Pediatrics: An Infant's Cause of Death: Hyaline Membrane Disease

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It was no surprise to the battery of physicians at Otis Air Force Base last week that the baby soon to be baptized Patrick Bouvier Kennedy (see THE NATION) had difficulty drawing his first breath. Like one out of every 15 U.S. babies, this one was premature, and the greater the degree of prematurity, the greater the danger that a baby's lungs will not inflate properly. Patrick also had a second strike on him: the danger of breathing difficulty is still greater for a premature baby delivered by caesarean section.

In most such cases, doctors still do not know the precise cause of the trouble, and they resort to the smokescreen term "idiopathic* respiratory distress." The difficulty probably begins in the womb. At the end of a full-term pregnancy, a woman's hormone balance changes drastically to bring on labor. By a mechanism not yet understood in detail, these same changes, transmitted through the placenta, prepare the baby for the superhuman feat of changing from an aquatic parasite, drawing oxygen from its mother's blood, to an in dependent air breather. If pregnancy is too short, these hormone triggers work weakly or not at all. The preemie delivered by caesarean has an especially urgent need for efficient lung-clearing reflexes, be cause the fluid in his lungs at the moment of delivery is al most certain to be contaminated with blood from the operation.

Mysterious Membrane. It is usually possible to tell within an hour after birth whether a preemie (or occasionally a full-term baby) is running into respiratory difficulties. His breathing gets faster and shallower; he may grunt on every exhalation or froth at the lips. In Patrick Kennedy's case, Pediatrician James Drorbaugh saw enough alarming signs to order him rushed, in an Isolette, to Children's Hospital Medical Center in Boston.

Ironically, as long as the baby lived, there was no way for even the most expert pediatricians to be sure what was happening in his lungs. They could tell whether the lungs were sufficiently inflated. (They were.) If there was a rattle in the stethoscope, they could be pretty certain of pneumonia. (There was none.) But the most likely and most life-threatening development was one that the doctors could not see and had no way of detecting for certain in a living patient: the development of a mysterious membrane around the inside walls of the lungs, which makes it impossible for the lung cells to take in enough oxygen from inhaled air and remove the carbon dioxide coming from the blood.

Extra Oxygen. Because the membrane looks glassy, this condition is called hyaline (from the Greek for glassy) membrane disease. But the pathologist who does a post-mortem examination on a baby is the only man who sees the glassy membrane. If the baby pulls through his first three or four days—usually aided by extra oxygen in his Isolette, and sometimes by a forced-breathing tube pushed down his windpipe through a cut in the neck—the membrane presumably disappears. Along with it go the respiratory difficulties. A baby who survives this crisis usually suffers no permanent damage, and develops as well as any other preemie.