Breath Taking. Michael J. Stephen
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alveoli.
The definitive discovery and demonstration of the existence of surfactant was a major breakthrough in the understanding of lung physiology, finally explaining the mechanism by which the lung seamlessly expands and contracts, thousands of times a day, without breaking apart with inspiration or collapsing with exhalation. While the heart has dense striated muscle, and the brain its conglomerated networks of communicating neurons, the lung is a thin, graceful structure of interconnecting fibrous tissue that is beautifully held together with a foamy substance that lubricates its functions in a quiet and effortless manner. It is an organ of elegance, not brute strength.
John Clements’s paper did not get accepted into the high-powered journal Nature, but appeared instead in a low-level publication, where it was not widely recognized as the landmark study it would become.43 It did, however, reach Dr. Avery, and in 1956 she drove to Bethesda to meet Dr. Clements in person. He knew nothing about neonatal respiratory distress, and she knew nothing about how to properly measure surface tension. He taught her everything he knew about lung physiology, as well as how to build an instrument so she could take her own pressure and surface tension measurements. Dr. Avery quickly came to believe that the afflicted newborns weren’t diseased because of the presence of something, that something being hyaline membranes, but because of the absence of something.44 That something, she believed, was surfactant.
She went back to her lab and built her own balance to measure surface tension, and then she discerned that the lungs of babies who had died from respiratory distress syndrome had very high surface tension. By comparison, the lungs of normal infants had a much lower surface tension. This was the breakthrough she had been looking for since her time as a child visiting the hospital with Dr. Bacon, and the breakthrough humanity had been waiting for since the first premature baby had been born and died a perplexing death.
Dr. Avery published her findings in 1959 in the American Journal of Diseases of Children. Entitled “Surface Properties in Relation to Atelectasis and Hyaline Membrane Disease,” the paper broke the field of neonatal respiratory distress syndrome wide open.45 The key to the disease had been pinpointed. The immature lungs were not making surfactant, the surface tension in the alveoli was way too high, and the alveoli were crashing closed. Hyaline membranes were formed as a byproduct of the inflammation and destruction. Some babies lived long enough for surfactant production to kick in and open up their alveoli, but many did not.
Funding poured in from the National Institutes of Health, and over the ensuing decades, researchers at several different institutions made significant progress toward a cure. Doctors used ventilators to stent the lungs and alveoli open, and steroids were shown to speed up surfactant production in premature babies. Later, an artificial surfactant was manufactured to serve as a replacement. Today the mortality from respiratory distress syndrome is 5 percent of what it was before Dr. Avery’s brilliant insight.
Mary Ellen Avery went on to accomplish other great things in her life. She helped found the field of specialized care for the newborn, known as neonatology, and her textbook, Avery’s Diseases of the Newborn, has been the standard in its field for decades. She became a full professor of pediatrics, and the first female chief of a clinical department at Harvard Medical School. Her guidance produced tens, if not hundreds, of leaders in pediatrics across the country.
As for my son, all has gone well since his delayed first breath of life. He made the difficult transition from living in water to living in air. That day, my son taught me that breathing can be difficult. We take it for granted, but it is a complex process involving the coordination of multiple organs, with the lungs in the center. And a lung is not just a simple pump, pushing gas around. As Dr. Avery began to teach us, it is an organ alive with immunology and chemistry, one that does an extraordinary amount of work under extreme stress from the moment we enter this world.
39. Mary Ellen Avery, MD, interview by Lawrence M. Gartner, American Academy of Pediatrics, Oral History Project, 2009. https://www.aap.org/en-us/about-the-aap/Gartner-Pediatric-History-Center/DocLib/Avery.pdf.
40. Amalie M. Kass and Eleanor G. Shore, “Mary Ellen Avery,” Harvard Magazine, March-April 2018. https://harvardmagazine.com/2018/02/dr-mary-allen-avery.
41. John A. Clements and Mary Ellen Avery, “Lung Surfactant and Neonatal Respiratory Distress Syndrome,” American Journal of Respiratory and Critical Care Medicine 157, no. 4 (1998): S59–S66.
42. John A. Clements, “Lung Surfactant: A Personal Perspective,” Annual Review of Physiology 59 (1997): 1–21.
43. Clements, “Surface Tension of Lung Extracts,” Experimental Biology and Medicine 95 (1957): 170–172.
44. Julius H. Comroe Jr., Retrospectroscope: Insights into Medical Discovery (Menlo Park CA: Von Gehr Press, 1977), 149–150.
45. Mary Ellen Avery and Jere Mead, “Surface Properties in Relation to Atelectasis and Hyaline Membrane Disease,” American Journal of Diseases of Children 97 (May 1959): 517–523.
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