L36 - Infectious causes of upper airway obstruction Flashcards
List 5 common oropharynx infections?
Acute epiglottitis
Corynebacterium diphtheriae
Bilateral peritonsillar abcess
Deep fascial space infections
EBV mononucleosis
Name one common larynx URTI?
Laryngotracheobronchitis (croup)
Epidemiology, clinical features, pathogen and diagnosis of acute epiglottitis?
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
Investigation techniques, management of acute epiglottitis?
- 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
Gram- stain, morphology, classification of the most common bacteria causing acute epiglottitis? Growth requirements?
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
Epidemiology, clinical features, pathogen of Peritonsillar abscess (quinsy)?
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)
Management of peritonsillar abscess (quinsy)?
AIRWAY PROTECTION!
Antibiotic
Drainage of abscess
Compare Strep. pyogenes to viridans Streptococcus? What URTI do they commonly cause?
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
List the three major deep spaces involved in deep fascial space infections?
- submandibular & sublingual space (Ludwig’s angina)
- lateral pharyngeal/parapharyngeal space
- retropharyngeal space
Underlying cause, clinical features, pathogen in Submandibular and sublingual space infection?
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
Management of submandibular and sublingual space infections?
- AIRWAY PROTECTION!
- Antibiotic
- Soft tissue decompression
- Dental assessment
Underlying cause, clinical features, complications and pathogen in Lateral pharyngeal/ parapharyngeal space infection?
- 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
Investigation and management of lateral pharyngeal space infections?
CT/MRI to assess extent of infection
Blood culture + Pus culture
AIRWAY PROTECTION!
Antibiotic
Surgical drainage
Treat primary infective focus
Underlying cause, clinical features, complications and pathogen in Retropharygeal space infections?
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)
Investigation and management of retropharyngeal space infections?
- 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
What is the most common cause of stridor in children?
Croup (laryngotracheobronchitis)
Epidemiology, clinical features and pathogens in Croup?
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
Investigation and management of croup?
- Neck XR: subglottic swelling, “hourglass” or “steeple” sign***
- Nasopharyngeal aspirate (NPA) for respiratory virus antigens
- AIRWAY PROTECTION!
- Racemic adrenaline ± steroid
Compare between acute epiglottitis and Croup:
Age, Appearance and Onset?
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)
Compare between acute epiglottitis and Croup:
severity of fever, stridor and cough?
Acute epiglottitis:
- High fever (>38 C)
- Moderate to severe stridor
- Minimal or no cough
Croup:
- Moderate fever
- Mild- moderate stridor
- BARKING cough
Compare between acute epiglottitis and Croup: effects on speech and swallowing?
Acute epiglottitis:
- Dysphonia + drooling saliva
Croup:
- Hoarse voice + able to swallow
List some non-infections causes of URT obstruction?
- Tumour
- Goitre
- Bilateral vocal cord palsy
- Foreign body aspiration
(Others: Angioneurotic edema, Subcutaneous emphysema)
Between deep fascial space infections, differentiate the sites of swelling?
Submandibular and sublingual space: Floor swelling
Lateral pharyngeal space: Jaw angle swelling
Retropharyngeal space: Posterior pharynx swelling
Defining clinical features to distinguish the exact location of Lateral pharyngeal space infection ( Anterior or Posterior)?
Anterior = +++ pain and trismus
Posterior = +++ Dyspnea (shortness of breath)
Which URTI can lead to mediastinitis?
Retropharyngeal space infections
Lateral pharyngeal space infection can spread to which adjacent sites?
Submandibular and sublingual space
Carotid sheath
Retropharyngeal space
Masticator spaces
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
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
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
