Delivery room blood pressure percentiles of healthy,singleton, liveborn neonates

Background: Arterial blood pressure (BP) is one of the four vital signs that reflect cardiovascular status in neonates. The present study aimed to obtain BP percentiles among healthy, singleton, liveborn neonates between 34 and 43 weeks of gestation who were less than 1 h old. Methods: BP measurements were taken after birth in supine‐positioned neonates in the delivery room using an oscillometric device. A total of 982 well‐nourished neonates who did not require resuscitation, were not fetally malnourished, were not admitted to the neonatal intensive care unit and were without obvious congenital abnormalities were included in the study. Results: Sex‐ and type‐of‐delivery‐specific 5th and 95th percentiles BP measurements were obtained for gestation. Mean BP values for systolic, diastolic and mean of term neonates were 63.98 ± 12.29 mmHg, 38.34 ± 11.06 mmHg and 49.32 ± 11.33 mmHg, and late preterm neonates were 61.80 ± 12.46 mmHg, 33.17 ± 9.97 mmHg and 46.52 ± 10.8 mmHg, respectively. There were weak but significant correlations between birthweight, birth length and head circumference and systolic, diastolic and mean arterial BP values (r = 0.20, r = 0.15 and r = 0.20, respectively, P < 0.001). Neonates who were delivered vaginally had higher mean BP values for systolic, diastolic and mean than neonates delivered by cesarean section (P < 0.05). Female neonates had higher systolic BP values than male neonates (P < 0.05). Conclusion: Data presented in this study include sex‐ and delivery‐mode‐specific BP percentile curves using an oscillometric method and serve as a valuable reference for physicians in dealing with the management of singleton, liveborn late preterm and term newborns in the delivery room intensive care.     

Morphine in ventilated neonates: its effects on arterial blood pressure

OBJECTIVE: To study the effects of continuous morphine infusion on arterial blood pressure in ventilated neonates. DESIGN: Blinded randomised placebo controlled trial. SETTING: Level III neonatal intensive care unit in two centres. PATIENTS: A total of 144 ventilated neonates. Inclusion criteria were postnatal age <3 days, ventilation <8 hours, and indwelling arterial line. Exclusion criteria were severe asphyxia, severe intraventricular haemorrhage, major congenital anomalies, neuromuscular blockers. INTERVENTION: Arterial blood pressure was measured before the start and during the first 48 hours of masked infusion of drug (morphine/placebo; 100 microg/kg + 10 microg/kg/h). OUTCOME MEASURES: Arterial blood pressure and blood pressure variability. RESULTS: There were no significant differences in overall mean arterial blood pressure between the morphine group (median (interquartile range) 36 mm Hg (6) and the placebo group (38 mm Hg (6)) (p = 0.11). Although significantly more morphine treated patients (70%) showed hypotension than the placebo group (47%) (p = 0.004), the use of volume expanders and vasopressor drugs was not significantly different (morphine group, 44%; placebo group, 48%; p = 0.87), indicating the limited clinical significance of this side effect. Blood pressure variability was not influenced by routine morphine analgesia (p = 0.81) or additional morphine (p = 0.80). Patients with and without intraventricular haemorrhage showed no differences in blood pressure (Mann-Whitney U test 1953; p = 0.14) or incidence of hypotension (chi(2) test 1.16; df 1; p = 0.28). CONCLUSIONS: Overall arterial blood pressure, use of inotropes, and blood pressure variability were not influenced by morphine infusion. Therefore the clinical impact of hypotension as a side effect of low dose morphine treatment in neonates is negligible.     

足月新生儿脐血血清游离卡尼汀浓度及相关因素研究

目的了解足月新生儿脐血血清游离卡尼汀浓度及其相关影响因素。方法收集2004年11月至2005年2月出生的足月新生儿89例,男46例,女43例。平均胎龄(39.4±0.9)周,出生体重(3427.2±414.4)g,身长(49.8±2.5)cm,头围(34.8±1.4)cm,Apgar评分为8~10分。平产50例,剖宫产39例。于出生后即采集脐血2ml,用高效液相(HPLC)法测定脐血血清中卡尼汀浓度。结果89例正常新生儿平均脐血血清卡尼汀浓度为(52.2±22.9)μmol/L。其中男性组为(49.3±18.7)μmol/L,女性组为(55.3±26.5)μmol/L,两者之间差异无显著性(P=0.216);平产组为(52.4±24.5)μmol/L,剖宫产组为(51.9±20.9)μmol/L,两者之间差异无显著性(P=0.924)。根据新生儿出生体重分为<3000g(11例)、3000~3999g(68例)和≥4000g(10例)3组,其血清卡尼汀平均值分别为(61.5±26.2)μmol/L、(52.0±23.1)μmol/L和(42.8±12.3)μmol/L。脐血卡尼汀浓度与出生体重呈负相关(r=-0.239,P=0.026);与孕母年龄、新生儿胎龄、身长和头围无相关性。结论本组足月新生儿脐血血清卡尼汀浓度为(52.2±22.9)μmol/L,与新生儿出生体重呈负相关,与孕母年龄、新生儿胎龄、身长、头围、性别和分娩方式无相关性。     

