Intrapartum surveillance of IUGR fetuses with cardiotocography and fetal pulse oximetry

OBJECTIVE: To investigate the efficacy and safety of intrapartum fetal pulse oximetry, as a predictor of metabolic acidosis at birth of fetuses with intrauterine growth retardation (IUGR). STUDY DESIGN: We studied 18 IUGR fetuses (group I) and a control group of 30 appropriate for gestational age (AGA) fetuses (group II) during labor. Both groups had abnormal fetal heart rate tracings and were monitored simultaneously throughout labor with cardiotocography and fetal pulse oximetry. Apgar scores, pH and base excess of fetal blood obtained from the umbilical artery after delivery were compared in both groups. SETTING: The Fetal Surveillance Unit of the 2nd Department of Obstetrics and Gynecology, Aretaieion Hospital, Medical School, Athens University. RESULTS: In IUGR fetuses, when their oxygen saturation value (FSPO2) was less than 34%, cord artery pH was 7.10 +/- 0.04, base excess -13 +/- -1 mmol/l and Apgar scores < or =5 at the 5th min, and when FSPO2 was over 35%, artery pH was 7.29 +/- 0.08, base excess -8 +/- -2 mmol/l and Apgar scores > or =7 at the 5th minute. In cases of drops of FSPO2)below 30% for more than 2 min, labor was completed operatively and cord pH was 7.00 +/- 0.04, base excess -15 +/- -2 mmol/l and Apgar scores < or =5 at the 5th minute. In AGA fetuses, when FSPO2 was over 30%, artery pH was over 7.20, base excess <-11 mmol/l and Apgar scores > or =9 at the 5th minute; in contrast, when FSPO2 was <30% for 2 min, a cesarean section was performed and cord pH was < or =7.02, base excess > or =-13 mmol/l and Apgar scores < or =4 at the 5th minute. CONCLUSIONS: In IUGR fetuses, FSPO2 values less than 34% represent an acidotic status, while values of > or =35% are well tolerated. Fetal pulse oximetry proved reliable, according to umbilical cord blood measurements and Apgar scores, reducing cesarean deliveries in cases of nonreassuring cardiotocographic patterns in IUGR fetuses.     

Effect of delayed sampling on umbilical cord arterial and venous lactate and blood gases in clamped and unclamped vessels

BACKGROUND: Cord blood lactate at birth is a marker of antenatal hypoxia, and is comparable to pH as a prognostic tool. OBJECTIVE: To determine, by a prospective observational study, the effect of delayed sampling from arteries and veins that were double clamped to isolate the blood from the placenta (clamped), and from vessels that were not isolated from the placenta (unclamped). METHODS: Paired samples taken from clamped and unclamped vessels at 0, 20, 40, and 60 minutes were analysed for lactate, base excess, pH, and Pco(2). Data were analysed as the change from time 0 at 20, 40, and 60 minutes. RESULTS: Thirty eight placentas of infants delivered by elective caesarean section were studied. Arterial samples were taken from 20 placentas, and venous samples from 18 placentas. Arterial and venous lactate was significantly higher than at time 0 by 20 minutes in both clamped and unclamped vessels. Changes in unclamped vessels were greater than in clamped vessels. The pH remained unchanged over 60 minutes in clamped vessels, but changed significantly in unclamped vessels. Base excess changed significantly in both clamped and unclamped vessels. CONCLUSIONS: Cord blood samples taken after 20 minutes delay are unreliable for lactate measurement, even if the vessel has been doubly clamped to isolate the blood from the placenta. Current guidelines that state that blood can be sampled from a clamped cord for up to one hour after delivery should not apply to the interpretation of lactate or base excess. Delayed sampling from unclamped cords is very unreliable.     

The effect of varying arterial oxygen tension on neonatal acid-base balance.

