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Definition of perinatal asphyxia
168
Editorial correspondence
3.
Weed LH, Hughson W. Intracranial venous pressure and cerebrospinal fluid pressure as affected by the intravenous injection of solutions of various concentrations. A m J Physiol 1921;58:101-30. 4. Sperling MA. Diabetes mellitus. In: Behrman RE, Vaughn VC III, Nelson WE, eds. Nelson textbook of pediatrics. 13th ed. Philadelphia: WB Saunders, 1987:1252. 5. Harris GD, Fiordalisi I, Finberg L. Safe management of diabetic ketoacidemia. J PEDIATR 1988;113:65-7.
Definition of perinatal asphyxia To the Editor." The publication by Mimouui et al. (J P~mATR 1988;113:34553) is an interesting and potentially valuable contribution. However it is flawed by the authors' definition of perinatal asphyxia. For the purposes of the article, the definition is fetal distress before delivery as monitored by the fetal heart rate, neonatal asphyxia as indicated by a 1-minute Apgar score of 6 or less, and intrauterine fetal death. The authors did not consider the clinical features of the neonate beyond 1 minute of life. As demonstrated by a number of studies (e.g., Sykes et al.1), there ispoor correlation between the 1-minute Apgar score and the presence of neonatal asphyxia as indicated by arterial blood gas values.
John It. Menkes, MD Professor of Neurology and Pediatrics University of California, Los Angeles Los Angeles, CA 90024 REFERENCE
1. Sykes GS, et al. Do Apgar scores indicate asphyxia? Lancet 1982;1:494.
Reply To the Editor: We refer Dr. Menkes to the first part of our discussion, in which we extensively discuss the possible limitations of using the Apgar score in the definition of perinatal asphyxia. Furthermore, we did "consider the clinical features of the neonate beyond 1 minute of life": the 5-minute Apgar scores are shown in the article and were studied in relation to fetal distress. Even cord blood gas values have their flaws; among them is the fact that cord blood gases are profoundly affected by maternal acid-basestatus. Most studies trying to correlate Apgar scores and cord blood pH have not taken into account maternal acid-base status, which may have significantly confounded their results. Neonatologists are well aware of many infants Who are well at birth but who have very low cord pH Values, and vice versa.
Francis Mimouni, MD Assistant Professor of Pediatrics Reginald C. Tsang, MBBS Professor of Pediatrics Obstetrics, and Gynecology Director, Di~,ision of Neonatology University of Cincinnati Medical Center and College of Medicine Cincinnati, OH 45267-0541
Fhe Journal of Pediatrics January 1989
Intravenous immune globulin doses and infection prophylaxis in very low
birth weight neonates To the Editor: We have read with interest the article by Dr. Francisco Noya and colleagues (J PEDIATR1988;112:278-83), entitled "Disposition of an immunoglobulin Intravenous Preparation in Very Low Birth Weigh t Neonates~.'' The authors evffluated serum IgG kinetics in 20 very low birth weight (VLBW) neonates receiving single doses of 500 or 750 mg/kg of in(~ravenously administered immune globulin (IGIV) during the first week of life. On the assumption that the critical serum level of IgG could be 300 mg/dl, the authors "suggest that IGIV doses of 500 mg/kg or 750 mg/kg would produce 'protective' IgG levels for 3 to 4 weeks after infusion." if it is assumed that the serum level of 300 mg/dl of IgG is critical in VLBW neonates, then most VLBW neonates, as well as 17 of-20 subjects enrolled in the study ofNoya et al., would not need IGIV infusions, at least during the first days of life, because of basal serum IgG levels >300 mg/dl. On the contrary, because of increased susceptibility to infection, i t seems reasonable to secure, for prematureneonates, Serum IgG levels at least as high as those of full-term neonatesL; this level needs to be achieved as rapidly as possible after birth and to be maintained all through the first month of life to determine whether IGIV prevents sepsis in premature neonates. In 1984 we assayed 2 serum IgG levels in 15 premature neonates (mean gestational age 31.3 • 2.9 weeks, range 26 to 34; mean birth weight 1423 +_ 293 gm, range 950 to 1790 gm) who were receiving intact polyethylene glycol-treated 1GIV preparation (Venogamma, ismunit). Ten neonates were given 0.5 gm/kg and five neonates 0.3 gm/kg of IGIV on days 1, 2, 3, 7, 14, 21, and 28 of life. We concluded that t h e i G I V dose of 0.3 gm/kg cannot be Considered adequate to achieve serum IgG concentrations constantly >800 mg/dl during the first month of life. Doses of 0.5 gm/kg are necessary on the first and second days of life and every week afterward. We, too, recommend the monitoring of serum IgG levels, because of the important individual differences in half-life, the rates of catabolism, and the distribution between intravascular and extravascutar compartment.
Prof. A, Stabile S. Miceli Sopo, MD M. Pastore, MD Prof. M. A. Pesaresi Department of Pediatrics Catholic University Rome, Italy
REFERENCES
1.
2.
Stiehm ER, Fudenberg HH. Serum levels of immune globulin in health and disease: a survey. Pediatrics 1966;37:71527. Stabile A, Miceli Sopo S, Flamini G, et al. The behaviour of gammaglobulins for intravenous use in preterm infants. lmmunol Clin Sper (Italy) 1985;4:245-9.
