Plasma thrombomodulin level in newborn infants with and without perinatal asphyxia

To determine whether vascular endothelial damage occurs in neonates with asphyxia, we examined the plasma thrombomodulin level at birth in infants with and without asphyxia. The plasma thrombomodulin concentration in 11 asphyxiated infants was significantly elevated compared with that in 48 infants without asphyxia (38.1 vs 27.0 μg/l, p < 0.0001). The plasma thrombomodulin-to-serum creatinine ratio was also significantly elevated (0.62 vs 0.48 μg/μmol, p = 0.0005). The plasma thrombomodulin concentration and the plasma thrombomodulin-to-serum creatinine ratio in infants without asphyxia did not differ between the two types of delivery: normal vaginal delivery and elective caesarean section. Stepwise regression analysis showed the serum D-dimer concentration, plasma pH and serum creatinine concentration were significant independent variables for plasma thrombomodulin concentration, whereas base deficit, platelet count, fibrinogen concentrations and antithrombin III activity were not. Our data suggest that vascular endothelial damage might occur in asphyxiated infants.     

Effect of Bifidobacterium administration on very‐low‐birthweight infants

Background: The aim of this study was to evaluate the efficacy and safety of early administration of Bifidobacterium bifidum OLB6378 (B. bifidum) on accelerating enteral feeding and bacterial colonization in very‐low‐birthweight (VLBW) infants. Methods: We conducted a single‐center prospective pilot study. Thirty‐six VLBW infants were randomly divided into two groups: group E, wherein B. bifidum was supplemented within 48 h of birth, and group L, wherein it was supplemented more than 48 h after birth. Results: Group E and group L reached a total feeding volume of 100 mL/(kg/day) after 10 [7–13] days and 11 [10–15] days, respectively (median [quartile]). The daily bodyweight gain in group E was significantly higher (21.4 ± 3.2 g/day vs 18.3 ± 4.0 g/day, P < 0.02; 11.1 ± 1.5 g/kg/day vs 10.4 ± 1.2 g/kg/day, P < 0.04). No significant differences were found in the fecal Bifidobacterium level between the groups quantitated with a real‐time polymerase chain reaction assay at 1 and 4 weeks of age. However, the highest colonization rate of Bifidobacterium was observed when the supplementation started between 24 and 48 h after birth. The incidence of morbidities between the groups was similar. Conclusion: The early administration of B. bifidum to VLBW infants seems effective in promoting growth during the stay in the neonatal intensive care unit without increasing the incidence of morbidity. Furthermore, the preferable timing of starting the probiotic supplementation for VLBW infants is at latest less than 48 h after birth.     

Development of the intestinal flora in very low birth weight infants compared to normal full-term newborns

Development of faecal flora was studied in seven very low birth weight (VLBW) infants, who were fed on human milk and whose birth weights ranged from 810–1350 g. The intestine of the VLBW infants was first colonised by enterobacteria and streptococci, as it was in full-term infants. VLBW infants differed, however, from full-term infants in that both types of organism continued to be predominant for a longer period, and establishment of bifidobacterial flora was retarded. Bifidobacteria first appeared in the stools of VLBW infants at a mean age of 10.6±2.7 days and became predominant at a mean of 19.8±8.9 days, in contrast to full-term, breast-fed infants in whom bifidobacterial flora appeared at as early as 4 days of age. The delay seemed to be related to the low milk intake of the VLBW infants.The number of viable staphylococci in the stools of VLBW infants was generally higher than that in full-term infants. Although emergence of Bacteroides, Clostridium and lactobacilli was delayed compared with full-term infants, differences in their occurrence and prevalence between VLBW and fullterm infants were not remarkable.Abbreviation VLBW very low birth weight     

Pulmonary hemorrhage in very low‐birthweight infants: Risk factors and management