Acute severe hypoxia, when the arterial partial pressure of O2 (PaO2) is sufficiently reduced, causes a shift from aerobic to anaerobic metabolism and can be fatal to neonates. The ability of the neonate to accommodate this shift, and prevent acidosis, could play a role in its ability to tolerate hypoxia. This study examines the effect of varying degrees of acute hypoxia on acid-base homeostasis in the neonate using a model of right to left shunting where PaO2 is decreased and, if severe, arterial partial pressure of CO2 is increased. Three-d-old swine were anesthetized, intubated, and mechanically ventilated. Ventilation with a gas mixture of medical air and 95% N2:5% CO2 resulted in four groups: 1) normoxia (n = 5); 2) mild hypoxia (n = 4); 3) moderate hypoxia (n = 3); and 4) severe hypoxia (n = 5), with PaO2 of 10.7, 8.0, 5.3, and 2.7 kPa (80, 60, 40, and 20 mm Hg), respectively. Acid-base status was evaluated via changes in arterial blood partial pressure of CO2, pH, HCO3-, and base excess at 0, 30, 60, and 120 min. Only the severe hypoxia group had significantly elevated (p less than 0.0001) arterial partial pressure of CO2 compared to the other groups at 60 and 120 min [8.7 +/- 0.5 and 8.0 +/- 0.5 kPa (65.5 +/- 3.7 and 60.0 +/- 3.7 mm Hg), respectively]. Base excess was unaltered in the normoxic and mild and moderate hypoxic groups, indicating no change in metabolic acid-base status. The severe hypoxic group had progressively decreased HCO3-, base excess, and pH at 60 and 120 min.(ABSTRACT TRUNCATED AT 250 WORDS)     

Whole blood ionized magnesium in neonatal acidosis and preterm infants: a prospective consecutive study

The mineral magnesium is a crucial enzymatic cofactor in the cellular bioenergetic process and alternations in magnesium metabolism may be associated with neurological impairment in newborn infants. Therefore, ionized magnesium (IMg) was measured in 14 newborn infants with acidosis [umbilical arterial cord pH 7.00 +/- 0.06, Apgar score 8.3 +/- 1.6 after 5 min, gestational age (GA) 276 +/- 16 d] and 15 premature infants (umbilical arterial cord pH 7.31 +/- 0.07, GA 236 +/- 12 d). Nineteen healthy mature infants served as controls. Arterial umbilical cord samples were taken immediately after delivery and capillary blood samples were taken 2, 6, 12 and 24 h after delivery by heel stick. IMg was measured by NOVA 8. The results showed an increased umbilical cord blood IMg in infants with acidosis compared with both premature and normal infants (0.58 +/- 0.08 mmol l(-1) vs 0.51 +/- 0.03 mmol l(-1) and 0.49 +/- 0.03 mmol l(-1); p < 0.0001). In infants with acidosis IMg declined significantly 2 h after delivery to 0.49 +/- 0.05 mmol l(-1) (p < 0.0001) and did not show any further significant changes during the first day of life. In premature infants and controls IMg levels were constant during the observation period. Conclusion: These findings suggest that elevated IMg is associated with neonatal acidosis.     

Is it possible to predict the blood volume of a sick preterm infant?

OBJECTIVE: To investigate the relation between the measured intravascular blood volume (BV) and current methods of indirectly assessing BV status in sick preterm infants on the first day of life. METHODS: Thirty eight preterm infants of gestation 24-32 weeks (median 30) and weight 480-2060 g (median 1220) were studied. Red cell volume was measured by the fetal haemoglobin dilution method in six infants and by the biotin labelled autologous red cell dilution method in the remaining 32. Total BV was calculated by dividing red cell volume by packed cell volume. Indirect assessments of BV status using heart rate (HR), core-peripheral temperature difference, mean arterial pressure, base excess, and packed cell volume were recorded. RESULTS: The mean (SD) initial measured BV was 71 (12) ml/kg (range 53-105). The mean HR was 148 beats/min (range 130-180), which correlated positively (r = 0.39, p = 0.02) with BV (higher HR was associated with higher BV). The mean base excess was -3.19 mmol/l (range -18 to +6.2). The negative base excess correlated significantly positively (r = 0.41, p < 0.01) with BV (more acidotic babies tended to have higher BV). There was no significant correlation between core-peripheral temperature difference, mean arterial pressure, or packed cell volume and BV. Regression analysis showed that base excess and HR were significantly related to BV; base excess alone can predict variability in BV only to 17%, and base excess with HR can predict variability in BV to 29%. CONCLUSION: The conventional clinical and laboratory indices are poor predictors of measured blood volume.     

Amylin peptide levels are raised in infants of diabetic mothers.

