母血-脐血及母乳中维生素E含量及其相关性的探讨

目的：考察胎盘、乳腺对维生素E的运转状况。方法：配对测定了12名健康孕产妇血中、母乳中及新生儿脐血中的维生素E浓度,比较其水平并进行相关性分析。结果：母血中维生素E浓度为16.23 mg/L,脐血和母乳分别为2.72 mg/L和9.12 mg/L,其维生素E水平高低依次为母血>母乳>脐血。母血—脐血间维生素E浓度的相关性分析为r=0.30,P>0.5,两者间无相关性;母血—母乳间维生素E浓度的分析提示：r=0.44,P<0.2,两者间存在弱相关性。结论：胎盘对维生素E的转运能力低下;而乳腺对维生素E具有较强的转运能力,围产期保持孕产妇良好的维生素E营养水平有利于提高母乳中维生素E含量,对改善新生儿维生素E营养状况有重要意义。     

Peripheral circulation in the newborn: Interaction of peripheral blood flow,blood pressure,blood volume,and blood viscosity

Peripheral blood flow and systolic blood pressure (strain-gauge plethysmograph), blood volume (Evans blue) and whole blood viscosity (cone-plate viscometer) have been measured in 66 premature and full-term infants 6 to 144h of age. Blood flow and blood volume were moderately decreased in the infants with respiratory distress. Highly significant (P<0.001) correlations were found betwen blood flow and blood volume (r=0.77), blood pressure and blood volume (r=0.50), peripheral resistance and blood volume (r=-0.44), blood flow and blood pressure (r=0.50), blood flow and peripheral resistance (r=-0.67), peripheral resistance and blood viscosity (r=0.45), and blood viscosity and haematocrit (r=0.86). There was no correlation between peripheral blood flow and blood viscosity. However, at given blood volume, peripheral blood flow decreased with increasing blood viscosity. These results indicate that in newborn infants peripheral blood flow, blood pressure and peripheral resistance are influenced by blood volume, but also depend on blood viscosity.Supported by Deutsche Forschungsgemeinschaft (SFB 147)     

Serum zinc and copper levels in the maternal blood and cord blood of neonates

Estimation of serum zinc and copper in the maternal blood and cord blood of neonates was carried out to correlate the trace metals in the neonates and their mothers in relation to gestational age and birth weight. Sixty-five healthy neonates, both term and preterm and their mothers were selected. This cross sectional study was done at Azimpur Maternity Centre, Dhaka Medical College Hospital and Chemistry Division, Atomic Energy Centre, Dhaka, Bangladesh from July 1997 to June 1998. The estimation of trace metals was carried out by Atomic Absorption Spectrophotometry (AAS). The mean serum zinc levels in the maternal blood and cord blood were 0.47 ± 0.24 μg/ml and 0.85 ± 0.33 μg/ml respectively and the mean copper levels in the maternal blood and cord blood were 1.37 ± 0.62 μg/ml and 0.31 ± 0.32 μg/ml respectively. Cord blood zinc level was significantly higher and cord blood copper level was significantly lower than the corresponding maternal blood levels. There was no significant correlation between gestational age and serum zinc levels in the cord or maternal blood. But significant inverse correlation was found between gestational age and serum levels of copper in the maternal and cord blood.     

Cord blood gases and absence of end-diastolic blood velocities in the umbilical artery

Umbilical artery and vein blood gases were compared in three groups of pregnant women delivered by elective caesarean section: group 1 (n = 21), normal controls; group 2 (n = 15), complicated pregnancies with normal umbilical artery blood flow velocity waveforms; and group 3 (n = 14), complicated pregnancies with absent end-diastolic blood velocity in the umbilical artery. Newborns in group 3 were found to be small for gestational age and to have significantly lower oxygen pressure and saturation. These fetuses were thus in a state of chronic hypoxia, which may predispose for development of intra-uterine distress. Doppler ultrasound examination can be useful in identifying this high risk group requiring intensified surveillance.     

Fluid, blood, and blood product management in the craniofacial patient.

This report is a retrospective review of the perioperative management of 56 children who underwent craniofacial surgical procedures. The use of a combination of 5% dextrose in normal saline or 5% dextrose in Ringer's lactate and normal saline resulted in postoperative sodium values in a normal range. In patients receiving a combination of 5% dextrose and electrolyte No. 48 and normal saline, the mean postoperative sodium level was 130 mEq/l with 9 of 18 patients below 130 mEq/l. Two patients in the series suffered clinical seizures on postoperative day 1 as a result of serum sodium levels of 122 and 121 mEq/l, respectively. We recommend that only solutions with a sodium content between 77 and 154 mEq/l be used routinely in the perioperative management of craniofacial patients.     

