Pediatric Annals

EDITORIAL 

Old Problems and New Approaches in Neonatology

Milton I Levine, MD

Abstract

The July issue of Pediatrie Annaìs, guest edited by Dr. Gordon B. Avery, introduced a two-part symposium on neonatology by presenting articles of general importance to the practicing pediatrician. These included regionalization of perinatal care; the pediatrician's place in the Level II nursery; neonatal resuscitation; screening of the newborn for defects; and the art of communication with parents of high risk infants.

This second portion of the symposium covers advances that have been made dealing with technical problems that still confront neonatologists and pediatricians. To those of use who practiced pediatrics 30 to 50 years ago, the modern approaches to the problems of the premature infant are especially exciting. We have watched the gradual acquisition of knowledge in this area of neonatology. Over the past 50 years, neonatologists have gained an understanding of some major problems and have succeeded in overcoming a few, such as Rh incompatibility and (to a large extent) retrolental fibroplasia. Now we are on the verge of successfully treating hyaline membrane disease

In 1940, the standard pediatrie textbook, by Holt and Mc In tosh, stated that in the premature infant there is often 1) respiratory failure as a result of intracranial membrane responsible for most early deaths; 2) maternal anesthesia causing a marked effect on the infant's respiratory centers; and 3) aspiration of mucus due to poor pharangeal reflexes. These various etiologies seemed logical but our efforts at treatment were completely inadequate. In retrospect, most of these infants suffered from hyaline membrane disease. I was especially interested, for at that time I was in charge of the pediatrie pulmonary service at the New York Hospital-Cornell Medical School.

I remember that during the 1940s Dr. Alvin Barack, a prominent pulmonary physiologist at the Columbia University College of Physicians and Surgeons, developed a positive pressure mechanism with a sudden pressure release to produce a cough in adults. I was anxious to use the method on premature infants with respiratory distress, thinking that if I could bring up the mucus "clogging the infant's breathing tubes" I could possibly relieve the difficulty in breathing. But I was unable at that time to obtain a face mask that would fit securely over a tiny face. 1 realized later that my efforts would have been in vain. In 1959 Avery and Mead demonstrated that the respiratory distress syndrome was due to a deficiency of pulmonary surfactant and that clogging by mucus, poor pharyngeal reflexes, and cerebral hemorrhage were rare causes.

Once the etiology of the condition was established, the problem of preventing or relieving it became the scientific target. In 1972 G. C. Liggins reported a controlled study using intramuscular maternal antepartum glucocortoid treatment to prevent the formation of the hyaline membrane in respiratory distress syndrome. The results were apparently very successful in speeding lung maturation. This approach has been repeated in many studies using betamethasone or dexamethasone to antepartum mothers either intramuscularly or intravenously at least 24 hours before birth. In all of these the results were uniformly successful.

However, the great majority of premature infants are born without maternal glucocortoid treatment. These still present the serious problem of supplying surfactant and are discussed in the first article.

"Surfactant Therapy in the Newborn" is authored by Dr. James W. Kendig, Assistant Professor of Pediatrics, and by Dr. Donald L. Shapiro, Professor of Pediatrics, both at the University of Rochester Medical Center, Rochester, New York.

Here is presented the most recent knowledge on efforts of surfactant replacement. Although most centers use calf lung surfactant extract, several synthetic preparations are now being investigated. The problem of chronic lung disease (bronchopulmonary dysplasia) is discussed…

The July issue of Pediatrie Annaìs, guest edited by Dr. Gordon B. Avery, introduced a two-part symposium on neonatology by presenting articles of general importance to the practicing pediatrician. These included regionalization of perinatal care; the pediatrician's place in the Level II nursery; neonatal resuscitation; screening of the newborn for defects; and the art of communication with parents of high risk infants.

This second portion of the symposium covers advances that have been made dealing with technical problems that still confront neonatologists and pediatricians. To those of use who practiced pediatrics 30 to 50 years ago, the modern approaches to the problems of the premature infant are especially exciting. We have watched the gradual acquisition of knowledge in this area of neonatology. Over the past 50 years, neonatologists have gained an understanding of some major problems and have succeeded in overcoming a few, such as Rh incompatibility and (to a large extent) retrolental fibroplasia. Now we are on the verge of successfully treating hyaline membrane disease

In 1940, the standard pediatrie textbook, by Holt and Mc In tosh, stated that in the premature infant there is often 1) respiratory failure as a result of intracranial membrane responsible for most early deaths; 2) maternal anesthesia causing a marked effect on the infant's respiratory centers; and 3) aspiration of mucus due to poor pharangeal reflexes. These various etiologies seemed logical but our efforts at treatment were completely inadequate. In retrospect, most of these infants suffered from hyaline membrane disease. I was especially interested, for at that time I was in charge of the pediatrie pulmonary service at the New York Hospital-Cornell Medical School.

I remember that during the 1940s Dr. Alvin Barack, a prominent pulmonary physiologist at the Columbia University College of Physicians and Surgeons, developed a positive pressure mechanism with a sudden pressure release to produce a cough in adults. I was anxious to use the method on premature infants with respiratory distress, thinking that if I could bring up the mucus "clogging the infant's breathing tubes" I could possibly relieve the difficulty in breathing. But I was unable at that time to obtain a face mask that would fit securely over a tiny face. 1 realized later that my efforts would have been in vain. In 1959 Avery and Mead demonstrated that the respiratory distress syndrome was due to a deficiency of pulmonary surfactant and that clogging by mucus, poor pharyngeal reflexes, and cerebral hemorrhage were rare causes.

