THORAX AND LUNGS

• Course and unit objectives

  • Read course and unit objectives
  • Read and comprehend study guide prior to class attendance
  • Read and comprehend required learning resources
  • Engage in classroom discussions
  • Participate in weekly discussion board (Canvas)
  • Answer and submit course unit tasks
• Upper airway structures


  • Nasopharynx
  • Oropharynx
  • Larynx

  
• Functions of the larynx

  • Warms, filter and humidify
  • Helps to make sound
  • Sends air to lower airways
• Lower airway structures


  • Trachea
  • Bronchioles
  • Alveoli

  
• Trachea


  Divides into the right and left mainstem bronchi and continues to divide into smaller passages
• Bronchioles


  Terminate into the alveolar ducts and alveoli
• Alveoli


  The gas exchanging units in the lungs
• Thoracic structures


  • 2 clavicles
  • 2 scapula
  • 1 Sternum (breast bone)
  • 12 pair of ribs - allow chest to contract and expand during each breath
  • 12 thoracic vertebrae

  
• Respiratory muscles


  • Diaphragm
  • Intercostal Muscles
  • Trapezius
  • Sternocleidomastoid

  
• Functions of the Respiratory System Structures

  • The exchange of oxygen and carbon dioxide through respiration
  • Plays a role in maintaining acid base balance
  • Begins at the nose continues as a series of airways or passages extending to the alveoli where gas exchange takes place
  • The nasal, oropharynx, and conducting airways are the dead space
  • The primary muscle of respiration is the diaphragm
  • The secondary muscles are called the accessory muscles (anterior and posterior)
  • The negative lung pressure that is needed for breathing is maintained by the pleura

  
• Mechanical Process


  1. Accomplished by pulmonary ventilation

  2. The exchange of air between the lungs and the atmosphere

  3. Consists of two phases: inspiration/inhalation and expiration/exhalation
• Physiological Process


  Occurs on three levels: external respiration, internal respiration, and cellular respiration
• External respiration


  The exchange of gases (oxygen and carbon dioxide) between the alveoli and the blood through the alveolar-capillary membrane

  
• Internal respiration


  The exchange of gases between the systemic capillaries and the tissue at the cellular level
• Cellular respiration


  Exchange of gases within the cell
• Respirations by age


  • Newborn and children: obligatory nose breathers, primarily abdominal, breath sounds are louder, harsher, and more bronchial, RR=irregular, with brief periods of apnea, shape of the chest is more round than oval, with the ribs in a horizontal position
  • After about age 2: the ribs become more oblique, and the breathing pattern becomes primarily intercostal
  • Aging: musculoskeletal changes, fibrotic alveoli, decreased surface area for exchange of gases, breathing and lung capacity decrease as a result of muscle weakness and decreased elasticity
  • Pregnancy: increases in tidal volume and respiratory rate allow for a 20 percent increase in oxygen consumption, later in the pregnancy, the diaphragm rises and the costal angle widens to accommodate the enlarging uterus

  
• Anatomical landmarks of the lungs

  • Right lung has three lobes, left lung has two lobes
  • In front: the apices of the lungs extend about 2 cm (3⁄4 to 1 inch) above the inner aspect of the clavicles, then continue downward to the sixth intercostal space at the midclavicular line (MCL)
  • At the side: the lower border of the lung is at the eighth rib at the midaxillary line
  • At the back: the apices of the lungs start at T1 and extend to T10 and T12 on deep inspiration, the right lung may be slightly higher because of the liver

  
• Assessment Proper


  Inspection / Interview:

  • Normal: Awake, alert, oriented to time, place, person, immediate, recent, remote memory intact
  • Deviations from normal: Early signs of hypoxia include confusion, restlessness, irritability, short attention span, short-term memory may also be affected by hypoxia

  Inspect Skin And Nails:

  • Normal: Peripheral cyanosis may be normal response to exposure to cold temperatures, no edema, positive capillary refill, nailbeds pink, negative clubbing
  • Deviations from normal: Pale diaphoretic, central cyanosis, peripheral cyanosis, ruddy reddish color, clubbing, peripheral edema, cyanotic or dusky nails, yellow-brown stains on nails and fingers, purple / dusky lower extremities

  Inspect / Palpate Head & Neck:

  • Normal: Trachea should arise out of sternal notch and should be midline, no pursed-lip breathing, nasal flaring, neck vein distension, use of accessory muscles, visible neck vein in older people or those with overdeveloped neck muscles, no hypertrophy of neck muscles unless occupationally related, no visible / palpable lymph nodes
  • Deviations from normal: Tracheal shifts, pursed-lip breathing, nasal flaring, neck vein distention, use of scalene, sternocleidomastoideus (SCM), and trapezius accessory muscles

  Auscultate / Palpate Cardiovascular:

  • Normal: Heart, regular rate and rhythm (HRRR), no extra sounds
  • Deviations from normal: Right – sided S3 and S4, absent / diminished pedal pulses and ankle, pedal edema
• Respiration patterns


