Chapter 11 Thorax and Lungs (Jarvis)

Lobes of the Lung Lateral Chest

Lateral chest ➢ Lung tissue extends from apex of axilla down to seventh or eighth rib. ➢ Right upper lobe extends from apex of axilla down to horizontal fissure at fifth rib. ➢ Right middle lobe extends from horizontal fissure down and forward to sixth rib at midclavicular line. ➢ Right lower lobe continues from fifth rib to eighth rib in midaxillary line.

Lobes of the Lung Posterior Chest

Posterior chest ➢ Most remarkable point about posterior chest is that it is almost all lower lobe. ➢ Upper lobes occupy a smaller band of tissue from their apices at T1 down to T3 or T4. ➢ At this level, lower lobes begin, and their inferior border reaches down to level of T10 on expiration and to T12 on inspiration. ➢ Right middle lobe does not project onto posterior chest at all.

Common respiratory conditions

• Atelectasis • Congestive heart failure • Lobar pneumonia • Bronchitis • Pneumocystis carinii pneumonia • Emphysema • Tuberculosis • Asthma (reactive airway disease) • Pulmonary embolism • Pleural effusion thickening • Pneumothorax • Acute respiratory distress syndrome

Percussion of Anterior Chest

• Begin percussing apices in supraclavicular areas. ➢ Then, percussing interspaces and comparing one side to other, move down anterior chest. ➢ Interspaces are easier to palpate on anterior chest than on back. ➢ Do not percuss directly over female breast tissue because this would produce a dull note; shift breast tissue over slightly using edge of your stationary hand. ➢ In females with large breasts, percussion may yield little useful data. • Note borders of cardiac dullness normally found on anterior chest. ➢ Do not confuse these with suspected lung pathology. ➢ In right hemithorax, upper border of liver dullness is located in fifth intercostal space in right midclavicular line. ➢ On left, tympany is evident over gastric space

Breath Sounds

• Evaluate presence and quality of normal breath sounds. • Instruct person to breathe through mouth, a little bit deeper than usual. • Use flat diaphragm endpiece of stethoscope and hold it firmly on person's chest wall; listen to at least one full respiration in each location. • Side-to-side comparison is most important. • Do not confuse background noise with lung sounds. • Become familiar with these extraneous noises that may be confused with lung pathology if not recognized. ➢ Examiner's breathing on stethoscope tubing ➢ Stethoscope tubing bumping together ➢ Patient shivering ➢ Patient's hairy chest; movement of hairs under stethoscope sounds like crackles (rales); minimize this by pressing harder or by wetting the hair with damp cloth. ➢ Rustling of paper gown or paper drapes • While standing behind person, listen to following lung areas: ➢ Posterior from apices at C7 to bases around T10 ➢ Laterally from axilla down to seventh or eighth rib • Continue to visualize approximate locations of lobes of each lung so that you correlate your findings to anatomic areas.

Thorax and Lungs Examination Summary Checklist

• Inspection ➢ Thoracic cage, respirations, skin color, and condition ➢ Person's facial expression, and LOC • Palpation ➢ Confirm symmetric expansion and tactile fremitus. ➢ Detection of any lumps, masses, or tenderness • Percussion ➢ Lung fields and estimate diaphragmatic excursion • Auscultation ➢ Assess breath sounds, and note any abnormal/adventitious breath sounds. ➢ Perform bronchophony, whispered pectoriloquy, or egophony as needed.

Lobes of the Left Lung

• Left lung contains only two lobes, upper and lower. • These are seen laterally as two triangular areas separated by oblique fissure. • Left upper lobe extends from apex of axilla down to fifth rib at midaxillary line. • Left lower lobe continues down to eighth rib in midaxillary line. • Using these landmarks, take a marker and try tracing outline of each lobe on a willing partner. • Take special note of three points that commonly confuse beginning examiners. ➢ Left lung has no middle lobe.• Left lung contains only two lobes, upper and lower. • These are seen laterally as two triangular areas separated by oblique fissure. • Left upper lobe extends from apex of axilla down to fifth rib at midaxillary line. • Left lower lobe continues down to eighth rib in midaxillary line. • Using these landmarks, take a marker and try tracing outline of each lobe on a willing partner. • Take special note of three points that commonly confuse beginning examiners. ➢ ➢ Left lung has no middle lobe. .• Left lung contains only two lobes, upper and lower. • These are seen laterally as two triangular areas separated by oblique fissure. • Left upper lobe extends from apex of axilla down to fifth rib at midaxillary line. • Left lower lobe continues down to eighth rib in midaxillary line. • Using these landmarks, take a marker and try tracing outline of each lobe on a willing partner. • Take special note of three points that commonly confuse beginning examiners. ➢ Left lung has no middle lobe. ➢ Anterior chest contains mostly upper and middle lobe with very little lower lobe ➢ Posterior chest contains almost all lower lobe.

