HA Oxygenation & Perfusion + Lung Sounds Study Guide

HA EXAM 2

Ventilation

Moving air in and out of the lungs (breathing)

Diffusion (gas exchange)

O2 moves from alveoli into blood; CO2 moves from blood into alveoli

Perfusion

Blood flow that delivers O2 to the tissues

Big idea of oxygenation

Ventilation moves air, diffusion swaps gases, perfusion delivers blood. A problem in any one = low O2

Hypoxemia

Low O2 in the BLOOD (PaO2 < 80 mmHg, SpO2 < 95%)

Hypoxia

Low O2 at the TISSUES (result of hypoxemia or poor perfusion)

Hypercapnia (hypercarbia)

Too much CO2 in the blood (PaCO2 > 45)

Dyspnea

Feeling short of breath (subjective; what the client says)

Orthopnea

Short of breath lying flat; ask "How many pillows do you sleep on?"

Paroxysmal nocturnal dyspnea (PND)

Waking up at night gasping for air; think heart failure

Tachypnea

Adult RR > 20

Bradypnea

Adult RR < 12

Apnea

No breathing

Cyanosis

Bluish color; a LATE sign of hypoxia

Clubbing

Rounded fingertips, nail angle 180° or more; CHRONIC low O2 (COPD, CF, heart defects)

Atelectasis

Collapsed alveoli; common after surgery and with immobility

Surfactant

Substance that keeps alveoli from collapsing

Compliance

How easily the lungs stretch

Hemoptysis

Coughing up blood (think TB, cancer, PE)

Barrel chest

AP diameter = lateral diameter (1:1); seen in COPD/emphysema; EXPECTED finding in COPD

Normal adult chest shape

AP to lateral ratio about 1:2 (wider than deep)

Infant chest shape

Round chest, 1:1 ratio is NORMAL for infants

SpO2 vs SaO2

SpO2 = pulse oximeter reading; SaO2 = saturation measured in the ABG

Path of air (in order)

Nose/mouth → pharynx → larynx → trachea → carina → mainstem bronchi → bronchioles → alveoli

Job of the nose

Warms, filters, and humidifies air

Epiglottis

Flap that covers the airway so food doesn't go into the lungs

Carina

Where the trachea splits into right and left bronchi; about the level of the sternal angle (T4)

Alveoli

Tiny air sacs where gas exchange actually happens

Right lung lobes

3 lobes (upper, middle, lower)

Left lung lobes

2 lobes (makes room for the heart)

Right mainstem bronchus

Shorter, wider, straighter; aspirated objects and a too-deep ET tube usually go RIGHT

Pleura

Two thin layers (visceral on lung, parietal on chest wall) with fluid between so they glide

Pleural effusion

Fluid buildup in the pleural space

Pneumothorax

Air in the pleural space; lung collapses

Diaphragm

Main breathing muscle; contracts and moves DOWN so air rushes in

Inspiration vs expiration

Inspiration is ACTIVE; expiration is normally PASSIVE

Accessory muscles

Sternocleidomastoid, trapezius, intercostals; using them = respiratory distress

What controls breathing

Brainstem (medula and pons)

Normal drive to breathe

Rising CO2 level

Hypoxic drive (COPD)

Some chronic CO2 retainers breathe in response to low O2; give O2 carefully, titrate to SpO2 88–92%

Sternal angle (angle of Louis)

Bump on the sternum at the 2nd rib; used to count ribs and intercostal spaces

Apex of lungs

3–4 cm above the clavicles

Base of lungs

About 6th rib in front, 10th rib (T10) in back

Infants and young kids (respiratory)

Small narrow airways, nose breathers, belly breathers, higher RR; swelling or mucus blocks airways fast

Nasal flaring and retractions in kids

Signs of respiratory distress

Pregnancy and breathing

Uterus pushes diaphragm up; mild SOB late in pregnancy can be normal

Older adults (respiratory changes)

Weaker muscles and cough, stiffer chest, less elastic lungs, fewer cilia, kyphosis; higher risk of pneumonia, aspiration, atelectasis

Older adult first sign of hypoxia or infection

Confusion (may NOT have a fever)

Number one changeable lung risk

Smoking / vaping

Pack-years formula

Packs per day × years smoked (2 packs/day × 10 years = 20 pack-years)

