Respiratory System Study Guide PDF

**[INTRODUCTION TO THE RESPIRATORY SYSTEM]** **I. Introduction to the Respiratory System** - **External Respiration:** - Defined as the exchange of oxygen and carbon dioxide between the lungs and the environment. - Involves inhaling air that is warmed, moistened, and filter...

**[INTRODUCTION TO THE RESPIRATORY SYSTEM]** **I. Introduction to the Respiratory System** - **External Respiration:** - Defined as the exchange of oxygen and carbon dioxide between the lungs and the environment. - Involves inhaling air that is warmed, moistened, and filtered. - Works with the cardiovascular system to deliver oxygen to cells for metabolism. - Failure of either system leads to rapid cell death due to oxygen deprivation. - **Internal Respiration:** - Defined as the exchange of oxygen and carbon dioxide at the cellular level. - Oxygen enters cells, and carbon dioxide leaves them, following a concentration gradient via diffusion. - The blood stream acts as a transporter of these gases. **II. Upper Respiratory Tract** - **Nose:** - Air enters through the nares (nasal openings) and is filtered, moistened, and warmed. - The nasal septum divides the nares. - The mucous membrane lining is vascular, providing warmth and moisture and secretes 1 liter of moisture daily. - Tiny hairs trap foreign particles, preventing them from entering the lower respiratory tract. - **Turbinates (conchae):** Three scroll-like bones that increase surface area for air warming and moisturizing. - **Paranasal Sinuses:** Hollow cavities (frontal, maxillary, sphenoid, and ethmoid) that lighten the skull, give resonance to the voice, and are lined with mucous membranes. - **Smell Receptors:** Located in the nasal cavity mucosa; they are the nerve endings of the olfactory nerve (CN I). - **Nasolacrimal ducts (tear ducts):** Communicate with the upper nasal chamber, causing nasal secretions during crying. - **Pharynx (throat):** - A passageway for both air and food, extending about 5 inches (13 cm) from the base of the skull to the esophagus. - **Subdivisions:** - **Nasopharynx:** The most superior portion, containing the adenoids (pharyngeal tonsils). - **Oropharynx:** Posterior to the mouth, containing the palatine tonsils. - **Laryngopharynx:** Directly superior to the larynx. - **Eustachian Tubes:** Connect the nasopharynx to the middle ear, which can lead to ear infections from pharyngeal infections, especially in children. - **Larynx (voice box):** - Connects the pharynx to the trachea and contains the vocal cords; the opening between the vocal cords is the glottis. - Supported by nine areas of cartilage. - **Thyroid cartilage (Adam\'s apple):** The largest cartilage area, which enlarges during puberty in males. - **Epiglottis:** A leaf-shaped cartilage that protects the larynx during swallowing, preventing food from entering the trachea. - **Trachea:** - A tube-like structure, with C-shaped cartilaginous rings, extending about 4 1/3 inches (11 cm) to the mid-chest, where it divides into the right and left bronchi. - Located anterior to the esophagus and connects the larynx with the bronchi. - Covered in the neck by the isthmus of the thyroid gland. - The open part of the C-shaped cartilage allows esophageal expansion during swallowing, while the trachea remains open for breathing. - Lined with mucous membranes and cilia, which move debris upward toward the nasal cavity. - The cough reflex is triggered by large particles, helping to expel foreign material. **III. Lower Respiratory Tract** - **Bronchial Tree:** - The left bronchus enters the left lung. - **Right Bronchus:** Larger in diameter and more vertical than the left, making it a common site for aspirated foreign objects. - **Left Bronchus:** Smaller in diameter and more horizontal compared to the right. - **Bronchioles:** Smaller structures of the bronchi. - **Terminal Bronchioles (alveolar ducts):** Lined with ciliated mucous membrane. - **Alveoli:** Terminal structures of the bronchial tree where gas exchange occurs. - Have thin walls to facilitate gas exchange. - Lie in contact with blood capillaries for diffusion of gases. - Coated with surfactant to reduce surface tension and prevent collapse. **IV. Mechanics of Breathing** - **Thoracic Cavity:** - Primarily occupied by the lungs. - The **mediastinum** (interpleural space) contains the heart and great vessels. - The **intrapleural space** is enclosed by the sternum, ribs, and thoracic vertebrae. - **Lungs:** - Paired, spongy, cone-shaped organs. - The right lung has 3 lobes, and the left lung has 2 lobes. - **Blood Supply:** - Pulmonary arteries carry blood from the heart. - Gas exchange occurs via diffusion. - Oxygenated blood returns to the left atrium via pulmonary