David O Hakanson

Necrotizing enterocolitis and hyperviscosity in the newborn infant

During a one-year prospective survey to determine the incidence of hyperviscosity in small-for-gestational age infants, we found a significant increase in the incidence of necrotizing enterocolitis in SGA infants with HV. Of the 14 SGA infants with HV, five developed NEC, and of 65 SGA infants with normal blood viscosity,one had NEC (p less than 0.005). Comparison of clinical features of the five HV infants with NEC with those reported in the literature showed that the infants with HV and NEC had had longer gestational periods and higher weights and, in contrast to those reported in the literature, were free of clinical evidence of asphyxia distress. The respiratory disorders have been proposed as the clinical events that might lead to ischemia of the intestine and subsequently to NEC. It is proposed that HV may be another factor leading to ischemia in the gastrointestinal tract with subsequent development of NEC.

CALCEMIC RESPONSES TO PHOTIC AND PHARMACOLOGIC MANIPULATION OF SERUM MELATONIN

ABSTRACT. Phototherapy of newborn rats (NBR) resulted in a decrease in serum calcium and melatonin levels. Transcranial light penetrance in NBR increased with wavelength. Below 640 nm (penetrance = 6.9%), no hypocalcemic effect could be demonstrated. Shielding the occiput of NBR prevented a decrease in serum calcium during phototherapy and substantially reduced the decrease in melatonin found in unshielded NBR. Intraperitoneal injection of propranolol, an inhibitor of melatonin synthesis, caused a decrease in serum calcium in shaded NBR. In contrast, when melatonin was injected with propranolol a decrease in serum calcium did not occur. Additionally, intraperitoneal isoproterenol before phototherapy protected against a decrease in serum calcium. These data are consistent with an hypothesis that a decrease in serum calcium during phototherapy results from transcranial photic inhibition of melatonin synthesis.

Hyperviscosity in the small-for-gestational age infant.

Small-for-gestational age infants are prone to hyperviscosity but the precise incidence is unknown. A prospective survey was conducted on 4,974 consecutive livebirths for hyperviscosity in small-for-gestational age infants. Small-for-gestational age is defined as birth weight below the 10th percentile of the intrauterine growth curve and signs of malnutrition and hyperviscosity as venous blood viscosity (measured by a microviscometer) above the 2 SD of the norm. 79 infants were identified as small-for-gestational age. Of these, 14 were hyperviscous and 65 were normoviscous. The venous hematocrit range from 61 to 70% in hyperviscous and 37 to 62% for normoviscous. A predefined symptom complex referrable to cardiovascular, respiratory, gastrointestinal, and central nervous systems were assessed by an unbiased observer; 57% of hyperviscous and 25% of normal viscous infants were symptomatic (p 2). The data indicate that the hyperviscosity syndrome occurs in 17.7% of small-for-gestational age infants; venous hematocrit (64%) is predictive of hyperviscosity, and that in spite of a positive correlation between symptom complex and hyperviscosity, there is a lack of specificity for the clinical manifestation of this neonatal complication.

Foam-stability test on gastric aspirate and the diagnosis of respiratory-distress syndrome.

Gastric aspirate, collected from 79 infants within 30 minutes of birth, was subjected to the foam-stability test. The lecithin/sphingomyelin ratio was determined in 27. The results were compared with the incidence of respiratory-distress syndrome as determined independently by different investigators. Of the 59 infants with a positive foam-stability test on gastric aspirate, three had transient respiratory distress, and one the respiratory-distress syndrome; 17 of 22 had lecithin/sphingomyelin ratios greater than 2.0. Of nine infants who had intermediate test results, three were normal, four had transient respiratory distress, and two had the respiratory-distress syndrome. In all the 11 infants with negative foam-stability tests the respiratory-distress syndrome developed. The three gastric aspirates tested in this group had lecithin/sphingomyelin ratios of less than 1.5. These data indicate that the foam-stability test on gastric aspirate is a reliable index of fetal lung maturity in infants whose amniotic fluid is not available.

Reliability of bacterial culture of blood obtained from an umbilical artery catheter

NEONATAL SEPTICEMIA should be considered in newborn infants with respiratory distress? In small premature infants with respiratory distress, blood cultures from a peripheral vein are often technically difficult to obtain. Although these infants frequently requir e umbilical artery catheterization in the first hours of life for blood gas analysis, the reliability of blood cultures obtained from the umbilical artery catheter has not been documented. We wish to report our experience with neonates on whom paired umbilical artery blood and peripheral blood cultures were obtained during the first nine hours of life.

Pineal and Adrenal Effects on Calcium Homeostasis in the Rat

ABSTRACT: In human infants and newborn rats, white light at the intensity used to treat hyperbilirubinemia lowers serum calcium concentration. Occipital shielding or (in newborn rats) exogenous melatonin prevents this effect. Propranolol, by inhibiting melatonin synthesis, also causes hypocalcemia, which is preventable by melatonin. Metyrapone or adrenalectomy prevents hypocalcemia after light exposure or propranolol. Exogenous corticosterone lowers serum calcium; this is prevented by supplementary melatonin. In adult rats, the change in calcium after light, propranolol, or corticosterone is minimal. After parathyroidectomy or a diet with a high calcium/low phosphorus ratio, the hypocalcemic effect of these three agents is restored. Bone samples removed after light exposure or corticosterone administration show increased calcium uptake; this is blocked by supplementary melatonin in vivo or by addition of melatonin to the incubation medium. We postulated that the hypocalcemic effect of light or propranolol was due to an acute increase in corticosterone-mediated bone calcium uptake when circulating melatonin was decreased by reduction of the rate of melatonin synthesis. In our study, pinealectomized rats showed no change in serum calcium after light or propranolol; their hypocalcemic response to corticosterone was greater than that of shamoperated controls. Exogenous parathyroid hormone prevented light-induced hypocalcemia in newborn rats.

