Is serum troponin T a useful marker of myocardial damage in newborn infants with perinatal asphyxia?

AIM

To assess the correlation of echocardiographic signs of myocardial damage to serum cardiac troponin T (cTnT) concentrations in newborn infants with perinatal asphyxia.

METHODS

Electocardiograms (ECG) and echocardiograms (Echo) were obtained during the first 24 h of life from 29 asphyxiated and 30 control infants and correlated with cTnT concentrations. The echocardiographic parameters included systolic ventricular performance, preload, afterload, diastolic function, stroke volume (SV), left ventricular output (LVO), hyperechogenity of the papillary muscles and insufficiency of the atrioventricular valves.

RESULTS

LVO and SV were lower but CTnT were significantly higher in asphyxiated than in control infants: 0.15 (010-0.23) vs. 0.05 (0.02-0.13), p < 0.001). Asphyxiated infants with signs of myocardial damage were associated with significantly higher cTnT than those without, 0.20 (0.11-0.28) and 0.11 (0.05-0.14 ug/L), p = 0.04.

CONCLUSION

Cardiac troponin may prove to be valuable in evaluating myocardial damage in birth asphyxia. However, the degree of prematurity may complicate the assessment.

[Peculiarity of cell energy metabolism in newborns with hypoxic-ischemic encephalopathy caused by asphyxia]

The authors have studied changes of activity of succinate dehydrogenase (SD) of peripheral blood lymphocytes of newborn with hypoxic-ischemic encephalopathy at early neonatal period and against cerebrokurin medicine administration. Newborn children with hypoxic-ischemic encephalopathy due to severe asphyxia have significant disturbancies of cyto-energy metabolism which is proved through decrease in activity index of SD and decrease in quantity of the cells with moderate and high activity. Lymphocytes of newborns with severe asphyxia were caracterized on six days by absence of the cells with moderate and high activity. Newborns with severe asphyxia who had been prescribed cerebrokurin had on their six days considerable increase in lymphocytes with moderate and high activity.

Interleukin-8 and monocyte chemotactic protein-1 mRNA expression in perinatally infected and asphyxiated preterm neonates

BACKGROUND

Inflammation due to perinatal infection (PI) and perinatal asphyxia (PA) may cause damage to various tissues and very often to the immature brain of the fetus and the newborn. Previously, we have shown that the neonatal immune system has the ability to produce increased chemokine protein levels in the serum during the inflammatory response caused by PI and PA.

AIM

The aim of our present study was to investigate mRNA levels of the proinflammatory chemokines interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) in peripheral blood leukocytes from infected and asphyxiated neonates.

METHODS

Forty-two premature neonates were studied; 11 with PI, 16 with PA and 15 without PA and PI, were used as controls. IL-8 and MCP-1 mRNA levels were investigated in whole blood and in phytohemagglutinin-activated lymphocytes using semi-quantitative polymerase chain reaction and real-time polymerase chain reaction, respectively.

RESULTS

IL-8 mRNA levels were significantly increased in whole blood both during PA and PI, while MCP-1 mRNA levels were not. In vitro activated lymphocytes expressed significantly increased IL-8 mRNA levels during PI, whereas no increase was observed during PA. MCP-1 mRNA levels were significantly increased in activated lymphocytes during PA, while no increase was observed during PI.

CONCLUSIONS

Our data show that chemokine mRNA levels expressed by activated lymphocytes during inflammation caused by PIs are different to those expressed during PAs. These findings might have important implications during the administration of specific chemokine antagonists in order to prevent or reduce tissue damage caused by inflammation.

Effect of perinatal factors on cord blood thyroid stimulating hormone levels

OBJECTIVE

To study the influence of perinatal factors on cord blood (CB) TSH levels.

INFANTS AND METHODS

In a prospective cross-sectional study, CB TSH levels were measured in 1,590 live-born infants using IRMA. The effect of various perinatal factors on the CB TSH levels was analyzed statistically.

