Monday, January 26, 2009

Review on Thorax and Lungs

Before trying to study a particular system, it is very important to have a good lecture on the anatomy and physiology.
In this nursing lecture, you will be able grasp the lessons easily and adapt it in your nursing study.

  1. Outline
    • Structure and Function
    • Subjective Data
    • Objective Data
    • Abnormal Findings
  2. Structure and Function
  3. Thoracic Cage /Cavity
    • Shape- bony, conical shape, narrower at top borders – it is defined by:
        • Sternum – 3 parts: manubrium, body, xiphoid process
        • Ribs – 12 pairs, 1 st seven attach to the sternum (costal cartilages) Ribs 8,9,&10 attach to the costal cartilage above, Ribs 11 & 12 are floating ribs
        • 12 Thoracic vertebrae
        • Diaphragm – the floor, separates the thoracic cavity from the abdomen
  4. Anterior Thoracic Landmarks
    • Suprasternal Notch – U shaped depression
    • Sternum – “breastbone” = 3 parts
      • Manubrium
      • Body
      • Xiphoid process
      • Angle of Louis – manubriosternal angle continuous with the 2 nd Rib
      • Costal angle- usually 90 0 or <. (increases when rib cage is chronically overinflated)
  5. Posterior Thoracic Landmarks
    • Vertebra Prominens – Flex head, feel most prominent bony projection at base of neck = C7 next lower one is T1
    • Spinous Processes – spinal column-
    • Scapula – symmetrical , lower tip at the 7 -8 th Rib
    • 12 th Rib = midway b/t spine & side
  6. Reference Lines
    • Anterior Chest
      • Midsternal line
      • Midclavicular line
    • Posterior Chest
      • Vertebral line – midspinal
      • Scapular line
    • Lateral Chest
      • Anterior Axillary line
      • Posterior Axillary line
      • Mid–axillary line
  7. The Thoracic Cavity
    • Mediastinum middle of the thoracic cavity & contains;
      • Esophagus
      • Trachea
      • Heart
      • Great Vessels
    • Pleural Cavities on either side of the mediastinum contain the lungs
  8. Lung Borders
    • Anterior Chest –
      • Apex 3 -4 cm. ↑ inner 1/3 of the clavicles
      • Base – rests on the diaphragm, 6 th rib, MCL
    • Lateral Chest
      • Extends from Axilla apex to 7 th –8 th rib
    • Posteriorly
      • Apex of lung is at C7 – Base T10 (on deep inspiration to T12)
  9. Lobes of Lung
    • Right Lung
      • 3 lobes, upper, middle , lower
      • Shorter due to liver
    • Left Lung
      • LUL = Left Upper and Lower ( 2 lobes)
      • Narrower due to heart
    • Lobes
      • Diagonal sloping segments
      • Oblique fissures
  10. 3 Important Points
    • Left Lung – no middle lobe
    • Anterior chest contains upper & middle lobes with very little lower lobe
    • Posterior chest has almost all lower lobe. Rt middle lobe does not project into the posterior chest
  11. Pleurae
    • The Pleurae form an envelope b/t the lungs & chest wall
    • Visceral pleura – lines outside of lungs
    • Parietal pleura – lines inside of chest wall & diaphragm
    • Pleural Cavity – the inside of the envelope- space b/t visceral & parietal pleura, lubrication. Normally has a vacuum or neg. pressure
  12. Tracheal & Bronchial Tree
    • Trachea – anterior to esophagus-
      • 10-11 cm.long, begins at cricoid cartilage
      • Bifurcates just below the sternal angle ( AKA angle of Louis, manubriosternal angle) into the
      • Right Main Stem Bronchus – shorter, wider, more vertical ( Intubation – listen to breath sounds bilaterally)
      • Left Main Stem Bronchus
  13. Tracheal & Bronchial Tree
    • The trachea & bronchi provide the passage for air to get into the lungs from the environment = Dead Space (no air exchange takes place here)
    • Bronchi
      • Secrete mucus – captures particles
      • Cilia – moves the trapped particles up to be expelled or swallowed
    • Acinus
      • Functional respiratory unit consisting of,
      • Bronchioles, alveolar ducts, alveolar sacs, & alveoli
      • Gaseous exchange in alveolar duct & alveoli
  14. Mechanics of Respiration
    • 4 Major Functions of the Respiratory System
      • Supply O 2 for energy production
      • Remove CO 2 , waste product of energy reactions
      • Homeostasis, acid-base balance of arterial blood
      • Heat exchange
    • Respiration maintains pH ( acid- base balance) of the blood by supplying O 2 & eliminating CO 2 .
