The nightmare of the deadly Las Vegas mass shooting rings close to home for one Orlando-area trauma surgeon.

Dr. Gary Parrish was on the front lines at Orlando Health’s trauma unit after the Pulse shooting.

Since that tragic night in June 2016, Parrish has been asked to share his experience with other trauma units across the country, providing insight to other surgeons and medical staff on what procedures they could improve upon in the hours and days after a mass casualty event.

But no one could have predicted how soon his advice would be put into practice.

On Sunday night, the sounds of rapid gunfire drowned out the sounds of a country music concert on the Las Vegas Strip — another mass shooting in the U.S. was underway.

In the aftermath: at least 58 dead, more than 520 injured — eclipsing the Pulse attack as the deadliest mass shooting in modern American history.

But for doctors and nurses at Las Vegas’ University Medical Center, their response may have been helped by Parrish's insights.

He provided firsthand knowledge of the controlled chaos that ensues after a mass casualty event. He, along with dozens of others, fought to save lives as patient after patient arrived at Orlando Regional Medical Center the night of the Pulse nightclub shooting.

Since then, Parrish has offered his expertise in an effort to give trauma staff and hospitals vital information on logistics and caring for patients and staff.

“Any time you hear somebody else’s story and what they went through, sometimes there are small bits of information that might be helpful if you have to go through those events,” he said Wednesday.

Parrish thinks the staff at UMC wanted to hear what he had to say because the cities of Orlando and Las Vegas are similar in population and tourist traffic.

He said UMC staff were prepared for the mass casualty event not only because of its own excellent training, but perhaps from some of the information he shared with them about patient management, logistics and how to cope with possibly unfamiliar forms of trauma.

“Any one patient saved is a benefit for the institution and for the community,” Parrish said.