14th June 2021

A 14-year-old boy has been brought to A&E by his mother

A 14-year-old boy has been brought to A&E by his mother. She has been very worried about his recent weight loss. He has told her that he is “too fat” and has been refusing to come downstairs for meals. The other day she found him in the bathroom, making himself vomit. This morning he complained of feeling dizzy and then fainted. On examination, he looks very pale and is visibly underweight, and erosion is noted on his teeth. Routine bloods, including a venous blood gas, are performed.

Which of the following abnormalities would be most likely to be seen on the blood gas?

Select the SINGLE most appropriate option from the list below. Select ONE option only.