Background: Beginning 2007, the intratracheal route of epinephrine to end massive pulmonary hemorrhage (MPH) in very low‐birthweight (VLBW) infants was modified at Kaohsiung Veterans General Hospital. The aim of the present study was to assess the change in outcomes for these infants, and to evaluate the risk factors of MPH. Methods: Using the database of the Premature Baby Foundation of Taiwan, the mortality, risk factors and characteristics of VLBW infants with or without MPH were compared between 2000–2006 and 2007–2010. Results: Between January 2000 and December 2010, 399 VLBW infants were admitted to Kaohsiung Veterans General Hospital. Mean birthweight (BW) was 1099.6 ± 272.7 g, and mean gestational age (GA) was 28.7 ± 2.9 weeks. The overall survival rate was 84.2%. Sixteen (4%) had MPH: 11 in the first group (2000–2006; 18.2% survival rate), and five in the second group (2007–2010; 80% survival rate; P= 0.0000002). Infants with MPH had lower mean BW (864.9 ± 301.4 g, P= 0.0004), smaller mean GA (26.1 ± 2.0 weeks, P= 0.0002), significantly lower Apgar scores at 1 and 5 min, higher severity of respiratory distress syndrome (RDS; grades 3 or 4), and greater use of surfactant than infants without MPH. They also had more intraventricular hemorrhage and higher mortality. Conclusions: Smaller GA, lower BW, lower Apgar scores at 1 and 5 min, severe RDS (grades 3 or 4), and use of surfactant place VLBW infants at greater risk of MPH. Proper prenatal care and preventing premature labor and delivery were the most important preventative factors. A quick, deep thrust of intratracheal epinephrine with a catheter may improve survival.     

Interleukin‐6 polymorphism and bronchopulmonary dysplasia risk in very low‐birthweight infants

Background: The aim of the present study was to evaluate the role of interleukin (IL)‐6‐634 polymorphism in neonatal disorders such as bronchopulmonary dysplasia (BPD) and periventricular leukomalacia (PVL) in very low‐birthweight (VLBW) infants. Methods: This prospective cohort study included 202 infants (gestational age at birth, 23–34 weeks; birthweight, 500–1499 g). Genotypic analysis (polymerase chain reaction–restriction fragment length polymorphism) was performed with DNA extracted from whole‐blood samples. Results: Genotype distribution (66.8% CC, 28.2% CG, 5.0% GG) was similar to that in the adult Japanese population. BPD occurred in 85 infants (42.1%) among 202 VLBW infants. The duration of O₂ therapy in infants with CG/GG genotypes was significantly longer than that in infants with the CC genotype (CG/GG vs CC: 40.3 ± 52.2 days vs 28.4 ± 32.6 days, P < 0.05), but the prevalence of BPD was not associated with the CG/GG genotype (CG/GG, 40.0%; CC, 46.3%, P= 0.24). Infants with CG/GG genotypes were more likely to have received postnatal corticosteroid therapy for BPD than those with the CC genotype (CG/GG vs CC: 20.9% vs 11.1%, P= 0.05). PVL occurred in six infants (3.0%). There was no significant difference in the prevalence of PVL among IL‐6‐634 polymorphisms (CG/GG, 3.0%; CC, 3.0%, P= 0.65). Conclusions: IL‐6‐634 polymorphism is associated with duration of oxygen therapy in VLBW infants. This suggests that the IL‐6‐634 polymorphism G allele is an aggravating factor of BPD. IL‐6‐634 polymorphism is not associated with PVL.     