RESULTS

The mean TSH level in the study group was 10.6 +/- 6.7 microU/ml (range 0.01-66.4 microU/ml). A significant fall in CB TSH levels was noted with increasing gestational age. A similar decline was noted in TSH levels with increase in birth weight. No significant difference in TSH levels was noted between males and females, or AGA and SGA (n = 296) infants. Infants with birth asphyxia (Apgar score < 4 at 5 min) had significantly higher CB TSH levels (mean 31 microU/ml, n = 18) as compared to those without (mean 10.4 microU/ml) (p < 0.01). The highest TSH levels were noted in neonates delivered by forceps extraction (mean 29.4 microU/ml, n = 17) and lowest levels in infants born by elective Caesarian section (mean 8.7 microU/ml, n = 149).

CONCLUSION

CB TSH levels fall with increase in gestational age while birth asphyxia and difficult deliveries tend to elevate them.

Cord blood IGF-1 and IGFBP-3 levels in asphyxiated term newborns

OBJECTIVE

Determination and pathogenesis of perinatal asphyxia is still an important problem. During the asphyxial insult and recovery phase, alteration of the growth factors has been demonstrated and there is evidence that expression of insulin-like growth factors (IGF) and their insulin-like growth factor binding proteins (IGFBP) in injured sites in experimental studies. Aim of this study was to evaluate relationship between serum IGF-1, IGFBP-3 levels and perinatal asphyxia.

PATIENTS AND METHODS

18 term-newborn who defined as perinatal asphyxia and 12 term-healthy newborn were enrolled. Umbilical cord IGF-1 and IGFBP-3 levels were detected and searched correlation with apgar scores and umbilical artery gas analysis as pH, pC02, pO2, base excess, HCO3, ctO2, SO2 and lactate levels.

RESULTS

Cord blood IGF-1 and IGFBP-3 levels for asphyxiated newborns were lower than normal group (27.8+/-2.6 ng/ml, 55.1+/-2.8 ng/ml respectively, p<0.01 for IGF-1; 1107.7+/-320.4, 1682.5+/-364.1, p<0.001 for IGFBP-3). Cord blood IGF-1 levels were positively correlated with birth weight; first and 5th minute Apgar score, cord blood arterial pH, ABE, HCO3, SO2 levels. Cord blood IGFBP-3 levels were positively correlated with first and 5th minutes Apgar scores, cord blood arterial pH, pCO2, ABE, HCO3, sO2, and also negatively correlated with cord CO2 and cord lactate levels.

CONCLUSION

Our study demonstrates that exposure to hypoxia and acidosis at birth strongly correlated with a fall in IGF-1 and IGFBP-3 levels in cord blood.

Delivery as a "physiological stress" and its influence on some parameters of oxidative stress

OBJECTIVES

In healthy term newborns (HTN) to determine on the 1st and 5th day of life the activity of total antioxidant capacity (TAS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) and to compare the values with the group of asphyxiated term newborns (ATN).

PATIENTS/METHODS

The series consisted of 15 HTN and 24 ATN. In both groups TAS, MDA, GPX and SOD were investigated.

RESULTS

Reference values in HTN (1st/5th day of life) for TAS were 0.52+/-0.03/0.49+/-0.04 mmol/l, for MDA 0.72+/-0.07/1.08+/-0.09 micromol/l, for SOD 594.20+/-16.47/591.23+/-14.14 Ug/Hb and for GPX 25.48+/-1.32/25.98+/-1.20 Ug/Hb. In a group of ATN the obtained values were (1st/5th day of life): TAS 1.1+/-0.08/0.98+/-0.08 mmol/l, MDA 2.08+/-0.22/2.21+/-0.34 micromol/l, SOD 509.18+/-26.8/564.49+/-36.4 Ug/Hb and GPX 30.2+/-1.9/32.45+/-2.69 Ug/Hb.

CONCLUSIONS

Statistically significant differences were found on the 1st and 5th day of life between the two groups investigated in values of MDA (**p<0.01) and TAS (**p<0.01). Increased values of MDA in the group of ATN on the 1st and 5th day of life confirmed the presence of lipoperoxidation. The obtained values of TAS on the 1st and 5th day of life in the group of ATN were surprisingly higher than in HTN. The increase of TAS in ATN could point to a certain ability of ATN to prevent the damage of balance between overproduction of MDA and antioxidants. The results of SOD and GPX activity were not statistically significant, yet they are indicative of the biochemical reaction of the organism of term newborns to asphyxia.

