Chest Disorders

Anatomy of the Thoracic Cavity and Mechanics of Breathing

The thoracic cavity is a well-protected, airtight chamber enclosed by the rib cage, thoracic vertebrae, and the sternum. Inside this space reside the vital organs of respiration and circulation, primarily the lungs and the heart. The internal lining of the chest wall is covered by the parietal pleura, while the visceral pleura closely adheres to the outer surface of the lungs. Between these two delicate membranes lies the intrapleural space, which normally contains a microscopic amount of serous fluid that reduces friction during respiratory movements.

Breathing relies entirely on pressure gradients created by changes in thoracic volume. During inspiration, the diaphragm contracts and flattens, while intercostal muscles pull the ribs upward and outward. This action enlarges the thoracic cavity, dropping intrapleural pressure below atmospheric pressure and drawing air into the lungs. Expiration is typically a passive process driven by the elastic recoil of lung tissue and the relaxation of respiratory muscles.

Common Pleural and Chest Wall Conditions

Pathologies affecting the chest typically disrupt the delicate negative pressure of the pleural space or interfere with chest wall movement.

Pneumothorax: Air enters the intrapleural space, disrupting negative pressure and causing partial or complete lung collapse. A tension pneumothorax is a life-threatening variant where air enters but cannot escape, shifting mediastinal structures and compressing the heart.
Hemothorax: Blood accumulates in the pleural cavity, often resulting from blunt or penetrating chest trauma, which compresses lung tissue and leads to hypovolemia.
Pleural Effusion: Excess fluid accumulates in the pleural space due to heart failure, infection, or malignancy, restricting normal lung expansion.
Flail Chest: Multiple adjacent rib fractures cause an unstable chest wall segment, resulting in paradoxical chest movement during respiration.

Clinical Manifestations and Patient Assessment

Patients experiencing chest disorders present with distinct clinical signs that reflect impaired gas exchange and compromised thoracic mechanics.

Dyspnea: Shortness of breath is the universal hallmark, often worsening with exertion.
Chest Pain: Sharp, pleuritic pain that intensifies with deep inspiration or coughing.
Asymmetrical Chest Expansion: Visible difference in the movement of both sides of the chest, common in pneumothorax or flail chest.
Absent Breath Sounds: Auscultation reveals diminished or absent breath sounds over the affected lung area.
Tracheal Deviation: A late, critical sign of tension pneumothorax where the trachea shifts toward the unaffected side.

Diagnostic Evaluation and Interpretation

Accurate diagnosis of thoracic disorders requires a combination of imaging, physical examination, and laboratory testing.

Test / Procedure	Clinical Purpose	Expected Finding in Pathology
Chest X-Ray	Visualizing lung fields and pleural space	Presence of air, fluid, or mediastinal shift
ABG Analysis	Assessing oxygenation and acid-base balance	Hypoxemia and respiratory alkalosis or acidosis
Thoracentesis	Sampling pleural fluid for analysis	Exudative or transudative fluid confirmation
Pulse Oximetry	Monitoring peripheral oxygen saturation	Decreased SpO2 levels below normal limits

Medical and Surgical Management: Chest Tube Systems

Restoring negative intrapleural pressure is the cornerstone of managing significant pneumothorax or hemothorax. This is achieved by inserting a chest tube into the pleural cavity and connecting it to a water-seal drainage system.

The traditional three-chamber chest drainage system includes a collection chamber for drained fluids, a water-seal chamber that acts as a one-way valve allowing air to exit while preventing backflow, and a suction control chamber that regulates negative pressure.

Nurses must maintain a closed, secure system at all times. Tideling—the fluctuation of fluid in the water-seal chamber with respiration—is normal and indicates patency. Bubbling in the water-seal chamber often indicates an air leak within the patient or tubing system.

Nursing Care Plan and Complication Prevention

Comprehensive nursing care for patients with chest disorders focuses on promoting optimal gas exchange, managing pain, and preventing secondary complications such as infection or empyema.

Encouraging deep breathing exercises, incentive spirometry, and early ambulation helps prevent atelectasis. Nurses should regularly assess insertion sites for signs of subcutaneous emphysema, infection, or accidental tube dislodgement. Emergency equipment, including sterile petroleum gauze and clamps, must remain immediately accessible at the bedside of any patient with a chest tube.

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