86 PROSPECTIVE RANDOMIZED CONTROLLED TRIAL OF CONVENTIONAL TREATMENT OR TRANSPORT FOR ECMO IN INFANTS WITH SEVERE PERSISTENT PULMONARY HYPERTENSION (PPHN): TWO YEAR FOLLOW UP

28 of 31 ECMO eligible infants born July, 1988 to March, 1992 with severe PPHN were assigned randomly when oxygenation index (OI) was ≥ 40 for four hours to be transported for ECMO (n=15, birthweight 3601 ± 622 g; OI 63 ± 28) or to receive conventional therapy at our center (n=13, birthweight 3403 ± 640 g; OI 60 ± 28). Fourteen of the 15 infants (93%) transported for ECMO survived to hospital discharge (including 3 who did not receive ECMO), while 7 of 13 (54%) conventionally treated infants survived (p<05). One ECMO infant died after hospital discharge at age 3 months of SIDS. Outcome for the survivors (mean ± SD):ECMO salvaged sicker neonates (mean OI at study entry for ECMO survivors was 60 ± 21 vs 44 ± 5 for conventionally treated survivors); nevertheless, transport for ECMO was not associated with worse neurodevelopmental outcome at 2 years. These data support the use of ECMO in term infants with severe respiratory distress.

HYPERVISCOSITY IN THE SMALL-FOR-GESTATIONAL AGE INFANT

SGA infants are prone to hyperviscosity but the precise incidence is unknown. A prospective survey was conducted on 4,794 consecutive livebirth for hyperviscosity in SGA infants. SGA is defined as birth weight below the 10th percentile of intrauterine growth curve and signs of malnutrition; and hyperviscosity as venous blood viscosity (measured by micro-viscometer) above the 2 S.D. of the norm. 79 infants were identified as SGA and of these, 14 were hyperviscous (HV) and 65 were normal viscous (NV). The venous hematocrit range from 64-70% in HV and 37-62% for NV. A pre-defined symptom complex referable to cardiovascular, respiratory, gastrointestinal, and central nervous systems were assessed by 2 unbiased observers; 57% of HV and 25% of NV infants were symptomatic (p<.05 by Chi square). The data indicated that HV occur in 17.7% of SGA infants; venous hematocrit (>64%) is predictive of HV; and that in spite of a positive correlation between symptom complex and HV, there is a lack of specificity for the clinical manifestation of HV.

58 NEONATAL HYPERVISCOSITY SYNDROME: LONG-TERM BENEFIT OF PARTIAL PLASMA EXCHANGE TRANSFUSION

Partial plasma exchange transfusion(XT) has been recommended as the treatment of choice in neonatal hyperviscosity although there remains no statistical proof that it prevents long-term CNS or other sequelae.In order to study the long-term effect of XT, 24 infants found to have hyperviscosity of whole blood were assigned randomly to receive XT within 12 hrs of birth or to receive only supportive treatment. Twelve infants received XT with fresh frozen plasma while the other 12 received no XT. Gestational ages ranged between 36 and 40 weeks (x=37.6); all infants were appropriate-for-gestational age. All infants were seen in follow-up at 8 months of age at which time Bayley Scales of Infant Development were administered.Infants in the XT group had higher scores than the non-XT group for both mental(MDI) and motor(PDI) indices (XT group: 111 and 105, non-XT: 96 and 93). The differences were not statistically significant for either index, but approached significance for the MDI(p<0.1; >.05).Neuromuscular development also was assessed at 8 months by a physical therapist. One infant in the non-XT group was found to have a hemiparesis for which no cause other than the hyperviscosity could be identified.Absolute benefit for partial plasma exchange transfusion in the treatment of neonatal hyperviscosity cannot be claimed from this study but therapeutic benefit is suggested.

1202 ABNORMAL GENITALIA IN MALES WITH SILVER-RUSSELL (SR) DWARFISM: A NOT INFREQUENT COMPLICATION

The patient to be described weighed 1210 gm at birth, with estimated (Dubowitz) gestation of 38 weeks. The mother had congenital hydrocolpos, hydronephrosis and bicornuate uterus. Length was 37 cm; head circumference 30 cm. There were hypoglycemia and thrombocytopenia in the neonatal period. The face was triangular, with the appearance of a large head and small chin, typical for SR dwarfism. The phallus was 2 cm long and was partially concealed by a rostral investment of scrotal folds. Testes were palpable bilaterally in the canals. Karyotype was 46,XY. Voiding cystourethrogram revealed a urethra with male configuration, as well as a 9 mm hypoplastic vagina posterior to the urethra. This is consistent with failure of Mullerian inhibiting factor to function in fetal life. Several patients with the SR syndrome have been found to have obstructive abnormalities of the GU system (Pediatrics 51:216, 1973). At 8 month follow-up the scrotum was almost flat, with only one testis barely palpable in the right canal. Literature review on both sexes with the SR syndrome revealed that 28% of documented cases were males with abnormal genitalia. Several reports described adequate masculinization at puberty. The latter finding is important to bear in mind when consideration is given to the possibility of assigning a female gender role if the penis is small.