Sodium and Potassium in Red Blood Cells of Premature Infants during the First Few Days: Risk of Hyperkalaemia

ABSTRACT. Erythrocyte sodium and potassium were studied in 64 newborn infants including 21 very low birthweight infants (birthweight < 1500 g) during the first three days after birth. Erythrocyte sodium showed a positive correlation with gestational age ( r =0.63, p <0.01) and birthweight ( r =0.66, p <0.01). Erythrocyte potassium was negatively correlated with birthweight ( r = -0.33, p <0.05). The Na/K ratio in red blood cells showed a positive correlation with gestational age ( r =0.60, p <0.01) and birthweight ( r =0.65, p <0.01). In VLBW infants plasma potassium rose significantly ( p <0.01) from 0–6 h to 12–30 h and decreased from 12–30 h to 30–60 h ( p <0.05). Erythrocyte potassium decreased slightly from 0–6 h to 12–30 h, but not significantly. A new finding that "more immature infants have higher potassium and lower sodium concentration in RBC" may suggest a potential risk of hyperkalaemia in tiny infants.     

Bone mineral density of the lumbar spine in very-low-birth-weight infants: a longitudinal study

To examine osteopenia in very low birth weight (VLBW) infants we used repeated dual-energy X-ray absorptiometry in a prospective study of lumbar spinal bone mineral density (BMD) in Japanese VLBW infants (birthweight 426–1498 g; n = 61, group 1) aged 40 weeks postconception to 3 years of age. Control subjects were Japanese infants with birthweight 1500–1999 g (group 2), 2000–2499 g (group 3), or more than 2500 g (group 4). BMD in group 1 during the early period after birth was very low, increased rapidly for 1 year, and then gradually increased until 3 years of age (r =  0.931, P < 0.0001). BMD at the age of 40 weeks postconception was 0.085 ± 0.026, 0.132 ± 0.039, 0.178 ± 0.042, and 0.196 ± 0.046 g/cm² in groups 1, 2, 3, and 4, respectively (P < 0.0001). However, at 1 and 2 years of age no differences were observed among the groups in BMD. Conclusion This study shows that lumbar spinal BMD in VLBW infants can normalize by the age of 2 years. Received: 12 May 1999 / Accepted: 11 October 1999     

Plasma concentration of granulocyte-colony-stimulating factor in neonates

We determined the plasma concentration of granulocyte-colony-stimulating factor (GCSF) and the neutrophil count in 108 infants (gestational age 23–41 weeks; birthweight 478–4935 g). The GCSF levels in the very low birthweight infants without infection were comparable to those in the full-term infants. Infants as premature as 23 weeks of gestation showed similar GCSF levels to mature neonates. GCSF levels decreased significantly by day 7 after birth. The levels were not significantly correlated with the neutrophil count. The mean plasma level of GCSF increased significantly when infection developed and was significantly higher in the infants with sepsis than in those with non-septic infections ( p < 0.01). The results suggest that GCSF may be the major determinant of neutrophil kinetics both during fetal life and after birth.     

Estimation of Digoxin Dosage in VLBW Infants Using Serum Creatinine Concentrations

ABSTRACT. Digoxin steady state plasma concentrations (C_ss) and the corresponding serum creatinine concentrations were studied in 17 VLBW infants. Birth weight was in the range of 760-1500 g (mean 1068 g), gestational age ranged from 26 to 32 weeks (mean 28.7 weeks). Digoxin steady state plasma concentrations were found in the range of 0.5-6.5 μg/ml (mean 1.88 μg/ ml) during maintenance therapy with 1.6-8.4 μg/kg BW/24 h (mean 4.4 μg/kg BW724 h) given in two divided doses intravenously. No digoxin-like immunoreactive substance could be detected in the plasma of 18 infants (10 patients with a birth weight <1500 g, 8 patients with a birth weight of 2100-4 730 g) that were not treated with digoxin. The calculated digoxin clearance ranged from 0.38-4.03 ml/min/kg BW. Serum creatinine concentrations were found in the range of 35-274 μmol/l (0.4-3.1 mg/100 ml). A hyperbolic correlation may be derived from the digoxin clearance and the corresponding serum creatinine concentration. A linear relationship was observed between the dose normalized digoxin concentrations (y=C_ss/dose in 24 h) and the respective creatinine concentrations x (v=0.52x-0.05; n=17; 5=0.24; r=0.86; p<0.01). According to this equation we suggest a dosing schedule for digoxin in VLBW infants with impaired renal function. Digoxin maintenance dose is derived from the digoxin target and the creatinine serum concentration. This dose recommendation proved reliable on four VLBW infants (birth weight 770-1260 g) with decreased renal function.     