    • Normal Range Values of Arterial Bld. Gases
      • pH= 7.35- 7.45
      • Pa CO 2 = 35-45mmHg
      • PaO 2 = 80-100mmHg
      • SaO 2 = 94-98%
    • Lungs help to maintain the pH balance by adjusting the amt. of CO 2 through:
      • Hypoventilation
      • Hyperventilation
  15. Respiration = breathing
    • Inspiration
    • Expiration
    • Control of Respiration
      • Involuntary control by respiratory center in the brain stem consisting of the pons & medulla
      • Hypercapnia is an ↑ in CO 2 in the Bld. And provides the normal stimulus to breath
      • Hypoxemia
  16. Subjective Data
    • Cough
    • SOB
    • Chest Pain
    • Respiratory Infections
    • Smoking
    • Environmental Exposure
    • Self-care behaviors
  17. Objective Data
    • Inspect
    • Palpate
    • Percuss
    • Auscultate
    • After Posterior Thyroid Exam
    • Posterior chest, Lateral chest, then Anterior chest
    • Remember to clean stethoscope end piece and warm prior to use on client.
    • Quiet environment conducive to hearing lung sounds
  18. Equipment for Exam
    • Stethoscope
    • Ruler – 15cm.
    • Tape measure
    • Washable marker
    • Alcohol swabs
  19. Posterior Chest
    • Inspect Thoracic Cage
      • Shape and configuration
      • Anteroposterior Diameter should be < diameter =" Ratio">
      • Note Position of Person to breathe.
        • ? orthopnea
      • Skin Color & Condition, nail color
  20. Barrel Chest
  21. Pectus Carinatum (Pigeon)
  22. Pectus Excavatum (Funnel)
  23. Posterior Chest
    • Palpate
      • Symmetric Expansion- warmed hands – thumbs @ T9-T10- pinch sm. Fold of skin
  24. Posterior chest
      • Tactile Fremitus – palpable vibration of sound from the larynx- use palmer base of fingers- “99” or Blue Moon
      • Symmetry important – vibration should feel the same bilaterally.
      • Avoid palpating over scapulae because bone dampens out sound
    • ↓ fremitus = obstructed bronchi, pleural effusion, pneumothorax or emphysema
    • Note any barrier that is b/t the sound and your hand will↓ fremitus
    • ↑ fremitus occurs only with gross changes (Lobar pneumonia).
      • Entire Chest wall – gently palpate. Note
        • Tenderness, skin temp., moisture, lumps, lesions
      • Crepitus = coarse crackling sensation palpable over skin surface. (Subcutaneous emphysema when air escapes from lung into S/C tissue)
  25. Posterior Chest
    • Percuss start at the apices, across shoulders, then interspaces side to side (5cm. Intervals) Avoid scapulae & ribs
      • Resonance predominates in healthy lung
      • Hyperresonance – too much air, emphysema, pneumothorax
      • Dull = abnormal density, pneumonia, tumor, atelectasis
  26. Expected Percussion notes
  27. Diaphragmatic Expansion
    • Lower lung borders in expiration & inspiration
    • 1 st Exhale & hold- percuss down the scapulae line until sound changes from resonant to dull. Mark with marker
    • Estimates the level of the diaphragm separating the abd cavity. May be higher on Rt. Due to liver
  28. Diaphragmatic Expansion
    • Now take deep breath & hold.
    • Percuss from mark to dull sound and mark.
    • Measure the difference. Should be + bilaterally 3-5cm in adult may be 7-8 cm in well conditioned person
    • Note hold your own breath when conducting this test!!!!!!!!!
