Low lung compliance causes

Decreased thoracic cage flexibility (aging, deformity)

High compliance cause

Increased recoil or excess surfactant (NOT decreased)

Turbulent airflow significance

Normal in large airways; not a cause of low compliance

Negative intrapleural pressure

Keeps lungs expanded against chest wall

Intrapulmonary pressure

Fluctuates with breathing

Chest wall pressure

Exerts negative pressure aiding inspiration

Pulmonary embolism effect

Ventilation without perfusion (V/Q mismatch)

Alveolar dead space

Alveoli ventilated but not perfused

Hypercapnia definition

PCO₂ > 45 mmHg

Hypercapnia ABG changes

Decreased pH, increased HCO₃⁻ (renal compensation)

Chronic hypoxia effects

Increased erythropoietin, hyperventilation, cognitive changes, pulmonary vasoconstriction

Pleural effusion signs

Diminished breath sounds, dyspnea, hypoxemia

Pleuritic pain significance

Suggests pleuritis, not simple effusion

Pleuritis signs

Sharp unilateral chest pain worse with deep breathing/coughing

Pneumothorax signs

Increased RR, asymmetric chest movement, decreased breath sounds, hyperresonance

Atelectasis causes

Immobility, mucus plugging

Atelectasis prevention

Deep breathing and coughing

Pulmonary fibrosis

Stiff, noncompliant lungs causing rapid shallow breaths

Pulmonary hypertension early signs

SOB, decreased exercise tolerance

Pulmonary hypertension late signs

Right-sided HF, peripheral edema

Bronchiectasis signs

Recurrent infections, copious purulent sputum, possible anemia

Hospital-acquired pneumonia

Occurs ≥48 hours after admission

Pneumococcal pneumonia signs

Clear sputum, fine crackles, faint breath sounds

Legionella pneumonia signs

Confusion, dry cough, diarrhea, hyponatremia

Latent TB

Not contagious

TB treatment

Requires long-term multi-drug therapy

Rhinosinusitis complications

Periorbital edema, abnormal eye movements, mental status changes

Influenza complications

Can lead to viral or bacterial pneumonia

Influenza prevention

Vaccination recommended for high-risk groups

Croup cause

Parainfluenza virus

Croup treatment

Humidified air/mist tent + oxygen

Bronchiolitis danger sign

Diminishing wheeze + cyanosis = impending respiratory failure

RDS surfactant timing

Type II alveolar cells mature at 24–28 weeks

RDS cause

Surfactant deficiency causing alveolar collapse

RDS treatment

CPAP, synthetic surfactant, warm environment, glucose monitoring, minimal stimulation

Bronchopulmonary dysplasia causes

High oxygen exposure, barotrauma from mechanical ventilation

Alveolar stage

Single capillary network forms; lungs capable of respiration

Saccular stage

Terminal sacs and surfactant begin

Pseudoglandular stage

Conducting airways form

Canalicular stage

Primitive alveoli form

Emphysema effects

Decreased elastic recoil, increased residual volume, increased dead space, increased airway resistance

Safe oxygen in COPD

Target SpO₂ 88–92%; Venturi mask preferred

Long-term COPD meds

Salmeterol (LABA), Tiotropium (anticholinergic)

Small cell lung cancer

Highly metastatic, poor prognosis

SCLC paraneoplastic syndromes

Cushing syndrome, SIADH

Adenocarcinoma

Peripheral lung cancer at sites of scarring

Large cell carcinoma metastasis

Brain, bone, liver

Respiratory failure signs

Accessory muscle use, nasal flaring, grunting, retractions, cyanosis

Carbon monoxide poisoning treatment

Hyperbaric oxygen to increase dissolved O₂ and displace CO

Tension pneumothorax (ventilator)

Sudden hypotension, tachycardia, JVD; check ventilator tidal volume

Aspiration pneumonia cause

Vocal fold dysfunction (not epiglottis)