BACKGROUND: Amylin is a novel 37 amino acid peptide hormone that is co-secreted with insulin from the pancreas in response to food intake. As a potent inhibitor of gastric emptying it plays an important role in the control of carbohydrate absorption. Feed intolerance is common in infants of diabetic mothers (IDM). AIMS: To establish a normal range of amylin levels in healthy neonates, and to determine whether serum amylin levels are raised in IDM. METHODS: A serial sample of 221 infants > or =28 weeks gestation was enrolled prior to delivery over a 12 month period. Blood samples collected immediately after birth (umbilical cord), and at the routine Guthrie test were analysed for amylin and insulin levels. RESULTS: Amylin levels in umbilical cord (n = 181) and Guthrie samples (n = 33) of healthy infants were 5.7 (3.0-9.1) and 6.9 (2.9-9.0) pmol/l respectively. IDM had significantly raised amylin levels in both cord (n = 31; 32.7 pmol/l, 25.9-48.1) and Guthrie samples (n = 8; 18.1 pmol/l, 15.3-23.6). Amylin correlated positively with insulin (n = 42; r = 0.67; 95% CI 0.4 to 0.81), birth weight (r = 0.22; 95% CI 0.08 to 0.36), and gestation (r = 0.18; 95% CI 0.03 to 0.32). Umbilical cord venous amylin levels showed agreement with arterial cord amylin levels (n = 34, mean bias -0.2, 95% CI 3.1 to -3.6). CONCLUSIONS: Amylin levels are significantly increased in the umbilical cord and Guthrie blood samples in IDM.     

Blood gas values in clamped and unclamped umbilical cord at birth

AimTo determine the reliability of the cord blood gas analysis on the unclamped cord compared to the standard technique of sampling on double clamped cord.Study designProspective observational study conducted on 46 singleton neonates vaginally delivered at term. Matched pairs of umbilical artery and vein blood samples were collected from unclamped cord within 90 s after birth and from the same cord after clamping, with the clamping occurring immediately after the first blood collection. A blood gas analysis was performed on each collected sample.Outcome measuresArterial and venous blood samples were analyzed for pH, PO₂, pCO₂, SaO₂, hemoglobin concentration (ctHb) and base excess (BE). The values were compared between the two groups (clamped vs unclamped) using a Wilcoxon test.ResultsNo significant difference was found in pH, PO₂, pCO₂, SaO₂ and ctHb values on arterial blood between unclamped and clamped cord. The only significant difference was related to BE (p < 0.001). For the venous blood, the values of pH, PO₂, pCO₂ were comparable between unclamped and clamped cord, while the values of SaO₂, ctHb and BE were significantly different (p < 0.05).ConclusionNo significant difference was found in almost all the arterial blood gas parameters and in the main venous blood gas parameters between unclamped and clamped cord. Sampling of cord blood for gas analysis may be performed on the unclamped cord right after birth without reducing the accuracy of the analysis.     

Plasma ionized magnesium levels in neonatal respiratory distress syndrome

Measurement of ionized magnesium (IMg) provides an accurate assessment of the free form of Mg, which is the physiologically active form and is most reflective of the biologically active and not easily measurable intracellular Mg fraction. Plasma levels of IMg were measured by ion-selective electrode method in premature newborns with respiratory distress syndrome (RDS), and relationships and correlations between IMg levels and various demographic, prognostic and laboratory characteristics were investigated by comparing the premature newborns with (study group; n = 19) and without RDS (control group; n = 20) in the present study. The values of the postnatal arterial pH and base excess and plasma IMg levels were significantly different between the study and control groups, and the number of newborns with any morbidity was significantly higher in the study group. Within the study group there were significant negative correlations between the plasma IMg levels and the values of the umbilical cord arterial pH (r = -0.621, p = 0.005) and base excess (r = -0.746, p = 0.001), and the value of the postnatal arterial base excess (r = -0.585, p = 0.008). The newborns who died later had higher plasma IMg levels than those who survived (0.89 +/- 0.45 vs. 0.63 +/- 0.24 mmol/l, p = 0.026). These findings suggest that increase of plasma IMg may be due to extracellular movement of Mg, which is a principally intracellular ion, as a result of acidosis, hypoxia and probable cellular injury during the early course of RDS. The exact pathophysiological mechanism responsible for IMg increase, and whether determination of plasma IMg level, including umbilical cord blood IMg measurement, can be used as an early or predictive indicator of RDS in the diagnosis remain to be determined in further large-scale studies.     

