Sandbox:Amd

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Amandeep Singh M.D.[2]

Differential diagnosis

Abbreviations: AP= Anteroposterior, CXR= Chest X-ray, CT= Computed tomography, ABG= Arterial blood gas, V/Q= Ventilation/perfusion scan , EKG= Electrocardiogram, COPD= Chronic obstructive pulmonary disease, BNP= Brain natriuretic peptide, DVT= Deep vein thrombosis, HRCT= High Resolution CT, IgE= Immunoglobulin E

Causes of cyanosis Cyanosis Clinical manifestations/association Diagnosis Additional findings Symptoms Signs Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Respiratory Airway disorder Severe croup ✔ − ✔ ✔ − − − Audible stridor at rest Lymphocytosis AP Neck X ray for soft tissues: Steeple sign Lateral neck X ray: Distended hypopharynx during inspiration Clinical diagnosis Croupy cough and stridor Intercostal, subcostal retractions Epiglottitis ✔ − ✔ ✔ − − − Stridor Leukocytosis with neutrophilia Blood cultures Throat culture in intubated patients Lateral neck X ray Thumbprint sign (swollen epiglottis) Laryngoscopy Sore Throat Dysphagia Odynophagia Muffled voice Drooling Foreign body aspiration ✔ − ✔ ✔ ✔ − − Decreased breath sounds Wheezing ABGs CXR Hyperinflation (children) Atelectasis (adults) Objects CT scan Foreign body Entrapment with edema or granulation tissue Bronchoscopy Complications: Inflammation Mediastinitis Local emphysema Atelectasis Cyanosis Bacterial tracheitis ✔ − ✔ ✔ ✔ − − Inspiratory stridor Blood cultures Gram stain Lateral neck X ray Confusing Steeple sign Irregular tracheal margin Laryngotracheo-bronchoscopy Brassy cough Retractions No drooling Hoarseness Disease Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Additional findings Parenchymal disorder Massive pulmonary embolism ✔ − ✔ ✔ ✔ − ✔ Reduced breath sounds Rales, crackles Loud P2 ABGs D-dimer EKG BNP CXR V/Q scan Spiral CT pulmonary angiogram Venous ultrasound for DVT D-dimer Spiral CT pulmonary angiogram Ventilation/perfusion scan Tachycardia Shock Pulmonary hypertension can occur Pneumonia − ✔ ✔ ✔ ✔ ✔ − Reduced breath sounds Rales, crackles, wheeze Pleural friction rub ABGs Leukocytosis Pancytopenia Hyponatremia CXR CT chest Bronchoscopy Sputum culture and gram stain Blood cultures Urine antigen Chest X-ray Tachycardia Bradycardia (Legionella) CURB-65 Asthma (Late) − ✔ ✔ − ✔ ✔ in interstitial lung disease − End expiratory wheeze Absent wheeze and breath sounds in severe form ABG Eosinophilia IgE CXR to rule out other diagnosis complications like pneumonia, atelactasis HRCT Allergic bronchopulmonary aspergillosis Bronchiectasis Spirometry/ Pulmonary function testing Reversible obstructive disease Peak expiratory flow measurement is easy and very helpful GERD is a cause in case of refractory asthma. Triad of asthma, nasal polyps and rash is indicative of aspirin sensitivity. Cystic fibrosis ✔ ✔ when infected ✔ ✔ − Wheeze or crackles Sputum stain and culture Sweat test Genetic test for CFTR (gene) CXR Hyperinflation Peribronchial thickening Nodules Bronchiectasis HRCT for detecting lung changes Clinical history Sweat test Usually present since birth Recurrent pneumonia Recurrent wheezing Recurrent sinusitis Gastrointestinal manifestations Meconium ileus Pancreatic insufficiency Disease Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Additional findings COPD (Severe emphysema) ✔ − ✔ − ✔ − ✔ Reduced breath sounds Prolonged expiration Wheeze Inspiratory crackles Hematocrit ABG Sputum staining and culture Alpha 1-antitrypsin test CXR Elongated heart Flattening of diaphragms Prominent hilar vasculature HRCT Bullae HRCT Spirometry (FEV1) to assess severity Pulmonary hypertension Right heart failure Empyema ✔ ✔ ✔ − − Crackles Thoracentesis Chest X-ray Pleural opacity Localization of effusion Physical examination Crackles Egophony Increased tactile fremitus Chest wall disorders Flail chest − ✔ − − − Pneumothorax ✔ − ✔ − ✔ − − − Pulmonary arterio-venous malformation − ✔ ✔ − ✔ ✔ − Decreased or absent breath sounds over the area Cardiovascular Congenital heart diseases Disease Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Additional findings Atrioventricular canal defect ✔ ✔ + ✔ + Ebstein anomaly ✔ ✔ ✔ Hypoplastic left heart syndrome ✔ ✔ Pulmonary atresia ✔ ✔ Tetralogy of Fallot ✔ ✔ ✔ Pulmonic stenosis ✔ ✔ Total anomalous pulmonary venous drainage ✔ ✔ Transposition of the great vessels ✔ ✔ Truncus arteriosus ✔ ✔ Disease Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Additional findings Heart failure ✔ ✔ + − + ✔ + Valvular heart disease ✔ + − − − − Myocardial infarction ✔ ✔ − ✔ − − − Hematologic Methemoglobinemia ✔ Polycythemia ✔ Central Nervous system Disease Peripheral Central Dyspnea Fever Chest pain Clubbing Peripheral edema Auscultation Lab Findings Imaging Gold standard Additional findings Coma ✔ Seizures ✔ Head trauma ✔ Breath holding spells ✔ Miscellaneous Shock ✔ Smoke inhalation ✔ + + + Toxic gases + + + + ± Cold exposure ✔ − − − − − − Drugs† − − − − −