For suspected decompression sickness, initial oxygen therapy should be provided at what concentration?

For suspected decompression sickness, initial oxygen therapy should be provided at what concentration?

• A. 21% oxygen
• B. 50%
• C. 100% oxygen
• D. 90%

Answer: (C)

High-concentration oxygen therapy maximizes nitrogen washout and improves tissue oxygenation in suspected decompression sickness. After a rapid ascent, dissolved nitrogen can form bubbles in tissues and blood, leading to obstruction and hypoxia. Providing 100% oxygen raises the alveolar oxygen tension and creates a large diffusion gradient for nitrogen to move from tissues and bubbles into the blood, where it is carried to the lungs and exhaled. This accelerates bubble dissolution and reduces ongoing vascular blockages, while also ensuring tissues receive ample oxygen. For this reason, 100% oxygen is the initial management, typically given for at least a short period (often about 60 minutes) or until symptoms improve, with definitive treatment being hyperbaric recompression. Lower concentrations do not promote as rapid nitrogen elimination, so they are not as effective as the full 100% dose in the acute setting.

High-concentration oxygen therapy maximizes nitrogen washout and improves tissue oxygenation in suspected decompression sickness. After a rapid ascent, dissolved nitrogen can form bubbles in tissues and blood, leading to obstruction and hypoxia. Providing 100% oxygen raises the alveolar oxygen tension and creates a large diffusion gradient for nitrogen to move from tissues and bubbles into the blood, where it is carried to the lungs and exhaled. This accelerates bubble dissolution and reduces ongoing vascular blockages, while also ensuring tissues receive ample oxygen. For this reason, 100% oxygen is the initial management, typically given for at least a short period (often about 60 minutes) or until symptoms improve, with definitive treatment being hyperbaric recompression. Lower concentrations do not promote as rapid nitrogen elimination, so they are not as effective as the full 100% dose in the acute setting.