Pulmonary artery pressure in term and preterm neonates

Systolic pulmonary artery pressure (PAP) during the first 4 days after birth was determined in 41 healthy term and 46 preterm infants by measuring ductal Doppler flow velocity and systemic arterial pressure (SAP). Among preterm infants, 21 had respiratory distress syndrome (RDS) and 25 did not. Sequential indices within 96 h of age were presented respectively. At the ages of 2 and 12 h the ratio between pulmonary and systemic arterial pressure was significantly higher in term than in preterm infants without RDS ( p < 0.05). At the age of 24 h, PAP to SAP ratio was similar in all study groups. Between 48 and 72 h, PAP to SAP ratio was significantly higher in preterm infants with RDS than in infants without RDS ( p < 0.05). Our findings indicated that: (1) in healthy fullterm infants pulmonary artery pressure fell to subsystemic level during the first 12 h. indicating the critical time in circulatory transition; (2) prematurity did not affect ductal closure times significantly; and (3) RDS was associated with prolonged ductal patency and delayed postnatal circulatory adaptation characterized by pulmonary hypertension.     

Alterations of intracranial pressure and cerebral blood flow velocity in healthy neonates and their implication in the origin of perinatal brain damage

Intracranial pressure and cerebral blood flow velocity were recorded in term healthy neonates during the first 3 days of life using non-invasive methods (LADD-fontanometry and cw-Doppler sonography). Intracranial pressure increased from 4.0±2.7 cm H₂O to 5.8±2.7 cm H₂O and maximal cerebral blood flow velocity in the anterior cerebral artery (ACA) increased from 33 cm/s to 58 cm/s as calculated from a Doppler shift of 0.63 to 1.10 kHz and vascular resistance decreased between the 1st and 3rd day of life. These alterations could not be demonstrated in the femoral artery. This is in accordance with other registrations obtained by different methods and under various conditions. They allow an explanation of some well known physiological phenomena like alterations of cranial volume and the structure of the bony skull in the first days of life. Furthermore, these physiological variations may have implications for the origin of cerebral damage during the perinatal period, especially of hypoxic-ischaemic encephalopathies.Abbreviations ACA anterior cerebral artery - CA carotid artery - FA femoral artery - IP intracranial pressure - MFV mean flow velocity - PI pulsatility index (Pourcelot) - REM rapid eye movements sleep state - TAM time-average-mean - V cranial volume     

Home blood pressure in children and adolescents: a comparison with office and ambulatory blood pressure measurements

Aim: To compare BP measurements of children and adolescents using different methods office BP (OBP), ambulatory BP monitoring (ABPM) and home BP measurement (HBPM) and to study their correlations. Method: Individuals were evaluated between 5 and 15 years of age who had been referred because of a previous high BP. OBP was measured with the OMRON‐705CP. Three measurements were carried out at 5‐min intervals. HBPM were taken using the same device, two measurements at 5‐min intervals in the morning and in the evening during 7 days. ABPM was performed using the SpaceLabs 90207 monitors. Results: A total of 109 children and adolescents were evaluated (9.82 ± 2.63 years), 52.3% boys, 56.9% non‐white. The office systolic BP (SBP) was lower than in daytime ABPM (p < 0.001) but similar HBPM (p = 0.294), and the office diastolic BP (DBP) was lower than daytime ABPM (p < 0.001) and in HBPM (p = 0.035). The SBP and DBP at HBPM was lower than daytime ABPM (p < 0.001). Daytime ambulatory BP was more closely associated with home readings (SBP r = 0.731 and DBP r = 0.616) than with office’s readings (SBP r = 0.653 and DBP r = 0.394). Conclusion: The BP of children and adolescents varies depending on the place and manner of measurement. ABPM presents better correlation with HBPM than with the office measurements.     

