Oxygen desaturation during sleep in infants and young children with congenital heart disease.

Oxygen saturation (SaO2) during sleep and pulmonary functions were evaluated in 19 infants with congenital heart disease, aged 6 +/- 4 months, and in 11 normal infants, aged 8 +/- 5 months, to determine whether infants with congenital heart disease have more frequent oxygen desaturation during sleep and, if so, its relationship to underlying pulmonary function. Infants with congenital heart disease were classified as acyanotic (n = 11) or cyanotic (n = 8) on the basis of their aortic SaO2 at the time of cardiac catheterization (greater or less than 90% SaO2). Pulmonary function tests included respiratory rate, functional residual capacity, total respiratory system compliance, and maximal flows at functional residual capacity. Significant differences were found in the values for the lowest SaO2 of each 5-minute epoch (SaO2L) averaged during the entire sleep time (normal 94% +/- 2%, acyanotic 90% +/- 3%, and cyanotic 74% +/- 4%; p less than 0.01). The three groups also differed significantly in frequency distributions of percentage of total sleep time with SaO2L less than 90% (SaO2%T) (normal 10% +/- 17%, acyanotic 36% +/- 34%, and cyanotic 97% +/- 4%; p less than 0.05). Compared with the control group, the acyanotic group had a higher respiratory rate (66 +/- 19 breaths/min vs 35 +/- 6 breaths/min; p less than 0.01), a lower tidal volume (65% +/- 29% predicted vs 105% +/- 18% predicted; p less than 0.01), and a lower total respiratory compliance (59% +/- 18% predicted vs 106% +/- 30% predicted; p less than 0.01). A negative correlation existed between SaO2%T and aortic SaO2 (R2 = 0.64; p less than 0.01). We conclude that oxygen desaturation occurs during sleep in infants with congenital heart disease; the presence of desaturation appears to be related to the initial degree of hypoxemia and the presence of abnormal pulmonary function.     

Hemoglobin desaturation during sleep and daytime in patients with cystic fibrosis and severe airway obstruction

Transcutaneous hemoglobin saturation by pulse oximetry was evaluated during sleep and for 2-3 h during the day in 31 patients with cystic fibrosis (median age 15.2 years; range 7.6-33.6 years) and severe airway obstruction. Pulse oximetry readings were analyzed as a cumulative percentage of time in which oxygen saturation was < 90% during both sleep and daytime. Each patient was also examined using clinical and radiological scores, spirometry and arterial blood-gas analysis. The agreement between arterial and transcutaneous saturation was evaluated in 29 patients. The difference between transcutaneous and arterial saturation was 2.4 +/- 2.0% and it increased as arterial saturation decreased. Clinical and radiological scores and spirometry parameters showed a poor correlation with both overnight and daytime desaturation. An arterial saturation < 94% may indicate a risk of consistent desaturation. This occurred for more than 50% of the time in 11 of 20 patients during sleep and in 5 of 20 patients during daytime hours.     

Delayed umbilical cord clamping in preterm infants: A feasibility study

Objectives: To assess: (i) the size of placental transfusion following a 30 s delay in cord clamping following vaginal and Caesarean births; and (ii) the feasibility of delaying cord clamping in the labour ward and particularly in the operating theatre.
Methods: Fourty-six infants born at 26–33 weeks gestation were randomized to having the umbilical cord clamped either immediately or 30 s after birth. The venous haematocrit was measured at 1 and at 4 h of age.
Results: There were trends towards higher mean haematocrits in the infants following delayed clamping, but these were not significant either at 1 h (55±7.7 vs 52.9±7) or at 4 h of age (55±7 vs 52.5±7). The trends were more marked in the infants born by Caesarean section, and in those born at 26–29 weeks gestation.
Conclusions: A 30 s delay in cord clamping is feasible at both vaginal and Caesarean births, but does not lead to the predicted difference in infant haematocrit. Although physiological studies suggest that a placental transfusion of 15–20 mL/kg occurs within 30 s of delivery, these data suggest that future trials should either delay cord clamping for more than 30 s, or should alter the position of the infant in relation to the uterus in order to facilitate the transfusion. Delayed cord clamping is feasible at Caesarean section.     

