ALBUQUERQUE, N.M. — Q: “What grief hath set the jaundice on your cheeks?” (from Shakespeare, “Troilus and Cressida”)
A: I suspect my cheeks have been jaundiced twice, but I don’t think grief had much to do with it. I can only remember once, in 1970, when I came down with hepatitis A in my first year in New Mexico.
New Mexico was then a hot bed of “the yellow disease,” and I caught it, probably from one of my many patients who felt terrible, turned a bright yellow, threw up and eventually recovered. I went to my first New Mexican Halloween party as a pumpkin. These days I wouldn’t catch it – we give a vaccine against hepatitis A to all toddlers, and as a consequence, years go by between cases.
The first time, I believe, was when I was newly born. Almost all newborn infants are a little or a lot jaundiced. Their eyes get yellow, their skin gets yellow; even their tears and their spinal fluid turn yellow for a few days or weeks. The word jaundice is related to the French word, jaune, for yellow – the condition jaundice is a symptom, usually of liver disease.
Newborns get jaundiced for the same reason they need diapers: they are immature. In this case, though, maturing of the liver to be able to handle the yellow pigment called bilirubin, occurs quickly, usually within days.
Bilirubin is formed by all of us as we recycle our red blood cells. When red cells age, they’re removed from the circulation, and the hemoglobin in those red cells is broken down. One of the products is bilirubin. The reason all of us aren’t jaundiced is that our livers process that bilirubin into a form that can be eliminated in bowel movements.
In adults and older children, jaundice is often ominous, whether by that name or the terms doctors sometimes use, icterus or hyperbilirubinemia (high bilirubin level in the blood). Causes of the failure of the liver to do its job can be relatively benign, like my hepatitis, but they also can be quite serious, such as spread of a tumor to the liver or the cirrhotic destruction of the liver that occurs in alcoholics.
I’ve just spent several days working in our hospital’s newborn nursery. I’ve seen lots of yellow little people. We expend a lot of effort on making sure they don’t get too yellow. We measure the bilirubin with a skin-reading light meter or with a blood test, or both. We want to avoid the bilirubin level rising too far, too fast, because we can do something about it. And we must, to avoid the brain damage that occurs when bilirubin levels get so high the yellow substance enters the brain.
Years ago, I became adept at a procedure we rarely perform any more: the exchange transfusion. By means of a catheter in a baby’s vein, we would remove the baby’s blood, tablespoon by tablespoon, replacing it with blood from the blood bank. Though this is still done in extreme cases, it has become rare (I haven’t done one in a decade or more). The treatment of choice is almost always the application of a bright light to the baby’s skin.
That doesn’t make intuitive sense, does it? In the 1950s, two separate “experiments of nature” led to the discovery of “phototherapy,” as we call it. One occurred in an English hospital, where nurses noted that babies kept near a window had less jaundice than those whose cribs were farther away. Two, laboratory workers found that when blood samples drawn to test for bilirubin were exposed to light, the levels were lower than expected. In both cases, the light had caused a change in the structure of the yellow molecule of bilirubin, resulting in its destruction.
I can remember only one patient, Jamie, for whom I have cared over the years who had symptoms of the brain damage caused by bilirubin, called kernicterus or bilirubin encephalopathy. He had seizures, problems with movements, and was hard of hearing. Kernicterus can also cause mental retardation, even death. That one patient had been badly damaged; it’s a condition well worth avoiding.
These days most hospitals test all babies for bilirubin. Allowing a child to be affected with kernicterus is considered a sentinel event. It just shouldn’t happen, and that’s why we pay such attention to bilirubin in our smallest patients.
We act well before there’s any chance at all of kernicterus, so we’ll never see kernicterus again. Sometimes it seems as if the concern about bilirubin reaches hysteria levels. Jamie would not agree.
Lance Chilton, M.D., is a pediatrician at the Young Children’s Health Center in Albuquerque, associated with the University of New Mexico. Send questions to firstname.lastname@example.org.