Page 131 - Critical Care Notes

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■ Administer hyperbaric O 2 therapy within 2–6 hr after exposure if symptoms
are severe or if COHgb levels ≥25% (controversial).
■ Provide supportive care.
Pneumothorax
Pneumothorax is defined as air entering the pleural space and interrupting the
negative pressure, with resulting partial or total lung collapse.
Types of pneumothorax include:
■ Spontaneous pneumothorax: Rupture of subpleural bleb with unknown
cause that may be related to smoking and connective tissue disorder.
Patients with chronic lung disease (COPD) have a higher incidence.
■ Traumatic pneumothorax: Caused by blunt chest trauma, penetrating
injury, pulmonary contusion → rib fracture or puncture directly to the lung
→ penetrates parietal and visceral pleura → punctures the lung parenchyma
→ lung air pressure from positive to negative pressure environment (inside
the lung) → pneumothorax. If pneumothorax remains confined →↑ air in
pleural space on inspiration → air cannot exit on expiration → pressure ↑.
■ Tension pneumothorax: Resulting from increased pressure in the pleural
space that causes the lung to collapse. The increase in pressure may impair
circulation by compressing the heart and vena cava.
Pneumothorax can also be categorized by size:
■ Small pneumothorax (<15%)
■ Moderate pneumothorax (15%–60%)
■ Large pneumothorax (>60%)
Clinical Presentation
Pneumothorax manifests with:
■ Respiratory distress, including shortness of breath, dyspnea, or air hunger
■ Use of accessory muscles
■ Anxiety
■ Sharp pleuritic chest pain that increases with deep inspiration or chest
movement and cough on the ipsilateral side, with pain possibly radiating to
the shoulder, neck, or epigastrium
■ Decreased or absent breath sounds, hyperresonance to percussion, absent
tactile fremitus on the affected side, asymmetrical chest wall movement
■ Hypoxemia, decreased oxygenation levels
■ Cool, clammy skin or central cyanosis if hypoxemia severe
■ Tachycardia, hypotension
■ Subcutaneous emphysema → swelling in affected area with crepitus upon
auscultation

RESP