Rapid whole blood lactate measurement in the fetus and mother during labour

Using a new rapid method, fetal and maternal whole blood lactate was measured before the onset of labour at elective Caesarean section in 8 patients, during labour in 34 normal patients, and in a further 28 patients whose babies showed varying degrees of clinical depression and/or acid base abnormality at birth. The mean (+/- SEM) umbilical venous and arterial and maternal venous lactate values in the 8 cases delivered by elective Caesarean section were 1.20 (+/- 0.16), 1.46 (+/- 0.22) and 1.14 (+/- 0.46) mmol/l, respectively. For the normal group the mean fetal lactates (+/- SEM) in the latent and active phases of labour, and in the umbilical vein and artery, were 1.91 (+/- 0.25), 2.42 (+/- 0.46), 2.71 (+/- 0.19) and 3.09 (+/- 0.20) mmol/l, respectively. The mean maternal venous lactate (+/- SEM) in the latent and active phases of labour and at delivery were 1.07 (+/- 0.09), 1.45 (+/- 0.12) and 2.69 (+/- 0.24) mmol/l. the rise in fetal lactate throughout labour was due in part to the rise in maternal lactate. Increasing neonatal depression was associated with increasing fetal lacticacidaemia. This associationachieved statistical significance at delivery.     

Clinical value of a single postnatal lactate measurement after intrapartum asphyxia

Our aim was to compare the respective values of base deficit and lactate in birth asphyxia. METHODS: Base deficit and lactate levels were measured from radial artery blood samples taken at 30 min of life in 115 term newborns suspected as having been asphyxiated during labour. Both base deficit and lactate levels were compared between patients who further developed moderate or severe encephalopathy and those who experienced no or only mild encephalopathy. Receiver operating characteristics curves and clinical values of both indicators were computed. RESULTS: The correlation between base deficit and lactate was significant (r2 = 0.51, p < 0.0001). Both indicators were significantly associated with neonatal outcome. Lactacidaemia lower than 5 mmol/l and/or base deficit level lower than 10 mEq/l were not followed by neurological complications. Plasma lactate concentration greater than 9 mmol/l was associated with moderate or severe encephalopathy with a sensitivity of 84% and a specificity of 67%. Base deficit and lactate had similar clinical values. CONCLUSIONS: Base deficit and lactate measurements in arterial blood at 30 min of life are equally valuable in assessing the severity of birth asphyxia.     

选择性头部亚低温治疗新生儿缺氧缺血性脑病临床多中心研究疗效阶段性分析

目的：通过临床多中心随机对照研究观察选择性头部亚低温治疗新生儿HIE的有效性。方法：收集2002年5月至2004年11月30日之前入选的至今已经完成18个月随访的新生儿HIE患儿共187（低温组104例，对照组83例）例进行初步疗效分析。低温组生后6h以内开始选择性头部低温联合全身轻度低温治疗，维持鼻咽部温度34±0.2℃，直肠温度维持在34.5℃以上；持续72h，然后自然复温。常温组维持直肠温度在36～37.5℃之间。生后 18个月进行神经发育评估（Gesell，s Development Diagnosis），主要观察严重伤残的发生率和死亡率。患儿存在脑瘫或智力发育迟滞中的任何一项定义为严重伤残。结果：187例中共失访30例（16％），实际有效病例157例（低温组88例，常温组69例）。低温组和常温组死亡和严重伤残的联合发生率分别为31.8％和50.7％（odds ratio：0.45，95％ CI 0.23－0.86，P=0.02）；其中死亡率分别为20.5％和31.9％（odds ratio：0.54，95％ CI 0.26－1.11，P=0.10）；严重伤残率分别为14.3％和27.7％（odda ratio：0.43，95％ CI 0.17－1.11，P=0.07）。进一步分析亚低温对不同严重程度的HIE的治疗效果，在中度HIE患儿中，低温治疗组死亡和严重伤残的联合发生率为24.2％，较对照组（52％）显著降低，(odds ratia:0.29,95% CI 0.10-0.9, P=0.03)；重度HIE患儿低温组和对照组的死亡和严重伤残的联合发生率分别为为55.6％和73.3％（P=0.13）。结论：选择性头部低温联合全身轻度低温72小时，可以显著降低HIE新生儿严重伤残率的发生,尤其是中度HIE患儿。     

The association of nuchal cord with cerebral palsy is influenced by recording bias