Editorial correspondence
3.
Weed LH, Hughson W. Intracranial venous pressure and cerebrospinal fluid pressure as affected by the intravenous injection of solutions of various concentrations. A m J Physiol 1921;58:101-30. 4. Sperling MA. Diabetes mellitus. In: Behrman RE, Vaughn VC III, Nelson WE, eds. Nelson textbook of pediatrics. 13th ed. Philadelphia: WB Saunders, 1987:1252. 5. Harris GD, Fiordalisi I, Finberg L. Safe management of diabetic ketoacidemia. J PEDIATR 1988;113:65-7.
Definition of perinatal asphyxia To the Editor." The publication by Mimouui et al. (J P~mATR 1988;113:34553) is an interesting and potentially valuable contribution. However it is flawed by the authors' definition of perinatal asphyxia. For the purposes of the article, the definition is fetal distress before delivery as monitored by the fetal heart rate, neonatal asphyxia as indicated by a 1-minute Apgar score of 6 or less, and intrauterine fetal death. The authors did not consider the clinical features of the neonate beyond 1 minute of life. As demonstrated by a number of studies (e.g., Sykes et al.1), there ispoor correlation between the 1-minute Apgar score and the presence of neonatal asphyxia as indicated by arterial blood gas values.
John It. Menkes, MD Professor of Neurology and Pediatrics University of California, Los Angeles Los Angeles, CA 90024 REFERENCE
1. Sykes GS, et al. Do Apgar scores indicate asphyxia? Lancet 1982;1:494.
Reply To the Editor: We refer Dr. Menkes to the first part of our discussion, in which we extensively discuss the possible limitations of using the Apgar score in the definition of perinatal asphyxia. Furthermore, we did "consider the clinical features of the neonate beyond 1 minute of life": the 5-minute Apgar scores are shown in the article and were studied in relation to fetal distress. Even cord blood gas values have their flaws; among them is the fact that cord blood gases are profoundly affected by maternal acid-basestatus. Most studies trying to correlate Apgar scores and cord blood pH have not taken into account maternal acid-base status, which may have significantly confounded their results. Neonatologists are well aware of many infants Who are well at birth but who have very low cord pH Values, and vice versa.
Francis Mimouni, MD Assistant Professor of Pediatrics Reginald C. Tsang, MBBS Professor of Pediatrics Obstetrics, and Gynecology Director, Di~,ision of Neonatology University of Cincinnati Medical Center and College of Medicine Cincinnati, OH 45267-0541
Fhe Journal of Pediatrics January 1989
Intravenous immune globulin doses and infection prophylaxis in very low
birth weight neonates To the Editor: We have read with interest the article by Dr. Francisco Noya and colleagues (J PEDIATR1988;112:278-83), entitled "Disposition of an immunoglobulin Intravenous Preparation in Very Low Birth Weigh t Neonates~.'' The authors evffluated serum IgG kinetics in 20 very low birth weight (VLBW) neonates receiving single doses of 500 or 750 mg/kg of in(~ravenously administered immune globulin (IGIV) during the first week of life. On the assumption that the critical serum level of IgG could be 300 mg/dl, the authors "suggest that IGIV doses of 500 mg/kg or 750 mg/kg would produce 'protective' IgG levels for 3 to 4 weeks after infusion." if it is assumed that the serum level of 300 mg/dl of IgG is critical in VLBW neonates, then most VLBW neonates, as well as 17 of-20 subjects enrolled in the study ofNoya et al., would not need IGIV infusions, at least during the first days of life, because of basal serum IgG levels >300 mg/dl. On the contrary, because of increased susceptibility to infection, i t seems reasonable to secure, for prematureneonates, Serum IgG levels at least as high as those of full-term neonatesL; this level needs to be achieved as rapidly as possible after birth and to be maintained all through the first month of life to determine whether IGIV prevents sepsis in premature neonates. In 1984 we assayed 2 serum IgG levels in 15 premature neonates (mean gestational age 31.3 • 2.9 weeks, range 26 to 34; mean birth weight 1423 +_ 293 gm, range 950 to 1790 gm) who were receiving intact polyethylene glycol-treated 1GIV preparation (Venogamma, ismunit). Ten neonates were given 0.5 gm/kg and five neonates 0.3 gm/kg of IGIV on days 1, 2, 3, 7, 14, 21, and 28 of life. We concluded that t h e i G I V dose of 0.3 gm/kg cannot be Considered adequate to achieve serum IgG concentrations constantly >800 mg/dl during the first month of life. Doses of 0.5 gm/kg are necessary on the first and second days of life and every week afterward. We, too, recommend the monitoring of serum IgG levels, because of the important individual differences in half-life, the rates of catabolism, and the distribution between intravascular and extravascutar compartment.
Prof. A, Stabile S. Miceli Sopo, MD M. Pastore, MD Prof. M. A. Pesaresi Department of Pediatrics Catholic University Rome, Italy
REFERENCES
1.
2.
Stiehm ER, Fudenberg HH. Serum levels of immune globulin in health and disease: a survey. Pediatrics 1966;37:71527. Stabile A, Miceli Sopo S, Flamini G, et al. The behaviour of gammaglobulins for intravenous use in preterm infants. lmmunol Clin Sper (Italy) 1985;4:245-9.