Effects of intralipid infusion on blood viscosity and other haemorheological parameters in neonates and children

Aim: To study acute haemorheological effects of intralipid in preterm and full-term neonates and children. Circulatory complications of intralipid infusion, such as increases in pulmonary and peripheral flow resistance, have been associated with impaired blood rheology. Methods: During total parenteral nutrition, 10 preterm infants, 10 full-term neonates and 10 children received an initial dose of intralipid as continuous infusion (0.6 g/kg) over 4 h. Additionally, blood of 10 healthy preterm infants, 10 full-term neonates and 10 adults was incubated with intralipid. Whole blood and plasma viscosity (capillary viscometer), red blood cell (RBC) deformability (rheoscope) and RBC aggregation (Myrenne aggregometer) were measured before and after intralipid infusion and before and after in vitro incubation of blood with intralipid. Results: During intralipid infusion, plasma triglyceride levels increased from 0.13 ± 0.27 to 2.16 ± 0.68 g/l in the preterm infants, from 0.14 ± 0.21 to 1.64 ± 0.54 g/l in the full-term neonates and from 0.65 ± 0.31 to 2.26 ± 0.60 g/l in the children. Whole blood viscosity decreased by about 10% after intralipid in all three groups due to similar decreases in haematocrit. RBC aggregation decreased by about 20% after intralipid infusion. Plasma proteins, plasma viscosity and RBC deformation were not affected by intralipid. In vitro incubation of blood with intralipid resulted in a marked reduction of RBC aggregation that was related to the intralipid concentration. At intralipid concentrations of 4 and 8 mg/ml, no RBC aggregation was noted in preterm and full-term neonates. In adults, RBC aggregation decreased by 50%.

Conclusions: Previously described deleterious effects of intralipid on circulation can not be explained by changes in haemorheological properties.     

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)     

The effect of intra-partum and intra-uterine asphyxia on placental transfusion in premature and full-term infants

Blood volume and its components were estimated using ¹²⁵iodinated human serum albumin in 194 newborn infants with 26 to 41 week gestations. Umbilical cords were ligated 15 seconds after vaginal delivery (n=141) and within 5 seconds after delivery by Caesarean section (n=53). The infants were divided into four groups according to the mode of delivery and presence of prenatal complications: group I: vaginal deliveries (n=96) and group II: Caesarean section (n=25) without preceding complications; group III: infants with intra-uterine asphyxia (n=56); group IV: infants with tight umbilical cord loops around neck (n=17). Subgroups were established with respect to gestational age and to one-minute Apgar scores. Significantly different blood volume (BV) and red cell mass (RCM) values between the subgroups were only found in group I with respect to different Apgar scores: Ia Apgar>5: BV 77.9±6.2; RCM 37.5±5.1 ml/kg; Ib Apgar<6: BV 70.0±4.4; RCM 29.6±2.9 ml/kg (P<0.005). Intra-partum asphyxia did not affect BV (71.3±4.8 ml/kg) and RCM (31.2±3.6 ml/kg) in group II. BV and RCM were significantly (P<0.005) lower than in group Ia. In group III, BV (90.4±7.0 ml/kg) and RCM (46.9±6.3 ml/kg) were significantly (P<0.005) higher than in group I, irrespective of the mode of delivery and Apgar scores. The infants of group IV had the lowest volumes (BV 67.5±5.7; RCM 27.4±2.7 ml/kg). Values obtained in premature and full-term infants were similar in the respective groups. These results indicate that infants with intra-partum asphyxia and with tight nuchal cords do not participate in placental transfusion or even lose some blood into the placenta. However, infants with intrauterine asphyxia (excepting those with tight nuchal cords) receive marked placental transfusion in utero.Supported by Deutsche Forschungsgemeinschaft, SFB 147     

Short-term effects of blood transfusion on blood volume and resting peripheral blood flow in preterm infants