OBJECTIVES: To determine if the association of cerebral palsy (CP) with umbilical cord around the fetal neck (nuchal cord) is the result of recording bias. STUDY DESIGN: Population-based case control study. RESULTS: There were 68 cases with cerebral palsy and 157 controls (singleton term infants matched for gestational age and hospital of birth). CP was associated with tight nuchal cord overall (OR=2.8, 95% CI 1.1-6.8). Where cord around the neck is recorded at the discretion of the accoucheur (37 cases, 97 controls), there was an association between tight nuchal cord and CP (OR=5.4, 95% CI 1.4-20.4) and, in controls only, between Apgar score <7 at 1 min (OR=16.9, 95% CI 1.4-456.3). In the hospital where records included a tick box for nuchal cord (31 cases, 60 controls), an association between CP and tight nuchal cord could not be demonstrated (OR=1.4, 95% CI 0.4-4.9). Nor was there an apparent association between nuchal cord and Apgar score <7 at 1 min (OR=2.6, 95% CI 0.4-15.9) in controls. CONCLUSIONS: The presence of nuchal cord is subject to recording bias. In a retrospective study, this can lead to an association of CP with nuchal cord that is not evident where documentation is systematic.     

Varying clinical presentations at onset of type 1 diabetes mellitus in children – epidemiological evidence for different subtypes of the disease?

Abstract: Objective: On the basis of 2121 case observations between 1987 and 1997, we describe the clinical and laboratory characteristics of diabetes mellitus type 1 at its onset. Our objective is to analyze whether clinical presentation follows a uniform pattern or whether there is evidence for different subtypes. Research design and methods: Thirty‐one pediatric hospitals and one diabetes center in Baden‐Wuerttemberg (BW), Germany, participated in this study. The hospital records of 2121 children below 15 yr of age were examined retrospectively. Statistical analysis was done after logarithmic transformation into a normal distribution. Results: The average duration of symptoms was found to be 15.2 d (95% CI (Confidence Intervals) = 14.3–16.1) ranging between 2.0 and 180 d (95% central range). The most frequent symptoms were polyuria and polydipsia; 7.2% presented with altered level of consciousness. The mean blood glucose value was 407.9 mg/dL (95% CI = 400.0–416.0), corresponding to 23.3 mmol/L (95% CI = 22.8–23.8). The median pH value was 7.35 (95% CI = 7.34–7.36), and the median base excess was ?5 mmol/L (95% CI =?5 to ?4). The younger patients had a shorter duration of symptoms and suffered most frequently from ketoacidosis. Conclusions: Although the symptoms of diabetes at its onset follow a uniform pattern, the clinical presentation and duration of symptoms indicate that there may be various forms of type 1 diabetes.     

Amylin peptide levels are raised in infants of diabetic mothers

Background: Amylin is a novel 37 amino acid peptide hormone that is co-secreted with insulin from the pancreas in response to food intake. As a potent inhibitor of gastric emptying it plays an important role in the control of carbohydrate absorption. Feed intolerance is common in infants of diabetic mothers (IDM). Aims: To establish a normal range of amylin levels in healthy neonates, and to determine whether serum amylin levels are raised in IDM. Methods: A serial sample of 221 infants ?28 weeks gestation was enrolled prior to delivery over a 12 month period. Blood samples collected immediately after birth (umbilical cord), and at the routine Guthrie test were analysed for amylin and insulin levels. Results: Amylin levels in umbilical cord (n = 181) and Guthrie samples (n = 33) of healthy infants were 5.7 (3.0–9.1) and 6.9 (2.9–9.0) pmol/l respectively. IDM had significantly raised amylin levels in both cord (n = 31; 32.7 pmol/l, 25.9–48.1) and Guthrie samples (n = 8; 18.1 pmol/l, 15.3–23.6). Amylin correlated positively with insulin (n = 42; r = 0.67; 95% CI 0.4 to 0.81), birth weight (r = 0.22; 95% CI 0.08 to 0.36), and gestation (r = 0.18; 95% CI 0.03 to 0.32). Umbilical cord venous amylin levels showed agreement with arterial cord amylin levels (n = 34, mean bias –0.2, 95% CI 3.1 to –3.6). Conclusions: Amylin levels are significantly increased in the umbilical cord and Guthrie blood samples in IDM.     

