CONFERENCE REPORT

Oxygen and Retrolental Fibroplasia in Neonates

A SPECIAL CONFERENCE of North though blindcness from too much oxygen is still Aimerican pediatricians, ophtlialmuologists, seen in some children. Since the current trend physiologists, pathologists, and biophysicists in the use of oxygen is toward a determinative was convened in Des Plaines, Ill., in June 1967 policy, rather than a rigid, restrictive policy, a to consider current practices of oxygeni adminis- critical evaluation of the risk of retrolental fi- tration in the management of hypoxemic pre- broplasia in infants was conisidered imperative. maturely born infants. The objectives of the confereince were to promote improved communi- Respiratory Distress Syndrome cation and cooperation among these groups in A respiratory distress syndrome is observed the investigation of the results of present-day in rouglhly 10 percent of neonates born before oxygeni therapy, with particular reference to 37 weeks of gestation and is the rimost frequent the risk of retrolental fibroplasia. single cause of death among neonates. Evidence Retrolental fibroplasia, first described in suggests that deaths associated with this dis- 1942, occurs almost exclusively in premature in- order increased during the decade of rigid oxy- fants during the first 3 months of postnatal life. gen restriction (1955-65) in nurseries for pre- About 30 percent of the infants wlho develop the mature infants, but evidence also suggests that disorder become blind. Oxygen administered in the frequency of neurologic sequelae, that is, concenitrations in excess of that in air for pro- cerebral palsy, rose as the incidence of retro- longed periods of time was identified in the lental fibroplasia fell. early 1950's as the sole and sufficient causative In the past 2 or 3 years, a concerted effort agenit. has been made to improve the outcome in hypox- At a symposium on retrolental fibroplasia emic infants with neonatal respiratory distress held during the 1954 meeting of the American by administering supplemental oxygen in con- Academy of Ophthalmology and Otolaryngol- centrations sufficient to relieve arterial desatu- ogy, participants recommended that (a) rou- ration. MIoreover, asphyxia in the immediate tine administration of supplemental oxygen to neonatal period is treated by resuscitation and premature babies be discontinued, (b) it be exposure to high concentrations of oxygen (80 given only if inifants are cyanotic or sliow signs to 90 percent) in an effort to forestall the de- of respiratory distress, and (c) oxygen therapy velopment of the respiratory distress syndrome be discontinued as soon as respiratory distress is by decreasing pulmonary arterial tone and relieved. thereby increasing pulmonary blood flow. As the use of oxygen was drastically curtailed If the infant's condition stabilizes, the oxy- inl nurseries throughout the world, the incidence gen concentration is lowered slowly after 24 of retrolental fibroplasia dropped sharply, al- hours. In some nurseries, oxygen in high con- centrations is continued until the expiratory The conference uws sponsored by the National So- grunt, virtually a constant sign in respiratory ciety for the Prevention of Blindness, Inc., and distress syndrome, disappears. In others, treat- supported in part by Public Health Service grant ment with oxygen in high concentrations con- 1 R 1 3 NBO 7564-01 from the National Institute tinues for only the first 2 or 3 hours after birth. of Neurological Diseases and Blindness. These oxygen administration practices are

