An 18-month-old baby girl is bought to the emergency department by her parents, as they are concerned about her noisy breathing. She has had a mild cough for the last 24 h and her temperature is elevated. She is up to date with her vaccinations and has had no developmental problems. There is no other relevant history.
Her oxygen saturation is 94 per cent on air. The baby is restless and has a hoarse cry.There is an audible stridor at rest. The baby has a low-grade fever with a mildly increased respiratory rate. There is no evidence of cyanosis. Auscultation of the chest is difficult but there is an audible inspiratory noise.
• What is the differential diagnosis?
• How do you define stridor?
• What are the causes of stridor?
In this case the two most likely diagnoses are croup (acute laryngo-tracheo-bronchitis) or acute epiglottitis. Laryngo-tracheo-bronchitis presents in childhood and is usually preceded by an upper respiratory tract infection. The child develops malaise, a high temperature and stridor. The stridor is the result of subglottic oedema which soon spreads to the trachea and bronchi. It is usually caused by a viral infection (parainfluenza). Mild cases of croup often respond to oral steroids. Severe cases may require ventilatory support as well as nebulized adrenaline and inhaled or intravenous steroids.
Acute epiglottitis is an absolute emergency and is usually caused by Haemophilus influenzae. There is significant swelling and any attempt to examine the throat may result in airway obstruction. It is rare in children these days because they receive the Haemophilus influenzae type B (HiB) vaccination aspart of their routine immunization programme. In adults it tends to cause a supraglottitis. It has a rapid progression and can lead to total airway obstruction. The patient must be sat upright and an airway secured with an endotracheal tube, by an anaesthetic specialist.
Stridor is defined as a high-pitched noise caused by turbulent airflow in the larynx or trachea as the result of narrowing of the airway.
Aetiology of stridor !
• vocal cord lesion/palsy, e.g. neurological, birth/surgical trauma
• laryngotracheal stenosis, e.g. congenital
• airway haemangioma
• vocal cord palsy secondary to thyroid or chest surgery
• acute epiglottitis/supraglottitis
• laryngeal carcinoma
• laryngotracheal stenosis, e.g. secondary to endotracheal intubation or heat inhalation
• inhalation of a foreign body
• trauma to the anterior neck
• airway compression by thyroid disease
• Stridor is an ominous sign and needs to be taken seriously.
• acute epiglottitis
• airway haemangioma
• foreign body
• airway compression, e.g. thyroid disease
• Treatment is urgent and the patient should be managed in a suitable area, e.g. theatre, resuscitation bay.
• Call for ear, nose and throat and anaesthetic help early