Lobes of the Lung Anterior Chest

• Lobes not arranged in horizontal bands; they stack in diagonal sloping segments and are separated by fissures that run obliquely through chest • Anterior chest ➢ On anterior chest, oblique fissure crosses fifth rib in midaxillary line and terminates at sixth rib in midclavicular line. ➢ Right lung also contains horizontal (minor) fissure, which divides right upper and middle lobes. ➢ This fissure extends from fifth rib in right midaxillary line to third intercostal space or fourth rib at right sternal border.

Thoracic Cavity

• Mediastinum: middle section of thoracic cavity containing esophagus, trachea, heart, and great vessels ➢ Right and left pleural cavities, on either side of mediastinum, contain lungs. ➢ Lung borders: In anterior chest, apex of lung tissue is 3 or 4 cm above inner third of clavicles. ➢ Base rests on diaphragm at about sixth rib in midclavicular line. ➢ Laterally, lung tissue extends from apex of axilla down to seventh or eighth rib. • Posteriorly, the location of C7 marks apex of lung tissue, and T10 usually corresponds to base. ➢ Deep inspiration expands lungs, and their lower border drops to level of T12. • Lobes of the lung ➢ Lungs are paired but not precisely symmetric structures. ➢ Right lung shorter than left because of under lying liver ➢ Left lung narrower than right because heart bulges to left. ➢ Right lung has three lobes, and left lung has two lobes.

Inspection of Anterior chestq

• Note shape and configuration of chest wall. ➢ Ribs are sloping downward with symmetric interspaces. ➢ Costal angle is within 90 degrees; development of abdominal muscles as expected for person's age, weight, and athletic condition. ➢ Note person's facial expression; facial expression should be relaxed, indicating unconscious effort of breathing. ➢ Assess the level of consciousness; level of consciousness should be alert and cooperative. ➢ Note skin color and condition; lips and nail beds are free of cyanosis; nails are of normal configuration. • Assess quality of respirations. ➢ Normal relaxed breathing is automatic and effortless, regular and even, and produces no noise. ➢ Chest expands symmetrically with each inspiration; note any localized lag on inspiration. ➢ No retraction or bulging of interspaces with inspiration ➢ Normally accessory muscles are not used to augment respiratory effort. ➢ Respiratory rate is within normal limits for person's age, and pattern of breathing is regular. ➢ Occasional sighs normally punctuate breathing.

Palpation of Anterior Chest

• Palpate symmetric chest expansion. ➢ Place your hands on anterolateral wall with thumbs along costal margins and pointing toward xiphoid process. ➢ Ask person to take a deep breath; watch thumbs move apart symmetrically, and note smooth chest expansion with fingers. ➢ Any limitation in thoracic expansion is easier to detect on anterior chest because greater range of motion exists here with breathing. • Assess tactile (vocal) fremitus. ➢ Begin palpating over lung apices in supraclavicular areas. ➢ Compare vibrations from one side to other as person repeats "ninety-nine." ➢ Avoid palpating over female breast tissue because breast tissue normally damps sound. • Palpate anterior chest wall. ➢ Note any tenderness; normally none is present. ➢ Detect any superficial lumps or masses, again, normally none is present. ➢ Note skin mobility, turgor, temperature, and moisture.

Culture and Genetics: Asthma

• Prevalence rate of asthma in the U.S. in 2011 was 8.4%. ➢ Most common chronic disease in childhood with a prevalence rate of 9.5% in children ages 0 to 17 years. ➢ Blacks, Hispanics, and American Indians experience more asthma-related problems and medical care than do Whites or Asians.

Pleurae

• The thin, slippery pleurae form an envelope between lungs and chest wall. • Visceral pleura lines outside of lungs, dipping down into fissures. • It is continuous with parietal pleura lining inside of chest wall and diaphragm. • Pleural cavity is potential space filled only with few milliliters of lubricating fluid. • Pleural cavity normally has a vacuum, or negative pressure, which holds lungs tightly against chest wall. ➢ Pleurae extend about 3 cm below level of lungs, forming the costodiaphragmatic recess. • Lungs slide smoothly and noiselessly up and down during respiration, lubricated by a few milliliters of fluid. • Similar to two glass slides with a drop of water between them; although it is difficult to separate slides, they slide smoothly back and forth. • This is a potential space; when it abnormally fills with air or fluid, it compromises lung expansion.

