Which neurologic signs would raise concern for Type II DCS during flight?

• A. Headache and dizziness
• B. Numbness only
• C. Altered mental status, ataxia, numbness, or weakness
• D. Nasal bleeding

Answer: (C)

Type II decompression sickness involves the brain or spinal cord, so neurologic findings point to serious CNS involvement. Altered mental status, ataxia (loss of coordination), numbness, or weakness together indicate that gas bubbles are affecting the central nervous system, which is the hallmark of Type II DCS. This scenario requires rapid action: administer 100% oxygen, descend to a lower altitude if possible, and arrange for prompt hyperbaric recompression after landing or as soon as available. Headache and dizziness can occur with milder or different issues and are not, by themselves, definitive for Type II DCS. Numbness alone could be an early or isolated sensory symptom but without CNS signs it’s less concerning for Type II. Nasal bleeding is not a typical sign of DCS related to CNS involvement and points more toward barotrauma.