Unidentified Canadian soldier with burns caused by mustard gas gets treatment. THE CANADIAN PRESS/HO, Library and Archives Canada

It's said that necessity is the mother of invention and nowhere was that more true than on the blood-soaked battlefields of the First World War, where millions of soldiers suffered horrific injuries on a scale never before witnessed in combat.

These wounds — shredded limbs, ripped-open torsos and burn-ravaged faces — created a desperate need for new surgical techniques and medical technologies, many of which in one form or another are still in use today.

"The weaponry that's used in the First World War in great numbers, which cause the most horrible injuries, is the concentration of artillery shells that were dropped on positions, doing terrible things to human bodies through high-explosive blasts, shell fragments and shrapnel," says Andrew Burtch, acting director of research at the Canada War Museum.

"These are weapons that reduced human beings to mist in some cases. They shear off noses and faces. They shred the extremities, they cause massive bleeding wounds in the stomach. They tear people into pieces.

"So the actual shock of seeing and trying to cope with these injuries poses a whole litany of medical challenges, not least of which is where to start, how to stop the bleeding, how to manage infection, how to keep people from dying of shock."

The first order of business was to get the wounded from the battlefield to medical aid and it quickly became apparent after the start of hostilities in 1914 that a formal system was needed.

While medical officers treated as many casualties as possible at the front lines, the enormous numbers of injured meant many of them had to walk or be carried by stretcher to field ambulances, which took them to dressing stations and then on to casualty clearing stations. Each step was farther from the front lines.

"The actual act of getting people to the hospitals was in itself an innovation of the First World War, in terms of the triage and chain of evacuation," says Burtch.

But the unending stream of bloodied soldiers too often overwhelmed medical personnel manning these crude stations, which were frequently just canvas tents, says the museum's website.

"Often the doctors and medical orderlies were forced to practise a system of triage, a selection process to determine which patients would be operated on immediately, which could wait a few hours and which were untreatable and, therefore, would be left to die."

Heavy bleeding and its companion condition, shock, could be a death sentence, so doctors needed to find a way to replace lost blood quickly.

Prior to the Great War, blood transfusions had been used sporadically, but they were risky, in part because compatible blood typing wasn't in widespread use.

In 1916-17, Maj. Lawrence Robertson of the Canadian Army Medical Corps performed a number of direct donor-to-patient transfusions in the field, without cross-matching blood types.

"Although primitive and sometimes leading to death because of challenges in pairing up blood types, it did manage to triple the survival rates of people suffering injuries to the trunk," Burtch says.

But it was Capt. Oswald Robertson of the U.S. Army Medical Officer Reserve Corps who showed in 1917 that blood could be donated in advance and stored using sodium citrate as an anticoagulant. The British-born American is credited with developing the first blood bank and a mobile one at that.

The use of stored blood was adopted by the U.S., Canadian and British medical corps, saving the lives of untold numbers of soldiers.

"So it certainly could be argued to be one of the advances of First World War medicine, a broader and more enhanced understanding and appreciation of the life-saving value of blood transfusions," Burtch concludes.

The Great War also saw the debut of the portable X-ray machine. Radium discoverer and Nobel Prize winner Marie Curie organized a campaign to turn cars into X-ray vans to help scan wounds at the front. These radiology vehicles, which French soldiers dubbed "petite Curies," allowed doctors to save lives and prevent disability by detecting broken bones or shrapnel and bullets buried in flesh.

Infection in the pre-antibiotics era was a dire threat on the Western Front. Farm fields in France and Belgium, fertilized for generations with manure, were rife with pathogens such as tetanus and the microbe that causes gas gangrene. As well, cholera, dysentery and lice-borne typhus could sweep through soldiers hunkered down in crowded, rat-infested, mud-filled trenches.

Yet even the primitive sanitation efforts of the day kept down deaths from sickness. In previous wars, illness usually killed more soldiers than the enemy. In the Boer war of 1899-1902, British and allied fatalities totalled about 22,000, but only about 8,000 were due to enemy action.

"The First World War is the first war when this is no longer true, when the majority of fatal casualties are the result of battle injuries," said Thomas Schlich, a medical historian at McGill University in Montreal.

