Jane doesn't look well. I am worried about her.
1. - I know. I am about to take her to the doctor.
2. - I know. I was about to take her to the doctor.
(In this dialogue, which one should we use, 'am' or 'was'?
Sentence 1 is in the present tense. It means that the speaker will soon take her to the doctor.
Sentence 2 is in the past tense. It means that he was going to take her to the doctor, but apparently is not now.
Sentence 1 is best in this context.