When the Boston Marathon turned into a life-or-death situation for so many runners and spectators Monday, several who survived expressed immediate gratitude -- even those who lost limbs in the attack.
But how does the body survive without an arm or a leg?
The immediate trauma is physical: According to medical reports, two of Monday’s 10 or so amputees lost their limbs at the site of the bombings. The others underwent surgical amputation at the hospital.
Loss of blood is the main life-threatening concern, doctors said. Near the finish line, doctors and bystanders wrapped gauze tourniquets around legs.
"The major risk at that point is that you bleed to death," said Dr. Alberto Esquenazi, chairman of Einstein Healthcare Network's Department of Physical Medicine and Rehabilitation and chief medical officer for MossRehab Medical Center in Pennsylvania. "If there's nothing to hold the blood, you go into cardio shock, and as a result you die."
Most of the worst injuries seemed occur to the legs, because the bombs exploded close to the ground. How fast you bleed depends on where the limb was severed, said Dr. Terrence Sheehan, Chief Medical Officer at Adventist Rehabilitation Hospital of Maryland and medical director of the Amputee Coalition. The closer to the hip, the larger the blood vessels and the harder to stop the bleeding.
"That's why the first responders were very important," Sheehan said.
Time is also of the essence to save the limb, Sheehan said: Without blood flow, limbs can survive anywhere from one to six hours. Once in the operating room, surgeons are trained to salvage the limb and reattach it if at all possible, both doctors said.
"That's the mindset of the surgeon, to save the limb: amputation is seen as failure," Sheehan said.
But on Monday, there wasn’t much question that many of the patients’ limbs could not be salvaged.
The operating rooms at Boston Medical had multiple surgeons to make team decisions, Dr. Tracey Dechert, a trauma surgeon at Boston Medical, told The New York Times.
"What we like to do is before we take off someone's leg -- it's extremely hard to make that decision -- is we often get two surgeons to agree," Dechert said.