THORAX & LUNG

1. THORAX & LUNG

2. ** position & landmarks: • - thoracic cage is a bony structure with a conical shape, defined by the sternum,12 pairs of ribs &12 thoracic vertebrae, floor is diaphragm separate it from abdomen,1st 7 ribs attached to sternum via costal cartilages, ribs 8,9&10 attach to costal cartilage above &ribs 11 and 12are floating.

4. - Anterior thoracic Landmarks: • 1- suprasternal notch: hollow U shaped depression just above sternum. • 2- sternum: breastbone, has 3 parts- manubrium, body,& xiphoid process • 3- manubriosternal angle: angle of Louis, its articulation of the manubrium &body of sternum. Continuous with 2 rib, helps localize a respiratory finding horizontally, each intercostal space is numbered by the rib above it. It marks the site of tracheal bifurcation into Rt &Lt main bronchi, lies above the fourth thoracic vertebra on back.

5. 4- costal angle: the Rt &Lt costal margins form an angle where they meet at the xiphoid process,90 degree or less, its over inflated in emphysema.

6. - Posterior Thoracic Landmarks: • its harder due to muscles. • 1- vertebra prominence: C7, if 2 bumps the lower is T1 • 2- spinous processes: align with their same numbered ribs only down to T4.after T4 the spinous processes angle downward from their vertebral body &overlie vertebral body &ribs below. • 3- Inferior border of the scapula: lower tip is at 7th or 8th rib. • 4- twelfth rib:

8. ** Reference lines: • - used to pinpoint a finding vertically on the chest, midsternal line & Midclavicular line .posterior chest has vertebral line &scapular line . lift arm up, Anterior axillary line, midaxillary line &posterior axillary line.

12. * The thoracic cavity: • mediastinum is the middle section of thoracic cavity containing esophagus, trachea, heart &great vessels. Pleural cavities contain lungs.

13. - lung borders: • anteriorly the apex is 3 or 4 cm above the inner third of the clavicles. The base at 6th rib in MCL. Laterally lung extend from apex of axilla down to 7th or 8th rib. posteriorly C7 marks apex & T10 to the base , in deep inspiration drops to T12.

14. * Lobes of the Lungs: • - Rt lung is shorter because of liver &Lt lung is narrower because of the heart. Rt lung has 3 lobes& Lt lung has 2 lobes, separated by fissures that run obliquely through the chest. • * Anterior: the oblique fissure crosses the fifth rib in MAL &terminates at the sixth rib in MCL. Horizontal fissure divides the Rt upper &middle lobes.

16. * posterior: almost all lower lobes, upper lobes occupies apices at T1 down to T3 or T4.note that Rt middle lobe doesn’t project onto posterior chest at all. • * Lateral: extend from apex of axilla down to 7th or 8th rib.

18. ** Pleurae: • form an envelop between the lungs &chest wall. Visceral pleura lines outside of the lungs, continuous with parietal pleura lining inside of chest wall & diaphragm. Space filled of lubricating fluid, its normally has a vacuum or negative pressure, pleurae extend about 3 cm below the level of the lungs forming costodiaphragmatic recess this space when it abnormally fills with air or fluid it compromises lung expansion.

19. ** Trachea & Bronchial Tree: • -trachea lies anterior to esophagus, begins at cricoid cartilage level,, bifurcate below sternal angle .posteriorly at level T4 or T5, Rt bronchus is shorter wider & more vertical than Lt. • - acinus is a functional respiratory unit consist of bronchioles, alveolar ducts, alveolar sacs &alveoli.

21. ** Mechanics of Respiration: • - functions of resp system: 1- supplying O2 to body for energy production 2- removing CO2 as a waste product of energy reactions 3- maintaining homeostasis (acid-base balance)4- maintaining heat exchange. • - lungs help maintaining balance by adjusting level of CO2 through respiration, hypoventilation (slow breathing) causes increase of Co2 &hyperventilation (rapid breathing) causes blown off CO2.

23. ** Control of Respiration: • resp centers in brain stem, change in CO2&O2 levels in blood, stimulus for breathing is hypercapnia, hypoxemia is less effective.

24. ** Changing Chest Size: • air pushes into lungs, chest increases (inspiration) &expelled from lungs as chest size recoils (expiration). This alter the vertical diameter by upward or downward movement of diaphragm & the anteroposterior diameter by elevation or depression of ribs.

25. in inspiration thoracic size increased creating a negative pressure more in relation to atmospheric pressure, so air rushes in to fill parital vacuum by diaphragm. Causes it to descend & flatten. Lengthening vertical diameter, elevate ribs so increase anteroposterior diameter. • in expiration its passive, as diaphragm relaxes, elastic forces within lung, chest cage & abdomen cause it to dome up, creates positive pressure within alveoli &air flows out.

