🌬️

Gas Exchange Alterations Overview

Jun 10, 2025

Overview

This lecture reviews critical alterations in gas exchange, including key respiratory conditions, their pathophysiology, risk factors, clinical presentations, diagnostic methods, and the nurse’s role in management.

Pathophysiology & Types of Gas Exchange Alterations

  • Gas exchange alterations include pleural effusion, tension pneumothorax, pulmonary embolism, respiratory failure, and acute respiratory distress syndrome (ARDS).
  • Pleural effusion involves fluid accumulation in the pleural space, impeding lung expansion and gas exchange.
  • Transudative effusion is due to pressure imbalance; exudative effusion results from increased capillary permeability.
  • Tension pneumothorax is lung collapse from trauma or medical procedures, causing rapid respiratory compromise.
  • Flail chest involves multiple rib fractures leading to chest wall instability and impaired ventilation.
  • Pulmonary embolism (PE) is blockage of pulmonary arteries, disrupting blood flow and causing ventilation-perfusion (V/Q) mismatch.
  • Respiratory failure can be hypoxemic (low oxygen) or hypercapnic (high CO2), caused by various pulmonary and non-pulmonary conditions.
  • ARDS is an acute, severe inflammatory lung injury with rapid-onset hypoxemia and reduced lung compliance.

Risk Factors & Epidemiology

  • Risk factors for pleural effusion include heart failure, liver cirrhosis, nephrotic syndrome, cancer, trauma, and aging.
  • Tension pneumothorax risk: trauma, central line placement, mechanical ventilation, lung biopsy, bronchoscopy, CPR.
  • PE risk factors: immobilization, hypercoagulability, vessel injury (Virchow’s Triad), and deep vein thrombosis.
  • Older adults are at higher risk for respiratory complications due to age-related changes and comorbidities.

Clinical Presentation & Diagnostics

  • Pleural effusion: dyspnea, pleuritic chest pain, decreased breath sounds, nonproductive cough.
  • Tension pneumothorax: tachycardia, hypotension, jugular distension, sharp pain, cyanosis, respiratory distress.
  • Flail chest: severe chest pain, paradoxical chest movement, respiratory insufficiency.
  • PE: dyspnea, chest pain, cough, syncope, shock, altered perfusion.
  • Diagnostics include chest x-ray, CT scan, ultrasound, ABGs, ECG, and lab tests.
  • ARDS: acute onset, refractory hypoxemia, bilateral lung infiltrates on imaging, rapid progression.

Nursing Roles and Management

  • Monitor vital signs, respiratory status, and oxygenation.
  • Assist with procedures (thoracentesis, chest tube placement, intubation).
  • Provide client education on symptom recognition and lifestyle management.
  • Manage pain, optimize nutrition, and coordinate care with multiple disciplines.
  • Prevent ventilator complications, maintain oral hygiene and skin integrity, and educate patients on oxygen safety.
  • For PE, administer anticoagulation therapy and monitor for therapeutic levels (INR).

Key Terms & Definitions

  • Pleural Effusion — Fluid buildup in the pleural space around the lungs.
  • Transudative Effusion — Fluid caused by pressure imbalance, typically clear.
  • Exudative Effusion — Protein-rich fluid from increased capillary permeability, often due to inflammation.
  • Tension Pneumothorax — Air in the pleural space causing lung collapse and mediastinal shift.
  • Flail Chest — Segment of chest wall moves independently due to multiple rib fractures.
  • Pulmonary Embolism (PE) — Blockage of a pulmonary artery by a clot or other embolus.
  • V/Q Mismatch — Imbalance between ventilation (airflow) and perfusion (blood flow).
  • Respiratory Failure — Inability of lungs to maintain adequate oxygen or CO2 removal.
  • ARDS — Acute respiratory distress syndrome, severe lung inflammation and hypoxemia.
  • Mechanical Ventilation — Machine-assisted breathing support for compromised patients.
  • ECMO — Extracorporeal membrane oxygenation, external blood oxygenation support.

Action Items / Next Steps

  • Review acute care content on detailed pathophysiology of respiratory conditions.
  • Familiarize yourself with diagnostics and nursing care for respiratory emergencies.
  • Complete assigned readings on gas exchange alterations and related nursing interventions.
  • Practice identifying clinical signs and developing nursing care plans for these conditions.