Respiratory and Oxygenation Pathophysiology: Asthma, COPD, Hypoxia, and Critical Lung Disorders|Latest Updated 2026

Respiratory and Oxygenation Pathophysiology: Asthma, COPD, Hypoxia, and Critical Lung Disorders|Latest Updated 2026 Ventilation Air movement through the respiratory system Perfusion Blood flowing through an organ (such as the lung) V/Q ratio (Gas exchange) Air flow and blood flow are matched (Optimally) Ventilation/perfusion mismatch When blood perfuses areas where O2 is not present or vice versa Hypoxia Low oxygen saturation of the body, not enough oxygen in the blood ischemic hypoxia Low blood flow to tissues anemic hypoxia due to anemia resulting from the inability of the blood to carry adequate oxygen hypoxemic low arterial blood oxygen levels Asthma An obstructive airway disease by CHRONIC inflammation leading to airway (Type I) hypersensitivity bronchospasm The immediate response causes airways to constrict leading to difficulty breathing Asthma signs and symptoms Wheezing, dyspnea, SOB, air-trapping (causes hyperinflation of the lungs) Two disorders of COPD Emphysema and chronic bronchitis Emphysema hyperinflation of air sacs with destruction of alveolar walls Chronic bronchitis inflammation of bronchi persisting over a long time causing edema, hypersecretion, chronic cough and bronchospasm COPD risk factors Genetics, Tobacco, Occupational dusts, indoor & outdoor pollution, gender, age, respiratory infections, Asthma, chronic bronchitis Pink puffers Nickname given to patients with emphysema, who often hyperventilate, giving a pink appearance to their skin. COPD maintenance therapy O2, bronchodilators, quitting smoking tension pneumothorax Air is trapped in the pleural space under positive pressure, displacing mediastinal structures and compromising cardiopulmonary function Open pneumothorax Involves an injury to the chest wall where there is air movement from outside the body into the thoracic cavity Closed pneumothorax Involves no opening to the outside of the thoracic cavity Non-tension pneumothorax Just one way flow of air with means that air can enter the pleural space but cannot leave Chylothorax (pleural effusion) A type pf pleural effusion containing lymphatic drainage that has backed up due to lymphatic obstruction Empyema (pleural effusion) Yellow-green pus (from a pneumonia), lung abscess, infected wound or spesis Transudate (pleural effusion) Clear, serous fluid that can come from non-inflammatory processes such as heart failure, ascites or atelectasis Atelectasis A partial lung collapse or inadequate inflation of a lung