It’s 7 a.m. and traffic is just starting to build up on Speer Boulevard outside of Denver Health’s Emergency Building. In a second-floor lounge, nurses from the Surgical Intensive Care Unit (SICU) are filtering in for a shift-change meeting. Some are coming off a 12-hour shift; others are just starting their days. They chat about pets or patients, intermingling work talk with lighthearted banter. Altogether, there are 60 nurses who staff a unit with 20 beds, many of them filled with the hospital’s most critically ill patients.

These nurses see everything: Car crash survivors who were scooped off the pavement. Skiers who didn’t turn in time. Hikers who fell. Gunshot wounds. Heart attacks. Patients recovering from major surgeries. Because people never stop getting sick and injuries happen every day, the SICU never shuts down. But twice a day, the nurses here gather to develop plans of treatment, swap information, and catch their collective breath.

SICU patients require highly skilled nursing, the kind that includes careful observation, monitoring equipment, mechanical ventilation, and sometimes, end-of-life care. The level of treatment in any intensive care unit must be a cut above the care available in intermediate care units, but at Denver Health, the care is top-tier. In fact, Denver Health boasts some of the best trauma outcomes in academic medical centers nationwide, which means that even in the worst medical situations, this unit is keeping its patients alive. During the second and third quarters of 2010, the unit logged zero central line infections—infections are a troublesome and sometimes fatal issue in many SICUs—a laudable feat considering that 3.6 infections per year is the national norm.

Twenty-two percent of the nurses in the unit have more than 10 years of experience in the SICU—they’re as adept as doctors at inserting an IV or making critical decisions when a patient’s vital signs crash. They know medication, they understand surgeries, and they coordinate care with other hospitals from which they sometimes get transfer patients.

“You need to have senior nurses,” says surgical critical care specialist Jim Haenel. “You need a nurse with, say, 22 years of experience. [A young doctor] may want to go down one path and a veteran nurse can pull him back. These nurses are fountains of information.”

But being a SICU nurse isn’t an easy career path. Injuries are often grisly. Patients are frequently too sick or too drugged to respond to—or even remember—their nurses. And patients’ families are often devastated and in need of care themselves. To deal with it all, the nurses learn to compartmentalize their jobs. For some that means training for marathons on their days off, and for others that means keeping quiet at the family dinner table about what happened at work that day. “This isn’t a job for everyone,” nurse Nicole Stafford says. “We take the really hard cases.” And Denver Health’s SICU takes a lot of them: 1,200 patients move through the unit each year. “There is a saying among the nurses here that after three years, you may have seen every type of patient,” says 19-year-veteran nurse Theresa Nino. “But after five years you are good at it.”

Today’s morning shift change is like any other. until it isn’t. A call comes in from another Colorado hospital. An automobile accident victim from Pueblo is en route to Denver via helicopter. Within seconds, the SICU nurses are on the phone with nurses from the transferring hospital to discuss X-rays. A gurney appears, waiting for its next patient. And as the helicopter lands, the nurses check IV lines, prep the patient for surgery, and talk to the doctor about the patient’s plan of care. The scene is organized chaos, but the SICU nurses move with practiced care. They know that any misstep or ill-timed interaction can be a matter of life or death. It’s a high-stress profession, but the nurses don’t seem to notice. After all, this is their job—and they know exactly how to do it well.