Below are what I think the most important advances in medicine since there was such a discipline. With the exception of the first development they are not listed by importance. But the first is so important that it out ranks all the remaining 11 combined. Many of the following discoveries are interrelated. The reader should have no difficulty in connecting them.
1. Plumbing. I’m referring to the separation of drinking water from sewage. The plumber and his congeners have saved more lives than all the doctors who have lived or ever will live. The elimination of water borne diseases in the developed world is the greatest triumph of modern medicine (medicine here is defined very loosely).
2. Vaccines. The use of vaccines to prevent infectious diseases goes back as much as 1,000 years to medieval China. It really achieved effectiveness in the late 18th century when the English surgeon William Jenner used a vaccine that induced cowpox in humans to prevent the far more dangerous and deadly smallpox. So effective has been smallpox vaccination that the disease in now extinct. A battalion of diseases is now preventable because of vaccination. So effective is this technique that it allows the badly informed to think that avoiding vaccination may convey more benefit than harm. The recent resurgence of measles is an example of the foolishness of affluence. In 1850 life expectancy in the US was greater at age 20 than at birth, so great was the toll of infectious diseases on the young. The reduction of fatal childhood diseases to its current vanishingly low level is largely the result of 1 and 2.
3. Modern Obstetrics. The 1850 census alluded to above showed that women had a significantly shorter life expectancy than did men. This difference was entirely due to the hazard of childbirth which until the advent of modern obstetrical care was a death defying act. The high quality of obstetrical care that we now enjoy, such that a maternal death is an extremely rare event, is due in part to some of the other improvements in medical care described below. Today not only is childbirth safe, but is also more comfortable than it was until comparatively recent times. Ignaz Semmelweis was responsible for the first major reduction in maternal mortality. He showed that hand washing largely prevented puerperal sepsis. Despite his success he was mocked by his colleagues, driven mad, and committed to an asylum where he died from an infected wound. The wound was secondary to a beating he received at the asylum.
4. Surgical Asepsis. The work of Louis Pasteur and Joseph Lister led to the practice of hygienic techniques in the operating room. Lister, unlike his Hungarian predecessor was honored for his work and made a Baron. He also was elected President of the Royal Society. Life is consistently unfair.
5. Anesthesia. Modern anesthesia, though it has roots going back centuries is a largely American phenomenon. Ether was independently used for surgical anesthesia by several Americans. Chloroform was developed by another American. It received great attention when it was used to assist delivery of one of Queen Victoria children – Prince Leopold. Regardless of who gets the credit for the first use of anesthesia, the subsequent development of safer drugs and better management techniques made possible the development of the myriad surgical procedures that pervade every aspect of modern medical practice. Interestingly, the father of American surgery William Halsted also developed regional anesthesia. He used himself as a test subject and became hooked on cocaine and then morphine. Despite having William Osler as his personal physician, he was never able to kick his habit.
6. Antibiotics. The antibiotic era began with the development of arsphenamine by Paul Ehrlich and Sahachiro Hata. It was used to treat syphilis. The sulfonamide derivative drugs appeared in the 1930s. Penicillin was named by Alexander Fleming though he was not the first scientist to notice the antibacterial properties of the Penicillium mold. Ernst Chain, Howard Florey and Edward Abraham purified penicillin. The drug was widely used during World War II, but did not become available to the general public until after the war. Fleming, Chain, and Florey received the Nobel Prize for their penicillin work. As the prize can only go to three people poor Abraham was left out. He subsequently developed the cephalosporin antibiotics. He patented the drugs and donated the fortune the patents yielded to establish two charitable trusts devoted to biomedical research. Antiviral agents were developed later in the 20th century. The chemists are in a never ending arms race against the pathogens which quickly develop resistance against the drugs designed to wipe them out. Another Darwinian struggle, the outcome of which remains uncertain.
7. Blood transfusion. The concept of blood transfusion and it obvious utility were it possible to perform safely was around for centuries. But it was the epochal work of Karl Landsteiner that made it possible. He discovered both the ABO blood groups and then almost four decades later the Rh factors. Along the way he also discovered the polio virus. Of course, he was awarded a Nobel Prize; he probably deserved several more. Once we had the blood factors, incompatible transfusions were eliminated and the practice became universal. It’s impossible to imagine modern medical practice without the procedure.
8. Eyeglasses and Cataract Surgery. Without glasses an aging population would gradually go blind and the extra years of life now enjoyed by most modern humans would be terrible to contemplate. The first reading glasses were made in northern Italy at the end of the 13th century. Ben Franklin, America’s greatest polymath, invented bifocals in the 18th century. Glasses can take you only so far. Most of the geriatric population will develop cataracts. The current state of cataract surgery is so advanced that removal of an opaque lens and its replacement with an artificial one is a brief outpatient procedure with a very low complication rate. The effect of this procedure on the quality of life cannot be overstated.
9. Insulin and hormone replacement. Banting and Best discovered isolated insulin in 1921. The hormone rapidly entered clinical practice for the treatment of type 1 diabetes mellitus. This medical feat is emblematic of all the other discoveries and isolation of hormones, enzymes, and vitamins which have have revolutionized medical care.
10. Blood Pressure Treatment. As the scourges of human existence were eliminated in the last century, the most common human disease became hypertension. Uncontrolled high blood pressure is the major cause of cardiovascular renal disease. The second half of the 20th century was marked by the discovery and invention of multiple classes of antihypertensive drugs. The development of these drugs was made feasible by a century of exploration of the causes of elevated blood pressure. Today, the physician has diuretics, ACE inhibitors, ARBs, calcium channel blockers, among others to control hypertension in the vast majority of patients.
11. Dentistry. Poor oral hygiene is a cause of chronic inflammation which exacts a major deleterious effect on blood vessels and the immune system. Modern dentistry and personal attention to good oral hygiene should allow almost all to maintain their teeth even if they live to some eternal biblical age. If your mouth is in poor shape the odds are beyond calculation that the rest of you will be too.
12. Agriculture. Modern agriculture is so advanced that the famine and starvation which threatened mankind for almost all of its existence is now solely the result of bad politics. Malthus thought population would grow exponentially while food production would increase arithmetically. He got the sequence reversed. Starvation is a threat only in the benighted parts of the planet.
So what’s left to do? Most importantly, we have to figure out how to pay for the seemingly limitless demand for all sorts of medical care – a lot of which is close to useless. Next, if we want to live longer, we must solve the problem of aging. We’ve gone just about as far as possible dealing with disease. If we do solve aging, Malthus may turn out to be right afterall.