Late-onset neutropenia in very low birthweight infants

AIM: To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm(-3) at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication. METHODS: Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured. RESULTS: Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm(-3) was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 microg dl(-1), and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts. CONCLUSION: Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.     

Late-onset neutropenia in very low birthweight infants

Aim : To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm⁻³ at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication. Methods : Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured. Results : Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm⁻³ was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 μg dl⁻¹, and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts.
Conclusion : Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.     

Early neonatal hyperkalaemia in the extremely premature newborn infant

The incidence of hyperkalaemia in 43 consecutive infants born at less than 28 weeks gestation and cared for in our neonatal intensive care unit was documented. Plasma K levels were related to indices of renal function as well as to the degree of illness in the infants. The mean gestational age was 26.0 weeks (range 24-27 weeks) and the mean birthweight was 815 g (range 395-1170 g). Twenty-six of the infants (60%) had at least one plasma K greater than 5.5 mmol/L and 13 (30%) had a maximum plasma K greater than 7 mmol/L. The mean postnatal age at which the plasma K exceeded 7 mmol/L was 25 h (range 10-39 h). Five infants with plasma K greater than 7 mmol/L developed cardiac arrhythmias and four died of this complication. Only one infant had a large intraventricular haemorrhage. Only two of 16 infants with an initial plasma K less than 5 mmol/L had a maximum plasma K greater than 7 mmol/L, compared with eight of 10 with an initial plasma K greater than 6 mmol/L (P less than 0.005). Plasma K also correlated directly with plasma urea (P less than 0.001) and plasma creatinine (P less than 0.025), and inversely with urine volume (P less than 0.05). Plasma K did not correlate with K intake, arterial pH, presence of asphyxia, severity of respiratory illness, gestation or birthweight. The rapidity with which the plasma K concentration reached potentially hazardous levels in some infants makes it imperative to measure plasma K within 6 h of birth and to continue to monitor levels at least every 6 h for the first 48 h in all infants born at less than 28 weeks gestation.     

Postnatal and postprandial changes in plasma concentrations of glicentin in term and preterm infants

Aim: To examined the changes in basal plasma concentrations of glicentin in developing children and the postnatal and postprandial changes in plasma glicentin levels in infants. Methods: Glicentin, an active component of enteroglucagon, is considered to have a significant trophic action on the intestinal mucosa. Fasting plasma concentrations of glicentin in healthy children and in term and preterm infants were measured before and 30 min after feeding during the first 14 d of life. Results: Plasma basal concentrations of glicentin in children under 1 y of age were significantly higher than those in children aged 1 to 15 y. Plasma basal concentrations of glicentin at 5 or 6 d (2496 and 2190 pg/ml) and at 14 d (2987 and 2817 pg/ml) after birth were significantly higher than those at 1 or 2 d (1098 and 1240 pg/ml) after birth in normal birthweight (NBW) and low-birthweight (LBW) infants. There was no significant difference in the glicentin level between infants at 1 or 2 d (1864 pg/ml) and at 5 or 6 d (1910 pg/ml) after birth in very-low birthweight (VLBW) infants, but the levels at 14 d (3310 pg/ml) after birth were significantly higher than either of those levels. Plasma glicentin concentrations after feeding were significantly higher than those before feeding at 1 or 2 d and at 5 or 6 d after birth in NBW and LBW infants, but a significant increase in the plasma glicentin level after feeding was first observed at 14 d after birth in VLBW infants. There were no significant differences in the basal plasma (2401 and 2718 pg/ml) and postprandial (3007 and 3912 pg/ml) glicentin levels between breastfed and formula-fed infants.