Nucleated red blood cell counts and erythropoietin levels in high-risk neonates

BACKGROUND: The presence of increased numbers of nucleated red blood cells (NRBC) and increased levels of erythropoietin (EPO) in the circulation of neonates has been associated with states of relative hypoxia. The aim of this study is to assess the pattern of NRBC counts and EPO levels in a group of high-risk neonates under stress conditions and determine the short-term outcome for these babies by using these parameters. METHODS: There were 69 high-risk neonates; 14 intrauterine growth retarded (IUGR), 25 preterm infants, 18 term infants with asphyxia and 12 infants of diabetic mothers. Control groups included healthy, term infants delivered either vaginally (n = 18) or with cesarean section (n = 19). Three blood samples were obtained from each infant within 12 h (initial), 3 days and 7 days after birth to measure NRBC counts and EPO levels. Neonatal and short-term outcomes at 3 and 6 months of age were determined. RESULTS: There was no significant difference among the groups with regard to the initial serum EPO concentrations. The initial NRBC counts were significantly lower in the control groups compared with the study groups (P = 0.002). While there was no significant difference between patients with good and poor outcome in terms of EPO concentrations of initial samples, a significant difference existed in terms of NRBC counts (P = 0.038). CONCLUSIONS: Both serum EPO level and NRBC count provide limited clinical benefit in the detection of pathological conditions of the neonatal period, but NRBC count determination seems to be especially helpful in predicting short-term neurodevelopmental outcome.     

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目的探讨全自动换血术对高胆红素血症新生儿血液学指标的影响,评估其疗效与安全性以及间接胆红素和白蛋白比值的临床意义。方法 2008年1月至2010年5月南方医科大学南方医院对74例重症高胆红素血症患儿均采用周围动静脉同步换血术,监测换血前后胆红素、白蛋白、间接胆红素与白蛋白比值、电解质、血常规。结果血中胆红素、白蛋白、间接胆红素与白蛋白比值、电解质(Na+、K+、Cl-、Mg2+)、血常规换血后均较换血前明显下降,但Ca2+、P3+浓度换血后较换血前升高,差异均有统计学意义。换血术后无患儿发生不良反应。结论换血对胆红素、白蛋白、间接胆红素与白蛋白比值、Na+、K+、Cl-、Mg2+、Ca2+、P3+、白细胞、红细胞、血红蛋白、红细胞压积、血小板均有影响,应注意监测。特别要注意监测间接胆红素与白蛋白比值,该比值是评估胆红素毒性的危险指标。比值越高,其危险性越高,越需要输注白蛋白。     

ABPM vs office blood pressure to define blood pressure control in treated hypertensive paediatric renal transplant recipients

While 24-h ambulatory blood pressure monitoring (ABPM) is an established tool for monitoring antihypertensive therapy in adults, data in children are scarce. We retrospectively analysed whether office blood pressure (BP) is reliable for the diagnosis of BP control in 26 treated hypertensive paediatric renal transplants. Controlled office BP was defined as the mean of three replicate systolic and diastolic BP recordings less than or equal to the 95th age-, sex- and height-matched percentile on the three-outpatient visits closest to ABPM. Controlled ABPM was defined as systolic and diastolic daytime BP < or =95th distribution adjusted height- and sex-related percentile of the adapted ABPM reference. Eight recipients (30%) with controlled office BP were in fact categorized as having non-controlled BP by ABPM criteria. Overall, when office BP and ABPM were compared using the Bland and Altman method, the 95% limits of agreement between office and daytime values ranged from -12.6 to 34.1 mmHg for systolic and -23.9 to 31.7 mmHg for diastolic BP, and the mean difference was 10.7 and 3.9 mmHg respectively. Office readings miss a substantial number of recipients who are hypertensive by ABPM criteria. Undertreatment of hypertension could be avoided if ABPM is applied as an adjunct to office readings.     

Feasibility of using finger arterial pressure in neonates

The feasibility of using a Finapres device to reproduce the beat to beat signal of arterial blood pressure in eight neonates was assessed and compared with intra-arterial measurement of arterial blood pressure in the umbilical artery, using a catheter. The two methods gave similar results. Continuous recording of arterial blood pressure in neonates using Finapres is feasible and reliable.

