Mediastinum and pleura Flashcards
components of anterior mediastinum
Thymus Gland, Substernal thyroid and parathyroid tissue, Lymphatic vessels and nodes, Connective Tissue
components of middle mediastinum
Heart, Pericardium, Aortic arch and great vessels, Innominate veins and SVC, Trachea and major bronchi
Hila, Lymph nodes, Phrenic and upper vagus nerves, Connective tissueHeart, Pericardium, Aortic arch and great vessels, Innominate veins and SVC, Trachea and major bronchi
Hila, Lymph nodes, Phrenic and upper vagus nerves, Connective tissueHeart, Pericardium, Aortic arch and great vessels, Innominate veins and SVC, Trachea and major bronchi
Hila, Lymph nodes, Phrenic and upper vagus nerves, Connective tissue
components of posterior mediastinum
Esophagus, Descending aorta, Azygous and hemiazygous veins, Thoracic duct, Lymph nodes, Vagus nerves (lower portion), Sympathetic chains, Connective tissue
Symtoms of mediastinal mass
compression/invasion of adjacent structures, fever, anorexia, weight loss, endocrin symptoms, auto immune (thymus related)
compare mediastinal masses in adults vs children
adults are usually anterior, wheras children are usually posterior masses
list Anterior mediastinal masses
Thymoma (thymic neoplasm), Teratoma (germ cell tumor), Terrible Lymphoma, Thyroid tissue neoplasm, plus mesenchymal neoplasm, diaphragmatic hernia and primary carcinoma
List middle mediastinal masses
Lymphadenopathy, developmental cysts, etc
List posterior mediastinal masses
Neurinomas (peripheral nerve)
What diagnostic tests are used to diagnose mediastinal mass
CXR to determine compartment, CT chest to differentiate btw cysts and solid lesions, fatty structures, lymphadenopathy vs vascular. CBC, needle aspiration, surgical (mediastinoscopy), Beta-HCG, alpha fetoprotein
Complications of mediastinal masses
Tracheal Obstruction, SVC Syndrome , Vascular invasion with hemorrhage , Esophageal Rupture
What condition is often associated with thymomas
paraneoplastic syndromes such as lupus, polymyositis, myocarditis, Sjogrens, and sarcoidosis
What is the pleura
•Two single-cell thick, continuous membranes that line the outer surface of the lung, inner surface of the thoracic cavity and meet at the hilar root of lung.
What is a pneumothorax and list the potential causes
Air in the pleural space. Causes: spontaneous (primary occurs in absence of underlying disease or secondary occurs as complication of underlying disease) or traumatic (iatrogenic from medical treatment/procedure or non iatrogenic)
Causes of primary spontaneous pneumothorax
rupture of subpleural emphysematous blebs which are common in the lung apices in patients who smoke, have a family history or in tall thin males. Other risk factors include narrowed airways and missing bronchi.
List causes of secondary spontaneous pneumothorax
inherited disease (folliculin gene defect), COPD, PCP, MTb, necrotizing pneumonia, cystic fibrosis, interstitial lung disease, pneumoconiosis, lung cancer
Causes of non iatrogenic traumatic pneumothorax
penetrating or blunt tauma to chest (increases alveolar pressure from chest compression)
List causes of iatrogenic and non-iatrogenic traumatic pneumothorax
Placement of central lines, barotrauma (intubation, mechanical ventilation)
Clinical presentation of pneumothorax
Acute onset chest pain, Dyspnea , Cough, Anxiety , Cyanosis, Respiratory distress
Physical exam of pneumothorax
Hyper resonant chest percussion , Decreased / absent breath sounds , Decreased fremitus, Chest wall trauma, Decreased rib space
Lab findings in spontaneous pneumothorax
hypoxia, increased A-a gradient, respiratory alkalosis
CXR of pneumothorax
Pleural line, increased hemithorax volume, tracheal/mediastinal shift towards contralateral hemothorax or depression of ipsilateral hemidiaphragm
Treatment of pneumothorax
Observation, Supplemental oxygen (100%), Simple aspiration, Tube thoracostomy (chest tube), Pleurodesis, open thoracotomy
Prevention of pneumothorax after initial pneumothorax
Sclerosis of pleural space using chemical or surgical technique to prevent recurrenc. Chemical agents include talc and tetracycline, but talc can be associated with ARDS and chronic pleural fibrosis/ restrictive disease. Video assisted thoracoscopic surgery and open thoracotomy is most effective approach but high mortality.
What is a tension pneumothorax
Medical emergency. Intrapleural pressure exceeds atmospheric pressure throughout expiration and often during inspiration. Causes hemodynamic compromise by decreasing venous return and limiting cardiac output
Symptoms of tension pneumothorax
Tachycardia, hypotension, Respiratory distress, cyanosis, profuse diaphoresis
Treatment of tension pneumothorax
DO NOT wait for CXR results. Emergently insert an 18 gauge angiocath in the second intercostal space along the midclavicular line and attach IV tubing to the end which is placed in a cup of saline. Place tube thoracostomy if pneumothorax confirmed
Pleural effusion definition
Normal fluid is 0.2-0.3 mL/kg. Pleural effusion results when the rate of pleural fluid formation exceeds drainage. Associated with both localized pleural disorders and systemic conditions that affect the pleura.
Clinical presentation of pleural effusion
Dyspnea, Pleuritic chest pain, Dry cough, Symptoms associated with underlying cause, Decreased breath sounds, dullness to percussion, decreased tactile and vocal fremitus on examination
Pleural effusion CXR findings
meniscus sign and dense opacity
Types of pleural effusions
Transudative effusions result from alteration in hydrostatic forces that affect fluid formation (non-protein rich). Exudative effusions are due to alterations in permeability of the pleura or rate of fluid removal (protein rich).
Diagnostic procedure for pleural effusion
Thoracentesis- collect fluid from the effusion and assess for transudate vs exudate
Trasudate vs exudate
Transudate: LDH plasma/LDH serum < 0.6 and Protein plasma/Protien serum < 0.5. Exudate: LDH pl/LDH ser > 0.6 or Protpl/Protser > 0.5 or LDHpl > 0.667 upper limit normal for serum
Pleural fluid analysis
LDH (+ serum), Total protein (+ serum), pH, glucose, CBC, gram stain, culture, AFB/fungal stains and culture, cytology
Conditions that cuase transudative pleural effusion
Congestive heart failure, cirrhosis with ascites, nephrotic syndrome, peritoneal dialysis, myxedema. Etc
Conditions that cause exudative pleural effusion
infection, cancer, PE, Asbestos, sarcoidosis, uremia, etc
Pleural abnormalities
Pleural Thickening, Pleural Plaques, Pleural Tumors
Describe pleural tumors
Most are malignant and most are metastatic (from lung, breast, lymphoma, GI or GU)
Describe pleural plaques
Develop from chronic inflammation and asbestos (20-30 yrs after exposure)
Describe pleural thickening etiology
Inflammation following infection, Hemorrhage, Prior treatment for effusion/ptx, Occupational exposure (i.e. asbestos), Trauma, Neoplasm. Begins as inflammation and fibrosis along visceral pleura with secondary response of parietal pleura
