Hints for a nurse pratictioner

As per the title, I’m a NP working in Emergency care and first responding (in my country we don’t have paramedics).

I’ve studied BPD and have a couple of frequent callers affected by BPD, one in particular who’s very difficult to deal with, in terms of destructive behaviours.

I get that my patients’ first critic is themselves, and self-esteem and value are deeply variabile, however manipulation seems to be the first dialogue tactic, followed by rudeness and opposition?

What can I do to reassure them that I come from a place of openness and availability and not of judgement? Thank you.