Trauma Surgeon Peggy Knudson Tells Vox News How Doctors Save Lives After a Mass Shooting
In the wake of October's mass shooting at a Harvest country music festival in Las Vegas, Vox News reached out to UCSF trauma surgeon M. Margaret “Peggy” Knudson, M.D., FACS for her thoughts on how doctors manage an influx of mass shooting victims, and the critical techniques for ensuring their patients' survival.
Knudson, a professor in the UCSF Department of Surgery at Zuckerberg San Francisco General (ZSFG), is a nationally recognized expert on mass trauma events and war injuries. Currently Medical Director for the Military Health System (MHS) Strategic-ACS Partnership, Knudson served as a Senior Visiting Surgeon in the Iraq war theater and treated victims of the Asiana Airlines crash at San Francisco International airport in 2014.
In a recent seminal talk, "When Peace Breaks Out", Knudson argued for training civilian and military surgeons alike to handle mass trauma cases, whether arising from domestic terror events, natural or man-made disasters, and casualties of future wars. One of her central tenets is that advanced trauma care techniques learned on the battlefield in recent American wars can be used to save lives after mass shootings. In her interview with Vox, Knudson underscored three key practices that can literally make the difference between life and death in the crucible of a mass casualty event.
1) Stop the bleeding
The most common reason people die at the scene of a mass shooting event is bleeding. (The second most common cause of death at these events is massive brain injury.)
Before the Iraq and Afghanistan wars, the use of tourniquets in medicine had fallen out of favor. "Tourniquets to control extremity bleeding were not used, and best practice was that they shouldn't be used," said Rasmussen. But new evidence changed the practice: Military health professionals saw early on that patients on whom tourniquets were used were more likely to survive their injuries.
This change in practice is why the Department of Homeland Security launched the Stop the Bleed campaign in 2015, encouraging bystanders in violent attacks to compress the wounds of victims if health professionals haven’t yet arrived at the scene. And people who were at the Las Vegas country music festival when the shooting happened reported seeing bystanders using belts as tourniquets. “In the past 15 years of war," Margaret Knudson, a professor of surgery at the University of California San Francisco, added, "those techniques have saved many lives on the battlefield."
2) Small stopgap surgeries
Some gunshot victims need immediate surgery.
But doing all the necessary surgeries immediately in a mass casualty event is usually impossible. So doctors now do smaller and quicker surgeries first, with one key goal: saving lives. This type of care was perfected in Iraq and Afghanistan, and it’s called damage control surgery.
For example, for a patient with a more minor blood vessel injury on the leg, doctors may put a small piece of plastic in place (called a "shunt") to keep the blood flowing. That can allow them to move on to do other, more critical surgeries on the same patient or help other patients in a more critical state. Later, the doctors can go back and do a more definitive surgery to repair the broken blood vessel. "We do these abbreviated surgeries whenever we can," and they help save lives, said Knudson.
3) Help clotting by giving blood plasma and platelets first
Patients wounded by gunshot typically have lost a lot of blood. If they need surgery, they’ll also probably need blood transfusions.
Blood transfusions often involve supplementing patients with specific blood components (also known as products) — like blood plasma, including red blood cells, which carry oxygen, or platelets, which are essential for making blood clot.
In the past, doctors would first respond by giving patients saline solutions (mixtures of sodium chloride in water) in addition to or followed by blood products. But in the recent wars, military doctors started to notice that patients actually fared better when they got the blood products immediately.
"When someone loses 20 to 30 percent of their blood volume from a gunshot wound," said Rasmussen, "we don't give them ... saline solutions. We try to give plasma, platelets, and packed red blood cells right away."
Studies conducted during the wars also helped doctors refine the ratios and amounts of blood products to give to the injured. "We learned from military experience that it’s really important to give clotting factors almost first, and in a better ratio," Knudson said. That decreased mortality in military wounds, and it’s dramatically changing the way we care for patients in the civilian world. "Not only does it save some of the blood by using products judiciously but it also allows you to [better] direct what you give," said Knudson.