  29. Exhale Inhale
  30. Posterior Chest
    • Auscultate
      • Position client
      • Instruct to breath through mouth, little deeper than usual
      • Tell you if becomes light headed
      • Use flat diaphragm & hold firmly on chest
      • Must listen to at least 1 full respiration before moving stethoscope side to side
      • Compare both sides (lung fields)
  31. Auscultation Sequence
  32. Normal Breath Sounds
    • Bronchial – Anterior Chest only = over trachea & larynx
      • Quality = harsh, hollow, tubular
      • Inspiration <>
      • Amplitude = Loud
  33. Breath Sounds
    • Bronchovesicular both anterior & posterior
      • Over major bronchi, posterior b/t scapulae, anterior upper sternum, 1 st & 2 nd ICS
      • Pitch = high
      • Inspiration = Expiration
      • Moderate amplitude
    • Vesicular – Anterior & posterior
      • Quality = rustling, wind in trees
      • Inspiration > Expiration
      • Soft amplitude
  34. Location of Breath Sounds
    • Decreased or Absent Breath Sounds
      • Causes =
      • obstruction of the bronchial tree by secretions, mucous plug, F.B
      • ↓ lung elasticity, emphysema = lungs hyperinflated
      • Pleurisy, pleural thickening, pneumothorax (air), pleural effusion (fld.) in the pleural space
    • Increased Breath Sounds = dense lung tissue enhances sound transmission as in consolidation ie. pneumonia
    • Silent chest = ominous
  35. Adventitious Sounds
    • Not normally heard in the lungs. Caused by moving air colliding with secretions or by popping open of previously deflated airways
    • Crackles (Rales)
      • Fine – high pitched popping- not cleared by coughing. Simulate sound by rolling strand of hair b/t fingers near ear or moisten thumb& index finger & separate them near your ear
      • Course crackles- (opening a velcro fastener)
    • Pleural Friction Rub – coarse & low pitched, 2 pieces of leather rubbed together close to ear
  36. Adventitious Sounds
    • Wheeze (Rhonchi)
      • High pitched, musical squeaking = air squeezes - asthma
      • Low pitched musical snoring, moaning, =obstruction
    • Stridor – high pitched, inspiratory, crowing, louder in neck = croup, acute epiglottitis
  37. Coarse Crackles
  38. Fine Crackles
    • Voice Sounds normal voice transmission is soft, muffled & indistinct. Pathology that ↑ lung density makes words clearer
      • Bronchophony – “99”
      • Egophony- ee-ee-ee if disease sounds like aa-aa-aa Record as “E -> A changes”
      • Whisper pectoriloquy 1-2-3
      • These tests are only done if lung pathology is suspected
  39. Anterior Chest
    • Inspect
      • Shape & Configuration
      • Expression- relaxed
      • LOC – alert & cooperative
      • Skin color & condition
      • Quality of Respirations – reg. & even, no retraction or use of accessory muscles
  40. Anterior Chest
    • Palpate
      • Symmetric Chest Expansion
      • Tenderness, turgor, temp., moisture
    • Tactile Fremitus
      • Compare both sides
  41. Symmetric Expansion
  42. Sequence for percussion & auscultation
  43. Tactile fremitus
  44. Percussion
    • Apices in Supraclavicular Areas
    • Interspaces = Resonance
      • Dullness
        • Female breast tissue
        • Liver – Rt. 5 th intercostal space midclavicular
        • Heart – Lt. 3 rd intercostal space midclavicular
      • Flat = muscle & bone
      • Tympany = stomach (Lt. Side)
  45. Expected Percussion Notes
  46. Auscultate
    • Apices (supraclavicular) to 6 th rib
    • Bilateral moving down
    • One full respiration
    • Directly over chest wall – displace female breast tissue
  47. Location Of Breath Sounds
  48. Pulse Oximeter
    • Noninvasive measurement of arterial oxygen saturation = SpO 2 by measuring the relative amt. of light absorbed by oxyhemoglobin and unoxygenated hemoglobin. It compares light emitted to amt absorbed. Normally 97 -98%
  49. Terms for Documentation
    • Rate
      • Eupnea 12 – 20 bpm normal
      • Tachypnea > 24, rapid, shallow
      • Bradypnea <>
      • Apnea = No respirations for 10 sec. or more
    • Pattern = breathing rhythm. Normal respirations are regular and even.
      • Cheyne – stokes = resp wax & wane in reg pattern with periods of apnea(20sec)
      • Biot’s or ataxisic Sim. To cheyne –stokes but pattern irreg.
    • Depth – on inspiration the normal depth is nonexaggerated and effortless.
      • Shallow
      • Sighing – purposeful to expand the alveoli
    • Symmetry – bilateral rise and fall of the chest with respiration
    • Audibility – normally be heard by the unaided ear several centimeters from the patient’s nose/mouth
    • Patient position – healthy person breathes comfortably in supine, prone or upright position
      • Orthopnea
    • Mode of Breathing – normally inhale/exhale through nose
    • Sputum
      • Sample
      • Color
        • Mucoid, yellow/green, rust/blood tinged, black, pink
      • Odor
      • Amount
      • Consistency




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