Sleep characteristics in children with Down syndrome.

BACKGROUND: Obstructive sleep apnea syndrome is common in children with Down syndrome (DS). Little is known about sleep patterns, especially arousals, awakenings, and movements during sleep in children with DS. OBJECTIVE: To determine the characteristics of sleep disorders in children with DS and to define the associations between respiratory disturbance and arousals, awakenings, and movements. METHODS: The study included 23 children with DS, compared with 13 children with primary snoring. All underwent a 6- to 8-hour sleep study. RESULTS: The respiratory disturbance index was significantly higher in the children with DS (2.8 +/- 2.3 events/h vs 0.6 +/- 0.4 events/h; P <.05). Sleep was significantly fragmented in children with DS, who had a significantly higher arousal/awakening (A/Aw) index (24.6 +/- 7.9 events/h) compared with the comparison group (17.6 +/- 4.0 events/h) (P <.02). A higher percentage of jerks associated with A/Aw and respiratory event-associated A/Aw was observed in patients with DS (45.2% +/- 25% and 8.6% +/- 6.4%, respectively) compared with the control patients (10.2% +/- 4.5% and 1.5% +/- 2.1%) (P <.02). The median length of occurrences of stage 2 sleep was 27% shorter in the DS group (P <.03). The number of shifts from "deeper" to "lighter" stages of non-rapid eye movement sleep was 30% greater (P <.02) in the DS group. CONCLUSION: Children with DS have significant sleep fragmentation, manifested by frequent awakenings and arousals, which are only partially related to obstructive sleep apnea syndrome.     

Catecholamine Surge and Metabolic Adaptation in the Newborn after Vaginal Delivery and Caesarean Section

The immediate postnatal metabolic adaptation and sympatho-adrenal activation were studied in infants delivered vaginally or by elective caesarean section. Vaginally delivered infants showed high catecholamine levels at birth compared to infants born by caesarean section under epidural or general anaesthesia. Umbilical arterial glucose levels were significantly higher in the vaginal group than in both caesarean section groups. At 30 min, all groups showed a marked decrease with several infants showing asymptomatic hypoglycaemia in the caesarean section group. C-peptide levels showed no difference at birth but later became significantly higher in the vaginal group. Although the levels of free fatty acids and glycerol were low at birth, they were significantly higher in the vaginal group. In all groups they increased substantially with time. Considering the marked differences in catecholamine levels, the differences in metabolic adaptation were unexpectedly small. This implies an attenuated metabolic response to sympatho-adrenal stimulation in the newborn.     

Does bladder voiding during sleep and wakefulness change the behavioural state of infants?

AIM: To evaluate whether bladder voiding in healthy infants is accompanied by body movements or any changes in heart rate (HR), respiratory frequency (RF) or electroencephalogram (EEG) frequency during sleep and during wakefulness. METHODS: Polygraphic recordings were performed on 33 healthy infants (17 female) born at term. The infants' age at study entry was 41+/-10 d, and actual body weight was 4876+/-403 g (mean+/-SD). Bladder voiding was recorded by an adapted enuresis detector connected to the polygraphic computer unit. RESULTS: Awakening was observed in 12 (36%) infants 77+/-9 s before bladder voiding. Twenty-one infants (64%) continued sleeping during bladder voiding. In sleeping infants, bladder voiding occurred during non-REM sleep only, and was accompanied by a cortical arousal. During wakefulness, RF was lower, and HR and EEG frequency were higher, but stayed constant during bladder voiding. CONCLUSION: Our observations demonstrate that bladder voiding in healthy infants during sleep is accompanied by body movements and changes in HR and EEG frequency, indicating cortical arousals, whereas during wakefulness these changes cannot be observed.     

Alterations in head shape of newborn infants after caesarean section or vaginal delivery.

