Exam (elaborations) Med Surg (NUR201) (Med Surg (NUR201)) Exam 3 study guide latest 2021/2022

Exam 3 study guide Chp 25 med surg Pg458 The primary purpose of the respiratory system is gas exchange, which involves the transfer of oxygen and carbon dioxide between the atmosphere and the blood and making it available to the tissues and organs of the body Pg-455 • The upper respiratory tract includes the nose, mouth, pharynx, adenoids, tonsils, epiglottis, larynx, and trachea. The inside of the nose is shaped into 3 passages called turbinates Pg-456 The lower respiratory tract consists of the bronchi, bronchioles, alveolar ducts, and alveoli. Gas exchange takes place by diffusion across the alveolar-capillary membrane. Rt lung has 3 lobes lt lung has 2 lobes Anatomical dead space- the amount of air in the trachea and bronchi Pg-457 Surfactant is a lipoprotein that helps to keep the alveoli open, thus preventing alveolar collapse. • Contraction of the diaphragm, the major muscle of respiration, results in decreased intrathoracic pressure, allowing air to enter the lungs. When there is not enough surfactant the alveolar collapse which is termed atelectasis Oxygenation involves the delivery of oxygen from the atmospheric air to alveolar capillaries and eventual diffusion into the alveoli. Pg 457 Blood supply-lungs have 2 different types of circulation, pulmonary and bronchial. Pulmonary circulation provides the lungs with blood that takes part in gas exchange. Pulmonary artery receives deoxygenated blood from the right ventricle of the heart and delivers it to pulmonary capillaries that lie directly alongside the alveoli. O2-co2 exchange occurs at this point. The pulmonary veins return oxygenated blood to the left atrium, which then delivers it to the left ventricle and into systemic circulation. Bronchial circulation starts with the bronchial arteries, which arise from the thoracic aorta. Bronchial circulation does not take part in gas exchange but provides o2 to the bronchi and other lung tissues. Deoxygenated blood returns from the bronchial circulation through the azygos vein into the superior vena cava. Pg 457 Chest wall- shaped and supported by the 24 ribs, 12 on each side. The thoracic cage which consist of the ribs and sternum, protect the lungs and the heart from injury. The mediastinum is the space in the middle of the thoracic cavity. It contains the major organs of the chest including the heart, aorta, and esophagus. The mediastinum physically separates the right and left lungs. The chest cavity is lined with a membrane called parietal pleura. The lungs are lined with a membrane called the visceral pleura. Both join to form one continuous membrane. The Pg-457 Intrapleural space- space between the pleural layers. Normally contains 20-25mL of fluid. This serves 2 purposes: 1) lubrication allowing the pleural layers to slide over each other during breathing 2) increases unity between the plural layers promoting expansion of the pleurae and lungs during inspiration. Fluid drains from plural space vial lymphatic circulation. Conditions that cause the accumulation of greater amounts of fluid are called a pleural effusion. Inspiration is an active process, involving muscle contraction. • Expiration is a passive process. When elastic recoil is reduced, expiration becomes a more active, labored process. In adults, a normal tidal volume (VT), or volume of air exchanged with each breath, is about 500 mL Pg 458- Diaphragm- major muscle of respiration during inspiration the diaphragm contracts, moves downward, and increases intrathoracic volume, at the same time internal intercostal muscles relax, external muscles contract. Pg 458 Manifestations of inadequate oxygenation Early CNS-unexplained apprehension, restlessness. Early and late- confusion, lethargy. Late- combativeness, coma Early respiratory- Tachypnea, dyspnea on exertion. Late- dyspnea at rest, use of accessory muscles, retraction of intercostal spaces on inspiration, pause for breath between sentences or words Early cardiovascular-tachycardia mild hypertension, dysrhythmias. early and late- dysrhythmias. Late-cyanosis cool clammy skin hypotension. Other early/late signs- diaphoresis, decreased urine output, unexplained fatigue Pg-459 Respiratory defense mechanisms-they are efficient in protecting the lungs from inhale particles, micro organisms, and toxic gases. Nasal hairs filter inspired air. Mucociliary clearance system-h velocity flow of airbelow the larynx. Aka mucociliary escalator, moves mucus. Cilia cover the airways from the trachea to the respiratory bronchioles. They beat rhythmically about 1000x per minute moving mucus toward mouth. Cough reflex- the cough is a protective reflex that clears the airway by a high pressure, high flow of air. Reflex bronchoconstriction-is another defense mechanism. In response to the inhalation of large amounts of irritating substances. Coarse crackles sound like-low pitched, similar to someone blowing into a straw under water on inspiration. Alveolar macrophages- because there are no ciliated cells below the level of the respiratory bronchioles the primary defense mechanism is the alveolar level is macrophages. They rapidly phagocytize inhaled foreign particles, such as bacteria. Pg 460 Gerontologic differences *respiratory structures-chest wall stiffening, costal cartilage calcification, barrel chest appearance, kyphotic posture, decreased elastic recoil, decreased chest wall compliance, decreased functioning Alveoli, normal pH, and PAC02, decreased respiratory muscle strength. Decreased viral capacity decreased cough effectiveness increased residual volume, increased functional residual capacity, decreased breath sounds particularly at lung bases, decreased PA02 and SA02, normal pH, and PAC02. Defense mechanisms: decreased cell mediated immunity, decreased specific antibodies, decreased cellular function, decreased