Respiratory System Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Overview • Exchange of gases between the environmental air and blood • Processes – Ventilation: Movement of air into and out of the lungs – Diffusion: Movement of gases between air spaces in the lungs and the bloodstream – Perfusion: Movement of blood into and out of the capillary beds of the lungs to body organs and tissues – Pulmonary system: Carries out the first two processes. – Cardiovascular system: Carries out the third process. 2 Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins It’s all About the Alveoli… • Alveoli: Primary gas exchange units • Lungs contain approximately 25 million alveoli at birth and 300 million by adulthood • Pulmonary circulation has a lower pressure (18 mmHg) than systemic circulation (90 mmHg). • Only one third of vessels filled with blood at any given time. One of the reasons position changes are important Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Alveolocapillary Membrane Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pulmonary and Bronchial Circulation Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Signs and Symptoms of Dysfunction • Dyspnea • Hyperventilation • Abnormal breathing patterns • Coughing • Hypoxema • Hypercapnia • Cyanosis • Changes in mentation Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Signs and Symptoms of Pulmonary Disease Hypoventilation • Alveolar ventilation is inadequate in relationship to the metabolic demands. • Leads to respiratory acidosis from hypercapnia. • Is caused by airway obstruction, chest wall restriction, or altered neurologic control of breathing. Hyperventilation • Alveolar ventilation exceeds the metabolic demands. • Leads to respiratory alkalosis from hypocapnia. • Is caused by anxiety, head injury, or severe hypoxemia. Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Hypoxemia • PO2 less than 60 mm Hg – Cyanosis – Agitated or combative behavior, euphoria, impaired judgment, convulsions, delirium, stupor, coma Hypotension and bradycardia • Activation of compensatory mechanisms – • PCO2 greater than 50 mm Hg • Respiratory acidosis • Impaired function of vital centers – Hypercapnia – Increased respiration – Decreased nerve activity º Carbon dioxide narcosis º Disorientation, somnolence, coma – Decreased muscle contraction º Vasodilation Headache; warm flushed skin Sympathetic system activation Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pulse Oximetry Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pleura • Parietal pleura lines the thoracic wall and superior aspect of the diaphragm. • Visceral pleura covers the lung. • Pleural cavity or the space between the two layers contains a thin layer of serous fluid. Pleural Effusion • Hydrothorax: serous fluid • Empyema: pus • Chylothorax: lymph • Hemothorax: blood Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Empyema – Infected pleural effusion – Pus in the pleural space – Clinical manifestations • Cyanosis, fever, tachycardia (rapid heart rate), cough, and pleural pain – Treatment • Administration of antimicrobial medications • Drainage of the pleural space with a chest tube • Severe cases: Ultrasound-guided pleural drainage, instillation of fibrinolytic agents, or deoxyribonuclease (DNase) injected into the pleural space • Surgical debridement Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Restrictive Lung Disorders • Atelectasis – Collapse of previously expanded lung tissue (adult) or incomplete expansion of lungs at birth. • Primary atelectasis (lung tissue remains un-inflated at birth due to insufficient surfactant) • Secondary atelectasis (obstruction, compression, decreased surfactant) Surfactant impairment – Clinical manifestations • Dyspnea, cough, fever, and leukocytosis – Treatment: Prevention • Deep breathing Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Restrictive Lung Disorders • Restrictive disorders characterized by difficult to inflate lungs • Pulmonary fibrosis – Excessive amount of fibrous or connective tissue in the lung – Caused by scar tissue, inhalation of dangerous substances • Pulmonary edema is excess water in the lung and is a common complication of cardiac disorders. • Pneumonia is infection of the lower respiratory tract by microorganisms Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Changes in Airflow with Total Laryngectomy Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nursing Process: Care of a Patient with a Laryngectomy - Planning • Adequate level of knowledge (patient, family) • Reduction of anxiety • Maintenance of patent airway • Effective means of communication • Attaining optimum hydration, nutrition • Improved body image, self-esteem • Self-care management • Absence of complications Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Tracheostomy • Surgically created stoma (opening) used to – Establish a patent airway – Bypass an airway obstruction – Facilitate secretion removal – Permit long-term mechanical ventilation – Facilitate weaning from mechanical ventilation Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Parts of Tracheostomy Tube Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Tracheostomy Tubes Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Tracheostomy Care • Cleansing inner cannula – Gather equipment, position patient, don PPE, set up equipment – Don sterile gloves – Unlock and remove inner cannula; place in sterile saline, cleanse, rinse, reinsert • Cleanse stoma Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Chest Trauma • Traumatic injuries to chest contribute to majority of all traumatic deaths • Range of injuries – Simple rib fractures → life-threatening organ rupture – Blunt – Penetrating • Open wound through pleural space Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Chest Trauma • Hemothorax – Blood in pleural space – Treat with chest tube • Hemopneumothorax • Chylothorax – Lymphatic fluid in pleural space – Treat conservatively, with meds, surgery, or pleurodesis Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Chest Trauma: Emergency Management • Assess for signs of cardiovascular compromise – Rapid, thready pulse – Decreased BP with narrowed pulse pressure and/or asymmetric readings – Distended neck veins – Muffled heart sounds – Chest pain – Dysrhythmias Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pneumothorax • Air enters the pleural cavity. • Air takes up space, restricting lung expansion. • Partial or complete collapse of the affected lung: – Spontaneous: air-filled blister on the lung ruptures – Traumatic: air enters through chest injuries º Tension: air enters pleural cavity through wound on inhalation, cannot leave on exhalation º Open: air enters pleural cavity through the wound on inhalation and leaves on exhalation Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pneumothorax From Thibodeau and Patton K: The Human body in health and disease, ed 5, St Louis, 2010, Mosby Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pneumothorax Types • Spontaneous – Rupture of blebs – Can occur in healthy or chronically ill persons • Iatrogenic – Caused by medical procedures • Open – Air enters through an opening in the chest wall • Closed – No external wound Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Pulmonary Embolism (From Brooks ML: Exploring medical language – a student-directed approach, St Louis, 2005, Mosby, Elsevier) Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins PE Risk Factors • Deep vein thrombosis • Smoking • Immobility or reduced mobility • Heart failure • Surgery • History of DVT • Malignancy • Obesity • Oral contraceptives/ hormones • Pregnancy/delivery • Clotting disorders • Atrial fibrillation • Central venous catheters • Fractured long bones Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Tuberculosis • World’s foremost cause of death from a single infectious agent • Causes 26% of avoidable deaths in developing countries • Lungs most commonly infected • 1/3 of world’s population has TB • countries • Drug-resistant forms • Mycobacterium tuberculosis hominis – Aerobic – Protective waxy capsule – Can stay alive in “suspended animation” for years Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Diagnostic Studies • Tuberculin skin test (TST) – AKA: Mantoux test – Assess for induration in 48 – 72 hours – Positive if ≥15 mm induration in low-risk individuals – Response ↓ in immunocompromised patients • Reactions ≥5 mm considered positive • Interferon-γ gamma release assays (IGRAs) • Chest x-ray • Bacteriologic studies Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Asthma • A chronic inflammatory disease of the airways that causes hyperresponsiveness, mucosal edema, and mucus production • Inflammation leads to cough, chest tightness, wheezing, and dyspnea. • The most common chronic disease of childhood • Can occur at any age • Allergy is the strongest predisposing factor. Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Asthma • Treatment – – – – Oxygen and inhaled beta-agonist bronchodilators Inhaled corticosteroids Leukotriene agonists Immunotherapy • Monoclonal antibodies to IgE – Education about allergens and irritants and peak flowmeters Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins COPD • Risk factors • Cigarette smoking • Occupational chemicals and dust • Air pollution • Severe recurring respiratory infections • Treatment • Nursing care Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Cor Pulmonale • Right-sided heart failure secondary to lung disease or pulmonary hypertension – Decreased lung ventilation – Pulmonary vasoconstriction – Increased workload on the right heart – Decreased oxygenation – Kidney releases erythropoietin more RBCs made polycythemia makes blood more viscous – Increased workload on the heart Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
