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NCM 112 MIDTERMS by TONS and MADS MIDTERMS COVERAGE: Respiratory and Cardiovascular WEEK 5 - INTRODUCTION TO RESPIRATORY DISORDERS VID: Respiratory System - not transcribed BOOK: CHAP 21 Page 486 RESPIRATORY SYSTEM (More info in Chap 21) A. PRIMARY FUNCTIONS a. Oxygen transport i. O2 is supplied and CO2 is removed ii. Cells are in close contact with capillaries that permit easy passage or exchange of O2 and. iii. Diffuses through membrane of tissue cells, used by mitochondria for cellular respiration. b. Respiration and Ventilation: i. O2 concentration in blood within capillaries of lungs is lower than in the lungs’ air sacs (alveoli) → oxygen diffuses from the alveoli to the blood. ii. CO2 higher concentration in the blood than in alveoli diffuses from the blood into the alveoli. iii. Movement of air in & out of airways (ventilation) c. Pulmonary Diffusion and Perfusion: Works in concert with CV system i. Diffusion: O2 and CO2 are exchanged at air–blood interface. ii. Alveolar–capillary membrane - ideal for diffusion because of its thinness and large surface area. B. SECONDARY FUNCTIONS a. Facilitates sense of smell b. Produces speech c. Maintains acid-base balance d. Maintains body water levels e. Maintains heat balance C. Gas exchange: delivering O2 to tissues through bloo vdstream, expelling waste gas CO2 during expiration. ANATOMY - Upper and lower respiratory tracts: 2 tracts responsible for ventilation (movement of air in and out of airways). I. UPPER RESPIRATORY TRACT (upper airway)- warms and filters inspired air so that the lower respiratory tract (lungs) can accomplish gas exchange. A. Larynx (voice organ/box) 1. Cartilaginous epitheliumvvnvj tv lined structure that connects pharynx and trachea. 2. Major function: vocalization. 3. Protects lower airway from gvvvforeign substances and facilitates coughing. 4. Consists of the following: a) Epiglottis: valve flap of cartilage that covers opening to larynx during swallowing b) Glottis: (entrance to larynx); opening between the vocal cords in the larynx c) Thyroid cartilage: largest of cartilage structures; part of it forms Adam’s apple d) Cricoid cartilage: the only complete cartilaginous ring in larynx (below thyroid cartilage) e) Arytenoid cartilages: used in vocal cord movement with thyroid cartilage f) Vocal cords: ligaments controlled by muscular movements that produce sounds; located in lumen of larynx B. Nose - passageway for air to pass to and from lungs. 1. Filters impurities and humidifies and warms air as it is inhaled. 2. External portion protrudes from the face and is supported by nasal bones and cartilage. 3. Anterior nares (nostrils): external openings of nasal cavities. 4. Internal portion is hollow cavity separated into right and left nasal cavities by the septum. 5. Each nasal cavity is divided into 3 passageways by projection of turbinates from lateral walls. 6. Turbinate bones conchae, because of their curves, increase mucous membrane surface of nasal passages and slightly obstruct air flowing through them. Air entering nostrils is deflected upward to the roof of the nose comes into contact with large surface of moist, warm, highly vascular, ciliated mucous membrane (nasal mucosa) that traps practically all dust and organisms in inhaled air. 7. Nerves detect odors; others provoke sneezing to expel irritating dust. 8. Mucus, secreted continuously by goblet cells, covers surface of nasal mucosa and is moved back to nasopharynx by action of the cilia C. Sinuses (Paranasal Sinuses) 1
NCM 112 MIDTERMS by TONS and MADS a) I: epithelial cells that form alveolar walls. b) II: metabolically active, secrete surfactant c) III: macrophages, large phagocytic cells ingest foreign matter; defense mechanism. III. Accessory Muscles of Respiration A. Scalene – Elevate first 2 ribs B. Sternocleidomastoid – Raises sternum during inhalation. C. Trapezius & Pectoralis – Fix the shoulder. VENTILATION 1. Inspiration - Occurs during first 3rd of respiratory cycle a. When capacity of chest is increased, air enters through trachea (inspiration) because of lowered pressure within and inflates the lungs. b. Requires energy 2. Expiration - during the later two thirds a. When chest wall and diaphragm return to their previous positions (expiration), lungs recoil and force air out through the bronchi and trachea. b. In respiratory diseases, such as COPD, expiration requires energy c. Passive, requiring very little energy PERFUSION - availability & movement of capillary blood for exchange of gasses, nutrients, and cellular metabolites. RESPIRATORY ASSESSMENT I. Health History - focuses on physical & functional problems, effects on ADLs, usual work and family activities A. Severe dyspnea: modify or abbreviate questions and timing of health history to avoid increasing breathlessness & anxiety. B. Identifying chief reason for seeking health care C. Determine when it started, how long it lasted, if it was relieved and how relief was obtained. D. Obtain information on precipitating factors, duration, severity, and associated factors or symptoms. E. Common (Major) Signs & Symptoms 1. Dyspnea (subjective feeling of difficult or labored breathing, breathlessness, SOB) a) Common to many pulmonary and cardiac disorders: decreased lung compliance or increased airway