Two teenagers, and I'm the referee by text in the middle of my evening shifts

I'm on evening shifts in the emergency department for most of this month. My 16 year old and 14 year old come home to our helper, who is there until eight, and from about seven onwards my phone starts. 'He's taken the charger.' 'She won't let me use the table for my project.' 'Tell her it's my turn for the TV.' I can't answer in the middle of a resuscitation, and when I check an hour later they've usually sorted it out or moved on to the next one. We've agreed house rules before. They hold when I'm at home. For parents who work shifts, how do you set things up so the children don't route every disagreement through you?