Could he have aspirated? Mendelson's syndrome.
D000328:Adult; D001784:Blood Gas Analysis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000097:blood / Q000000981:diagnostic imaging* / Q000628:therapy; D011859:Radiography