Alterations of head shape in preterm, small-for-dates, and term normal infants were studied by measuring occipitofrontal circumference (OFC), biparietal diameter (BPD), and occipitofrontal diameter (OFD) at intervals after birth. In 9 preterm infants born by elective caesarean section ther was a 5-2% reduction in BPD and 2-0% reduction in OFC at the age of 7 days. In 18 term infants born by elective caesarean section these changes were 2-4% and 0% respectively in BPD and OFC. In 25 preterm infants born by vertex vaginal delivery there was a significant fall in OFC of 0-7% at the age of 7 days and of 2-4% in BPD, but no significant change in OFD. In 19 small-for-dates infants born vaginally OFC increased 1-0% and OFD 2-7% at 7 days, but BPD decreased 2-5%. After the first week all three measurements increased in both groups of vaginal deliveries. The results show that shrinkage and biparietal flattening of the skull occur during the first week of life in preterm and term infants born by caesarean section and in preterm infants born vaginally. This fact should be borne in mind when comparing the measurements of an infant''s head size with published norms.     

阻塞性睡眠呼吸暂停综合征儿童睡眠结构的改变

目的　研究阻塞性睡眠呼吸暂停综合征对儿童睡眠结构的影响。方法　对阻塞性睡眠呼吸暂停综合征患儿进行多导睡眠监测 ,并与同年龄组儿童睡眠结构正常值进行比较。结果　与正常值相比 ,阻塞性睡眠呼吸暂停综合征组的睡眠结构存在如下异常 :睡眠I期 :阻塞性睡眠呼吸暂停综合征组 ( 4 5 .8± 2 .0 ) % ,正常值 ( 2 .3± 1.1) % (t=2 2 .4 6 ,P <0 .0 1) ;睡眠Ⅱ期 :阻塞性睡眠呼吸暂停综合征组 ( 2 3.9±l.7) % ,正常值 ( 4 7.9士 4 .4 ) % (t =- 14 .18,P <0 .0 1) ;慢波睡眠 :阻塞性睡眠呼吸暂停综合征组 ( 15 .6± 1.8) % ,正常值 ( 2 1.1± 5 .0 ) % (t=- 3.12 3,P <0 .0 1) ;快动眼睡眠 :阻塞性睡眠呼吸暂停综合征组 ( 14 .7± 1.5 ) % ,正常值 ( 2 8.2± 4 .1) % (f =- 8.92 3,P <0 .0 1) ;差异均有显著性。结论　阻塞性睡眠呼吸暂停综合征可引起儿童睡眠结构的紊乱 ,主要表现为睡眠时频繁唤醒 ,睡眠片段化 ,浅睡眠增加 ,深睡眠和快动眼睡眠减少 ,导致患儿学习困难 ,智力下降 ,生长停滞。     

Passive compliance of the total respiratory system in newborn infants born by cesarean section

The compliance of the total respiratory system (CRS) was measured by the occlusion technique: a) at H1-H2, H6-H7 and D3-D4 in 8 full-term newborns after cesarean section; b) at H1-H2 and H6-H7 in 6 full-term newborns delivered vaginally and at D3-D4 in 10 full-term newborns delivered vaginally. At H1-H2 respiratory frequency measured by inductive plethysmography was not significantly different between newborns after cesarean section (60 +/- 6 c/min) and newborns delivered vaginally (53 +/- 16 c/min). CRS normalized for body weight was not significantly different between newborns after cesarean section and those delivered vaginally at H1-H2 (0.6 +/- 0.1 vs 0.7 +/- 0.1 ml/cmH2O/kg) and at H6-H7 (0.7 +/- 0.1 vs 0.8 +/- 0.3 ml/cmH2O/kg). At D3-D4, CRS was significantly greater than at H6-H7 in newborns after cesarean section (1.1 +/- 0.2 ml/cmH2O/kg, p less than 0.001) and in newborns delivered vaginally (1 +/- 0.1 ml/cmH2O/kg, p less than 0.02). We conclude that in newborns after cesarean section without tachypnea, the evolution in CRS is similar to that in newborns delivered vaginally.     

