What's the Difference Between Stridor and Stertor?

Patient Presentation
A 16-month-old female came to clinic with increased secretions and problems breathing.
She had underlying severe mental retardation, cerebral palsy, gastroesophageal reflux with aspiration and increased oral secretions usually controlled by Robinul®.
She has had copious rhinorrhea for 2 days and increased oral secretions.
Her parents describe a barky-sound when breathing in since the previous night.
She has had a fever to 100.6° F but no coughing, emesis, rashes or other symptoms.
The pertinent physical exam shows an ill-appearing female with increased work of breathing. Her respiratory rate was 58 breaths/minute and temperature of 38° C. Her weight was 50% for a 12 month old.
She had copious, clear rhinorrhea and increased oral secretions with drooling. She occasionally would choke on the secretions but easily cleared them.
She had a mid-pitched inspiratory sound coming from the upper airway that sounded like stridor.
During inspiration she had some tracheal tugging but no intercostal retractions.
Her lung examination was normal with transmitted upper airway sounds.
The rest of her examination was consistent with her baseline.
The work-up included a nasal wash for respiratory pathogens that was negative and a chest radiograph that was negative.
The patient was referred to otolaryngology for further evaluation. In the office, she was noted to have significant floppiness of the upper airways along with enlarged tonsils and adenoids.
Her laryngeal apparatus appeared normal.
The diagnosis of upper respiratory tract infection causing stertor and enlarged tonsils and adenoids was made.
The primary care physician did not know the difference between stertor and stridor so the otolaryngologist explained how they were similar but distinctly different sounds with different causes.
The patient’s clinical course over the next 2 days included having a direct laryngoscopy and bronchoscopy and tonsillectomy and adenoidectomy.
Following surgery, she was placed on dexamethasone to decrease swelling and discharged on day 3.

Upper respiratory tract infections are commonly caused by many different serotypes of rhinorviruses.
Other viruses can present similarly. Rapid antigen detection of nasal secretions is generally available and reliable.
The viruses specifically tested for varies by location but often includes viruses which may cause more severe disease especially Respiratory Syncytial Virus, Influenza A and B, and Parainfluenza and Adenovirus.
Identifying the virus aids in cohorting similar patients in the hospital, institution of infection control measures and with community surveillance.

Learning Point
Stedman’s Medical Dictionary defines stertor as “[a] heavy snoring inspiratory sound occurring in coma or deep sleep, sometimes due to obstruction of the larynx or upper airways.”
Causes of stertor include choanal stenosis, enlarged tonsils and/or adenoids, and redundant upper airway tissues.

Stedman’s Medical Dictionary defines stridor as “[a] high-pitched noisy sound occurring during inhalation or exhalation, a sign of respiratory obstruction.”Common causes are croup, foreign body, bacterial tracheitis, pharyngeal abscesses, allergic reactions and epiglottitis.

Questions for Further Discussion
1. What are some other common causes of stertor?
2. What are some other common causes of stridor?
3. What are indications for evaluation by an otolaryngologist?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MedlinePlus for these topics: Snoring.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Stertor. The American Heritage® Stedman’s Medical Dictionary.
Available from the Internet at http://dictionary.reference.com/browse/stertor (cited 2/4/08).

Stridor. The American Heritage® Stedman’s Medical Dictionary. Available from the Internet at http://dictionary.reference.com/browse/stridor (cited 2/4/08).

Benson BE, Baredes, S. Stridor. eMedicine.
Available from the Internet at http://www.emedicine.com/ped/TOPIC2159.HTM (rev. 8/29/2006, cited 2/4/08).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    6. Information technology to support patient care decisions and patient education is used.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    16. Learning of students and other health care professionals is facilitated.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    March 24, 2008