Serum total magnesium and ionized calcium concentrations in asphyxiated term newborn infants with hypoxic-ischaemic encephalopathy

Total magnesium, ionized calcium, potassium and sodium concentrations in mixed umbilical cord blood and venous blood serum at a median (min.-max.) age of 33 h (24-48 h) were assessed colorimetrically in 46 asphyxiated and 35 healthy term infants. Asphyxiated infants without any signs or with signs of mild hypoxic-ischaemic encephalopathy (HIE) had significantly higher, and infants with severe HIE lower umbilical cord blood serum total magnesium (mean (95%CI) 0.81 (0.75-0.87) mmol/l and 0.64 (0.47-0.87) mmol/l, respectively, p < 0.05) compared with the control group (0.72 (0.69-0.76)mmol/l). An increase in serum total magnesium in spite of normalized acid-base status in asphyxiated infants suffering from severe HIE compared with the control group infants was found by the second day of life (0.97 (0.87-1.07) mmol/l and 0.86 (0.81-0.9) mmol/l, respectively, p < 0.05). At the age of 24-48 h hypermagnesaemia (>2 SD) was discovered in 36%, hyponatremia (<2 SD) in 38%, and hypocalcaemia (<2 SD) in 23% of asphyxiated infants. Derangements (>2 SD) in at least two electrolytes by the second day of life were significantly associated with poor outcome. CONCLUSIONS: Magnesium, calcium and sodium derangements are a frequent finding in asphyxiated infants, and these abnormalities are significantly associated with poor outcome. For a better outcome prediction, the routine determination of magnesium in addition to other electrolytes in asphyxiated infants is recommended.     

High brain tissue oxygen tension during ventilation with 100% oxygen after fetal asphyxia in newborn sheep

The optimal inhaled oxygen fraction for newborn resuscitation is still not settled. We hypothesized that short-lasting oxygen ventilation after intrauterine asphyxia would not cause arterial or cerebral hyperoxia, and therefore be innocuous. The umbilical cord of fetal sheep was clamped and 10 min later, after delivery, ventilation with air (n = 7) or with 100% oxygen for 3 (n = 6) or 30 min (n = 5), followed by air, was started. Among the 11 lambs given 100% oxygen, oxygen tension (PO2) was 10.7 (1.8-56) kPa [median (range)] in arterial samples taken after 2.5 min of ventilation. In those ventilated with 100% oxygen for 30 min, brain tissue PO2 (PbtO2) increased from less than 0.1 kPa in each lamb to individual maxima of 56 (30-61) kPa, whereas in those given oxygen for just 3 min, PbtO2 peaked at 4.2 (2.9-46) kPa. The maximal PbtO2 in air-ventilated lambs was 2.9 (0.8-5.4) kPa. Heart rate and blood pressure increased equally fast in the three groups. Thus, prolonged ventilation with 100% oxygen caused an increase in PbtO2 of a magnitude previously only reported under hyperbaric conditions. Reducing the time of 100% oxygen ventilation to 3 min did not consistently avert systemic hyperoxia.     

Effect of different chloride infusion rates on plasma base excess during neonatal parenteral nutrition

Richards CE, Drayton M, Jenkins H, Peters TJ. Effect of different chloride infusion rates on plasma base excess during neonatal parenteral nutrition. Acta Pædiatr 1993;82:678–82. Stockholm. ISSN 0803–5253
Routine biochemical monitoring of parenterally fed newborn infants revealed plasma chloride levels which were higher than widely quoted reference ranges. The parenteral nutrition solutions were reformulated to reduce the chloride infusion rate. In a historically controlled study, 28 infants receiving the original formulation were compared with 31 infants receiving the new formulation. The mean plasma chloride level was 4.8 mmol/l lower in the new formulation group than in the original formulation group (95% confidence interval 2.5–7.2 mmol/l). The mean base excess level was 3.1 mmol/l higher in the new formulation group than in the original formulation group (95% confidence interval 1.9–4.8 mmol/l). A reduction in the chloride load by using acetate salts can be safely achieved and may decrease the plasma chloride levels and decrease acidosis during the first seven days of life.     

Effects of pentoxifylline on the cardiovascular manifestations of group B streptococcal sepsis in the piglet.