Wheeze detection as a measure of bronchial challenge in young children with cough-variant asthma and with classic asthma

AIM: Tracheal and chest auscultation for wheeze and transcutaneous oximetry have both been suggested as outcome measures of bronchial provocation tests in young children. The aims of this study were to compare the sensitivity of these two techniques as endpoints for methacholine challenge in young children with cough-variant asthma (CVA) and with classic asthma (CA), and to investigate whether oxygen saturation levels at the presence of wheezing differ in these two groups. METHODS: We performed a retrospective analysis of methacholine challenge test data from 4- to 6-year-old children with CVA (n = 41) and from those with CA (n = 53). The challenges used a modified auscultation method that set wheeze detection and/or oxygen desaturation for determining the endpoint. RESULTS: The frequency of wheeze detection at the endpoint was significantly lower than that of oxygen desaturation (46.3% vs. 78.0%) in the CVA group, which contrasted with findings (75.5% vs. 50.9%) in the CA group. Oxygen saturation levels at the presence of wheezing were significantly lower in the CVA group than in the CA group (94.5 +/- 1.5% vs. 95.9 +/- 1.8%, p = 0.006). CONCLUSION: Wheeze detection is a less sensitive outcome measure than oxygen desaturation and is associated with a lower oxygen saturation level in young children with CVA, compared to those with CA.     

Birth by cesarean section is associated with elevated neonatal plasma levels of dimethylarginines

Background: This study was undertaken to compare the effects of vaginal delivery and cesarean section on the l‐arginine‐nitric oxide system by measuring levels of l‐arginine, an endogenous nitric oxide synthase antagonist asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in the cord blood and postnatally. Methods: Plasma samples were obtained from the umbilical vein and artery at birth and from peripheral venous blood on the second postnatal day in 30 full‐term newborn infants: 10 born vaginally and 20 born by cesarean section. Results: After vaginal delivery, ADMA concentration was higher in the umbilical vein than in the umbilical artery (mean 1.06 vs 0.90 µmol/L [P= 0.027]); and ADMA level fell after birth to 0.66 µmol/L on the second postnatal day (P= 0.007 vs umbilical artery). Newborns born by cesarean section had similar ADMA levels in umbilical arterial and venous blood, 1.19 and 1.18 µmol/L, and the ADMA level fell to 0.84 µmol/L by the second postnatal day (P < 0.001). Vaginal birth induced neither significant umbilical venoarterial difference nor a postnatal fall in SDMA. After cesarean section, SDMA was essentially the same in umbilical vein, umbilical artery and postnatal peripheral vein samples. At 2 days of age, both ADMA and SDMA levels stayed higher in infants born by cesarean section than in vaginally born infants. Conclusions: ADMA level falls after both vaginal and cesarean birth, whereas SDMA level does not. The higher ADMA level after cesarean birth compared with vaginal birth may contribute to decreased nitric oxide production and bioavailability in neonatal vascular beds.     

Neonatal pattern of breathing during active and quiet sleep after maternal administration of meperidine.

The aim of this study was to reappraise the effects of maternal meperidine administration on breathing pattern during the first hours of life taking into account the state of alertness. Because breathing instability is more pronounced during active sleep, we hypothesized that meperidine administration might create a greater risk for respiratory instability during active sleep, the prominent sleep state in newborns. We studied eight full-term, healthy newborns whose mothers had received a continuous i.v. infusion of meperidine (81 +/- 9 mg) that was terminated 5.5 +/- 2.1 h before delivery. These infants were compared with a control group of eight full-term newborns whose mothers did not receive any opioids. In both groups, all babies were delivered vaginally after a normal labor and had Apgar scores of 9 or 10 at 1 and 5 min. Neonatal gastric secretion and maternal venous and umbilical venous blood were sampled at delivery for determination of meperidine concentration. From 60 to 300 min after delivery, behavioral sleep states and thoracic and abdominal movement as well as transcutaneous arterial oxygen saturation (SaO2) were monitored continuously. The number of apneic spells lasting more than 3 s during 100 min of recording and the percentage of time with SaO2 below 90% in each sleep state were recorded. During quiet sleep, all respiratory variables were similar in both groups. During active sleep, there were significantly more apneic episodes (37.1 +/- 25.1 versus 11.2 +/- 13.9) and a higher percentage of time with SaO2 less than 90% (14.3 +/- 16.7% versus 1.3 +/- 1.5%) in the meperidine group than in the control group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Oxygen saturation trends immediately after birth