Once the etiology of the condition was established, the problem of preventing or relieving it became the scientific target. In 1972 G. C. Liggins reported a controlled study using intramuscular maternal antepartum glucocortoid treatment to prevent the formation of the hyaline membrane in respiratory distress syndrome. The results were apparently very successful in speeding lung maturation. This approach has been repeated in many studies using betamethasone or dexamethasone to antepartum mothers either intramuscularly or intravenously at least 24 hours before birth. In all of these the results were uniformly successful.

However, the great majority of premature infants are born without maternal glucocortoid treatment. These still present the serious problem of supplying surfactant and are discussed in the first article.

"Surfactant Therapy in the Newborn" is authored by Dr. James W. Kendig, Assistant Professor of Pediatrics, and by Dr. Donald L. Shapiro, Professor of Pediatrics, both at the University of Rochester Medical Center, Rochester, New York.

Here is presented the most recent knowledge on efforts of surfactant replacement. Although most centers use calf lung surfactant extract, several synthetic preparations are now being investigated. The problem of chronic lung disease (bronchopulmonary dysplasia) is discussed with the hope that modern surfactant replacement therapy will significantly reduce its incidence.

The second paper discusses "High-Frequency Ventilation" and has been written by Dr. Stephen J. Boros, Director of Neonatal Medicine at the Children's Hospital, St Paul, and Associate Professor of Pediatrics, University of Minnesota; and by Dr. Marc C. Mammel, Associate Director of Neonatal Medicine and Assistant Professor of Pediatrics at the same institutions.

This form of ventilation uses rapid rates of mechanical gas transport, dictating alveolar ventilation. The various approaches are defined with special emphasis on high-frequency positive pressure ventilation. This method produces lower proximal airway pressure and causes less lung distention and less chance of lung trauma. The use of highfrequency ventilation is described in the treatment of recurrent pneumothoraces, bronchopleural fistulae and pulmonary hypertension, and meconium aspiration syndrome.

The following contribution presents an exciting technique in the treatment of severe hyaline membrane disease where the predicted mortality rate can be 80% to 100%. "Extracorporea! Membrane Oxygenator Therapy" has been written by Dr. Billie Lou Short, Director of the ECMO Program and Associate Neonatologist at the Children's Hospital National Medical Center and Associate Professor of Child Health and Development at George Washington University; and by Dr. Andrea Lotze, Associate Neonatologist, and Assistant Professor of Child Health and Development at the same institutions in Washington, DC.

This new technique has successfully treated more than 1,000 infants with respiratory failure. Its success is due to providing complete lung rest when the lungs are fatigued and other conventional respiratory methods have failed. Numerous other conditions relieved by ECMO are listed with excellent survival rates. Here is a most interesting and important addition to modern pediatrie procedures for this condition.

The next article is a progress report on the "Retinopathy of Prematurity" and has been authored by Dr. Gordon B. Avery, Chairman of the Department of Neonatology at the Children's Hospital National Medical Center, Professor of Child Health and Development at the George Washington University School of Medicine, both in Washington, DC, and guest editor of this symposium.

Since hyperoxia was discovered to be an important etiologic factor in the production of retinopathy of the premature infant, a great many pediatricians felt assured that this major problem of premature well-being was overcome. Dr. Avery shows how incorrect this concept is. There are other problems due to the hypoxic state in which the premature infant is maintained. He also notes that retinopathy of prematurity is still a fairly prevalent condition in spite of our present methods of control. He mentions the use of cryotherapy in arresting progression of the retinopathy but looks forward to future methods of treatment that will provide a greater margin of safety.

The fifth contribution discusses "The Management of Hypoxic -Ischemie Encephalopathy" and is written by Dr. Lu-Ann Papile, Associate Professor of Pediatrics, Obstetrics, and Gynecology at the University of New Mexico School of Medicine, Albuquerque, New Mexico.

Dr. Papile notes at the outset of her discussion that significant episodes of intrapartum or neonatal asphyxia represent the single most frequent cause of neurological morbidity in the full term infant. She also highlights the fact that newborns suffering from hypoxic-ischemic encephalopathy may often have injury to other bodily organs as well.

The article outlines the management tit these newborns and considers not only those who are neurotically damaged hut also those with cardiac and renal problems and metabolic difficulties. Of special interest are recent efforts to reduce the brain edema that follows hypoxia and ischemia through drug therapy.

The final article deals with the "Aftercare of the High Risk Neonate" and has been contributed by Dr. Rebecca !chord, Developmental Pediatrician, Department of Neonatology and Pediatrie Medicine at the Children's Hospital National Medical Center, and Assistant Professor of Child Health and Development ot the George Washington University School of Medicine, Washington, DC.

There has been an increase in the survival rate of low birth weight infants, and these survivors are being cared for by the local pediatricians. This is especially true since complex home-based medical care services continue to grow steadily. The care of these medically fragile infants, as emphasized by Dr. !chord, involves monitoring growth, adjusting the diet, treating respiratory symptoms, evaluating fevers and intercurrent symptoms, and advising and reassuring the parents.

The article promises to be an excellent guide for the physician who is called on to care for these low bitth weight infants and to guide them successfully through the years that follow.

10.3928/0090-4481-19880801-04

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