A
  • Spread of infection from adjacent structures: Odontitis, pharyngitis, tonsillitis, parotitis, otitis, mastoiditis
  • Fever, sore throat, dysphagia, neck stiffness
  • Jugular vein thrombophlebitis (Lemierre syndrome)
  • Carotid artery erosion

pathogens of the primary site

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13
Q

Investigation and management of lateral pharyngeal space infections?

A

CT/MRI to assess extent of infection
Blood culture + Pus culture

AIRWAY PROTECTION!
Antibiotic
Surgical drainage
Treat primary infective focus

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14
Q

Underlying cause, clinical features, complications and pathogen in Retropharygeal space infections?

A

Odontitis, peritonsillar abscess, cervical vertebral osteomyelitis, perforated pharynx

Fever, sore throat, dysphagia, neck stiffness

Complication: Mediastinitis*

Pathogens of primary site:

  • Mixed oral flora (from pharynx or dental source)
  • Staphylococcus aureus (from vertebral osteomyelitis)
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15
Q

Investigation and management of retropharyngeal space infections?

A
  • Neck XR: prevertebral soft tissue swelling + Gas bubbles made by bacteria in abscess
  • CT for assessment of extent of involvement
  • Blood and pus culture
  • AIRWAY PROTECTION!
  • Antibiotic
  • Surgical drainage
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16
Q

What is the most common cause of stridor in children?

A

Croup (laryngotracheobronchitis)

17
Q

Epidemiology, clinical features and pathogens in Croup?

A

Young children of 3 months to 3 years old

URTI symptoms (2-3 days)
Fever, hoarseness, barking cough***, stridor 

Parainfluenza virus, influenza virus, respiratory syncytial virus, adenovirus, rhinovirus, Mycoplasma

18
Q

Investigation and management of croup?

A
  • Neck XR: subglottic swelling, “hourglass” or “steeple” sign***
  • Nasopharyngeal aspirate (NPA) for respiratory virus antigens
  • AIRWAY PROTECTION!
  • Racemic adrenaline ± steroid
19
Q

Compare between acute epiglottitis and Croup:

Age, Appearance and Onset?

A

Acute epiglottitis:

  • 2-4 years old
  • Toxic and unwell
  • Abrupt onset

Croup:

  • 3 months to 3 years old
  • Relatively well looking
  • Viral prodrome (several days, consists of fever, headache, nausea and vomiting, lethargy, and myalgias)
20
Q

Compare between acute epiglottitis and Croup:

severity of fever, stridor and cough?

A

Acute epiglottitis:

  • High fever (>38 C)
  • Moderate to severe stridor
  • Minimal or no cough

Croup:

  • Moderate fever
  • Mild- moderate stridor
  • BARKING cough
21
Q

Compare between acute epiglottitis and Croup: effects on speech and swallowing?

A

Acute epiglottitis:
- Dysphonia + drooling saliva

Croup:
- Hoarse voice + able to swallow

22
Q

List some non-infections causes of URT obstruction?

A
  • Tumour
  • Goitre
  • Bilateral vocal cord palsy
  • Foreign body aspiration

(Others: Angioneurotic edema, Subcutaneous emphysema)

23
Q

Between deep fascial space infections, differentiate the sites of swelling?

A

Submandibular and sublingual space: Floor swelling

Lateral pharyngeal space: Jaw angle swelling

Retropharyngeal space: Posterior pharynx swelling

24
Q

Defining clinical features to distinguish the exact location of Lateral pharyngeal space infection ( Anterior or Posterior)?

A

Anterior = +++ pain and trismus

Posterior = +++ Dyspnea (shortness of breath)

25
Which URTI can lead to mediastinitis?
Retropharyngeal space infections
26
Lateral pharyngeal space infection can spread to which adjacent sites?
Submandibular and sublingual space Carotid sheath Retropharyngeal space Masticator spaces
27
Case 1: M/41: Good past health c/o severe sore throat for 2 days Increase in pain, difficulty in swallowing saliva Progressive SOB, drooling of saliva and sweating Developed sudden cardiac arrest Difficult endotracheal intubation Dx?
Acute epiglottitis
28
``` Case 2: Depression c/o fever, sore throat for 2 days hoarseness, difficulty swallowing P/E: neck swelling Acute SOB with heavy stridor ``` Dx?
Acute epiglottitis
29
``` Case 3: Acute myeloid leukemia in relapse chemotherapy 3 weeks ago c/o fever, hoarseness Associated with sore throat, SOB P/E: inspiratory stridor ``` Dx? *check*
secondary infections complicating conditioning mucositis (after chemotherapy) or Bilateral vocal cord palsy