Being Calm in Different Scenarios

We have had a busy weekend, which included a trip to the ER for Y on Thursday night as well as the shades in my living room coming crashing down on Friday afternoon.
Y was feeling fine all Thursday and then woke up around 11 15 pm with heavy croup and difficulty breathing. When the usual tricks- steaming up the bathroom- didn't really work, our neighbor who is an EMT called us an ambulance and off we went to the pediatric ER.
Riding in an ambulance was a first for me and even though Y seemed very out ot it at the time, he clearly was aware of what was going on. He keeps talking about the fire truck and asking when he can ride it again :)
The EMTs gave him oxygen and saline on the ride over so by the time we got to the hospital, he was feeling much better and his breathing had returned to normal. The doctor there still gave him a dose of steroids to be sure, because croup usually takes a few days to get out of one's system and she did not want him to have another episode. Since then he has been coughing a bit, but otherwise acting pretty normal. It is amazing how kids bounce back. By the time we left the hospital at close to 2 am, he was in a great mood, chattering incessantly and wide awake.
What struck me about the whole incident is that I was able to stay very calm throughout. I matter of factly tried to help him breathe in the shower, packed our bag with snacks, reading material and insurance information and tried to keep Y comfortable in the ambulance when he was getting agitated because of the oxygen mask. I am not really trying to toot my own horn here, it is just good for me to know that I can stay on top of things in times of crisis.
I have a much harder time, however, staying calm when the crisis is not medical rather instigated by one of our children. On Friday afternoon, the kids were a bit wound up and I was trying to get everyone to lower the volume and play a bit more gently. All of a sudden there was a very large crash. I did not really see exactly what happened but I did see the vertical blinds lying on the floor of our living room, along with the six foot pole they are usually suspended from. A. was standing right next to them and looking quite shocked.
Thank goodness noone got hurt, but I was very upset and not very calm. A. had clearly yanked on the blinds one too many times. And I needed her to understand how dangerous and unacceptable her behavior was. I realized that I was not in a good place and could not discipline her without anger, so I left it to my husband. I guess we each have our own strenghts and he is better at keeping a cool head in situations like this whereas the medical stuff is more my forte...
The blinds are still sitting on the floor, because I could not get anyone to come fix them over the weekend. The children also managed to decorate them with yogurt but that is a story for a different time. The lesson of the weekend is maybe that parenting is challenging in many different ways and you never know what life is going to throw at you.
On a semi-related note, The Feminist Breeder has an interesting post on parenting/discipline and how other people judge us unfavorably most of the time.  I actually  related to a lot of what she was saying. If you have a minute, read her thoughts. I would be curious to know if you agree with her.