Brannstrom didn't move as Senators trainers quickly reached the ice and the stretcher was wheeled out of a tunnel.
Nine Ottawa players took a knee and the Islanders stood in a circle in a silent UBS Arena as Brannstrom was moved onto the stretcher.
Bo Horvat and Cal Clutterbuck scored in the first for the Islanders, who snapped a three-game losing streak (0-2-1).
The Senators tied the score during a second period in which the Islanders committed six penalties.
The Senators tied the score on Chychrun's even-strength goal at 12:25 of the second period, a little more than four minutes after Brannstrom was injured.
Persons:
Noah Dobson, Erik Brannstrom, Brannstrom, Bo Horvat, Cal Clutterbuck, Ilya Sorokin, Claude Giroux, Jakob Chychrun, Joonas Korpisalo, Dobson, Horvat, Rourke Chartier, Casey Cizikas, Giroux, Sorokin, Ryan Pulock, Brady Tkachuk
Organizations:
New York Islanders, Ottawa Senators, Senators, Nine Ottawa, Islanders, UBS Arena, Brannstrom, Cal, Ottawa, Thomson
Locations:
Elmont, N.Y