Hello and i hope I can help you today. If you had any serious complications from lack of oxygen during your c/section, you would have serious brain damage and would not have been released from the hospital. Headaches and feeling dizzy is most commonly caused by anemia, as you likely lost a lot of blood during your delivery especially with twins and a c-section. However, pre-eclampsia, which is a complication of pregnancy which most commonly occurs during labor and 24 hours after, can cause headaches and visual disturbances. This can occur atypically in twins and is very risky for the mother, as it can raise blood pressure so high it can put women at risk for strokes and seizures. I suggest you call your OB provider immediately as you really need your blood pressure checked as soon as possible. A blood test to rule out atypical preeclampsia is also necessary. If it is found you have simple anemia, prescribing iron, or even intravenous iron, can be given to help correct this. I hope this answer was helpful and that you see a local doctor soon to make sure your symptoms are nothing serious, however, this is not a long-term consequence of any problem with your breathing tube. Best wishes, Dr. Brown