Dynamics of hepatic enzyme activity following birth asphyxia

AIM

To investigate: 1) the occurrence of hypoxic hepatitis in full-term infants after birth asphyxia, 2) the temporal enzyme pattern in asphyxiated newborn infants, and 3) whether the degree of hypoxic hepatitis, as reflected by the rise in aminotransferase, correlates with the severity of the asphyxia and CNS symptomatology.

METHODS

Serum aminotransferases, lactate dehydrogenase, gamma-glutamyl transferase, total and conjugated bilirubin, cholinesterase activity, albumin, international normalized ratio (INR), and nucleated red blood cell count were prospectively measured in full-term asphyxiated newborn infants (n=26). Samples were collected three times during the first 72 h and once between days 6 and 12 after birth. Samples from healthy newborns (n=56), collected 24-172 h after birth, served as controls.

RESULTS

In 12 of the 26 asphyxiated infants, a serum alanine aminotransferase (S-ALAT) pattern compatible with hypoxic hepatitis was found. Five infants showed increased S-ALAT activity but with a different pattern. Similar patterns were seen in serum aspartate aminotransferase (S-ASAT). S-ALAT and -ASAT concentrations 0-72 h after birth correlated significantly with severity of hypoxic-ischaemic encephalopathy.

CONCLUSION

Birth asphyxia can induce an enzyme pattern in serum compatible to hypoxic hepatitis. There seems to be a correlation between aminotransferases in serum and the extent of CNS injury.

Retrospective diagnosis of hypoxic myocardial injury in premature newborns

Perinatal asphyxia has a high impact on neonatal mortality, morbidity, and neurological outcome. The hypoxic effects on brain, kidney and gastrointestinal system are well recognized in newborns. While it is known that hypoxia also effects cardiac function, there are few studies of quantitative myocardial injury in premature infants who suffered hypoxia.

AIM

To investigate usefulness of cardiac troponin (cTnT) and creatinine kinase MB (CK-MB) in the diagnosis of myocardial injury due to birth hypoxia and to correlate these markers with cardiac functions as measured by echocardiogram.

METHODS

We studied 43 preterm infants: 21 with birth asphyxia and 22 controls. Echocardiographic studies and quantitative determination of cTnT and CK-MB in blood serum was performed between the 12(th) and the 24(th) h of life.

RESULTS

cTnT and CK-MB levels were higher in asphyxiated infants compared to controls (0.287 +/- 0.190 vs. 0.112 +/- 0.099 ng/mL, P < 0.001) and (18.35 +/-14.81 vs. 11.09 +/- 5.17 ng/L, P < 0.05). Among controls, we observed an elevated value of cTnT in those with respiratory distress syndrome (RDS). We found a decrease in fractional shortening (P < 0.05) and an increase in tricuspid insufficiency (P < 0.01) in asphyxiated newborns.

CONCLUSIONS

cTnT and CK-MB levels are strong indicators of myocardial injury due to perinatal hypoxia. The cTnT level was most strongly related to RDS.

Platelet dysfunction in asphyxiated newborn piglets resuscitated with 21% and 100% oxygen

Hemostatic disturbances are common in asphyxiated newborns after resuscitation. We compared platelet function in hypoxic newborn piglets reoxygenated with 21% or 100% oxygen. Piglets (1-3 d, 1.5-2.1 kg) were anesthetized and acutely instrumented for hemodynamic monitoring. After stabilization, normocapnic hypoxia was induced with an inspired oxygen concentration of 10-15% for 2 h. Piglets were then resuscitated for 1 h with 21% or 100% oxygen, followed by 3 h with 21% oxygen. Platelet counts and collagen (2, 5, and 10 microg/mL)-stimulated whole blood aggregation were studied before hypoxia and at 4 h of post-hypoxia/reoxygenation. Platelet function was studied using transmission electron microscopy and by measuring plasma thromboxane B2 (TxB2) and matrix metalloproteinase (MMP)-2 and -9 levels. Control piglets were sham-operated without hypoxia/reoxygenation. The hypoxemic (PaO2 33 mm Hg) piglets developed hypotension with metabolic acidosis (pH 7.02-7.05). Upon reoxygenation, piglets recovered and blood gases gradually normalized. At 4 h reoxygenation, platelet aggregation ex vivo was impaired as evidenced by a rightward-downward shifting of the concentration-response curves. Electron microscopy showed features of platelet activation. Plasma MMP-9 but not MMP-2 activity significantly increased. Resuscitation with 100% but not 21% oxygen increased plasma TxB2 levels. Platelet counts decreased after hypoxia/reoxygenation but were not different between groups during the experiment. Resuscitation of hypoxic newborn piglets caused platelet activation with significant deterioration of platelet aggregation ex vivo and increased plasma MMP-9 levels. High oxygen concentrations may aggravate the activation of prostaglandin-thromboxane mechanistic pathway.