  • Normal / Eupnea: normal breathing pattern, 16–20 breaths/min and regular
  • Tachypnea: may be a normal response to fever, anxiety, or exercise, can occur with respiratory insufficiency, alkalosis, pneumonia, or pleurisy, more than 24 breaths / min and shallow
  • Bradypnea: may be normal in well – conditioned athletes, can occur with medication – induced depression of the respiratory center, diabetic coma, neurologic damage, less than 10 breaths / min and regular
  • Hyperventilation: usually occurs with extreme exercise, fear, or anxiety, causes include disorders of the central nervous system, overdose of the drug salicylate, or severe anxiety, increased rate and depth
  • Kussmaul: a type of hyperventilation associated with diabetic ketoacidosis, rapid, deep, labored
  • Hypoventilation: usually associated with overdose of narcotics or anesthetics, decreased rate, decreased depth, irregular pattern
  • Cheyne-Stokes Respiration: may result from severe congestive heart failure, drug overdose, increased Intracranial pressure, or renal failure, may be noted in elderly persons during sleep, not related to any disease process, regular pattern characterized by alternating periods of apnea and hyperpnea

  
• Well-conditioned athletes


  Can occur with medication-induced depression of the respiratory center, diabetic coma, neurologic damage
• Hypoventilation


  • Less than 10 breaths/min and regular
• Hyperventilation


  Usually occurs with extreme exercise, fear, or anxiety
• Causes of hyperventilation


  • Disorders of the central nervous system
  • Overdose of the drug salicylate
  • Severe anxiety
• Hyperventilation

  • Increased rate
  • Increased depth
• Kussmaul

  A type of hyperventilation associated with diabetic ketoacidosis, rapid, deep, labored
• Hypoventilation


  Usually associated with overdose of narcotics or anesthetics, Decreased rate, decreased depth, irregular pattern
• Cheyne-Stokes Respiration


  May result from severe congestive heart failure, drug overdose, increased Intracranial pressure, or renal failure, Regular pattern characterized by alternating periods of deep, rapid breathing followed by periods of apnea, May be noted in elderly persons during sleep, not related to any disease process
• Biot's Respiration


  May be seen with meningitis or severe brain damage, Irregular pattern characterized by varying depth and rate of respirations followed by periods of apnea
• Ataxic


  A more extreme expression of Biot's respirations indicating respiratory compromise, Significant disorganization with irregular and varying depths of respiration

  
• Air Trapping


  In chronic obstructive pulmonary disease, air is trapped in the lungs during forced expiration, Increasing difficulty in getting breath out
• Barrel Chest


  • Most often associated with emphysema, asthma
• Pectus Excavatum


  Congenital chest wall deformity - ribs and sternum grows abnormally producing cave-in (concave) shape

  
• Pectus Carinatum


  Deformed human chest - projecting breastbone, Defect in the connective tissue

  
• Tracheal Position


  Place your thumb and index finger on either side of the trachea, and note position and distance between trachea and sternocleidomastoid muscle, Normal - midline, Deviation from normal - Tumor or thyroid enlargement may cause tracheal deviation, Tension pneumothorax deviates trachea away from affected lung, In severe atelectasis, trachea may deviate toward affected lung (uneven pressure)
• Chest Tenderness & Crepitus

  Use light palpation to assess for tenderness and crepitus, Abnormal popping or crackling sound, Crunching sensation may be sometimes painful, Pathway of palpation - Start toward the midline at the level of the left scapula (over the apex of the lung), Move your hand left to right, comparing findings bilaterally, Move systematically downward and out to cover the lateral portions of the lungs at the bases, Normal - nontender, no deformities, no crepitus, Deviations from normal - muscle soreness from exercise or the excessive work of breathing may be palpated as tenderness, Pain/tenderness at costochondral junctions/vertebral connections of ribs may indicate fracture, inflamed cartilage at the rib/sternal junctions may indicate costochondritis, spontaneous pathological fractures from corticosteroid therapy or osteomalacia, Crepitus (subcutaneous emphysema) results from air leaking into subcutaneous tissue
• Tactile Fremitus


  Place the balls of your hands with your fingers hyperextended or the ulnar surface of your hand on the patient's chest, As you move your hand to each area, instruct the client to say "99", Assess all areas for symmetry and intensity of vibrations, Note level where fremitus is palpable, increased, diminished or absent, Normal - symmetric easily identified in the upper regions of the lungs, Deviations from normal - Increased fremitus occurs with conditions causing fluid or exudates in lungs, Decreased or absent fremitus occurs where there is air trapping, solid tissue, or decreased air movement
• Sequence for Percussing


  1. Anterior Thorax

  2. Posterior Thorax

  3. Lateral
• Normal Percussion Tones

  Anterior thorax - Resonance over normal lung tissue, Dullness over breast tissue, the heart and the liver, Tympany over the stomach, Flatness over the muscles and bones, Posterior thorax - Normal percussion tones heard
• Deviations from Normal Percussion Tones

  • Hyperesonance - trapped air/increased air in lungs (asthma, emphysema, pneumothorax)
  • Dullness - increased density, decreased air in the lungs (pleural effusion, atelectasis, lung consolidation, tumor)
• Auscultated Breath Sounds


  • BRONCHIAL (B) - exhales just above the clavicles on each side of the sternum
  • BRONCHOVESICULAR (BV) - inhales and exhales continous next to the sternum between the scapula
  • VESICULAR (V) - prolonged during inhalation shortened during exhalation - remainder of the lungs
  • TRACHEAL - inhales or exhales above supraclavicular notch