The effects of blood transfusion on cardiac output and blood pressure are variable, but resting peripheral blood flow (RPBF) may be a sensitive indicator of changes in blood volume. The purpose of this investigation was to study the effects of red cell transfusion on blood volume (Evans blue), blood pressure, RPBF in the leg (strain-gauge plethysmography) and blood viscosity (cone-plate viscometer) in preterm infants during the first week after birth. Fourteen infants with mean ± SD birth weight of 1658 ± 429 g, gestational age 33 ± 3 weeks and postnatal age 64 ± 40 h received 18 ±4 ml/kg of packed red cells (red cells 11±2 ml/kg, plasma 7± 1 ml/kg) because their hematocrit was less than 0.45 l/l. Mean blood volume before transfusion was 88±15 ml/kg. The increase in blood volume (9 ±4 ml/kg) measured 4 to 6 h after transfusion was smaller than the transfused volume (18 ± 4 ml/kg), due to a shift of plasma to the extravascular space. The plasma shift increased with increasing pretransfusion blood volume ( r = 0.70; p = 0.007). Red cell transfusion caused an increase in RPBF by 25% ( p <0.01), whereas systolic blood pressure (BP) increased by only 12%. Peripheral resistance (R = BP/RPBF) decreased by 9% (p<0.01). Blood viscosity (±) increased by 21'% ( p <0.001) and vascular hindrance (R/±) decreased by 24% ( p < 0.001), indicating vasodilatation of limb arteries. The increase in RPBF and the decrease in hindrance were particularly pronounced in infants with high pretransfusion blood volume. We conclude that the increase in blood volume after transfusion is not proportional to the transfused volume and that RPBF increases more than systolic blood pressure with increasing blood volume. The increase in RPBF can be explained by vasodilatation of limb arteries and by increased blood pressure.     

延迟钳夹脐带对早产儿早期血容量影响的临床研究

目的 探讨延迟钳夹脐带对早产儿早期血容量的影响.方法 将2007年10月至2010年6月在东莞市石龙博爱医院产科经阴道分娩的194例早产儿随机分为两组,即常规钳夹脐带组100例和延迟钳夹脐带组94例.比较分析两组经阴道分娩早产儿的钳夹脐带时间,生后24h、48h、72 h的Hb、RBC、红细胞压积、血压、血氧饱和度和贫血的发生率,以及生后第1天、第2天、第3天和第7天的静脉血胆红素值.结果 延迟钳夹脐带组脐带钳夹时间为(100.14±10.57)s,常规钳夹脐带组脐带钳夹时间为(22.40±5.02)s,两组脐带钳夹时间比较差异有统计学意义(P＜0.005).延迟钳夹脐带组早产儿生后前3 d的Hb及血压均比常规钳夹脐带组高,两组比较差异有统计学意义(P＜0.05).延迟钳夹脐带组94例早产儿中,3 d内发生贫血3例,发生率为3.19%,常规钳夹脐带组100例早产儿中,3 d内发生贫血11例,发生率为11.00%,延迟钳夹脐带组贫血发生率低于常规钳夹脐带组(P＜0.05).两组早产儿出生后7 d内的静脉血胆红素值比较无明显差异(P＞0.05).结论 延迟钳夹脐带对早产儿Hb及血压有明显影响,可提高阴道分娩早产儿早期血容量,减少早产儿早期贫血的发生.     

新生儿不同浓度红细胞换血治疗疗效及对内环境的影响

目的探讨新生儿换血治疗时不同红细胞和血浆比例对疗效及内环境(血细胞计数、电解质、血糖及酸碱平衡)的影响。方法回顾分析2015年1月至2018年12月经换血治疗的149例高胆红素血症新生儿的临床资料,根据换血时红细胞与血浆的比例分为2:1组(红细胞2 U﹕血浆100 mL,62例)和3:1组(红细胞3 U﹕血浆100 mL,87例)。探讨两组换血当时至12小时的血清总胆红素(TSB)下降程度、换血后继续光疗时间及再次换血比例的差异,比较换血前后两组新生儿血常规、电解质、血糖及血气分析的变化。结果两组新生儿的胎龄、出生体质量、性别及换血日龄等差异均无统计学意义(P0.05);两组在换血结束时及换血后12小时TSB的下降程度,继续光疗时间及再次换血比例的差异均无统计学意义(P0.05)。换血后,3:1组的RBC(3.7±0.4 vs 4.7±0.3)与Hb(118.9±12.1 vs 157.8±14.3)显著上升;同时,换血后两组新生儿的WBC、PLT、血清钠、HCO~-_3水平降低,而血清钾、血清钙、血糖浓度升高,差异均有统计学意义(P0.05);但两组间各指标的变化差异均无统计学意义(P0.05)。两组新生儿间常见换血并发症以及急性胆红素脑病和核黄疸的发生率差异无统计学意义(P_均0.05)。结论红细胞与血浆以2:1或3:1混合均可有效治疗新生儿高胆红素血症。3:1比例混合血可有效纠正贫血,且未加重换血后机体内环境的紊乱。     

