Green’s Dictionary of Slang

bagpipes n.

(US) the lungs.

[US]W.A. Caruthers Kentuckian in N.Y. I 20: He’s the chap what plumped a bullet right into old Tecumseh’s bagpipes.
[UK]A. Mayhew Paved with Gold 285: Keep them bag-pipes o’ your’n quiet.