Possible guidelines for autologous red blood cell donations before total hip arthroplasty based on the surgical blood order equation. - Nutall,G.A.; Santrach,P.J.; Oliver,W.C.; Ereth,M.H.; Horlocker,T.T.; Cabanela,M.E.; Trousdale,R.T.; Schroeder,D.R. (Mayo Clin Proc, 2000)