Time-Outs

When couples argue, they may reach a point in the discussion where the bad starts to outweigh the good. 
At this point, the relationship may begin to suffer and little, if anything is accomplished besides bringing of more negativity into the relationship. 
The use of a time-out protocol tool is crucial here.
I recommend a 45 minute time-out that can be called by either partner. 
During this time each party needs to work to calm down separately via exercise, journaling, chores, deep-breathing, etc.
When they've achieved clear thinking, I strongly suggest they each consider how they might have contributed to the build-up prior to the time-out being called: interrupting, name-calling, blaming, etc. (If you don't think you made a contribution, please...think again.)
At 45 minutes the person who called the time-out needs to reconnect.
At this point, it's key to offer each other an olive branch, by naming/owning their respective contribution to the conflict and their intent to work on it.
Having this breaking tool is important for the couple, if they are to feel secure enough to take on tough topics.
Besides, would you be willing to drive a car w/o breaks!?!

Trauma and its resolution.

One's ability to really articulate the meaning and the impact of past trauma on their lives is one indicator of how much resolution of these traumas they've achieved and how much work they still need to do.

Please...don't put your kids in the middle.

When there's trouble in your marital paradise, it's often harmful to talk about it with our underage children.
Kids tend to personalize and internalize the relational strife between their parents.
This is when it's crucial to redouble your efforts to act the role of the reassuring and consistently loving parent.
If you feel you must discuss your circumstances with someone other than your spouse, select someone who's likely to be object and least likely to hold a grudge against your partner.
I suggest a counselor who specializes in relationship counseling.
Your pastor, rabbi, priest, or imam might also be a good choice.