[The role of S100B-protein in neonatology, pediatric intensive care, and pediatrics]

During the last years neuromonitoring with various biochemical markers such as S100B protein has been introduced into the clinical settings of neonatal and pediatric intensive care. Several investigations have been undertaken to correlate S100B protein concentrations to the diagnosis and prognosis of neonates and children with severe cerebral disorders. This articles gives a review on the current knowledge, indications and limitations on the use of S100B protein after non-traumatic and traumatic brain injury in neonates and children.

Elevation of Cytokine Concentrations in Asphyxiated Neonates

BACKGROUND

Various cytokines are reportedly associated with many neonatal diseases. Asphyxia is considered to result in ischemia-reperfusion injuries and induces abnormal inflammatory responses involving excessive cytokine production.

OBJECTIVES

To evaluate alteration in sera levels of various cytokines/chemokines in case of perinatal asphyxia at birth.

METHODS

In order to determine the concentrations of various cytokines/chemokines in sera, we used a highly sensitive fluorescence microsphere method. We measured the concentration of 8 types of cytokines/chemokines in sera obtained from 17 cases of asphyxia, 10 normal neonates, and 6 healthy adults.

RESULTS

The concentrations of IL-6, IL-8, and IL-10 in the sera of asphyxiated neonates were higher than those in the normal neonates. Irrespective of the presence or absence of asphyxia, sera concentrations of IL-2, IL-4, IFN-gamma, and TNF-alpha were higher in the neonates than those in the adults. The concentration of IFN-gamma in the asphyxiated neonates was lower than that in the normal neonates. Sera levels of IL-10 were higher in the asphyxiated cases than those in the normal neonates. The sera levels of IL-6, IL-8, and IL-10 in asphyxiated neonates with either a poor outcome or death were higher than those without poor outcomes.

CONCLUSIONS

The concentrations of various types of cytokines/chemokines were different in neonatal sera and some of them increased drastically during asphyxia. The concentration of an anti-inflammatory cytokine IL-10 was elevated in asphyxiated neonates immediately after birth, thereby suggesting that IL-10 might be associated with neuroprotective functions.

S100B protein related neonatal hypoxia

Biochemical markers have played an increasingly relevant role in the assessment of neonatal asphyxia. The S100B protein is particularly important in research conducted in this field. The purpose of this study was to underline the importance of the S100B protein in the assessment of term newborn infants with hypoxic-ischemic encephalopathy, as well as to relate it to other substances also involved in the ischemic process. An assessment was made from September 2003 to October 2004 of 21 term newborn infants who developed hypoxic-ischemic encephalopathy. Samples were collected on the 1st and 4th day of life and S100B protein and lactate concentrations were calculated using the immune cytochemical method. A positive relationship was found between the two substances. Additionally, a comparison between the two substances showed a statistically significant correlation.

Magnesium therapy in birth asphyxia

OBJECTIVE

Glutamate plays a critical role in the hypoxic ischaemic neuronal death. Two mechanisms of glutamate- induced neuronal death have been identified. One is rapid cell death that occurs in minutes and the second is delayed cell death that occurs over hours and is initiated principally by the activation of the N-methyl D-Aspactate (NMDA) receptor. Magnesium (Mg) is an NMDA receptor blocker. Systemic administration of Mg after a simulated hypoxic ischaemic insult has been shown to limit neuronal injury in several animal models. However, before embarking on to the use of Mg for neuronal protection in the human neonate it is important to study the safety and side effects of Mg administration.

METHODS

Forty terms, appropriate for gestational age babies with severe birth asphyxia (1 min Apgar score < 3 and 5 min Apgar score < 6), were randomly assigned to either the study group or the control group. Infants in both groups were treated as per unit protocol except that babies in the study group received intravenous injection of magnesium sulphate 250 mg/kg within half an hour of birth and subsequently 125 mg/kg at 24 and 48 hours of life.