OBJECTIVE: To describe the changes in oxygen saturation (SpO2) in healthy infants during the first 10 minutes of life. STUDY DESIGN: In this observational study, infants > or = 35 weeks gestation at birth who did not require supplemental oxygen had continuous recordings taken of the preductal SpO2 over the first 10 minutes of life. RESULTS: A total of 115 infants were analyzed. On average, infants delivered by cesarean delivery had a 3% lower SpO2 than infants delivered by vaginal delivery (95% confidence interval [CI] = -5.8 to -0.7; P = .01). Infants born by cesarean delivery also took longer (risk ratio, 1.79) to reach a stable SpO2 > or = 85% (95% CI = 1.02 to 3.14; P = .04). At 5 minutes of age, median SpO2 values (interquartile range) were 87% (80% to 95%) for infants delivered vaginally and 81% (75% to 83%) for those delivered through cesarean section. The median SpO2 did not reach 90% until 8 minutes of age in either group. CONCLUSIONS: The process of transitioning to a normal postnatal oxygen saturation requires more than 5 minutes in healthy newborns breathing room air.     

Beta-adrenoceptor function in white blood cells from newborn infants: no relation to plasma catecholamine levels

The maturity of beta-adrenoceptors in newborn infants was studied in relation to the catecholamine surge during labor. Umbilical blood was collected at birth from 12 infants delivered vaginally and 13 infants delivered by elective cesarean section. Granulocytes and lymphocytes were isolated. Receptor numbers and binding affinity were determined in the granulocytes by incubation with 125I-iodohydroxybenzylpindolol. Receptor responsiveness was tested by assessing isoproterenol-induced cyclic AMP accumulation in lymphocytes. Significantly higher plasma noradrenaline, adrenaline, and dopamine concentrations were found in infants born vaginally (108; 8.9; 0.9 nmol/liter, liter, respectively, median values) as compared with those delivered by cesarean section (11.0; 2.4; 0.2 nmol/liter). No significant differences in beta-adrenoceptor binding sites (receptor number: 39.2 +/- 2.6 versus 44.7 +/- 5.9 fmol/mg protein and binding affinity: 66.6 +/- 7.8 versus 65.0 +/- 6.2 pM) or responsiveness (maximal isoprenaline induced cAMP formation 52.4 +/- 10.3 versus 40.6 +/- 8.9 pmol/10(6) cells) were found between the two groups of infants. Lymphocyte beta-adrenoceptor sensitivity was similar to that found in adults. The beta-adrenoceptors on whole blood cells seem to be mature at birth and have the same responsiveness as in adults. The higher catecholamine surge during vaginal delivery as compared to elective cesarean section does not seem to affect beta-adrenoceptor function. Our results do not support the idea that reduced beta-adrenoceptor function is the cause of the previously observed inappropriately small cardiovascular and metabolic responses to the exceptionally high plasma catecholamine concentrations at birth.     

Leukocyte counts in relation to the method of delivery during the first five days of life

The goal of the present study was to evaluate total and differential leukocyte counts during the first 5 days of life in relation to the method of delivery. We included 203 healthy term infants; of these, 114 were born by vaginal delivery, and 89 by elective cesarean section. Total and differential leukocyte counts were evaluated at the following intervals: 0-6, 7-12, 13-24, 25-48, 49-72, 73-96, and 97-120 h after birth. The cord serum cortisol level was measured as an indicator of the degree of delivery-related stress. Mean leukocyte and neutrophil counts were higher in infants born by vaginal delivery in cord blood and up to 12 h of life. No significant differences were observed in the immature: total neutrophil ratios between the two groups of infants. The cord serum cortisol level was higher in vaginally delivered infants. A significant correlation was found between cortisol and leukocyte, neutrophil, or lymphocyte counts. The method of delivery produces significantly different total leukocyte and neutrophil counts during the first 12 h after birth; after this time, there appears to be no more variation of leukocyte counts during the first 5 days of life.     