Normal blood pressures and the evaluation of sustained blood pressure elevation in childhood

A total of 3,861 school children in the age group 5-15 years were examined to establish the normative values for auscultatory blood pressure and to study the prevalence of sustained elevation of blood pressure in Indian children. Age-sex specific norms of systolic and diastolic blood pressure in the right upper limb were worked out. When the influence of age was minimised, the systolic and diastolic pressure still showed a positive correlation with height and weight. Two hundred and fifty five (6.60%) of the children screened were detected to have blood pressure level in excess of +2 SD of the mean for age and sex on first contact. The number declined to only 16 (0.41%) on re-evaluation 2 months after the initial contact. These 16 children continued to remain hypertensive during monthly follow up for 5 months. Family history of obesity, hypertension, or myocardial-infarction and/or stroke was met with in significantly higher (p less than 0.001) number of children with sustained hypertension as compared to normotensive students.     

Prostacyclin concentrations in cord blood and in the newborn

The levels of 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha) were measured in cord blood and in peripheral venous blood in newborns using gas chromatography coupled with negative ion chemical ionization mass spectrometry. The plasma concentrations of 6-oxo-PGF1 alpha in cord blood increased significantly between delivery and placental expulsion (P less than .005). In newborns, the circulation levels of 6-oxo-PGF1 alpha after four hours of life were low and comparable to adult levels. Large quantities of prostacyclin are produced by the uteroplacental unit during parturition, but only small amounts are transmitted to the newborn during a normal delivery. The low plasma concentrations of 6-oxo-PGF1 alpha in newborns suggest that prostaglandin I1 is not a circulating vasodilator during the first week of life.     

Use of blood and blood components and derivatives in newborn infants

OBJECTIVE: To describe the current rationale for the transfusion of blood, blood components, and plasma derivatives in term and preterm infants. SOURCES: Selection of relevant medical articles published within the last ten years. SUMMARY OF THE FINDINGS: Peculiar characteristics and special care concerning exchange transfusion, transfusion of red blood cells, platelets, granulocytes, and fresh frozen plasma were described. The recommendations for the use of hematopoietic growth factors, and plasma derivatives such as fibronectin, immunoglobulins, and albumin were also evaluated. CONCLUSIONS: The authors comment on the recommendations and contraindication of blood transfusions, and warn against the limitations and hazards involved.     

Hyperviscosity of the blood and haemostasis in the newborn infant

15 newborn infants with the hyperviscosity syndrome due to polycythaemia i.e. a central haematocrit of at least 65% and a raised whole blood viscosity, were examined for changes in their coagulation and fibrinolytic systems. 5 were thrombocytopenic but showed no other signs of activated coagulation. Neither did the only patient with positive ethanol gelation test measuring circulating fibrin/fibrinogen degradation products (FDP) appeared in only two and, with only one exception, an assay for fibrinolytic activity in plasma was negative. No defects were found in the coagulation system. Thus, in most of the patients there was no demonstrable abnormal proteolysis in the circulation. However, in such infants the normally low levels of antithrombin III (heparin cofactor activity) in combination with the impairment of the microcirculation might increase the risk of thrombotic complications. Haemodilution, preferably with plasma, is therefore advocated in the symptomatic patients.     

Comparison of blood gas values in arterial and venous blood

Objective : To compare pH and PCO₂ values of simultaneously obtained arterial, arterialized capillary, and venous blood samples and also to compare oxygen saturation (ASaO₂) measured in arterial blood and oxygen saturation by pulse oximetry (PSaO₂).Methods: Prospective study was done in the children admitted in the Pediatric Intensive Care Unit of Christian Medical College Hospital Vellore, requiring critical care. All the three blood gas samples (arterial, capillary and venous) were taken simultaneously and analyzed. Oxygen saturation by pulse oximetry was also recorded.Results: 50 children aged 14 days to 12 years were included in the study. Arterial and capillary pH values were highly correlated (r²=0.9024, p < 0.0001). Out of 16 children with arterial acidosis 9(56%) were identified by capillary blood gas. Arterial and venous pH values also showed good correlation (r²=0.8449, p eric 0.0001). The PCO₂ values of arterial and capillary blood gases were found to be highly correlated (r²=0.9534, p < 0.0001). The capillary blood gas accurately reflected the arterial PCO₂ in 41 (82%) patients. Arterial and venous blood gas PCO₂ values had less correlation (r²=0.5917, p=0.011). The arterial oxygen saturation (ASaO₂) and oxygen saturation by pulse oximetry (PSaO₂) were correlated moderately (r²=0.7241, p eric 0.0001).Conclusion: Even though arterial blood gas analysis is the gold standard, and when an arterial blood gas sample cannot be obtained, a combination of arterialized capillary blood gas and pulse oximetry can be effectively used in acutely ill children of all ages. Venous samples have a good correlation with arterial samples for pH but are not useful for monitoring blood gas status in acutely ill children.