Without antibiotics, doctors and nurses had to rely on iodine and tissue-removing debridement — the latter introduced during the conflict — to clean wounds to stave off infection.

But once patients survived amputations and severe facial disfigurement, doctors turned to the challenge of creating prostheses that would allow soldiers to return to the front in some capacity or go back to civilian life.

"The problem was what to do with these people? How can you re-integrate them into society?" said Schlich.

Faces ravaged by explosions, flamethrowers or blistering mustard gas spawned the First World War's version of modern-day plastic surgery.

In Britain, Dr. Harold Gillies invented a number of procedures to repair faces, grafting skin and tissue from other parts of the body to repair and rebuild cheeks, noses and chins. He also developed the pedicle tube graft — still used today — to provide blood flow to the reconstructed area from another part of the body.

Those whose faces were too far gone were fitted with a prosthesis, sometimes including an artificial eye, developed by dental technician Archie Lane, who worked with Gillies at the Queen's Hospital plastic surgery centre at Sidcup, England. Between 1917 and 1921, more than 5,000 servicemen were admitted to its wards.

U.S. sculptor Anna Coleman Ladd also lent her talent to help mutilated soldiers, creating paper-thin tin masks based on pre-war portraits, which were enamelled and coloured to match their complexions.

"It wasn't perfect by any means," says Burtch, "but it was a means to disguise the disfiguring injuries so they could have a semblance of a normal life."

For combatants who had lost a leg or arm, a prosthesis could give the appearance of wholeness, but having a functional limb that allowed a person to walk or work was a problem.

Prior to the war, the manufacture of artificial extremities had been a cottage industry, using mostly natural materials like leather and wood to create an arm or leg, says Schlich. But the vast number of war amputees required that prostheses be produced on an industrial scale, employing new materials such as lightweight metals.

At Walter Reed Hospital in the U.S., the goal of the Artificial Limb Laboratory, opened in 1917, was to give every soldier amputee a modern limb so he could return to work. A parallel endeavour, the Test Centre for Replacement Limbs, was created in Berlin.

"What is special about these places is that there, engineers, doctors and scientists worked together on the development of prostheses," he says.

One replacement appendage from Germany, the Siemens-Schuckert universal arm, was a glorified tool holder with interchangeable parts that was attached above the stump with a leather harness, he says. "You had a free end and you could put in whatever you needed — a hammer or cutlery or some part that would connect the wearer to an actual machine."

Schlich says this medical-industrial collaboration born of the Great War gave birth to the field of prosthetics, which still combines expertise from divergent disciplines to craft state-of-the-art artificial limbs. The carbon-fibre running blades that allowed Oscar Pistorius to compete in the 2012 Olympics "embody the development that had its origins 100 years earlier in World War I."

While many of the medical advances during the 1914-18 conflict dealt with healing the body, there were also psychological wounds, which left many soldiers with the uncontrollable tremors of "shell shock."

"This would often happen to men who had been blown up in the context of this unprecedented kind of trench warfare, using high explosives," says Dr. Edward Shorter, a medical historian and professor of psychiatry at the University of Toronto.

"These shells would go off near men and they would be buried by the earth thrown up by the explosion," says Shorter. Added to the horror was the sight of comrades slaughtered or mutilated by shelling or machine-gun fire.

"And this was incredibly traumatic, so they would be invalided out back to the rear and then often go to a rear base hospital, sometimes back to England, where they would recover slowly and then be fit for service again."

Known as "soldier's heart" during the American Civil War and combat fatigue in the Second World War, shell shock was the forerunner of today's post-traumatic stress disorder.

Treated with rest and sometimes electrical shocks to the muscles to ease the tremors — there was no psychotherapy or anti-anxiety drugs a century ago — shell shock resolved over time, unlike the effects of post-traumatic stress suffered by so many in the military today.

"This was not post-anything," says Shorter.

"After the war was over, there did not seem to be a lot of post-traumatic stress. Men went back to civilian life and married, worked normally ... Even though some soldiers were profoundly affected, the majority were not, in contrast to post-deployment today, where the symptoms of PTSD are extremely common."

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News from © The Canadian Press, 2014