Conclusion: The results of the study suggest that glicentin may play an important role in intestinal mucosal growth in the early period of life, although its role in VLBW infants should be further investigated.     

Concentration of Twelve Plasma Proteins at Birth in Very Low Birthweight and in Term Infants

ABSTRACT. Plasma samples obtained at birth from 70 very low birth weight (VLBW) infants (gestational age 24 to 34 weeks) and from 20 term infants were analysed for concentrations of 12 different proteins. The plasma concentrations of albumin, transthyretin (TTR), retinol-binding protein (RBP), vitamin D-binding protein, apolipoprotein A I, fibronectin, orosomucoid and α₁-antichymotrypsin were significantly lower in the VLBW infants than in the term infants, whereas the values of α-fetoprotein (AFP) were significantly higher in the VLBW infants. No differences were found between the two groups for apolipoprotein A II, apolipoprotein B and transferrin. Birth asphyxia and sex had no influence on the measured plasma protein concentrations. The plasma concentrations of apolipoprotein A I and A II were significantly lower in small-forgestational age (SGA), VLBW infants compared with appropriate-for-gestational age (AGA), VLBW infants. Possible acute inflammation (defined as raised concentrations of orosomucoid or α₁-antichymotrypsin) was associated with significantly higher values of vitamin D-binding protein in both VLBW and term infants, suggesting that this protein may act as an acute phase protein in newborn infants.     

Concentration of twelve plasma proteins at birth in very low birthweight and in term infants

Plasma samples obtained at birth from 70 very low birth weight (VLBW) infants (gestational age 24 to 34 weeks) and from 20 term infants were analysed for concentrations of 12 different proteins. The plasma concentrations of albumin, transthyretin (TTR), retinol-binding protein (RBP), vitamin D-binding protein, apolipoprotein A I, fibronectin, orosomucoid and alpha 1-antichymotrypsin were significantly lower in the VLBW infants than in the term infants, whereas the values of alpha-fetoprotein (AFP) were significantly higher in the VLBW infants. No differences were found between the two groups for apolipoprotein A II, apolipoprotein B and transferrin. Birth asphyxia and sex had no influence on the measured plasma protein concentrations. The plasma concentrations of apolipoprotein A I and A II were significantly lower in small-for-gestational age (SGA), VLBW infants compared with appropriate-for-gestational age (AGA), VLBW infants. Possible acute inflammation (defined as raised concentrations of orosomucoid or alpha 1-antichymotrypsin) was associated with significantly higher values of vitamin D-binding protein in both VLBW and term infants, suggesting that this protein may act as an acute phase protein in newborn infants.     

Urinary malondialdehyde concentration in preterm neonates: is there a relationship to disease entities of neonatal intensive care?

