988 Heart Rate and Heart Rate Variability in Normal and Aborted Sids Infants During Sleep

Abstract

A conservative approach to non-delivery of women with prolor ed premature rupture of membranes (PPROM) before 36 wks. was associated with congenital postural deformities and hypoplastic lungs but not with neonatal asphyxia or sepsis. PPROM> 24 hrs. occurred in 89 infants (15.8/1000 deliveries 1975-1977). Positional foot deformity (PFD), congenital dislocation of hips (CDH) and hypoplastic lungs (HL) were present only with PPROM a 28 wks. gestation or less. TOTAL 89 8118 5 1 The incidence of PFD and CDH in this group was significantly higher than in all newborns (5.5% and 1.1% vs. 0.4% and 0.5% respectively). 3/89(3.3%) of the infants were stillborn; 8/89 (9.0%) died; 8/11 perinatal deaths were ClOOO gm. There was no difference in the incidence of neonatal asphyxia in PPROM infants matched for gestational age and birth weights with non-PPROM controls. The one PPROM infant with infection survived Group B streptococcal septicemia.I£ Medicine, Depts. of Family and 1 'community Medicine, Pediatrics, and Obstetrics/Gynecology, TucsolA 5-year retrospective study of 4,430 deliveries assessed the influence of maternal obesity, pre-pregnant weight, weight gain, age, and diabetes on fetal outcome. Male babies were heavier than females (p<.05). Thus different curves may be needed to determine the designation "LGA" in some populations. Obese mothers, mothers who gained > 30 lbs. during their pregnancy, and Class A diabetics all had heavier babies and increased numbers of LGA births compared to controls (p<.01).When obesity and diabetes were present, 66.7% of the births were LGA vs. 12.1 -for controls (p<.01).The prevalence of major malformations correlated only with maternal diabetes, where there was a 4-fold increase over controls (11.3% vs. 2.7%, p<.05). Perinatal mortality was affected by maternal factors only insofar as they adversely affected birthweight or gestational age. Diabetes however, resulted in increased mortality at all birthweights and gestational ages, ant gave an overall perinatal mortality rate of 143/1000 births, which was almost 4 times greater than controls (p<.01).Maternal obesity, pre-pregnant weight, weight gain and diabetes are significant determinants of birthweight and the percentage of LGA births, whereas only maternal diabetes was found to directly increase the prevalence of major malformations or the perinatal death rate. Following our initial report regarding the use of tolazoline ir infants with persistent pulmonary hypertension, we have reviewed our subsequent experience with this drug in patients with hyalinc membrane disease (HMD) and meconium aspiration syndrome (MAS) whc had severe hypoxemia unresponsive to usual therapy. From 10/74-10/77 we infused tolazoline to infants on assisted ventilation xhen their Pa02 fell below 50 torr while in an Fi02 of 1.0 and requiring peak inspiratory pressures of > 40 cm H20. A bolus of 1-2 mg/kg was given via scalp vein, followed by 1-2 mg/kg/hr to a iaximum of 10 mg/kg/hr. Five of 15 patients with HMD who met this :riteria survived, with only one surviv...

Heart Rate Response to Tilting in Newborns in Quiet and Active Sleep

“…Baroreflex activ ity has been investigated by infusion of pres sor agents in adults [8,17,18], but the results are controversial. Infants have heart rate and variability differences between the two sleep states as do adults [6,7,9,10,12,19,20], although differences in other cardiovascular variables have not been investigated. We had expected to find a difference in RR change with tilting between the two sleep states, and failure to find this may indicate that the differences evident in adults have not yet matured in the young infant.…”

Effect of Sleep State on the QT Interval in Normal Infants

“…In the latter group, the range of the RR interval was too small (30-50 msec) for the QT interval to show any clear dependence. These and other studies from this laboratory (16) demonstrate that the RR interval is shorter in REM than in quiet sleep. Therefore, the use of Bazett's or other methods (23) would tend to minimize the observed difference in the QT, between REM and quiet sleep.…”