Medical staff in scrubs gather to turn off the tubes to a giant gas tank.
Denver Health Pediatric anesthesiologist Dr. Amanda Deis, front, and perioperative services manager Cory Ray, officially shut off centralized tanks that provided nitrous oxide anesthesia to operating rooms throughout the hospital as anesthesiologist Dr. David Abts looks on. The hospital has switched to smaller tanks located inside the operating rooms in attempt to cut down on the amount of nitrous oxide that leaks from large, centralized systems at hospitals. (Kathryn Scott, Special to The Colorado Sun)