It seems to have become the standard everywhere, across the NHL. If you want a reliable defenseman for your defensive squad in the playoffs, you have to pay a first round pick.
Indeed, LeBrun says the CH isn't necessarily ready to trade him quickly, as he still has another season left on his contract. This is a huge gamble for Kent Hughes, as Edmundson's injury history is starting to weigh heavily on him, even to the point where this season he seems to have really slowed down.
If he gets hurt again or struggles, Hughes could quickly regret not trading him first, especially if the price he received was actually a first round pick.