00:00The first blood transfusion in history happened in 1667.
00:04The blood came from a lamb. A French physician believed it could purify the soul.
00:10On June 15, 1667, in Paris, a dying 15-year-old boy was injected with 122 milliliters of lamb blood.
00:20The next morning, he woke up. Jean-Baptiste Denis became famous overnight.
00:26But the boy survived only because the amount was too small to trigger a fatal reaction.
00:32The real cost came five months later.
00:35A Parisian vagrant named Marouille received calf blood in front of a room of aristocrats.
00:41Hours later, fever, vomiting, nosebleeds.
00:45Then black urine, destroyed red blood cells clogging his kidneys.
00:50After a third transfusion, Marouille died.
00:53Dennis was acquitted of murder, but France banned blood transfusion entirely.
00:59The Royal Society in London also halted research.
01:03Transfusion was frozen for 150 years, three entire lifetimes.
01:08It was 1818 before anyone dared touch the field again.
01:13Dar.
01:14James Blundell devised human-to-human transfusion, draw blood from the husband, injected into the wife.
01:21Between 1825 and 1830, he performed 10 transfusions.
01:27Five survived.
01:29Getting a transfusion was a coin flip.
01:32That coin flip lasted 82 years.
01:35What broke the deadlock was Karl Landsteiner.
01:38In 1900, he mixed his colleagues' blood together and watched under a microscope.
01:45Some mixtures were fine.
01:47Others clotted instantly.
01:49He organized these reactions into blood types, A, B, and C, later renamed O.
01:56Two years later, his students discovered AB.
01:59In 1930, this won him the Nobel Prize.
02:04Transfusion was no longer a gamble.
02:06But blood clots within minutes of leaving the body.
02:10Early transfusions required donor and patient to lie side by side, connected by a tube.
02:16The breakthrough came from sodium citrate, which binds to calcium and stops clotting cold.
02:22In 1914, this became clinical practice.
02:25With glucose, 21 days preservation.
02:29With citric acid and phosphate, 35 days.
02:34Modern solutions, 42 days.
02:37Now back to a bleeding patient.
02:40Doctors don't flood you with fluids.
02:42They fight the deadliest combination, hypothermia, acidosis, coagulopathy, a vicious cycle.
02:50Cold blood stops clotting.
02:52Bleeding causes oxygen starvation.
02:55Acid buildup destroys clotting further.
02:59The solution is blood itself, red cells, plasma, platelets in a 1 to 1 to 1 ratio, derived from over
03:0620,000 combat casualty records.
03:09And one more drug, tranexamic acid.
03:12Give it within 3 hours of injury, it cuts bleeding deaths by a third.
03:17After 3 hours.
03:19It might actually kill you.
03:21Same drug.
03:24Same dose.
03:263 hours apart.
03:283 hours.
03:30The length of a soccer match.
03:323 centuries of medicine.
03:35Lamb blood experiments.
03:37Black urine.
03:39Blood transfusions by coin flip.
03:41A blood type chart.
03:44A drug with a 3 hour deadline.
03:47We can manufacture artificial hearts.
03:49We can build synthetic joints.
03:52We can send robots to Mars.
03:55But to this day, there is no artificial blood approved for regular use.
04:00Every bag of blood comes from exactly one place, another human being's arm.
04:06300 years of technology, and we never found a shortcut.
04:10The reason you survive isn't some machine.
04:13It's because one day, a stranger you will never meet sat down and rolled up their sleeve.
04:47I'll show you something in 10 minutes.
