It sounds to me like you handled it well. I also work in an ICU and frequent phone calls be be extremely disruptive to patient care and workflow in the unit. Most places I have worked ask for a designated family member on admission and we will only allow updates via telephone to that person. I have often had similar conversations (not quite to this extreme) with family members about coordinating updates, talking to each other, or physically coming to the hospital together to all get an update. It is unfortunate that the DON could not hear your side of this situation and understand patient care can be negatively impacted by an overbearing family. Family involvement is key, but when a family is trying to direct care at a level that is this disruptive, that is unacceptable. Ultimately you are there to care for the patient, not the entire family, although in the ICU, we often have no choice.