延迟脐带结扎对新生儿近远期影响的研究进展

新生儿娩出后通过脐带结扎与母体分离,临床上比较传统的做法是生后立即结扎脐带,但是随着对脐带结扎时间的深入研究,延迟脐带结扎的优势已经引起了人们的重视.该文围绕延迟脐带结扎分别对早产儿和足月儿的近远期影响这一课题进行探讨,发现延迟脐带结扎可以促进新生儿胎盘输血,使血容量增加,从而改善了新生儿的贫血状态,促进了循环与内环境的稳定,且未发现延迟脐带结扎对新生儿有不良影响.     

The effect of maternal and infant factors on cord blood yield

Umbilical cord blood (CB) can be used as an alternative hematopoietic stem cell source for transplantation in hematological malignancy and blood disorders. The success of transplantation is highly related to the levels of total nucleated cell and CD34⁺ cell counts. The evaluation of optimal conditions can decrease the rate of graft rejection due to low cell count and increases the quality of CB units (CBUs) in the blood bank and the success rate of engraftment. To this end, we review the maternal and infant parameters affecting the quality and quantity of CBUs.     

Influence of plasma preparations and donor red blood cells on the antioxidant capacity of blood from newborn babies: an in vitro study

We investigated in an in vitro transfusion model the early effects of plasma preparations and donor red blood cells on the antioxidant capacity of the cord blood from babies. Addition of pasteurized plasma protein solution to plasma from babies decreased the peroxyl radical trapping capacity (p <0.02). In contrast, fresh frozen plasma did not lower this capacity. Addition of adult donor red blood cells to the babies' red blood cells did not significantly decrease the glutathione-recycling capacity of the blood. On the basis of these in vitro results we hypothesize that the use of resuscitation fluids with low antioxidant capacity may temporarily decrease the ability of the baby to catabolize reactive oxygen species.     

红细胞储存时间对高胆红素血症新生儿换血治疗的疗效及内环境的影响

目的 探讨不同储存时间的红细胞对高胆红素血症新生儿换血治疗的疗效及内环境的影响。方法 回顾性分析2015年1月至2018年8月经换血治疗的135例高胆红素血症新生儿的临床资料,按输入红细胞的储存时间分为短期储存组（储存时间≤ 7 d,n=56）和长期储存组（储存时间 > 7 d,n=79）。比较两组患儿换血后0 h、12 h的血清总胆红素（TBIL）水平与TBIL下降率,以及换血后继续光疗时间及再次换血率。比较分析两组患儿换血前及换血后0 h的血常规、电解质、血糖及血气分析指标的变化。结果 换血后0 h,两组患儿TBIL水平及TBIL下降率比较差异无统计学意义（P > 0.05）;换血后12 h,长期储存组TBIL水平高于短期储存组,TBIL下降率低于短期储存组（P < 0.01）;长期储存组换血后的继续光疗时间更长（P < 0.05）;长期储存组低血钠、高血钾及代谢性酸中毒等换血并发症的发生率较短期储存组增加（P < 0.05）。结论 使用储存时间 > 7 d的红细胞输入不影响新生儿换血治疗的即时效果,但换血后继续光疗效果较差,亦增加了低血钠、高血钾及代谢性酸中毒的发生风险。