RESULTS

The mean cord blood serum Mg levels were 0.78 (+/- 0.047) mmol/L in the control group and 0.779(+/-0.045) mmol/L in the study group. The serum Mg levels at 3, 6, 12, 24, 48 and 72 hours of life were 1.87(+/-0.6), 1.65(+/-0.059), 1.468 (+/-0.91), 1.881 (+/- 0.053), 1.916 (+/- 0.053) and 1.493 (+/- 0.084) mmol/L respectively in the study group. All these values were significantly higher than those obtained in the control group (p< 0.001). No significant alterations in heart rate, respiratory rate, oxygen saturation and mean arterial pressure were seen, following magnesium infusion with either 250 mg/kg or 125 mg/kg dose. The serum Mg levels in the study group ranged between 1.493 (+/- 0.084) and 1.916(+/-0.053) mmol/L, which are considered to be in the neuroprotective range.

CONCLUSION

Injection MgSO4 administered in a dose of 250 mg/kg and 125 mg/kg as an intravenous infusion is safe and the Mg levels obtained are in the range considered to be neuroprotective.

[Clinical study on improving the diagnostic criteria for neonatal asphyxia]

OBJECTIVE

Diagnosing neonatal asphyxia solely according to Apgar score may lead to misdiagnosis. The aim of this study was to explore new and more accurate diagnostic criteria for neonatal asphyxia.

METHODS

Totally 10 376 live born neonates in our hospital were consecutively enrolled into the study. The following five items related to birth asphyxia, i.e., antepartum high-risk factors, Apgar scores, umbilical artery blood pH, organ injury, differential diagnosis on the causes of low Apgar score cases were examined and registered. The relationship among the first 4 items were analyzed. By differential diagnosis, the sensitivity and specificity of each index on diagnosing asphyxia and their complementary value on each other were investigated.

RESULTS

The items correlated well with each other (P < 0.01 or < 0.05) but were not entirely parallel and consistent; they could complement but could not substitute for each other. The sensitivity of antepartum high-risk factors, low Apgar scores, umbilical artery blood pH < 7.00 and organ injury was 100%, 100%, 44.44% and 100%, while the specificity was 17.99%, 98.90%, 96.05% and 96.62%, respectively. Of the 230 low Apgar score cases in this series only 50.9% coincided with asphyxia. For the 230 cases, when low Apgar score was combined with umbilical artery blood pH < 7.00, the sensitivity and specificity were 41% and 99.1% and when low Apgar score was combined with umbilical artery blood pH < 7.20, the sensitivity and specificity were 100% and 29.20%, respectively. After organ injury was added, the specificity was increased to 65.49%. When differential diagnosis was further added to exclude the other causes of low Apgar score cases, the misdiagnosis rate was minimized.

CONCLUSION

Up to now, no single accurate index for diagnosing neonatal asphyxia is available. In order to increase diagnostic bases and reduce misdiagnosis, the criteria of sole Apgar score should be replaced by multi-index diagnostic criteria. Based on the present study, a set of integrated diagnostic criteria for neonatal asphyxia is proposed: (1) prenatal high-risk factors, (2) low Apgar scores (respiratory depression must present), (3) umbilical artery blood pH < 7.00, if only pH < 7.20, the items (2) (4) (5) must be present, (4) hypoxic-ischemic organ injury (at least one organ dysfunction), (5) the other causes of low Apgar scores should be excluded. The last 4 indexes should all be met and the first one serves as reference. If multi-organ (three or more organs) dysfunction and (or) hypoxic-ischemic encephalopathy are present, severe asphyxia can be diagnosed.

Screening of foetal distress by assessment of umbilical cord lactate

PURPOSE OF INVESTIGATION

Studies on umbilical cord blood for determination of lactate indicate that high levels seem to be correlated to foetal metabolism for anaerobic glycolysis taking place in oxygen-deprived tissues of the foetus. These findings may be of particular-deprived clinical importance when foetal distress or foetal hypoxemia is caused by perinatal events.