     

Comparison of Dinamap 8100 with sphygmomanometer blood pressure measurement in a prepubertal diabetes cohort

OBJECTIVE: To compare the conventional sphygmomanometer with the semiautomated Dinamap 8100 (Critikon, Tampa, FL, USA) for the measurement of blood pressure in prepubertal children with insulin-dependent diabetes mellitus. METHODOLOGY: Blood pressure was measured using both methods in 61 prepubertal children (aged 8-13 years) on 189 occasions over 4 years. The measurements were compared using the Bland-Altman plot. Tracking correlations of blood pressure centiles over time were analyzed by the general estimating equation. RESULTS: Accuracy criteria of the Association for the Advancement of Medical Instrumentation were met and a British Hypertensive Society 'B' grading was reached. Differences in systolic and diastolic blood pressure were found between the two methods (P < 0.01). For systolic blood pressure, common correlations were 0.54 (Dinamap) and 0.51 (sphygmomanometer) and for diastolic blood pressure were 0.33 and 0.42, respectively. CONCLUSION: The Dinamap 8100 is an acceptable alternative in clinic practice and research for prepubertal children.     

Premedication for neonatal intubation in Australia and New Zealand: A survey of current practice

Aim: This study aims to describe the current approach to intubation premedication in neonatal intensive care units (NICUs) in Australia and New Zealand Methods: A literature review regarding intubation premedication in the newborn was carried out to inform questionnaire design. A web‐based survey of 28 NICUs and two neonatal emergency transport services was conducted and supplemented by telephone contact to ensure completion. Results: All the tertiary NICUs and neonatal emergency transport services in Australia and New Zealand use premedication for elective intubation of neonates. Eighty per cent of units have a written policy. There were 28 of 30 units (93%) that use muscle relaxants, mostly suxamethonium. The choice of sedative medication is varied. Conclusions: Australian and New Zealand neonatal units have a high use of intubation premedication including muscle relaxants, but vary considerably in their choice of sedative medication.     

Effect of body tilting on physiological functions in healthy term neonates

The effect of body tilting on physiological functions was studied in 32 healthy, full–term neonates at 2 and 24 h of age. The neonates were placed in the supine position and the physiological functions were measured in the sequence of –30^o (head–down), 0^o and 30^o (head–up) tilts. Arterial oxygen saturation and respiratory rate were comparable in the vaginal delivery and caesarean section groups. The baroreceptor responses were similar in the neonates delivered vaginally and by caesarean section. Mean heart rate increased on 30^o up tilting and the responses tended to be larger at 24 h compared with those at 2 h of age, but these differences were not significant. At 2 h of age, mean systolic and diastolic blood pressures decreased on 30^o up tilting. At 24 h of age, mean systolic and diastolic pressures decreased on up tilting (from –30^o to ^o) and the values were sustained on further up tilting (from –0^o to 30^o). The present results indicate that baroreceptor reflexes are present from birth and the responses tend to be less developed at 2 h than those at 24 h of age.     

Blood pressure in the neonate: three non-invasive oscillometric pressure monitors compared with invasively measured blood pressure

AIM: To compare blood pressure in neonates obtained from three different oscillometer blood pressure monitors (Dinamap, Criticare, Hewlett-Packard) with arterial blood pressure (Hewlett-Packard' invasive unit). STUDY DESIGN: A total of 32 randomized, non-invasive blood pressure series, each consisting of three measurements from each monitor, were obtained from 20 neonates (birthweight 531-4660 g). Each measurement was compared with the invasive pressure. RESULTS: Two factors appear to have a systematic effect on the difference between oscillometric and invasive pressure (the measurement deviance): the size of the infant, e.g., the arm circumference, and the monitor system. For small infants, the non-invasively measured value tends to be too high. The deviance is partly reversed for larger infants (dependency on size significant for mean and diastolic pressure, p < 0.001). The difference between monitor systems is clearly significant (p < 0.001). Hewlett-Packard gives the lowest pressure values for all pressures. Thus, Criticare and Dinamap tended to show values too high in the smallest infants, while Hewlett-Packard tended to give values too low in larger infants. Birthweight, present weight and arm circumference affected measurement deviance approximately equally strongly, while factors such as the infant's sex, need of breath support and umbilical or radial arterial line were non-significant. CONCLUSIONS: Blood pressure should preferably be measured invasively in severely ill neonates and preterm infants, being aware of pitfalls with measurements using different oscillometer monitors and the size/arm circumference of the infant.     

