Respiratory System - Chapter 3 PDF

Chapter 3 RESPIRATORY SYSTEM Key Terms   adenocarci nomas adult respiratory distress syndrome (ARDS) alveolar, or air-space, pneumonia  bronchogenic carcinoma  bullae  chronic bronchitis  emphysema  extrinsic asthma  interstitial pneumonia  intrinsic asthma  pulmonary...

Chapter 3 RESPIRATORY SYSTEM Key Terms   adenocarci nomas adult respiratory distress syndrome (ARDS) alveolar, or air-space, pneumonia  bronchogenic carcinoma  bullae  chronic bronchitis  emphysema  extrinsic asthma  interstitial pneumonia  intrinsic asthma  pulmonary mycosis  asthma   bronchial adenomas small cell (oat cell) carcinomas  squamous carcinoma  surfactant  bronchiecta sis Copyright © 2021 by Elsevier, Inc. All Rights Reserved.  2 Key Terms (Cont.)  bronchogenic carcinoma   chronic bronchitis  emphysema  extrinsic asthma  interstitial pneumonia  intrinsic asthma  pulmonary mycosis  small cell (oat cell) carcinomas  squamous carcinoma surfactant Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 3 Physiology of the Respiratory System  Primary function of the respiratory system is the intake of oxygen and the removal of carbon dioxide from the blood.  Alveoli are the smallest functional unit of the respiratory system where the actual gas exchange occurs. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 4 Internal Devices  Chest radiographs are used to verify the proper placement of the following devices:  Endotracheal tube  Central venous catheter  Swan-Ganz catheter  Transvenous cardiac pacemaker Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 5 Proper Endotracheal Tube Placement Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 6 Improper CV Line Placement Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 7 Summary of Internal Devices Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 8 Congenital/Hereditary Diseases  Cystic Fibrosis  Hyaline Membrane Disease Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 9 Cystic Fibrosis  Cystic fibrosis is characterized by the secretion of excessively viscous mucus by all the exocrine glands; it also affects the pancreas and digestive system.  It is caused by a defective gene in the middle of chromosome 7.  Ninety percent of the morbidity and mortality related to cystic fibrosis occurs as a result of respiratory involvement. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 10 Cystic Fibrosis (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 11 Hyaline Membrane Disease  Hyaline membrane disease is also known as idiopathic respiratory distress syndrome (IRDS).  It is one of the most common causes of respiratory distress in the newborn, primarily premature.  It is caused by a lack of surfactant in immature lungs. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 12 Hyaline Membrane Disease (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 13 Summary of Findings for Congenital/Hereditary Disorders Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 14 Inflammatory Disorders of the Upper Respiratory System  Croup  Epiglottitis Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 15 Croup 16  Croup is primarily a viral infection of young children that produces inflammatory obstructive swelling localized to the subglottic portion of the trachea.  It is characterized by a barking cough. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. Epiglottitis  Epiglottitis is most commonly caused by Haemophilus influenzae in children.  It causes thickening of epiglottic tissue and the surrounding pharyngeal structures.  Incidence has decreased due to routine childhood immunization. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 17 Epiglottitis (Cont.) Arrow points to enlarged epiglottis. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 18 Summary for Inflammatory Disorders of the Upper Respiratory System Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 19 Inflammatory Disorders of the Lower Respiratory System  Pneumonia  Anthrax  Lung Abscess  Tuberculosis  Pulmonary Mycosis  Respiratory Syncytial Virus (RSV)  Severe Acute Respiratory Syndrome (SARS) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 20 Pneumonia  Pneumonia is an inflammation of the lung that can be caused by a variety of organisms, most commonly bacteria and viruses.  Pneumonia produces three radiographic patterns:  Alveolar, or air-space, pneumonia  Bronchopneumonia  Interstitial pneumonia- may cause “honeycomb lung” shown as dense fibrous walls on a CT Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 21 Pneumonia (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 22 Pneumonia – CT Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 23 Anthrax  24 Anthrax is caused by Bacillus anthracis.  It can survive for decades in the soil without a host.  It is easily transmitted and highly fatal.  There are three ways to contract anthrax:  Cutaneous, through an opening in the skin – most common type  Inhalation (lungs) – usually fatal without prompt treatment  Gastrointestinal – caused by ingestion of contaminated meat Copyright © 2021 by Elsevier, Inc. All Rights Reserved. Lung Abscess  Lung abscess is a necrotic area of pulmonary parenchyma containing purulent (puslike) material.  Aspiration is the most common cause.  It also may be a complication of pneumonia, bronchial obstruction, a foreign body, or the hematogenous spread of organisms to the lungs either in a patient with diffuse bacteremia or as a result of septic emboli. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 25 Lung Abscess – CXR Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 26 Lung Abscess – CT Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 27 Summary for Inflammatory Disorders of the Lower Respiratory System Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 28 Tuberculosis  Tuberculosis is caused by Mycobacterium tuberculosis.   