Learn Italian: Con l'impegnativa, fanno il prelievo in cinque minuti. - With the referral, they do the blood draw in five minutes.

The preposition in is used to show how long an action takes to complete. The blood draw itself takes five minutes from start to finish. If the sentence used tra (or fra), like fanno il prelievo tra cinque minuti, it would mean the appointment begins five minutes from now.

What exactly is an impegnativa?

In the Italian healthcare system, an impegnativa is a doctor's referral or prescription for a test, procedure, or specialist visit. You usually need one to get blood work done at a public clinic.

Prelievo means 'blood draw' here, but does it have other meanings?

Yes! The verb prelevare means to extract or withdraw. While un prelievo commonly refers to a blood draw (un prelievo di sangue) in a medical context, it is also the standard word for an ATM cash withdrawal (un prelievo bancomat).

Why is fanno used here without a subject pronoun like loro?

Dropping the subject is standard in Italian, but here the third-person plural (fanno) is specifically being used to create an impersonal 'they'. It refers vaguely to the clinic staff or nurses, exactly like saying 'they take your blood' in English when you don't mean a specific group of people.