Trachea and Bronchial Tree

• Trachea lies anterior to esophagus and is 10 to 11 cm long in the adult. • Begins at level of cricoid cartilage in neck and bifurcates just below sternal angle into right and left main bronchi. • Posteriorly, tracheal bifurcation is at level of T4 or T5. • Right main bronchus is shorter, wider, and more vertical than the left main bronchus. • Trachea and bronchi transport gases between the environment and lung parenchyma. • Constitute dead space, or space that is filled with air but is not available for gaseous exchange. • This is about 150 mL in adult. • Bronchial tree also protects alveoli from small particulate matter in inhaled air. • Bronchi are lined with goblet cells, which secrete mucus that entraps particles; bronchi are lined with cilia, which sweep particles upward where they can be swallowed or expelled.

Reference Lines

• Use reference lines to pinpoint finding vertically on chest. • On anterior chest, note midsternal line and midclavicular line. • Midclavicular line bisects center of each clavicle at a point halfway between palpated sternoclavicular and acromioclavicular joints. • Posterior chest wall has vertebral (or midspinal) line and scapular line, which extends through inferior angle of scapula when arms are at sides of body. • Lift up the person's arm 90 degrees, and divide lateral chest by three lines: ➢ Anterior axillary line: extends down from anterior axillary fold where pectoralis major muscle inserts ➢ Posterior axillary line: continues down from posterior axillary fold where latissimus dorsi muscle inserts ➢ Midaxillary line: runs down from apex of axilla and lies between and parallel to other two

Auscultate Breath Sounds

➢ Auscultate lung fields over anterior chest from apices in supraclavicular areas down to sixth rib. ➢ Progress from side to side as you move downward, and listen to one full respiration in each location. ➢ Use sequence indicated for percussion; do not place stethoscope directly over female breast; displace breast and listen directly over chest wall. ➢ Evaluate normal breath sounds, noting any abnormal breath sounds and any adventitious sounds. ➢ If situation warrants, assess voice sounds.

Aging Adult

➢ Costal cartilages become calcified, which produces a less mobile thorax. ➢ Aging lung is more rigid structure that is harder to inflate. ➢ These changes result in an increase in small airway closure. ➢ With aging, histologic changes (i.e., a gradual loss of intra-alveolar septa and a decreased number of alveoli) also occur, so less surface area is available for gas exchange. ➢ Lung bases become less ventilated as a result of closing off of a number of airways. ➢ Histologic changes also increase the older person's risk of postoperative pulmonary complications.

Percussion of posterior chest

➢ Determine predominant note over lung fields; start at apices and percuss band of normally resonant tissue across tops of both shoulders. ➢ Then, percussing in interspaces, make side-to- side comparison all the way down lung region. ➢ Percuss at 5-cm intervals; avoid damping effect of scapulae and ribs. ➢ Resonance is low-pitched, clear, hollow sound that predominates in healthy lung tissue in adult. ➢ However, resonance is a relative term and has no constant standard. ➢ Resonant note may be modified somewhat in athlete with heavily muscular chest wall and in heavily obese adult in whom subcutaneous fat produces scattered dullness. ➢ Percussion sets into motion only outer 5 to 7 cm of tissue; will not penetrate to reveal any change in density deeper than that. ➢ Abnormal findings must be 2 to 3 cm wide to yield an abnormal percussion note; lesions smaller than that are not detectable by percussion.

Inspect the Posterior Chest

➢ Note shape and configuration of chest wall. ➢ Spinous processes should appear in a straight line; thorax is symmetric, in an elliptical shape, with downward sloping ribs, about 45 degrees relative to spine; scapulae are placed symmetrically in each hemithorax. ➢ Anteroposterior diameter should be less than transverse diameter. ➢ The neck muscles and trapezius muscles should be developed normally for age and occupation. • Note position person takes to breathe. • Include relaxed posture and ability to support one's own weight with arms comfortable at sides or in lap. • Assess skin color and condition. • Color should be consistent with person's genetic background, with allowance for sun-exposed areas on chest and back. • No cyanosis or pallor should be present. • Note any lesions; inquire about any change in nevus on back.

Four Mechanics of Respiration

➢ Supplying oxygen to the body for energy production ➢ Removing carbon dioxide as a waste product of energy reactions ➢ Maintaining homeostasis (acid-base balance)of arterial blood • By supplying oxygen to blood and eliminating excess carbon dioxide, respiration maintains pH or acid-base balance of blood. ➢ Maintaining heat exchange (less important in humans)