Obesity and breathing

Limits diaphragm and chest expansion; linked to sleep apnea

Immobility and lungs

Secretions pool → atelectasis and pneumonia

Opioids, alcohol, sedatives

Slow the RR (respiratory depression); alcohol also raises aspiration risk

Anxiety and breathing

Causes fast breathing (hyperventilation)

Occupational lung exposures

Coal dust, asbestos, silica, chemicals, farm dust; always ask about jobs

High altitude

Less O2 in air; body makes more RBCs over time

Carbon monoxide and pulse ox

Pulse ox reads FALSELY NORMAL; need ABG with CO-oximetry; teach CO detectors

Radon

2nd leading cause of lung cancer; teach home radon testing

Crowded living spaces

Increase spread of TB and flu

Client in respiratory distress (interview)

Treat FIRST; ask short yes/no questions; finish history after stable

OLDCARTS

Onset, Location, Duration, Characteristics, Aggravating, Relieving, Treatment tried, Severity

Clear or white sputum

Normal or viral

Yellow or green sputum

Infection

Rust-colored sputum

Pneumococcal pneumonia

Pink frothy sputum

Pulmonary edema; EMERGENCY

Pleuritic chest pain

Chest pain that gets worse when breathing in

Night sweats + weight loss + cough

Think TB

ACE inhibitors (respiratory side effect)

Dry cough

Beta blockers (respiratory risk)

Can trigger bronchospasm in asthma

Order of physical assessment (lungs)

Inspect → palpate → percuss → auscultate

EARLIEST sign of low O2

Change in mental status (restlessness, anxiety, confusion) plus rising HR and RR

Normal adult RR

12–20 breaths/min

Normal SpO2

95–100% (88–92% may be the goal for some COPD clients)

Tripod position

Leaning forward on arms; sign of respiratory distress (also helps COPD breathe)

Speaking in full sentences

Good sign; can't speak full sentences = distress

Symmetric chest expansion

Thumbs at T10, client breathes in, thumbs should move apart equally

Crepitus (subcutaneous emphysema)

Crackling feeling under the skin = air leaking into tissue

Tactile fremitus

Vibration felt when client says "99"

Increased tactile fremitus

Consolidation (pneumonia); solid conducts better

Decreased tactile fremitus

Air or fluid (pneumothorax, effusion, emphysema)

Resonant percussion

Normal lung

Dull percussion

Fluid or solid (pneumonia, effusion)

Hyperresonant percussion

Too much air (emphysema, pneumothorax)

Normal capillary refill

Less than 3 seconds

Pulse ox: causes of bad readings

Cold fingers, poor circulation, movement, dark nail polish, acrylic nails; try earlobe or forehead

What pulse ox does NOT show

CO2; a client can have good SpO2 and still retain CO2

How to auscultate lungs

Diaphragm on bare skin, client sits up and breathes deep through mouth, side to side, top to bottom, one full breath per spot

Vesicular breath sounds

Soft, low, over most lung fields; inspiration longer than expiration

Bronchovesicular breath sounds

Medium; between scapulae and next to sternum (1st–2nd ICS); inspiration = expiration

Bronchial breath sounds

Loud, high, hollow over trachea; ABNORMAL if heard over lung fields (consolidation)

Fine crackles (rales)

Like hair rolled between fingers or Velcro, late inspiration; fluid in alveoli (pneumonia, HF, atelectasis); do NOT clear with cough

Coarse crackles

Louder, bubbly, gurgling; mucus in larger airways

Wheezes (sibilant)

High-pitched musical whistle, usually on expiration; narrowed airways (asthma, COPD, bronchospasm)

Rhonchi (sonorous wheeze)

Low-pitched snoring; thick secretions in large airways; often CLEARS with coughing

Stridor

Loud high-pitched crowing on INSPIRATION, heard without stethoscope; upper airway blockage; EMERGENCY

Causes of stridor

Croup, epiglottitis, laryngeal swelling, after extubation, anaphylaxis, foreign body

Pleural friction rub

Grating, leather rubbing; inflamed pleura (pleurisy, pneumonia, PE); painful; STOPS when client holds breath

Pleural rub vs pericardial rub

Pleural rub stops when holding breath; pericardial rub keeps going

Diminished or absent breath sounds

Pneumothorax, effusion, atelectasis, severe COPD, airway blockage

Memory trick for lung sounds

Wheeze = narrow airway; Crackles = fluid; Rhonchi = mucus (cough it out); Stridor = upper airway, call for help