veins. - **Visceral pleura:** Covers the surface of each lung. - **Parietal pleura:** Covers the walls of the thoracic cavity. - **Pleural Cavity:** - Airtight vacuum with negative pressure that helps keep the lungs inflated. - Air in the lungs is at atmospheric pressure, which is higher than in the pleural cavity. - The pleura produces serous fluid to allow the lungs to slide over the thorax during breathing. - Excess serous secretion leads to pleural effusion, which might require thoracentesis. **V. Regulation of Respiration** - **Medulla oblongata and pons:** Control the basic rhythm and depth of respiration. - **Chemoreceptors:** - Located in the carotid and aortic bodies. - Sensitive to blood carbon dioxide, oxygen, and pH levels. - Normal arterial blood pH range is 7.35-7.45; normal venous range is 7.31-7.41. - Stimulate or suppress respirations to normalize blood values. - Increased carbon dioxide, decreased oxygen, or increased acidity trigger nerve impulses to modify respiratory rates. - **Carbon dioxide is the primary chemical stimulant for respiration**. **VI. Respiratory Assessment** - The respiratory system is always assessed as part of a patient\'s general health. - Patients needing extensive respiratory assessment include those with acute/chronic respiratory/cardiac conditions, history of respiratory impairment, or recent surgery. - Physical and emotional responses are related; thus, stress and anxiety should be assessed. - **Subjective Data:** - **Shortness of Breath (SOB) and Dyspnea on Exertion (DOE):** Subjective experiences that only the patient can accurately describe. - Assess onset, duration, precipitating factors, and relief measures. - **Cough:** Productive or non-productive, harsh/dry/hacking, and the color and amount of expectorated mucous. - **Objective Data:** - Begins with observation of patient's expression, chest movement, and respiratory expansion. - Assess respiratory rate and oxygen saturation. - Distress indicators such as wide-eyed, anxious look, flared nostrils, and chest retractions. - **Orthopnea:** Patient must sit or stand to breathe comfortably. - **Auscultation:** Assess all lung fields for adventitious breath sounds. - **Sibilant wheeze (wheeze):** High-pitched, squeaking or whistling sounds due to narrowed bronchioles. - **Sonorous wheeze (rhonchi):** Low-pitched, coarse, snoring sounds, often on expiration. - **Crackles:** Short, interrupted crackling or bubbling sounds, usually during inspiration. - **Pleural friction rubs:** Low-pitched, grating or creaking sounds when inflamed pleural surfaces rub together. - **Signs/Symptoms of Hypoxia:** Oxygen deficiency in cellular tissues. - Apprehension, anxiety, restlessness, decreased concentration, disorientation, decreased consciousness, fatigue, vertigo, behavioral changes, increased pulse (or bradycardia), increased respiratory rate (or shallow/slow respirations), elevated/decreased blood pressure, cardiac dysrhythmias, pallor, cyanosis, clubbing, dyspnea. **VII. Oxygen Therapy** - Various devices are used for oxygen therapy based on patient needs. - The nurse\'s skill with these therapies directly affects the patient's outcome. - Oxygen flow rate is ordered in liters per minute. - **Fraction of inspired oxygen (FiO2):** Percentage or concentration of oxygen delivered. - **Safety Precautions:** - Oxygen supports combustion, so avoid electric sparks, fire, smoking, open flames, lighters, matches, candles. - No wool blankets, non-fire-resistant clothing, or friction toys. - Electrical equipment must be in good working order with 3-pronged plugs. - Avoid petroleum jelly due to combustibility. - Oxygen cylinders should not be stored near heat sources. - **Humidification** is necessary to prevent drying of the mucous membranes. - **Lifespan Considerations:** - Arterial oxygen levels decrease with age (PaO2 can be 80-85 mmHg). - The respiratory drive is initiated by rising carbon dioxide levels but can shift to hypoxia in chronic conditions. - **In some patients with chronic pulmonary disease, high oxygen can reduce their respiratory drive and cause respiratory difficulty or even stop their breathing**. - Flow rates \> 2 L/min can eliminate respiratory drive in some patients. - Older adults are prone to skin impairment from nasal cannulas. - **Administration of oxygen requires critical thinking and evaluation of patient's response**. - Oxygen is treated like a drug and must be ordered by a healthcare provider. - The nurse is responsible for administration of oxygen in the correct manner, adjusting flow rate and evaluating the patient's response; proper device placement may be delegated to UAP, but not flow rate adjustment. - **Oxygen toxicity:** High levels of oxygen can cause scarring