Medical professionals are speaking out in response to the National Rifle Association's admonishing doctors advocating for tighter gun restrictions to "stay in their lane." Jason Han,  resident in cardiothoracic surgery, and Jessica Weaver, surgical critical-care fellow, at the Perelman School of Medicine at the University of Pennsylvania, share two memorable encounters.

Jason’s story: A trainee on the front lines

The loudspeaker blared a two-minute warning: Our next patient was about to arrive in the trauma bay.

More than 20 physicians and nurses rushed to the entrance to greet the ambulance, its lights glaring and sirens screaming.

"He was found down by the time we arrived. It's not clear what happened," a paramedic said.

I watched the trauma surgery resident systematically examine the patient to rule out the most urgent threats to his life. He was breathing on his own and had a strong pulse, both excellent signs. Aside from a small bloodstain visible in his dark hair, there was no sign of injury. No broken bones, no bruises. He looked fine. Yet he was unconscious.

The attending physicians motioned the nurses to send him for a CT scan to get a head-to-toe look inside. Meanwhile, the resident tapped on our patient's knee. "Wait," he suddenly said. "He doesn't have a reflex."

"Are you sure?" the surgeon asked. "That doesn't fit the rest of the exam."

"I'm certain," the resident replied.

As a third-year medical student, I was on my first night shift in the trauma unit. I didn't know what was happening, so I waited anxiously in the trauma bay for our patient to come out of the CT scanner.

The attending surgeon spoke to the radiologist and left us without a word, bracing to speak to our patient's family members.

I glanced over the shoulders of the doctors and nurses scrolling through the CT images, looking for what had happened to this man.

One by one, they filed out of the room after seeing one image: a straight line running through his brain.

It was so striking, so stark. At first I thought it was an error on the part of the machine.

Then, with a deep, sinking sensation, I realized what I was seeing: the path of the bullet that took down a man who looked perfect but for the small bloodstain on his hair.

I am now in my second year of residency. But I am still asking myself the same question I learned to ask as a medical student: "How much proof do I need before making a decision?"

Sometimes the proof is clear. Fever, elevated white blood cell count, and a chest X-ray showing a lung abnormality are enough to know a patient needs to be treated for pneumonia. Sometimes the proof is slower to come: Smoking cigarettes causes cancer. Vaccines save lives.

Other questions, however, are not so clear. How do we know that a highly invasive surgery will ultimately improve a patient's quality of life and not just extend suffering?

Guns present a similar quandary. How much proof do we need to decide that easy access to guns leads to senseless loss of lives in this country? How many school shootings with assault rifles do we need to mourn until we are convinced?

Seeking scientific proof is fundamentally what we in the medical community do. We constantly work to find ways to heal patients and, by extension, society. We search for ways to do no harm. I can't think of anything that is more within our lane.

Jessica’s experience: The constant that is never routine

"Trauma Alert GSW ETA 3-5MINS" reads the message that comes across my phone.

On the trauma service, every day we see patients who have been in car crashes, fallen off roofs, hit by cars, even physically assaulted. But the people most likely to need immediate surgery are the gunshot victims.

As I walk quickly to the trauma bay, I get the same message again. I wonder whether it's a mistake or whether there are actually two patients.

Then I hear the announcement that we have three victims coming.  We divide into teams and get ready.

The first victim is wheeled past me into the next bay over. All I can see is that he seems to be alive, and that he looks young.

Right behind him comes my patient, who lost his pulse on the way to the hospital and is now receiving CPR.

As a surgeon, my primary goal is to find the most serious injuries and control them long enough to get his heart working again.  CPR by itself doesn't work when there isn't enough blood left for the heart to pump.

As the ER resident places the breathing tube, I look the patient over. He has bullet holes in his arms, his legs, his chest, and his abdomen.  Anything and everything could be injured.

I do the only thing we have left in that situation. With no time to get him to the operating room, I go to work in the trauma bay.  I put a clamp on his aorta to divert any remaining blood to his brain.  I sew up holes in his heart and search for injuries to his lungs and major blood vessels. All the while, my colleagues are giving him blood and medicine, including injections of epinephrine directly into the heart to make it start again.

But it doesn't.

As we call time of death, I look up at my patient's face. He has braces on his teeth.

The first patient, the one who was rolled past me, will likely never walk again because of a spinal cord injury.  The third was shot in a leg but, fortunately, no major blood vessels were hit.

One life interrupted, one forever altered, one taken away, all in an instant.

I am dedicating my life to saving patients after the worst has happened. But I know the best thing I can do is to keep people from becoming my patients in the first place.

I see the results of gun violence like this all the time, but we cannot let it become routine. No other type of weapon can cause this much deliberate destruction so quickly.

We advocate for smoke alarms, seat belts, and bike helmets, because they save lives. Yet when gun violence strikes down more victims, we act as if we were powerless to stop it.

Saving lives is entirely within my lane, and I refuse to act powerless any more.

The opinions expressed in this article do not represent those of the University of Pennsylvania Health System or the Perelman School of Medicine at the University of Pennsylvania.