Which of the following is NOT a symptom of CO2 toxicity?

Carbon dioxide (CO2) toxicity, also known as hypercapnia, occurs when there is an excess of carbon dioxide in the bloodstream, which can lead to a variety of symptoms primarily related to respiratory and neurological effects. Common symptoms associated with CO2 toxicity include an increased respiratory rate as the body attempts to eliminate the excess CO2, confusion due to impaired cognitive function from elevated CO2 levels, and drowsiness as the brain becomes affected by altered blood gas levels.

Stomach cramps are not characteristic symptoms of CO2 toxicity. While gastrointestinal symptoms can arise from other conditions, the primary effects of CO2 toxicity are systemic and neurological rather than directly related to gastrointestinal distress. Therefore, among the symptoms listed, stomach cramps do not fit within the expected symptomatology associated with elevated carbon dioxide levels in the body, making it the correct answer to identify as NOT a symptom of CO2 toxicity.