in the pulmonary tissues and blindness; it is related to the duration of exposure and FiO2, not PaO2. **VIII. Oxygen Equipment** - **Nasal Cannula:** Tube inserted into the nasal cavity. - Delivers up to 6 liters per minute, providing 24-44% FiO2. - Humidify oxygen if flow is greater than 4 L/min. - Patients with obstructive pulmonary disease should be given 2-3 liters/minute. - Easy to dislodge and has a risk of necrosis. - **Mask:** - **Simple Face Mask:** Liter flow of 5-8 L/min, FiO2 of 35-55%. - **Face mask with reservoirs:** - **Partial rebreather:** 6-12 L/min, FiO2 of 60-90%. - **Non-rebreather:** 6-15 L/min, FiO2 of 70-100%; valves prevent the bag from deflating. - The reservoir bag must be completely full before being placed on the patient. - **Venturi (air-entrainment mask):** Delivers consistent and accurate FiO2 (24-55%), regardless of breathing pattern. **IX. Patient Teaching** - Proper application of oxygen equipment. - Review safety precautions. - Stress the dangers of adjusting oxygen flow rate without discussing it with the provider. - Ambulate or change position frequently to mobilize secretions. - Teach cough and deep breathing exercises. - Maintain adequate fluid intake; avoid caffeine and dairy products. - Teach rationale for prescribed medications and their side effects. - Perform oral hygiene regularly. **X. Diagnostic Procedures** - **Chest X-Ray:** Visualizes the thoracic cavity, lungs, heart, and vessels; identifies lesions, infiltrates, foreign bodies, or fluid; can confirm pneumothorax, pneumonia, pleural effusion, and pulmonary edema. - **Computed Tomography (CT) Scans:** Takes detailed pictures of lung tissue; painless, non-invasive, and can be diagonal or cross-sectional. - **Pulmonary Angiography:** Uses contrast material to visualize pulmonary vasculature, detecting pulmonary embolism and congenital lesions. - **Ventilation-Perfusion Scan (V/Q Scan):** Assesses airflow to alveoli (ventilation) and blood flow to alveoli (perfusion); abnormal scans suggest impaired circulation to the alveoli. - **Pulmonary Function Test (PFT):** Assesses the severity of disease in airways; includes lung volume, ventilation, spirometry, and gas exchange tests; measures lung volume, inspiratory capacity, and total lung capacity. - **Mediastinoscopy:** Surgical procedure to obtain lymph node samples for biopsy in the upper mediastinum, done under general anesthesia. - **Laryngoscopy:** Allows direct or indirect visualization of the larynx, done with local or general anesthesia. - **Bronchoscopy:** A bronchoscope is passed into the trachea and bronchi to visualize and examine the tracheobronchial tree, obtain biopsies, or collect secretions. - Patient treated as a surgical patient; informed consent is needed; patient is NPO until gag reflex returns. - Monitor for laryngeal edema/spasms; blood-streaked sputum is normal after biopsy. - **Sputum Specimen:** Obtained for microscopic evaluation; gram stain, and culture and sensitivity. - Must be brought up from the lungs; collect before antibiotics and meals. - Instruct the patient to inhale deeply, cough forcefully, and expectorate into a sterile container; hypertonic saline aerosol may help. - **Cytology Studies:** Performed on bodily secretions to detect abnormal or malignant cells. - **Lung Biopsy:** Obtains tissue for evaluation, can be done transbronchially or as an open-lung biopsy. - Open-lung biopsy is used when other procedures do not provide diagnosis; chest is opened with thoracotomy incision. - **Thoracentesis:** Surgical puncture to aspirate fluid from the pleural space for diagnostic or therapeutic purposes. - Fluid is examined for specific gravity, WBCs, RBCs, protein, glucose, pathogens, and abnormal cells. - Removal of fluid is limited to 1300 mL to avoid fluid shift and pulmonary edema. - **Arterial Blood Gas (ABG):** Essential for diagnosing and monitoring respiratory disorders; measures lungs' ability to exchange oxygen and carbon dioxide and acid-base balance. - **PaO2:** Amount of oxygen dissolved in plasma (mmHg). - **SaO2:** Amount of oxygen bound to hemoglobin (%). - **Normal Values:** - pH: 7.35-7.45. - PaCO2: 35-45 mmHg. - PaO2: 80-100 mmHg. - HCO3: 21-28 mEq/L. - SaO2: 95%. - Relationship between pH and PaCO2: As CO2 rises, pH decreases and as CO2 drops, pH rises. - Lungs attempt to compensate for metabolic imbalances by adjusting carbon dioxide levels. - The kidneys compensate for respiratory imbalances by adjusting HCO3- levels. - Performed at the bedside using a heparinized syringe and needle to draw blood from the radial artery after the Allen test is performed. - Pressure is applied to the puncture site after the blood sample is drawn; the sample is put on ice and sent for analysis.