“This is not a drill,” Dr. Michael Cheatham frantically told colleagues as he called them in after their full shifts were done, while home or on vacation.

As the wounded from the popular Pulse nightclub poured by “ambulance-loads” into the Orlando Regional Medical Center’s ER in the early morning hours Sunday, everyone answered Cheatham, the center's chief surgical quality officer, recounted at a press conference this week, “I'll be right there.”

A testimony to the staff's dedication shows in the large number of wounded who have survived. Of the 44 victims who arrived at the center, nine had fatal injuries and died before they could be helped. Of the others, 27 were hospitalized, with about half a dozen in intensive care. But after the initial tragic deaths, all were still alive as of 48 hours ago, according to Vox.

Another reason that survival rates were so good, ironically, is what has been learned from the tragedy of the battlefield.

“Advances in trauma care have accelerated over the past decade, spurred by the unprecedented burden of injury resulting from the wars in Afghanistan and Iraq,” according to a new consensus study and webinar from the National Academies of Sciences due for release June 17.

"During the height of the wars, we were treating injury patterns at a rate that was 10 to 100 times [that which] you would treat in any given city," Col. Todd Rasmussen, a physician who was in both wars, observed to Vox.

One key discovery from war's carnage was that an old technique, fallen into disfavor, could significantly boost survival in victims.

According to a 2016 paper in the Journal of Trauma and Acute Care Surgery on which he was lead author, “Military providers identified the significance of rapid, compressible hemorrhage as a cause of potentially preventable death,” adding that, although tourniquets were not new, their use had largely been abandoned before September 11, 2001. Faced with an unprecedented burden of massive extremity injury, vascular trauma and hemorrhage from explosive devices and high-velocity gunshot wounds, the military reappraised its stance and rapidly re-engineered, tested and deployed tourniquets and hemostatic bandages.”

Just as important, these tools were put into a kit carried by all war-fighters, giving all the ability to control bleeding. Studies backed up the importance of early and rapid bleeding control. Ultimately this led to Homeland Security's “Stop the Bleed” campaign in 2015, which spreads the word about bleeding control, urging bystanders to compress wounds before health care professionals arrive at shooting scenes.

Bleeding out is the leading cause of death at the scene of mass casualty situations like Orlando, followed by brain injury.

Rasmussen also noted that the approach to the administration of blood products has seen changes in recent years. Military experience, noted Rasmussen, now suggests that plasma and platelets should be given first. Earlier approaches would be to administer saline initially. "When someone loses 20 to 30 percent of their blood volume from a gunshot wound," he advised, "we don't give them ... saline solutions. We try to give plasma, platelets, and packed red blood cells right away."

In a 2012 Journal of Trauma Acute Care article, this approach showed itself to be significantly better than earlier ones. The authors found that “high transfusion ratios of fresh frozen plasma and PLT to red blood cells were correlated with higher survival but not decreased blood requirement.”

Using blood products rather than whole blood also lets that supply be rationed more effectively, noted M. Margaret Knudson, a professor of surgery at the University of California San Francisco, speaking to Vox, explaining that "not only does it save some of the blood by using products judiciously,” but this approach gives you a better way to “direct what you give."

Military experience has also led to changes in emergency surgery – most importantly a new emphasis on so-called “damage-control” surgery rather than extensive all-encompassing operations. "We do these abbreviated surgeries whenever we can," said Knudson. Then later, additional surgery may be performed in a more orderly environment.