For us hobbyist growers, not those that show at AOS sanctioned events, you should leave that stem intact. Only cut it back IF it turns completely brown, dry, and brittle. As long as there is any coloration, whether green to purple, that stem is viable and as often as not, will re-bloom on that stem next go'round. Be sure when/if you re-pot, you angle that plant so that any water that gets into the crown area will quickly drain off. Otherwise, you might get crown rot. Get in the habit of watering the orchid in the AM so that it has a better chance of drying out by nightfall. Also, keep the plant more on the surface of your orchid media. It loves to dangle its roots and grow them aerially.
