Pathophysiology: Final Exam Study Guide Notes

Lung Cancer

• Superior Vena Cava (SVC) Syndrome:
  • Occurs when a lung mass affects blood return to the heart.
  • Symptoms: Facial swelling, distended neck veins, shortness of breath, chest pain.
• Types of Lung Cancer:
  • Non-small cell lung cancer (NSCLC).
    • Subtypes: adenocarcinoma, squamous cell carcinoma, large cell carcinoma.
  • Small cell lung cancer (SCLC).
• Staging Lung Cancer:
  • TNM system:
    • Tumor size (T).
    • Node involvement (N).
    • Metastasis (M).

Chest Trauma

• Pneumothorax (CXR Findings):
  • Visible visceral pleural line.
  • Absence of lung markings peripheral to the pleural line.
  • Possible mediastinal shift (in tension pneumothorax).
• Pleural Effusion (CXR Findings):
  • Blunting of the costophrenic angle.
  • Homogenous opacity.
  • Possible mediastinal shift (if large).

Neuromuscular Disease

• Myasthenia Gravis (MG) vs. Stroke:
  • MG: Fluctuating muscle weakness (especially in eyes, face, throat).
  • Stroke: Sudden onset of weakness (typically unilateral), speech difficulty, facial droop.
• Spine Deformities (Scoliosis/Kyphosis) & Respiratory Distress:
  • CXR may show abnormal spinal curvature.
  • In distress: Provide respiratory support, consider non-invasive ventilation.
• Acute Guillain-Barre Syndrome:
  • Symptoms: Ascending paralysis, areflexia, possible respiratory failure.
  • Diagnostic Tests: Lumbar puncture (high protein), EMG/NCS.
• Nerves Involved in Normal Breathing:
  • Phrenic nerve (diaphragm).
  • Intercostal nerves (intercostal muscles).
  • Vagus nerve (airway control).
• Types of Stroke:
  • Ischemic (due to blockage).
  • Hemorrhagic (due to bleeding).

Interstitial Lung Diseases (ILD)

• Importance of Patient History & Occupational Exposures:
  • Exposure to silica (sand/quarries), asbestos (shipyards), or other dusts may cause ILD.
• Infections Associated with ILD:
  • Tuberculosis.
  • Certain viral infections.
  • Fungal infections (e.g., histoplasmosis).
• Expected PFT Findings in ILD:
  • Restrictive pattern: Reduced TLC, FVC, and DLCO with normal or increased \frac{FEV1}{FVC} ratio.
• Signs/Symptoms of ILD:
  • Progressive dyspnea.
  • Dry cough.
  • Fine inspiratory crackles.
  • Clubbing.
• Sarcoid Population:
  • More common in African-American females.
  • May present with bilateral hilar lymphadenopathy.

Sleep Apnea

• Definitions:
  • Apnea: Cessation of airflow for \geq10 seconds.
  • Hypopnea: Reduction in airflow \geq30% with \geq3% desaturation or arousal.
• AHI to Diagnose Obstructive Sleep Apnea (OSA):
  • AHI \geq5 with symptoms or AHI \geq15 regardless of symptoms.
• Risk Factors for Central Sleep Apnea:
  • Heart failure.
  • Stroke.
  • Use of opioids.
  • High-altitude breathing.
• Signs/Symptoms of OSAS:
  • Loud snoring.
  • Observed apneas.
  • Daytime sleepiness.
  • Morning headaches.

Pulmonary Embolism (PE)

• Basic Treatment:
  • Anticoagulation (e.g., heparin, DOACs).
  • Thrombolytics (if massive PE).
  • Supportive care.
• Effects of Blood Clot Blockage:
  • Reduced perfusion.
  • Hypoxemia.
  • Possible infarction.
  • Right heart strain.
  • Possible death.
• Medications for PE:
  • Anticoagulants: Prevent further clotting.
  • Thrombolytics: Break down clots.
• Echocardiogram Importance/Findings:
  • Can detect right ventricular dysfunction.
  • Increased pulmonary artery pressure.
  • Clots in transit.

Pleural Effusion

• Fluid Appearance & Disease Implication:
  • Serous (transudate): Heart failure.
  • Cloudy/purulent: Empyema/infection.
  • Bloody: Hemothorax, malignancy.
• Main Causes of Transudative Effusion:
  • Congestive heart failure.
  • Cirrhosis.
  • Nephrotic syndrome.