Center Kyle Turris is going from Ottawa to Nashville in the deal and agreed to a six-year, $36 million contract extension with the Predators.
Colorado gets a haul of players and draft picks: rookie defenseman Samuel Girard, forward prospect Vladislav Kamenev and a second-round pick from Nashville, and center Shane Bowers (a 2017 first-round pick), goalie Andrew Hammond and first- and third-round picks from Ottawa.
Duchene, 27, the third overall pick of the 2009 draft, was removed from Sunday's game against the Islanders when word of a deal came down.
Duchene, who has been on the trade market for a while, has four goals and six assists in 11 games this season.
He has spent all eight-plus seasons of his career with the Avalanche, for whom he had his best season in 2013-14, with 23 goals and 47 assists in 71 games. He had a career-best 30 goals the following season but dipped to 18-23-41 last season.
He is in the fourth year of a five-year, $30 million contract. Last season, Duchene had a minus-34 plus-minus rating, tied with teammate Tyson Barrie for worst in the NHL.
Turris is also 27 and a former third overall draft pick (2007 by Phoenix). He has three goals and six assists in 11 games this season, and three times he has topped 20 goals, including a career-best 27 last season.
The Senators acquired him from the Coyotes in December 2011 for David Rundblad and a second-round pick. Turris was in the final season of a five-year, $17.5 million deal.
The Avalanche won't have to wait long to see Duchene again, as they are headed to Sweden to play back-to-back games against Ottawa beginning Friday.