In a retrospective study, urinary malondialdehyde concentration in 45 preterm neonates (25–35 weeks' gestation) during their first month of life was measured by HPLC. Urine was collected on different days of life as a 3-h sample. The frequency of urine collection and measurement varied between one (n = 22) and seven times (n = 8) per child. The study group was divided into three categories according to birth weight: low-birth-weight infants (LBW) (n= 16), very low-birth-weight infants (VLBW) (n = 17) and extremely low-birth-weight infants (ELBW) (n=12). Urinary malondialdehyde concentration was highest in the ELBW group: 1.15 (0.66, 2.12) μmol/l (median and quartiles) versus 0.58 (0.34, 1.18) μmol/l in the VLBW and 0.60 (0.40, 1.06) μmol/l in the LBW groups (ELBW versus VLBW, p < 0.005; ELBW versus LBW, p<0.02). In oxygen-treated neonates, significantly higher malondialdehyde values were found compared to those without supplementary oxygen (0.89 (0.48, 1.74) versus 0.58 (0.32, 0.89) μmol/l; p < 0.005). Likewise, a higher malondialdehyde concentration was found in infants requiring mechanical ventilation (intermittent mandatory IMV or high frequency ventilation) compared to those breathing spontaneously (intermittent mandatory ventilation: 0.80 (0.42, 1.66); p < 0.05 and high frequency ventilation: 1.20 (0.83, 2.13); p < 0.001 versus 0.57 (0.33, 0.88) μmol/l). Malondialdehyde concentrations correlated significantly with FiO₂ yalues of the individual patients (r = 0.22; p<0.02). Comparing urinary malondialdehyde concentrations in infants with and without bronchopulmonary dysplasia, a significantly higher malondialdehyde concentration was found in the former group (0.96 (0.51, 2.07) versus 0.60 (0.32, 0.98) μmol/l;p<0.005)). Infants with patent ductus arteriosus had a higher urinary malondialdehyde concentration than those without patent ductus arteriosus (1.04 (0.58, 3.78) versus 0.64 (0.36,1.20) μmol/l;p 0.05)). Malondialdehyde concentrations were also higher in infants with intracranial bleeding compared to those without (0.83 (0.46, 1.42) versus 0.56 (0.33, 1.10) μmol/l; p<0.02)). No significant differences in urinary malondialdehyde concentration were seen, either in relation to i v feeding with or without lipid emulsion or to medication administered. Native malondialdehyde concentration in seven commercial preparations of lipid emulsion after various periods of storage was fairly constant (12.3 ± 0.4 μmol/l) (mean ± SD).     

Plasma and urine riboflavin during riboflavin-free nutrition in very-low-birth-weight infants

BACKGROUND: Very-low-birth-weight (VLBW; birth weight <1500 g) infants receive enteral and parenteral nutriture that provides greater daily riboflavin (vitamin B2) than does term infant nutriture, and elevated plasma riboflavin develops in these infants after birth. The purpose of this study was to measure plasma and urine riboflavin concentrations in VLBW infants during riboflavin-free nutrition. Our hypothesis was that elevated plasma riboflavin develops in VLBW infants because of high daily intake and immature renal riboflavin elimination. METHODS: Eighteen clinically healthy VLBW infants received parenteral nutrition and preterm infant formula during the first postnatal month. On postnatal days 10 and 28, the infants received specially prepared riboflavin-free enteral and parenteral nutrition for the 24-hour study period. Serial collections of plasma were made at time 0 and at 12 and 24 hours. Urine was collected continuously for the 24-hour period in 4-hour aliquots. Samples were analyzed for riboflavin concentration. RESULTS: During the 24-hour riboflavin-free study period on postnatal day 10, plasma riboflavin decreased 56% from 185 +/- 37 ng/mL (mean +/- SEM), and urine riboflavin decreased 75% from 3112 +/- 960 mg/mL. Similarly, on postnatal day 28, plasma riboflavin decreased 79% from 184 +/- 32 ng/mL, and urine riboflavin concentration decreased 91% from 5092 +/- 743 ng/mL during the 24-hour riboflavin-free study period. Riboflavin half-life (t(1/2)) was 18.5 hours on postnatal day 10 and decreased 48% by postnatal day 28. Riboflavin elimination was 145.1 +/- 20.6 mg/kg per day on postnatal day 10 and increased 40% by postnatal day 28. CONCLUSION: The VLBW infants who received parenteral nutrition and preterm infant formula had elevated plasma riboflavin on postnatal days 10 and 28. Plasma riboflavin t(1,2) was shorter and renal riboflavin elimination was greater on postnatal day 28 than on postnatal day 10. Plasma riboflavin was normal after 24 hours of riboflavin-free nutrition. The pattern of plasma and urine riboflavin in VLBW infants suggests a lower daily intake would maintain plasma riboflavin close to normal.     

Sodium and potassium in red blood cells of premature infants during the first few days: risk of hyperkalaemia.