Pentoxifylline (PTXF) is a methylxanthine that modifies leukocyte function and inhibits cytokine release. To evaluate its effects on the cardiovascular manifestations of sepsis secondary to group B streptococci, 14 anesthetized, mechanically ventilated piglets were studied over a 240-min period. Animals were randomly assigned to a treatment group that received a PTXF bolus (20 mg/kg) followed by a continuous infusion of 5 mg/kg/h before and during group B streptococci (1 x 10(8) colony forming units/kg/min) administration and a control group that received saline as a placebo. Comparison of the hemodynamic measurements and arterial blood gases during the first 90 min of PTXF treatment with those of the control group resulted in the following 90 min values: systemic arterial blood pressure was significantly higher in the PTXF group (89 +/- 10 versus 56 +/- 30 mm Hg; p less than 0.005) as was cardiac output (0.18 +/- 0.04 versus 0.10 +/- 0.07 L/kg/min; p less than 0.005). Pulmonary vascular resistance remained lower in the PTXF-treated animals (135 +/- 117 versus 248 +/- 119 mm Hg/L/min/kg; p less than 0.001), and these animals were less acidotic as measured by pH (7.07 +/- 0.2 versus 7.31 +/- 0.1; p less than 0.05) and base deficit (-15 +/- 9 versus -5 +/- 2 mmol/L; p less than 0.05). Median survival time was significantly longer in the PTXF group (210 versus 90 min; p less than 0.002). These data demonstrate that PTXF can ameliorate some of the deleterious hemodynamic manifestations of group B streptococci sepsis and result in improved survival in a young animal model.     

Reverse triiodothyronine, thyroid hormone, and thyrotrophin concentrations in placental cord blood.

Reverse triiodothyronine (rT3), triiodothyronine (T3), thyroxine (T4), thyroxine binding globulin (TBG), and thyrotrophin (TSH) were measured in sera from placental cord blood in an unselected series of 272 deliveries. In this series the concentrations of rT3 (mean 3.33 nmol/l, 95% confidence limits 1.6--7.0 nmol/l), were log normally distributed and did not overlap the adult normal range (0.11--0.44 nmol/l). There were no correlations between the cord blood concentrations of rT3, T3, T4, and TSH. The cord serum rT3 concentration was not influenced by maturity, birth-weight, or neonatal risk factors, whereas these factors did affect the concentrations of T3, T4, AND TBG. There is no arteriovenous rT3 concentration difference across the placenta, therefore the cord rT3 reflects the systemic rT3 concentration in the baby at birth. As rT3 in the neonate largely, if not entirely, derives from thyroxine from the fetal thyroid, measurement of the cord rT3 concentration may be a good immediate screening test for neonatal hypothyroidism.     

The relation between pre-eclampsia at term and neonatal encephalopathy

OBJECTIVES: To determine whether pre-eclampsia, hypothesised to be an inflammatory condition, is associated with fever in term labour, and confirm and examine the reported association of pre-eclampsia at term with neonatal encephalopathy. DESIGN: Prospective cohort study. SETTING: A Dublin teaching hospital. PARTICIPANTS: 6163 women in labour with singleton pregnancies at term at low risk for intrapartum hypoxia, recruited to a randomised trial examining the effect of admission cardiotocography on neonatal outcome. RESULTS: Pre-eclampsia was associated with maternal fever > 37.5 degrees in labour (odds ratio (OR) 3.39, 95% confidence interval (CI) 2.1 to 5.4); this was independent of obstetric intervention (adjusted OR 2.07, 95% CI 1.24 to 3.47). Pre-eclampsia was associated with neonatal encephalopathy (OR 25.5, 95% CI 8.4 to 74.7); this too was independent of obstetric intervention (adjusted OR 18.5, 95% CI 5.9 to 58.1). Cord arterial pH values were significantly lower in pre-eclamptics (7.20 v 7.24), although severe cord acidaemia was not significantly more common (OR 2.91, 95% CI 0.7 to 9.9). The association of pre-eclampsia with encephalopathy was independent of maternal fever (adjusted OR 16.5, 95% CI 5.1 to 54) and cord acidaemia (adjusted OR 13.5, 95% CI 3.2 to 56.7). CONCLUSIONS: The association of pre-eclampsia with maternal fever at term supports the hypothesis that pre-eclampsia is an inflammatory condition. The association of pre-eclampsia with neonatal encephalopathy is independent of obstetric intervention and cannot be explained by either acidaemia or maternal fever. A systemic inflammatory response in the fetus, perhaps secondary to oxidative stress, could explain the link between maternal pre-eclampsia and neonatal encephalopathy, and this may occur through cerebral vasoconstriction.