cell force decreased alveolar macrophage function, decreased sensation in pharynx. Decreased cough effectiveness, decreased secretion clearance, taking mucus, increased risk for upper respiratory aspiration, infection, influenza, pneumonia respiratory infections may be more severe and last longer. Respiratory control: decreased response to have hypoxemia, decreased response to hypercapnia, slight decrease PaO2 and increase PaCO2 before respiratory rate changes. Decreased ability to maintain acid-base balance, significant hypercapnia may develop from relatively small incidents. Retain secretions, excessive sedation, or poisoning that impairs chest expansion may substantially change PaO2 or SPO2 values. Pg 460-463, 467, 469-469 Know difference between subjective and objective data pertaining to respiratory exam Pg 469-470 ABGs-to determine oxygenation status and acid base balance. Know that nurse has to apply pressure to site for at least 5 min after procedure Pg 469- Arterial blood gas-ABGs determine oxygenation status, and acid base balance. Respiratory acidosis-kussmal breathing and tachypnea are common symptoms associated Pg 472-473 DIAGNOSTIC STUDIES OF RESPIRATORY SYSTEM • SpO2 monitoring and ABG analysis are classic diagnostic tests used to evaluate the respiratory system. • A chest x-ray is the most common test for assessment of the respiratory system, as well as the progression of disease and response to treatment. • Sputum studies are examined to identify infecting organisms or help confirm a diagnosis. • Skin tests are done to test for allergic reactions or exposure to tuberculosis or fungi. • Bronchoscopy is a procedure in which the bronchi are visualized through a fiberoptic tube. It may be used for diagnostic purposes, to obtain biopsy specimens, and assess changes resulting from treatment. Thoracentesis is the insertion of a large bore needle through the chest wall into the pleural space to obtain specimens for diagnostic evaluation, remove pleural fluid, or instill medication into the pleural space. • Pulmonary function tests (PFTs) measure lung volumes and airflow. • The results of PFTs can diagnose pulmonary disease, monitor disease progression, evaluate disability, and evaluate response to bronchodilators. • In the acute setting, more specific PFT parameters are used to determine the ability to wean and extubate from mechanical ventilation. • Exercise testing is used in diagnosis, measuring functional capacity and response to treatment, and determining level of activity tolerance. IMPORTANT POINTS FROM RATIONALS Coarse crackles are a series of long-duration, discontinuous, low-pitched sounds caused by air passing through an airway intermittently occluded by mucus, an unstable bronchial wall, or a fold of mucosa. Coarse crackles are evident on inspiration and at times expiration. Stridor is a continuous crowing sound of constant pitch from partial obstruction of larynx or trachea. Vesicular sounds are relatively soft, low-pitched, gentle, rustling sounds. They are heard over all lung areas except the major bronchi. Bronchovesicular sounds are normal sounds heard anteriorly over the mainstem bronchi on either side of the sternum and posteriorly between the scapulae with a medium pitch and intensity. With inadequate oxygenation, early manifestations include restlessness, tachypnea, tachycardia, and diaphoresis, decreased urinary output, and unexplained fatigue. Unexplained confusion, dyspnea at rest, hypotension, and diaphoresis; combativeness, retractions with breathing, cyanosis, and decreased urinary output; coma, accessory muscle use, cool and clammy skin, and unexplained fatigue are later manifestations of inadequate oxygenation. A patient with obstructive sleep apnea may have insomnia, abrupt awakenings, or both. Patients with cardiovascular disease (e.g., heart failure that may affect respiratory health) may need to sleep with the head elevated on several pillows (orthopnea). Sleeping more than 8 hours per night or needing to urinate during the night is not indicative of impaired respiratory health. PET is used to distinguish benign and malignant pulmonary nodules. Because malignant lung cells have an increased uptake of glucose, the PET scan (which uses an IV radioactive glucose preparation) can demonstrate increased uptake of glucose in malignant lung cells. This differentiation cannot be made using CT, a pulmonary angiogram, or thoracentesis. Clubbing, a sign of long-standing hypoxemia, is evidenced by an increase in the angle between the base of the nail and fingernail to 180 degrees or more, usually accompanied by an increase in the depth, bulk, and sponginess of the end of the finger. Tracheal deviation is a medical emergency when it is caused by a tension pneumothorax. Tactile fremitus increases with pneumonia or pulmonary edema and decreases in pleural effusion or lung hyperinflation. Diminished chest movement occurs with barrel chest, restrictive disease, and neuromuscular disease. Early clinical manifestations of hypoxemia include dysrhythmias (e.g., premature ventricular contractions), unexplained decreased level of consciousness (e.g., disorientation), dyspnea on exertion, and unexplained decreased urine output. Metabolic acidosis secondary to type 1 diabetes. What is the physiological response? When a patient with type 1 diabetes has hyperglycemia and ketonemia causing metabolic acidosis, the physiologic response is to increase the respiratory rate and tidal volume to blow off the excess CO2. Vomiting and increased urination may occur with hyperglycemia, but not as physiologic responses to metabolic acidosis. The heart rate will increase. Because thoracentesis involves the introduction of a catheter into the pleural space, there is a risk of pneumothorax. Thoracentesis does not carry a significant potential for causing bronchospasm, pulmonary edema, or respiratory acidosis.