Erythrocyte sodium and potassium were studied in 64 newborn infants including 21 very low birthweight infants (birthweight less than 1500 g) during the first three days after birth. Erythrocyte sodium showed a positive correlation with gestational age (r = 0.63, p less than 0.01) and birthweight (r = 0.66, p less than 0.01). Erythrocyte potassium was negatively correlated with birthweight (r = -0.33, p less than 0.05). The Na/K ratio in red blood cells showed a positive correlation with gestational age (r = 0.60, p less than 0.01) and birthweight (r = 0.65, p less than 0.01). In VLBW infants plasma potassium rose significantly (p less than 0.01) from 0-6 h to 12-30 h and decreased from 12-30 h to 30-60 h (p less than 0.05). Erythrocyte potassium decreased slightly from 0-6 h to 12-30 h, but not significantly. A new finding that "more immature infants have higher potassium and lower sodium concentration in RBC" may suggest a potential risk of hyperkalaemia in tiny infants.     

尿神经导向因子-1和肾损伤分子-1对窒息后新生儿急性肾损伤的诊断价值探讨

目的 分析尿神经导向因子-1(Netrin-1)和肾损伤分子-1(Kim-1)的变化对新生儿窒息引起的急性肾损伤(AKI)的早期诊断价值。方法 选取足月窒息新生儿80 例(轻度窒息组34 例,重度窒息组46 例),以及正常足月新生儿40 例(无窒息组)。分别收集三组新生儿出生后12 h、13~48 h 内尿标本,采用酶联免疫法(ELISA)检测尿Netrin-1 及Kim-1 的水平,同时抽取外周静脉血检测血肌酐(Scr)水平。结果 窒息组患儿生后48 h 内的尿Netrin-1 及Kim-1 水平明显高于无窒息组,生后13~48 h 内的Scr 水平高于无窒息组(P<0.05);AKI 组患儿生后48 h 内的尿Netrin-1、Kim-1、Scr 均高于非AKI 组(P<0.05);12 h 内的尿Netrin-1、Kim-1 预测窒息后AKI 的AUC 值分别为0.878(95%CI 0.775~0.981,P<0.01)和0.899(95%CI 0.829~0.969,P<0.01);新生儿窒息后12 h 内的尿Netrin-1、尿Kim-1、Scr 分别呈明显正相关(P<0.05)。结论 窒息新生儿发生AKI时尿Netrin-1 和Kim-1 水平明显增高;尿Netrin-1 和Kim-1 可作为早期判断窒息后AKI 的指标。     

Risk factors associated with feed intolerance in very low birthweight infants following initiation of enteral feeds during the first 72 hours of life

An observational study was carried out in the Kuala Lumpur Maternity Hospital to determine the risk factors associated with feed intolerance in very low birthweight (VLBW, <1501 g) infants given intermittent 3-hourly enteral feeds within 72h after birth. Feed intolerance developed in 85 (64.4 per cent) of 132 infants. Logistic regression analysis showed that the only significant risk factor associated with feed intolerance was the age when the first feed was commenced. For each hour delay in the age of the infants when the first feed was given, the adjusted odds ratios of feed intolerance was 1.03 (95 per cent confidence intervals: 1.01-1.05; p = 0.01). Other factors (modes of delivery, Apgar score at 1 min, sex, ethnicity, history of resuscitation at birth, birthweight, gestation, multiple pregnancy, perinatal asphyxia, types of milk, hypothermia before first feed, hypotension before first feed, respiratory distress syndrome, patent ductus arteriosus, septicaemia, theophylline therapy, indomethacin therapy, ventilatory support, continuous positive airway pressure, umbilical catheterization, and surfactant therapy) were not significantly associated with feed intolerance. Our study suggests that to promote tolerance of enteral feeds in VLBW infants, intermittent orogastric feeds should be commenced as soon as possible during the first 72 h of life.