Cascaded Email Alerts

Question

We are using Orion Performance Monitor to monitor our network and have set up email alerts for node status changes.  The email is sent to our cellphone as a text page.

There are many devices being monitored that are behind other devices and this continues to cascade down the network.  For example, if router C goes out, all the devices behind it are also offline.  If router B goes out, then all the devices behind it including everything behind router C are offline, etc.

Is there a way to set up the alerts so that if any device goes offline, a page goes out for that node, but if a device with nodes behind it goes down, only a page for that node goes out, rather than a page for every device behind it?