Hydration in the first 24 h of postnatal life in normal infants born vaginally or by caesarean section

A total of 65 infants, 48 born vaginally and 17 by segment caesarean section, were studied prior to labour for extracellular volume (ECV) (corrected bromide space) and total body water (TBW) (deuterium space) during the first 24 h of postnatal life. The infants were mature and growth retardation excluded. A ‘heel stick’ blood sample was taken for micro determination of Br and urine for ²H₂0 concentration. ECV varied from 343 ±27 ml/kg at 6 h to 358 ±21 ml/kg at 24 h and TBW was 75.5 ±3.4% of body weight. Contrary to current opinion, neither TBW nor cell hydration differed in infants born by caesarean section compared with those born vaginally. Such modern methodology to study infant body hydration and the critical assessment of growth and maturity demonstrates that hydration during the first 24 h of life is relatively stable and is not affected by the mode of delivery.     

Umbilical cord separation in the normal newborn

During a 13-month period, 363 infants were followed up through the first six weeks to determine the effect of perinatal factors (birth weight, gestational age, type of delivery, and pregnancy and neonatal complications) on umbilical cord separation. Also, breast-feedings and umbilical cord care were studied. Except for cesarean section deliveries, study infants were similar to all infants (N = 1474) admitted to the same nursery during the study period. Cord separation occurred from days three to 45, with a mean of 13.9 days. Infants born by cesarean section were found to have an increased interval for cord separation when compared with infants born vaginally (mean +/- SD, 15.9 +/- 5.0 days vs 12.9 +/- 4.2 days). In this study, delays in separation of the umbilical cord beyond 3 weeks of age was not associated with an increased risk of infection.     

Nocturnal oximetry in infants with cystic fibrosis.

AIM: To investigate whether children with cystic fibrosis under 3 years of age have disordered breathing and episodes of oxygen desaturation during sleep. METHODS: We studied 19 infants (9 boys and 10 girls) with cystic fibrosis, mean age 13.1 months (range 3-36 months) and 20 age and sex matched healthy subjects. Patients and controls underwent an overnight polysomnographic study and respiratory function testing on the following morning. RESULTS: Seven patients with ongoing respiratory tract inflammation had disordered breathing and episodes of oxygen desaturation during sleep. Pulse oximetry showed a significantly lower mean oxygen saturation (SaO(2)) and a higher percentage of total sleep time spent with SaO(2) less than 93% in symptomatic children than in controls. CONCLUSION: Results suggest that infants and young children with cystic fibrosis and mild airways inflammation (rhinitis, cough, red throat) have episodes of oxygen desaturation during sleep.     

Breathing patterns in term infants delivered by caesarean section

AIM: To compare the breathing patterns of infants born by elective caesarean section to those infants delivered by caesarean section after a failed trial of labour. METHODS: Healthy term infants born by caesarean section were studied. The study group (n = 13) had no trial of labour, whereas infants in the control group (n = 13) failed a trial of labour. Polysomnographic study was performed at 36 h of age. Heart and respiratory rate, type and duration of apnoeas, arterial oxygen saturation and lower limb movements were analysed. RESULTS: Term infants born by elective caesarean section had a shorter duration of pregnancy and weighed less. Their heart rate was faster, they had more mixed apnoeas, and during quiet sleep they had more central apnoeas of longer duration. CONCLUSION: Cardiorespiratory patterns in infants delivered by elective caesarean section are different from those delivered by caesarean section after a failed trial of labour.     

An old problem revisited-hyaline membrane disease and cesarean section

The incidence of hyaline membrane disease (HMD) was investigated retrospectively in 159 preterm infants below 35 weeks gestation, weighing less than 2,000 g, and born during the 5-year interval 1975–79. The incidence of HMD was compared between infants delivered by elective Cesarean section, Cesarean section after the onset of labor and by the vaginal route. A significant difference (P<0.001) was found in the frequency of HMD dependant on the mode of delivery; 50% of infants delivered by elective Cesarean section developed HMD versus 19.2% in the vaginally delivered group. In infants delivered vaginally premature rupture of membranes (PROM) lowered the incidence of HMD to 5% compared to 32.4% in infants without PROM (P<0.01). When infants (<2,000 g) delivered vaginally without PROM were compared with those delivered by elective Cesarean section, no difference in HMD-incidence was observed. Out of 43 infants with birthweight above 2,000 g, who developed HMD during the 5-year period the majority had been delivered by elective Cesarean section. The possible effect of fetal stress on lung maturation is discussed.