16 Public Health Reports usually monitored by serial measurement of genelwhen appropriate observation;, as indicated oxygen tension and saturation in arterial blood in (b) cannot be made; and (e) the need for or arterialized capillary blood. The facilities basic research in factors which control vaso- for reliable measurements of arterial oxygena- motion. tion, howeever, are not available in most hos- pitals, and it is feared that undetected hyper- Conclusions oxia may occur under these circumstances. The conference enmphasized tlte current im- Moreover, there is considerable disagreement portance of increased understanding of mutual concerning the interpretation of arterial oxygen problems by pediatricians and ophthalmologists. measurements in various sites, suclh as the radial Premature infants with major illnesses can be artery, the temporal artery, and 'he abdominal treated adequately only in optimally manned aorta below the ductus arteriosus, with respect and fully equipped intensive care units. Cur- to the risk of retrolental fibroplasia. Evidence rent support in terms of trained manpower, concerning the untoward effects of hyperoxia funds, and equipment for these facilities is on other organs, especially the lungs and the woefully inadequate. Ophthalmologists must brain, is accumulating, and the evidence of these examine every premature baby receiving sup- effects undoubtedly will also influence eventual plemental oxygen, and the eyes of children born decisions concerning the optimum method for prematurely should be examined regularly for treating hypoxemia in newborn infants. the first 2 years of life. Considerable discussion centered around the Participants in the conference agreed that following issues: (a) the need foi criteria for revised recommendations for oxygen adminis- supplemental oxygen administration; (b) the tration are hiiglhly desirable but that currenltly need for accuimulating evidence on the associa- available data are insufficielnt to justify a revi- tioni of clinical signs, arterial oxygen measure- sion of the present cautious recommendations. ments, funduscopic appearance, and psycho- A vital nieed exists for extensive researchl in motor development in oxygen-treated infants; these areas, along with the accumulation of con1- (c) the need for improved devices for monitor- siderably more cliniical data.-DR. WILLIAMi A. ing ambient oxygen concentration; (d) the need SILVERMIAN, Columnbia Un,iversity College of for caution in adminstering supplemental oxy- Physicians and Surgeons.

Conference Participants Dr. Peter A. M. Auld Robert W. Flower New York Hospital-Cornell Johns Hopkins Hospital School of Medicine University Medical Center Baltimore, Md. New York City, N.Y. Dr. Anita P. Gilger Dr. Philip G. Banister Cleveland, Ohio Department of Health, Education, and Welfare Dr. Margaret Henry Ottawa, Ontario, Canada University of California Dr. Richard Behrman San Francisco, Calif. University of Oregon Medical School Dr. Donald R. Johnson Portland, Oreg. University of Oregon Medical School Dr. William C. Cooper Portland, Oreg. Presbyterian Hospital Dr. V. Everett Kinsey New York, N.Y. Institute of Biological Sciences Dr. John J. Downes Rochester, Mich. Children's Hospital of Philadelphia Philadelphia, Pa. Continued

Vol. 84, No. 1, January 1969 17 Dr. Marshall Klaus Dr. Earl Stern University Hospitals of Cleveland University of California Medical Center Cleveland, Ohio San Francisco, Calif. Dr. Jonathan T. Lanman Dr. Leo Stern State University of New York Children's Hospital Downstate Medical Center Montreal, , Canada Brooklyn, N.Y. Dr. Avron Y. Sweet Dr. John C. Locke Cleveland Metropolitan General Hospital McGill University Cleveland, Ohio Montreal, Quebec, Canada Dr. Paul Swyer Dr. Andrew McCormick University of Toronto University of Toronto, Ontario, Canada , B.C., Canada Dr. William H. Tooley Dr. Richard E. Nachman University of California Medical Center The Johns Hopkins Hospital San Francisco, Calif. Baltimore, Md. Dr. Leonard Apt, Observer Dr. Thomas K. Oliver, Jr. University of California School of Medicine University of Washington School of Medicine Los Angeles, Calif. Seattle, Wash. Dr. Arnall Patz Johns Hopkins Hospital School of Medicine Baltimore, Md. Dr. David B. Schaffer Staff University of Pennsylvania Hospital Dr. J. S. Drage Philadelphia, Pa. National Institute of Neurological Diseases Dr. Sydney Segal and Blindness University of British Columbia Bethesda, Md. Vancouver, B.C., Canada Dr. Eileen G. Hasselmeyer Dr. William A. Silverman National Institute of Child Health Columbia University College of Physicians and Human Development and Surgeons Bethesda, Md. New York City, N.Y. Dr. John W. Ferree Dr. John C. Sinclair National Society for the Prevention Columbia University College of Physicians of Blindness, Inc. and Surgeons New York City, N.Y. New York City, N.Y. Mrs. Virginia S. Boyce Dr. Mildred T. Stahlman National Society for the Prevention Vanderbilt University School of Medicine of Blindness, Inc. Nashville, Tenn. New York City, N.Y.

18 Public Health Reports