resistance; Right ventricle affected because it pump blood through lungs against greater resistance. b) Associated w/ neurologic/neuromuscular disorders (myasthenia gravis, GBS, muscular dystrophy, post polio syndrome) that affect respiratory function. c) After physical exercise in people w/o disease d) Common at end of life. e) Acute diseases of lungs produce more severe grade of dyspnea than chronic f) Sudden dyspnea in healthy px: acute respiratory obstruction, pneumothorax, allergic reaction, or MI. (1) In immobilized patients, sudden dyspnea → pulmonary embolism. g) ARDS: Dyspnea and tachypnea with progressive hypoxemia from lung trauma, shock, cardiopulmonary bypass, or multiple blood transfusions. h) Heart disease/COPD: Orthopnea (inability to breathe easily except upright position) (1) COPD: Dyspnea w/ expiratory wheeze i) Noisy breathing from narrowing of airway or localized obstruction of major bronchus by tumor or foreign body. (1) Stridor: High-pitched sound heard (usually inspiration; partially blocked upper airway) (2) Asthma: Inspiratory and expiratory wheezing if no HF. j) Ask: (1) How much exertion triggers SOB? Does it occur at rest? With exercise? Running? Climbing stairs? (2) Is there an associated cough? (3) Is SOB related to other symptoms? (4) Was onset of SOB sudden/gradual? (5) What time of day/night SOB occur? (6) Is SOB worse when laying flat? (7) Is SOB worse while walking? If so, when walking how far? How fast? (8) How severe is SOB? Ccale of 1-10, if 1 is breathing w/o any effort and 10 is breathing difficult as it could be, how hard is it to breathe? k) Visual analogue or other scales to assess changes in severity of dyspnea 2. Cough - reflex; protects lungs from accumulation of secretions or inhalation of foreign bodies. a) Presence/absence: diagnostic clue (some disorders cause or suppress coughing ) b) Reflex impaired by weakness or paralysis of respiratory muscles, NGT, prolonged 3
NCM 112 MIDTERMS by TONS and MADS inactivity, depressed function of medullary centers (anesthesia, brain disorders). c) Irritation of mucous membranes anywhere in respiratory tract → COUGH d) Stimulus that produces cough: infectious process or airborne irritant (smoke, smog, dust, gas) e) Persistent frequent cough → exhausting, pain. f) May indicate serious pulmonary disease, cardiac disease, medication reactions (amiodarone, ACE inhibitors, smoking, GERD) g) To determine cause, describe the cough: (1) Dry, irritative cough: URTI viral or side effect of ACE inhibitor. (2) Irritative high-pitched cough: laryngotracheitis (3) Brassy cough: tracheal lesion (4) Severe or changing cough: bronchogenic carcinoma. (5) Pleuritic chest pain w/ coughing: pleural/chest wall (musculoskeletal) involvement. h)Inquire about onset & time of coughing. (1) Coughing at night: onset of left-sided HF or bronchial asthma. (2) Cough in morning with sputum production: bronchitis. (3) Cough worsens when supine: postnasal drip (rhinosinusitis). (4) Coughing after food intake: aspiration in tracheobronchial tree. (5) Cough of recent onset: acute infection. i) Persistent cough → embarrassment, exhaustion, inability to sleep, and pain. j) Violent coughing → bronchial spasm, obstruction, further irritation of bronchi → syncope (fainting). k) Severe repeated nonproductive uncontrolled cough → exhausting harmful. 3. Sputum Production a) coughs long enough → produces sputum. b)reaction of lungs to constantly recurring irritants. c) may be associated w/ nasal discharge. d) Nature of sputum is indicative of its cause. (1) Profuse purulent (thick, yellow, green, or rust-colored) or change in color: bacterial infection. (2) Thin mucoid: viral bronchitis (3) Gradual increase of sputum: chronic bronchitis or bronchiectasis (4) Pink Tinged mucoid: lung tumor. (5) Profuse, frothy, pink material, often welling up into throat: pulmonary edema. (6) Foul-smelling sputum & bad breath: lung abscess, bronchiectasis, or infection caused by fusospirochetal or other anaerobic organisms. 4. Chest Pain or Discomfort a) If associated with pulmonary conditions: (1) Sharp, stabbing, intermittent; or (2) Dull, aching, and persistent. b) Pain usually on the side where pathologic process is located, but may be referred elsewhere (neck, back, or abdomen) c) May occur with pneumonia, pulmonary embolism with lung infarction, pleurisy, or late symptom of bronchogenic carcinoma. d) Carcinoma: pain dull & persistent because cancer invaded chest wall, mediastinum, or spine. e) Lung disease does not always cause thoracic pain because lungs and visceral pleura lack sensory nerves and insensitive to pain stimuli. (1) Parietal pleura has rich supply of sensory nerves stimulated by inflammation & stretching of membrane → Pleuritic pain (sharp and seems to “catch” on inspiration) “like the stabbing of a knife.” (2) Lay on affected side because this splints chest wall, limits expansion and contraction of lung, reduces friction between injured or diseased pleurae (Pain associated with cough reduced manually by splinting rib cage.) f) Assess quality, intensity, radiation of pain & identify & explore precipitating factors & relationship to patient’s position, inspiratory and expiratory phases 5. Wheezing a) high-pitched musical sound on expiration (asthma) or inspiration (bronchitis). b) often major finding in bronchoconstriction 4