Lec 8: Thorax, Lungs, and Respiratory

external respiration def

gas exchange at alveoli

internal respiration def

gas exchange at cellular level

what makes up the thoracic cage

• clavicles

• manubrium (sternal angle at 2nd rib=angle of louis)

• sternum, 12 pairs of ribs, 12 vertebra posteriorly

• costal margin=inferior rib border

how do we count the intercostal/rib spaces

starting below the first rib

what makes up the thoracic cavity

• heart

• lungs

• thymus

• trachea

• esophagus

• aorta & great vessels

thymus

• gland of immune system

• shrinks post puberty, T-cell production

Visceral pleura

lines surface of lungs

Parietal pleura

lines thoracic wall, mediastinum, diaphragm

Pleural space

trauma can cause lung collapse (pneumothorax, hemothorax)

internal structures of the lungs

• trachea bifurcates:

  • sternal angle (anteriorly)

  • T4 (posteriorly)

• right main bronchus:

  • shorter, wider, more vertical than left

  • risk for foreign body aspiration

Inspiration (what happens)

• triggered by rise in blood co2

• inspiratory muscles contract (external intercostals/diaphragm)

• lung fields descend by 2 rib spaces

• 500-800 mL of air intake

Expiration compared to inspiration in length

longer (2x) & passive

respiratory muscles for easy inspiration

• external intercostal muscles

• diaphragm

what is the diaphragm innervated by

phrenic nerve C3-C5, CN X

Easy Expiration

passive

lower resp tract pic

lung landmarking pic

midclavicular line=MCL

anterior Lung Fields:

base rests on:

• supraclavicular=6th rib (midclavicular line)

• 8th rib (midaxillary line)

Right Upper Lobe (RUL) & Left Upper Lobe (LUL) dimensions

RUL apex 2.5 cm higher than LUL apex from liver displacing left lung

Right Middle Lobe (RML)

4th-6th rib (sternum), gives way to RLL at anterior axillary line

Lung fields aka where is the base and apex of the lungs approximately located

• apex=C7

• base=T10

• with deep inspiration, base may extend to T12

how can we calculate the size of the LUL

RUL + RML

RLL size & position is …

equal to LLL size & position

LUL and RUL lung field

C7-T3

LLL and RLL field

T3-T10

Lateral Lung Fields

upper/lower lobes bilaterally

Posterior Lung Fields

assessment for upper/lower lobes bilaterally

what do we look for during health history

• personal history

• medications

• family history

• lifestyle/personal habits

• occupational/environmental exposures

what do we look for during personal history

• resp conditions=asthma, bronchitis, pneumonia, COPD, sleep apnea, TB

• allergies

• immunizations=influenza, pneumococcal

what do we ask about for lifestyle/personal habitss

• smoking (cigarettes, cigars, vaping)

• hobbies

Respiratory-Specific Symptoms we look for during ROS

• tachypnea

• dyspnea

• shortness of breath

• sleep apnea

• pleuritic pain

• cough

• sputum: (mucoid? purulent? tenacious? – color, quality, quantity)/hemoptysis

• wheezing

• stridor

in what order do we conduct physical examination of the lungs

1. inspection

2. palpation

3. percussion

4. auscultation

f the patient has acute shortness of breath, immediate assessments include:

• RR

• pulse

• BP

• o2 saturation

• lungs are auscultated

• o2 administered

what do we look for with inspection

• LOC

• skin/mucus membranes

• facial expression

• posture

• shape of thorax

• resp movement/effort

• rate, rhythm, depth, quality (VS)

Thorax Shape expected findings

• anterior-posterior (AP or sagittal) diameter should be less than transverse

• ratio of AP:transverse=between 1:2-5:7

what are the findings indicative of a barrel chest

• 1:1 AP/transverse ratio

• COPD

how do we conduct palpation of the chest

superior to inferior

• 1,2,3,4,5, pattern

• left and right sides consecutively

• anterior & posterior assessment

what do we note during palpation

• tenderness

• masses

• lesions

• crepitus=bubble wrap sensation=air trapping

when do we palpate for tactile fremitus

when there are concerns about lung disease

how do we palpate for tactile fremitus

• ulnar surface of hand on chest wall to feel vibrations

• pt repeats 99

• variations in expected findings:

  • usually reduced at bases

  • most intense between scapulae

what does the finding of increased fremitus indicate

denser or inflamed lung tissue ex pneumonia

what does the finding of decreased fremitus indicate

• air or fluid in pleural space ex pneumothorax

• decrease in lung tissue density ex COPD, asthma

when do we palpate for chest expansion

concerns about lung volume from:

• muscle weakness, fracture, infection, resp disease

• combine with percussion for diaphragmatic excursion

how do we palpate chest expansion posteriorly

1. place palm of hands at level of T9 and T10 posteriorly

2. slide thumbs medially to raise a skin fold between

3. ask pt to inhale deeply

4. skin fold should expand/disappear

5. note symmetry

how do we palpate chest expansion anteriorly

hands at costal margin

what are the unexpected findings when testing chest expansion

low/asymmetrical

• thumbs should move 5-10 cm

how do we conduct percussion

• percuss from lung apex to lung base (avoid the clavicle and ribs)

• compare side to side

• anterior and posterior assessment

what are the expected findings of percussion

resonance throughout

what are the unexpected findings of percussion

• hyperresonance=air trapping ex COPD

• dullness=fluid ex pneumonia, effusion

when do we percuss for diaphragmatic excursion

concerns with chest expansion

• helps estimate how much diaphragm moves between inhalation/expiration

how do we percuss for diaphragmatic excursion

1. instruct to exhale and hold

2. percuss down mid-scapular line intercostal spaces

3. mark change to dullness

4. break (breath normally)

5. instruct to inhale and hold

6. percuss from first line down

7. should be at least 1-2 rib spaces (3-5 cm)

8. repeat on other side (can have unilateral paralysis)

what do we assess for during auscultation

• intensity/pitch

• quality

• duration

• adventitious sounds

what tips should we remember for auscultation

• not over clothing

• diaphragm of stethoscope

• ask pt to breath a little more deeply than normal, through their mouth

• listen to one full breath per location

• move side to side to compare symmetry

what do have to keep in mind when auscultating the lower lobes

auscultate laterally and posterior not anterior

• because lower lobes make up majority of posterior

what are the diff normal breath sounds

• tracheal

• bronchial

• bronchovesicular

• vesicular

tracheal breath sound location

• heard over trachea

• I=E

• very loud intensity

• high pitch

Bronchial breath sound

• heard over sternum

• I:E=1:2 or 1:3 aka expiratory longer

• loud intensity

• high pitch

Bronchovesicular breath sound

• heard 1st & 2nd intercostal space

• I=E

• medium intensity/pitch

Vesicular breath sounds

• heard over most lung fields

• I:E = 3:1 or 4:1 aka inspiratory longer

• soft intensity

• low pitch

what are the adventitious Lung Sounds

• wheezes

• crackles

• stridor

wheezes

• continuous sound, high or low

• more pronounced on expiration?

• from narrowed airways

crackles

• discontinuous brief popping sounds

• more common during inspiration (small airways snapping open)

  • fine vs coarse

stridor

• dont need stethoscope to hear it

• from laryngeal/tracheal inflammation or foreign object

Respiratory Distress (Red Flags!)

• short sentences, few words

• irritability

• positioning

• work of breathing

irritability red flag

• LOC alterations

• unable to focus

positioning red flag

• leaning forward

  • standing

• sitting, tripod position

Work of breathing red flag

• mouth breathing

• pursed lips

• nasal flaring

• accessory muscle use (neck & intercostal muscles)

expected findings pic

what does mucoid sputum indicate, what does it look like

clear, white or grey=bronchitis

what does purulent sputum indicate, what colour is it

yellow or green=presence of WBC and bacterial infection

what does tenacious sputum indicate

thick from dehydration/cystic fibrosis

what does bloody sputum indicate

lung cancer or TB

what does sputum from heart failure look like

thin, frothy, slightly pink