26. forced inspiration commands use of accessory neck muscles, in forced expiration the abdominal muscles contract powerfully to push viscera in& up against diaphragm making it dome upward.

27. ** Subjective Data: • cough • shortness of breath : {orthopnea: difficulty breathing when supine- paroxysmal nocturnal dyspnea: awakening from sleep with shortness of breath &needing to be upright } • chest pain with breathing • past history of respiratory infections

28. smoking history • environmental exposure • self-care behaviors

29. ** Objective Data:preparation: same as always INSPECT THE POSTERIOR CHEST:

30. * Thoracic cage : • note the shape &configuration of chest wall .spinous processes appear in straight line, thorax is symmetric, in an elliptical shape with downward sloping ribs, about 45 degree relative to the spine, scapulae symmetric. • Anteroposterior diameter should be less than transverse diameter, ratio from 1:2 to 5:7

31. Neck muscles &trapezius developed normally for age &occupation. • Note the position person takes to breathe, a relaxed posture • Assess skin color & condition, consistent with genetic background, no cyanosis or pallor, note any lesions.

32. ** PALPATE THE POSTERIOR CHEST: • symmetric expansion: confirm chest expansion by placing your warmed hands on posteriolateral chest wall with thumbs at the level of T9 or T10. slide your hands medially to pinch up a small fold of skin between your thumbs. Ask him to take a deep breath as he inhales deeply your thumbs should move apart symmetrically, note any lag in expansion.

34. Tactile Fremitus: • it’s a palpable vibration, use either palmar base of fingers or ulnar edge of one hand & touch the person's chest while he repeats the words"99 or blue moon". Start over the lungs apices &palpate one side to another. • - between scapulae Fremitus feel stronger on Rt side because Rt side is closer to bronchial bifurcation, avoid palpating over scapula because bone damps out sound transmission.

36. - factors affect normal intensity of tactile Fremitus: • 1- relative location of bronchi to chest wall, most prominent between scapula& around sternum • 2- thickness of chest wall, feels greater over a thin chest wall than obese or heavily muscular one. • 3- pitch &intensity: a loud, low –pitched voice generates more Fremitus than a soft high pitched one.

37. using the fingers gently palpate the entire chest wall, note any areas of tenderness, skin temperature& moisture, superficial lumps or masses, skin lesions.

38. ** PERCUSS THE POSTERIOR CHEST: • lung fields: start at the apices , make a side to side comparison all the way down the lung region. avoid damping effect of scapulae &ribs. Resonance predominates , hyperresonance as in emphysema or pneumothorax & dull note in atelactasis.

40. Diaphragmatic Excursion: • map out the lower lung border, both in expiration & in inspiration, ask him to exhale &hold it , while you percuss down the scapular line until the sound changes from resonant to dull on each side, make a spot. now make him to take a deep breath &hold it percusssing down from your first mark &mark the level sound change to dull, it should be equal bilaterally & measure about 3-5 cm

42. ** AUSCULTATE THE POSTERIOR CHEST: • - passage of air creates a characteristic set of noises that are audible through the chest wall . may be modified by obstruction within the respiratory passageways or by changes in the lung parenchyma, the pleura or the chest wall.

44. * Breath sounds: • instruct person to breathe through the mouth deeper than the usual, use the flat diaphragm of stethoscope , side to side comparison is most important, listen to lung areas-posterior from apices at C7 to the bases(T10) & laterally from axilla down to the 7th or 8th rib. • 1) Bronchial 2) Bronchovesicular 3) vesicular. Table 18-1 {ch.ch of normal breath sounds}

47. * Adventitious sounds: • crackles & wheeze, caused by moving air colliding with secretions in tracheobronchial passageways. Atelactic crackles is not pathologic they are short, popping doesn’t last beyond a few breaths, heard only in the periphery in dependent portions of lungs, disappear after the first few breaths or after a cough.

48. * Voice Sounds: • ask the person to repeat a phrase while you listen over the chest wall, normally voice transmission is soft, muffled & indistinct , hear it by stethoscope but can't distinguish exactly what is said, pathology that increases lung density enhances transmission of voice sounds, test for presence of bronchophony, egophony & whispered pectoriloquy.

49. 1- Bronchophony: ask him to repeat ninety nine while listen with stethoscope over chest wall, normally voice transmission is soft & indistinct but can't distinguish exactly what is said • 2- Egophony: auscultate chest while person phonates along "ee eee ee " sound, normally you should hear "eeeeee" through stethoscope • 3- Whispered pectoriloquy: ask person to whisper a phrase like one-two-three as you auscultate, normally faint muffled &inaudible .

50. ** INSPECT THE ANTERIOR CHEST: • note shape & configuration of chest wall, ribs are sloping down ward symmetrically • note facial expression, relaxed& benign. • Level of consciousness, should be alert & cooperative • Note the skin color & condition, lips & nails bed are free of cyanosis or pallor, any skin lesions