There are assorted non-magical Warlord powers that will work.
-Hyp.
That's right, shake it off men, RUB SOME MUD IN IT!!!! GET YOUR NO GOOD KEISTERS BACK IN THERE AND FIGHT!!!!!
K, everybody can spend a healing surge

There are assorted non-magical Warlord powers that will work.
-Hyp.
....except when you at at (or below) 0 hp, and have failed 2 death saving throws....and you're about to roll your third death save....Personally I see healing surges as your actual health as oppossed to your HP total
This essentially means that once you've used your Second Wind, you're unhealable unless by magic, and that assumes your Defenders haven't run out of powers.
Why use second wind in between encounters when you can just spend as many healing surges as you like during short rests?
That's why some people like to spend their second wind at the end of an encounter (if they haven't already used it), so if they are attacked during the rest, they have more hit points.