It is a rod-shaped bacterium with a protective waxy coat – permits it to live outside the body for a long time. It spreads mainly by droplets in the air. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 29 Tuberculosis (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 30 Respiratory Syncytial Virus (RSV)  RSV is the most common cause of bronchiolitis.  RSV attacks the lower respiratory tract, causes necrosis of the respiratory epithelium of the bronchi and bronchioles, and causes bronchiolitis.  Bronchial obstruction occurs due to necrotic material and edema that result from the infection.  Bronchiolitis produces bronchial spasm, and interstitial pneumonia occurs as a result of the obstruction. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 31 RSV (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 32 Severe Acute Respiratory Syndrome  Most commonly referred to by its acronym SARS.  First case appeared in China.  Causative agent – a SARS-associated coronavirus of unknown etiology.  SARS is transmitted by direct or droplet contact.  No known transmissions since 2004 Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 33 Summary of Findings for Viruses Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 34 Diffuse Lung Disease  Chronic Obstructive Pulmonary Disease  Sarcoidosis  Pneumoconiosis Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 35 Chronic Obstructive Pulmonary Disease (COPD)  COPD includes several conditions in which chronic obstruction of the airways leads to an ineffective exchange of respiratory gases and makes breathing difficult.  Chronic bronchitis  Emphysema  Asthma Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 36 Emphysema Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 37 Emphysema – CT Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 38 Asthma 39 Copyright © 2021 by Elsevier, Inc. All Rights Reserved. Summary of Findings for Diffuse Lung Disease Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 40 Summary of Findings for Diffuse Lung Disease (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 41 Pneumoconiosis  Pneumoconiosis is a severe pulmonary disease caused by inhalation of irritating particles.  Most common types:  Asbestosis  Silicosis  Anthracosis (coal worker’s disease) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 42 Summary of Findings for Pneumoconiosis Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 43 Neoplasms  Solitary Pulmonary Nodule  Bronchial Adenoma  Bronchogenic Carcinoma  Pulmonary Metastases Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 44 Bronchial Adenoma  Low-grade malignant lesions  Appears in a younger age group than bronchogenic carcinoma  Most common symptoms:  Hemoptysis  Recurring pneumonia Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 45 Bronchial Adenoma (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 46 Bronchogenic Carcinoma  Bronchogenic carcinoma is primary carcinoma of the lung.  It arises from the mucosa of the bronchial tree.  It is linked to smoking and to the inhalation of cancer-causing agents (carcinogens), such as air pollution, exhaust gases, and industrial fumes. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 47 Bronchogenic Carcinoma (Cont.)  Common types of bronchogenic carcinoma are non-small cell and small cell (oat cell).  Non-small cell types = 80% of all lung cancers  Squamous carcinoma – most common  Adenocarcinoma  Bronchiolar (alveolar cell) carcinoma – least common Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 48 Pulmonary Metastases  Pulmonary metastases develop from hematogenous or lymphatic spread.  Most commonly from musculoskeletal sarcomas, myeloma, and carcinomas of the breast, urogenital tract, thyroid, and colon.  Carcinomas of the breast, esophagus, or stomach may spread to lungs via direct extension due to anatomic proximity. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 49 Pulmonary Metastases (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 50 Summary of Findings for Pulmonary Neoplasms Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 51 Vascular Diseases  Pulmonary Embolism  Septic Embolism  Pulmonary Arteriovenous Fistula Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 52 Pulmonary Embolism  Pulmonary embolism is the most common lung pathology of hospitalized patients.  It may be fatal.  It is asymptomatic in about 80% of cases.  It is difficult to diagnose even in those with symptoms.  More than 95% of embolisms arise from deep vein thrombosis in the lower extremities. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 53 Pulmonary Embolism 54 Top image: NM lung scan Bottom image: CT Copyright © 2021 by Elsevier, Inc. All Rights Reserved. Septic Embolism  Septic embolism is a bacterial “shower” that enters pulmonary circulation, then gets trapped in the lung.  Septic embolisms arise primarily from   Heart – bacterial endocarditis  Peripheral veins – septic thrombophlebitis It is more common in IV drug abusers. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 55 Pulmonary Arteriovenous Fistula  Pulmonary arteriovenous (AV) fistula is an abnormal vascular communication between a pulmonary artery and a vein.  Multiple pulmonary AV fistulas are not uncommon.   Often have AV fistulas in other organs, as well. Very large or multiple fistulas can cause cyanosis due to too much venous blood shunting into arterial circulation. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 56 Summary for Pulmonary Vascular Diseases Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 57 Miscellaneous Lung Disorders  Atelectasis  Adult Respiratory Distress Syndrome  Intrabronchial Foreign Bodies  Mediastinal Emphysema (Pneumomediastinum)  Subcutaneous Emphysema Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 58 Atelectasis  Atelectasis is defined as a condition in which there is diminished air within the lung associated with reduced lung volume.  