Monophonic Inspiratory Wheezing

MANUAL OF CLINICAL DIAGNOSIS

Monophonic inspiratory wheezing refers to high-pitched, continuous breath sounds heard during inspiration, usually caused by partial obstruction of the large airways. These sounds, often termed “stridor” when particularly sharp and audible without a stethoscope, indicate significant airflow disruption in the upper airways, typically due to a fixed obstruction. Identifying and treating the underlying cause is crucial to prevent severe complications.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Acute Bilateral Vocal Cord Paralysis	Dyspnoea, weak or breathy voice, inspiratory stridor, difficulty speaking, monophonic wheezing	Medical history, physical examination, signs of respiratory obstruction	Laryngoscopy, video laryngoscopy
Inhaled Foreign Body	Sudden onset of coughing, choking, cyanosis, monophonic wheezing, unilateral decreased breath sounds	History of aspiration, physical examination, signs of obstruction	Chest X-ray, bronchoscopy
Tracheal Tumour	Progressive dyspnoea, stridor, persistent cough, haemoptysis, monophonic wheezing	Medical history, physical examination, signs of obstruction	Chest CT, bronchoscopy, biopsy
Tracheal Stenosis Secondary to Intubation	Dyspnoea, stridor, monophonic wheezing, respiratory difficulty, history of prolonged intubation	Medical history, physical examination, signs of obstruction	Chest CT, bronchoscopy, laryngoscopy
Extrinsic Airway Compression by Mediastinal Masses	Dyspnoea, cough, stridor, monophonic wheezing, dysphagia	Medical history, physical examination, signs of obstruction	Chest CT, magnetic resonance imaging (MRI), biopsy
Extrinsic Compression by Oesophageal Tumours	Dysphagia, regurgitation, stridor, monophonic wheezing, weight loss	Medical history, physical examination, signs of obstruction	Oesophageal endoscopy, chest and abdominal CT, biopsy
Blunt Tracheal Trauma	Chest pain, dyspnoea, haemoptysis, stridor, monophonic wheezing	History of trauma, physical examination, signs of obstruction	Chest CT, bronchoscopy, laryngoscopy