METHODS

The maternal and foetal heart rates, acid-base values measured and the outcome of 94 pregnancies complicated by intrapartum foetal asphyxia have been reviewed, and the maternal and foetal acid-base and lactate levels during the course of labour and at delivery were studied in patients with evidence of metabolic acidosis. Lactate concentrations were measured during labour and at delivery in blood samples obtained from the foetal presenting part and from the umbilical cord with the use of a rapid electrochemical technique. The foetuses were evaluated by means of the Apgar score, intrapartum cardiotocography, observation of the presence of meconium stained amniotic fluid, and clinical features of distress at birth.

RESULTS

Evidence of clinical foetal distress was not related to the severity of the asphyxia. An increased lactate level was found in asphyctic infants and a clear correlation between lactic acidosis and foetal distress was documented. Low Apgar scores were observed in infants with moderate or severe asphyxia at delivery. Scalp lactate correlated significantly with umbilical artery lactate, but not with 1-min or 5-min Apgar scores. The lactate concentration was higher in cases of instrumental delivery compared to spontaneous delivery. No perfect correlation was found between lactate level and neonatal outcome but there were not a significant number of neonates with immediate complications. The rate of forceps delivery in the distress group was significantly higher than that of the healthy foetuses, so spontaneous labour was less frequently associated with foetal distress than instrumental delivery. In the distress group, severe variable decelerations were generally recorded in the second stage of labour. The incidence of neonatal Apgar score < or = 7 in neonates with abnormal baseline foetal heart rate (FHR) was higher than in those with severe variable decelerations, mild variable decelerations, and transient tachycardia. Duration of the active second stage of labour was significantly with the presence of foetal lactate at the time of crowning of the foetal head and the presence of lactate in umbilical arterial and vein blood at delivery. Expulsion time > or = 45 minutes, compared with shorter active second stage, and acidaemia at birth implied larger arterial-venous lactate differences. The presence of foetal lactate at crowning was also significantly associated with the level of umbilical arterial-venous lactate difference.

CONCLUSION

Lactate and pH values provide the best parameters to distinguish between asphyctic and normal newborns, with lactate having the most discriminating power. The prospective value of the discrimination functions derived from lactate and pH data is good when the foetuses are allocated into normal parameters but poor when an attempt is made to allocate the foetuses into pathologic ones, with a high false-negative rate. However, the discriminating ability is improved when pathologic foetuses are included into one single abnormal group. These results confirm the potential use of rapid foetal blood lactate measurements for the early diagnosis of intrapartum foetal distress.

Cardiac troponin I in asphyxiated neonates

BACKGROUND

Cardiac troponins T (cTnT) and I (cTnI) are well-established markers in detecting myocardial ischemic damage in adults. Perinatal asphyxia is associated with cardiac dysfunction.

OBJECTIVES

To evaluate serum concentrations of cTnI in asphyxiated neonates and to investigate whether cTnI is correlated with the traditional markers of asphyxia.

METHODS

Blood samples were collected from 13 asphyxiated neonates (umbilical artery pH<7.18 and either a 1-min Apgar score<4 or a 5-min Apgar score<7) and 39 controls. Data on gestation, birth weight, sex, Apgar scores, mode of delivery, umbilical pH, creatinine, serum activity of aspartate and alanine aminotransferase, and QTc interval were investigated.

RESULTS

Median (range) cTnI concentrations were significantly higher in asphyxiated neonates with respect to healthy infants: 0.36 microg/l (0.05-11) versus 0.04 microg/l (0.04-0.06); p<0.01. In asphyxiated babies, no statistically significant correlations were found between concentrations of cTnI and the other markers of asphyxia.

CONCLUSIONS

In asphyxiated neonates, cTnI concentrations are higher with respect to healthy infants, suggesting the presence of myocardial damage in this group of high-risk patients. cTnI does not correlate with the traditional markers of asphyxia.