It is caused by bronchial obstruction, which may be due to:  Neoplasm  Foreign body (e.g., peanut, coin, or tooth)  Mucous plug Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 59 Atelectasis (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 60 Adult Respiratory Distress Syndrome (ARDS) Lung structure breaks down, with massive  leakage of cells and fluid into the interstitial and alveolar spaces.  Hypoxia and severe respiratory impairment results.  It is life threatening. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 61 Adult Respiratory Distress Syndrome (Cont.) Develops in those who have medical and  surgical disorders but no major lung disease.  It is most common in patients with nonthoracic trauma who develop hypotension and shock, so it is often called “shock lung.” Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 62 Adult Respiratory Distress Syndrome (Cont.) Other causes   Severe pulmonary infection  Aspiration  Inhalation of toxins and irritants  Drug overdose Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 63 ARDS 64 Copyright © 2021 by Elsevier, Inc. All Rights Reserved. Intrabronchial Foreign Bodies  Aspiration of solid foreign bodies into the tracheobronchial tree occurs almost exclusively in young children.  Radiopaque foreign bodies are easily detected on CXR.  Radiolucent foreign bodies are diagnosed by secondary signs in the lungs caused by partial or complete bronchial obstruction.  Lower lobes are more commonly affected.  Right side is affected more often than the left. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 65 Intrabronchial Foreign Bodies (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 66 Mediastinal Emphysema (Pneumomediastinum)  Mediastinal emphysema is defined as air within the mediastinum.  Causes include:   Spontaneous (severe coughing, vomiting, or straining ruptures alveoli, releasing air)  Chest trauma  Perforation of the esophagus or tracheobronchial tree  Spread of air along fascial planes in the neck, peritoneal cavity, or retroperitoneal space Air may also extend peripherally and rupture into the pleural space, causing an associated pneumothorax. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 67 Pneumomediastinum Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 68 Subcutaneous Emphysema  Subcutaneous emphysema is defined as free air in the tissues of the chest wall.  Caused by   Penetrating or blunt injuries that disrupt the lung and parietal pleura It is characterized by crepitation (a crackling sound or sensation) on palpation. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 69 Summary for Miscellaneous Lung Disorders Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 70 Disorders of the Pleura  Pneumothorax  Pleural Effusion  Empyema Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 71 Pneumothorax  Pneumothorax is the presence of air in the pleural cavity, resulting in a partial or complete collapse of the lung.  Causes:  Rupture of a subpleural bulla  Spontaneous event in an otherwise healthy young adult  Trauma (e.g., stabbing, gunshot, or fractured rib)  Iatrogenic causes (e.g., after lung biopsy or the introduction of a chest tube for thoracentesis)  Complication of neonatal hyaline membrane disease Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 72 Pneumothorax (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 73 Pleural Effusion  Pleural effusion is defined as the accumulation of fluid in the pleural space.  It is a nonspecific finding caused by a wide variety of pathologic processes.   Congestive heart failure  Pulmonary embolism  Infection (especially TB)  Pleurisy  Neoplastic disease  Connective tissue disorders Pleural effusion can occur as a result of abdominal disease, such as recent surgery, ascites, subphrenic abscess, and pancreatitis. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 74 Pleural Effusion (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 75 Empyema  Empyema is defined as a rare accumulation of infected liquid or frank pus in the pleural space.  It is usually caused by the spread of an adjacent infection (e.g., bacterial pneumonia, subdiaphragmatic abscess, lung abscess, and esophageal perforation).  It may occur after thoracic surgery, trauma, or instrumentation of the pleural space. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 76 Empyema (Cont.) Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 77 Summary of Findings for Pleural Disorders Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 78 Disorders of the Diaphragm  Diaphragmatic Paralysis  Eventration of the Diaphragm  Other Causes of Elevation of the Diaphragm Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 79 Diaphragmatic Paralysis  Diaphragmatic paralysis is caused by any process that interferes with the phrenic nerve.  It shows on images as the elevation of one or both leaves of the diaphragm.  It results in diminished lung volume. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 80 Eventration of the Diaphragm  Eventration of the diaphragm is a rare congenital abnormality in which one hemidiaphragm (very rarely both) is poorly developed and weak.  It permits the upward movement of abdominal contents into the thoracic cage.  It is usually asymptomatic.  It occurs more commonly on the left. Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 81 Other Causes of Diaphragm Elevation  Ascites  Obesity  Pregnancy  Any other process in which the intraabdominal volume is increased Copyright © 2021 by Elsevier, Inc. All Rights Reserved. 82