Twenty-four hour blood pressure monitoring in healthy children

Blood pressure and heart rate were measured every 20 min during the day and every 30 min during the night in 105 children (51 girls and 54 boys, aged 6–10 years) with a portable automated blood pressure monitor using an oscillometric principle of measurement. The monitor was well accepted by most of the children and the rate of invalid measurements was only 13%. Mean systolic and diastolic blood pressure was 114±7/72±5 by day and 99±7/56±6 by night. The corresponding heart rates were 93±8 and 72±9 beats/min. No significant differences were found between boys and girls. At night, systolic blood pressure dropped by 13%±4%, the diastolic value by 22%±7% and heart rate fell by 22%±6%. Mean systolic and diastolic blood pressure measurements correlated positively with the subject's height, whereas no correlation was found with age.     

脐血心钠素在监测高危新生儿水钠平衡中的意义

目的：心钠素(ANP)是一种具有多种功能的内分泌激素,其过度分泌可造成低钠血症。该文探讨脐血ANP测定在监测高危新生儿水钠平衡中的作用和临床意义。方法：选择117例高危新生儿依据Apgar评分的不同分为两大组,即单纯窒息组及评分正常组。单纯窒息组又分为轻度窒息组和重度窒息组,评分正常组又分为感染组和非感染组,另设40例正常新生儿为对照组。各组均在新生儿娩出后立即抽取脐血,应用放射免疫法测定ANP水平,同时抽取静脉血测定患儿的血清钠含量,并分别与对照组比较。结果：高危新生儿的脐血ANP水平明显高于正常新生儿,尤以早产儿1.46±0.39 ng/mL、严重感染新生儿1.16±0.35 ng/mL及重度窒息新生儿2.12±0.46 ng/mL增高最为明显(P<0.01)。而与其相对应的则是血清钠水平的下降,两者呈显著负相关。结论：高危新生儿脐血心钠素增高明显,易致低钠血症,早期测定可对新生儿抢救与治疗起到指导作用。     

Maternal blood pressure in pregnancy and newborn irritability

The neonatal period is being recognized as an important period for the development of patterns of interaction between mother and infant, and infant state has been shown to have a significant impact on mother-infant interactions. A major dimension of infant state, with implications for this interaction and for the development of later behaviour disorders, is the infant's irritability. Research with Navajo, Malay, Chinese and Tamil mothers and infants showed that normal variation in maternal blood pressure during pregnancy was related to newborn irritability as assessed with the Brazelton Scale. This relationship is discussed in terms of possible underlying mechanisms.     

动态血压在儿科的应用

动态血压监测能真实反映患者24h血压的平均水平、日常生活的血压变化和昼夜节律变化,较传统的血压监测有明显的优势.研究已经确定其在识别儿童白大衣性高血压及隐匿性高血压、预测靶器官损害、评价降压药物疗效、鉴别原发性高血压及继发性高血压等方面有一定价值.该文简述动态血压监测在儿科的临床应用.     

Breastfeeding duration and blood pressure among Brazilian adolescents

Objective: To assess the relationship between breastfeeding duration and blood pressure in a large birth cohort of Brazilians followed from birth to adolescence. Methods: All 5914 hospital births occurring in Pelotas in 1982 (over 99% of all deliveries) were studied prospectively. Detailed information on feeding practices was prospectively collected during childhood. In 1997 and 2001 we attempted to trace a sample of the cohort, whereas in 2000 we identified the male subjects when presenting for the army recruitment exam. Blood pressure measurements were taken in 1997 for both sexes, males in 2000 and females in 2001. Results: Information on breastfeeding collected between 1983 and 1986 was available for 90.8% of the 5914 original cohort subjects. We managed to follow 1076, 2250 and 1031 subjects in 1997, 2000 and 2001, respectively. Total breastfeeding duration was not associated with systolic and diastolic blood pressure in adolescence. Diastolic blood pressure at the age of 15 y (1997) was higher among girls who had been predominantly breastfed for at least 4 mo. After controlling for confounding variables (family income, maternal education at birth and maternal BMI at birth, skin colour, birthweight, gestational age, maternal smoking during pregnancy, adolescent smoking and alcohol drinking), the strength of the association was reduced and the 95% confidence interval encompassed the other blood pressure estimates. Furthermore, such association was not replicated in the 2001 follow-up visit.

Conclusion: Breastfeeding duration was not related to blood pressure in adolescence.