- Information
- AI Chat
Gas Exchange for Ventilation and Perfusion
Human Pathophysiology (NUR 252)
Creighton University
Recommended for you
Preview text
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. GAS EXCHANGE Ventilation is the movement of oxygen into the lungs and carbon dioxide out of the lungs. a. This is impaired if the airway is narrowed or if there is a lack of oxygen available in the atmosphere Perfusion is the movement of blood into and out of capillary beds of lungs and the body tissues. a. When perfusion is impaired, oxygen does not reach cells so ischemia may occur Dyspnea is the feeling of breathlessness and increased respiratory effort. This is a subjective sensation so we must believe them when they say they are short of breath, breathless, or cannot breathe. If it is more severe, these symptoms might be observed: a. Nasal flaring b. Retractions c. Sweating d. Tachypnea (increased rate of breathing) Dyspnea on exertion occurs during exercise and goes away when exercise stops. Orthopnea is feeling short of breath when lying flat. Sitting up will relieve this. Dyspnea at rest is an ominous sign. Coughing is a protective reflex that expels secretions and irritants from the lower airways. a. Acute cough resolves within weeks of illness onset b. Chronic cough lasts longer than 2 may be due to chronic bronchitis or asthma Changes in the sputum volume, consistency, or color may indicate underlying pulmonary disease. Hemoptysis is expectoration of bloody the secretions are bright red, frothy, and have increased pH a. Usually due to inflammation damaging the bronchi, pneumonia, TB, or cancer Wheezing is high pitched and due to narrowed airways. Rhonchi is low pitched and usually clears with coughing. Crackles are due to fluid in the lungs Pleural friction rub is a grating sound due to inflammation of the pleural space. Hypoventilation is decreased alveolar ventilation caused airway obstruction, chest wall restriction, or altered neurologic control of breathing. a. CO2 is removed slower than it is made which causes hypercapnia Hyperventilation is increased alveolar ventilation that exceeds metabolic demands and is produced anxiety, head injury, or severe hypoxemia a. CO2 is removed faster than it is produced which causes hypocapnia Cyanosis is a bluish discoloration of the skin caused desaturation of hemoglobin, polycythemia, or peripheral vasoconstriction. a. Only apparent when severely hypoxemic so it is not a good indicator of respiratory failure b. Central cyanosis is due to right to left cardiac shunts and causes blue lips and buccal membranes c. Peripheral cyanosis is due to poor circulation, so it is seen in fingers and toes Clubbing of the fingertips is enlargement at the distal portion of the finger and painless and occurs with chronic hypoxemia associated with diseases that interfere with oxygenation of the tissues. Chest pain can result from inflamed pleurae, tracheae, bronchi, or respiratory muscles. If it is a respiratory cause you should be able to push on it and cause the same pain. Hypoxemia is a reduced partial pressure of blood oxygen caused a. decreased oxygen content of inspired gas b. hypoventilation c. diffusion abnormality d. mismatch mismatch) e. shunting 20. Hypoxemia leads to compensatory hyperventilation that causes decreased CO2, which leads to an increased pH, which leads to respiratory alkalosis. 21. Pneumonia is a respiratory infection of the lower respiratory tract caused bacteria, viruses, fungi, protozoa, or parasites. a. Often caused aspiration: food, vomit, or liquid is aspirated and then an inflammatory response begins. People at risk for aspiration pneumonia are people with dysphagia (difficulty swallowing), impaired cough reflex, uncuffed or deflated tracheostomy, smokers, people with decreased level of consciousness b. People most at risk for pneumonia in general: i. Elderly ii. Immunosuppressed Alcoholics iv. Those with altered level of consciousness v. Smokers (have decreased cilia) vi. People with impaired swallowing c. If bacterial pneumonia, then usually caused Streptococcus pneumonia, which adheres to alveolar macrophages and causes an inflammatory response d. The alveolar macrophages are the most important protectors of the lungs e. With pneumonia, we see fever, chills, malaise, cough, yellow or green sputum, chest pain, and dyspnea on exertion. 22. There are three obstructive pulmonary disorders: asthma, chronic bronchitis, and emphysema. All three of these have dyspnea, wheezing, increased work of breathing, and decreased FEV1 (decreased volume of air expired in the first second). 23. Asthma is an obstructive pulmonary disorder that usually occurs acutely due to a type 1 hypersensitivity immune response involving the activity of antigen, immunoglobulin E, mast cells, eosinophils, and other inflammatory cells and mediators. 24. Asthma can be a. Intrinsic is when the trigger is unknown, but something triggers inflammation and bronchospasm b. Extrinsic is the typical asthma that is triggered an environmental allergen and leads to the mast cell degranulation and IgE response 25. Acute onset of asthma presents with wheezing, dyspnea, tachycardia, and tachypnea. If the attack is severe, there will be use of the accessory muscle and a thorax. 28. Vascular Disorders a. Pulmonary embolism is the occlusion of part of the pulmonary blood flow, commonly caused a deep vein thrombosis i. If there is decreased cardiac output, we will see shock which shows as decreased LOC, low urine output, fatigue, clammy skin, decreased pulses b. Pulmonary hypertension is increased pressure in the pulmonary circulation due to COPD and hypoventilation syndromes that cause chronic hypoxemia, which causes vasoconstriction in the lungs that leads to increase pressure i. Can cause fatigue, tachypnea, dyspnea, dyspnea on exertion, and right heart failure (because the blood will not want to enter the high pressure of the pulmonary circulation so the right side of the heart has to work extra hard to pump) 29. Smoking is the number one risk for cancers of the respiratory system. a. Generally, a person with cancer will have hoarseness, dyspnea, cough, hemoptysis, pericardial friction rub, and decreased breath sounds 30. Croup is an acute laryngotracheobronchitis and almost always occurs in children between 6 months and 5 years of age. It is commonly due to a viral upper respiratory infection. a. There is inflammation and edema of the upper airway because of the inflammation (will see narrowing of the trachea at the cricoid cartilage) b. Will see a low fever and sore throat, then harsh barking cough with inspiratory stridor and hoarse voice 31. Sudden Infant Death Syndrome is the number one cause of unexplained sudden infant death and often follows viral infections, but the etiology is unknown a. Risk if: i. Premature ba ii. Ba in first 6 months of life Prone position 1. Put ba to iv. Suffocation 1. Do not put stuffed animals in the bed 32. Respiratory Distress Syndrome in the Newborn is the number one cause of neonatal death and most commonly due to a lack of surfactant. a. Will see tachypnea, stridor, grunting, retractions, nasal flaring 33. Cystic Fibrosis is an autosomal recessive mutation that leads to altered chloride ion channels in epithelial cells, which leads to defective chloride transport, which leads to dry, sticky mucus secretions a. There is a decrease of pancreatic enzymes so there is an increased blood sugar b. Mucus obstructs the airway, impairing the alveoli, and preventing foreign particles from being cleared, resulting in chronic lung infections c. There is malabsorption that causes and loose, bulky stools d. We will see clubbing, recurrent pneumonia, fatty stools, and a sweat chloride test of
Gas Exchange for Ventilation and Perfusion
Course: Human Pathophysiology (NUR 252)
University: Creighton University