Umbilical cord unbound free fatty acid concentration and low apgar score

Increased levels of unbound Free Fatty acid (FFAu) have been found in adults undergoing coronary angioplasty as a result of acute hypoxia-ischemia. We hypohesized that infants suffering from a 1-minute Apgar score of less than 5 will demonstrate elevated FFAu levels in the cord blood. One hundred ninety-nine infants between 25 and 41 weeks gestational age were enrolled in the study. Infants with an Apgar score of less than 5 at 1 minute served as the study group. Blood samples were collected from the umbilical cord and serum FFAu levels were measured with the fluorescent probe acrylodan-derivatized intestinal fatty acid binding protein. The low Apgar score group (n=32, birthweight 3153+/-780 g, gestational age 37.9+/-3.1 weeks) and normal Apgar score group (n=167, birthweight 3067+/-847 g, gestational age 37.5+/-3.5 weeks) were significantly different with respect to Apgar score at 1 minute (3.0+/-1.2 versus 8.4+/-1.1), Apgar score at 5 minutes (6.9+/-versus 8.9+/-0.5), cord pH (7.16+/-0.12 versus 7.28+/-0.07), and in the frequency of meconium passage (40.6% versus 14.9%). Cord FFAu levels were 4.4+/-1.7 versus 3.2+/-1.2 nM (p<0.001), respectively. Cord FFAu correlated inversely with Apgar score at 1 minute (r=-0.31, p<0.05) and with cord pH (r=-0.12, p<0.05), but not with birthweight or gestational age. In infants with low 1-minute Apgar scores, cord free fatty acid levels were significantly elevated compared with those from controls.

Troponin-T levels in perinatally asphyxiated infants during the first 15 days of life

AIM

To measure serial cardiac troponin-T, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels in asphyxiated newborn infants during the first 15 d of life.

METHODS

Troponin-T, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase (LDH) concentrations were measured prospectively in blood samples obtained from 45 asphyxiated and 15 healthy term neonates within the first 2-4 h, third, seventh and 15th days.

RESULTS

Infants with severe asphyxia had significantly higher cardiac troponin-T levels than grade I and II asphyxiated and healthy neonates within the first 2-4 h of life (0.34+/-0.21 ag/ml vs 0.07+/-0.03 ag/ml, 0.12+/-0.07 ag/ml, 0.04+/-0.02 ag/ml, respectively). Troponin-T levels remained high on days 3 and 7 in severely asphyxiated neonates. The creatinine kinase-MB levels were significantly higher in grade II and III asphyxiated neonates than grade I asphyxiated and healthy neonates within the first 2-4 h. No difference was found in creatinine kinase-MB on day 3. There was cardiac involvement in 12 (80%) newborns of group III on B mode echocardiographic images on day 1. However, no echocardigraphic pathology was found in the seventh- and 15th-day echocardiographic analysis in any groups.

CONCLUSION

Our results suggest that asphyxia-related cardiac changes were significant but reversible in severely asphyxiated neonates, and troponin T is a good determinant of the degree of injury to the heart within the first week of life. Cardiac troponin T also has a wider diagnostic frame than other diagnostic markers of myocardial damage.

Room-air resuscitation causes less damage to heart and kidney than 100% oxygen

RATIONALE

Pure oxygen causes more oxidative stress than room air in resuscitation of asphyctic neonates, and consequently could be associated with increased tissue damage.

OBJECTIVES

To compare damage caused to heart and kidneys on reoxygenation in severely asphyctic term neonates resuscitated with room air (RAR) or 100% oxygen (OxR). Nonasphyctic term newborn infants served as a control group.

METHODS AND MEASUREMENTS

This is a prospective randomized clinical trial masked for the gas mixture. Reduced glutathione (GSH), oxidized glutathione (GSSG), and superoxide dismutase (SOD) activity were measured to assess oxidative stress. Plasma cardiac troponin T (cTnT) and urinary N-acetyl-glucosaminidase (NAG) assessed cardiac and renal damage, respectively. Daily determinations of NAG for a 2-wk period were performed to monitor postasphyctic renal damage.

MAIN RESULTS

Both asphyctic groups showed oxidative stress when compared with the control group as evidenced by diminished GSH/GSSG ratios, adaptive increases in SOD activity, and higher values of NAG and cTnT (markers of tissue damage). However, the OxR group showed significantly higher values of NAG and cTnT, lower GSH/GSSG ratios, and higher SOD activity than the RAR group. Moreover, NAG values persisted in being higher than normal in the OxR group for 2 wk after birth, whereas NAG in the RAR group dropped to normal within the first week. A linear correlation between cTnT or NAG and GSSG was found.

CONCLUSIONS

The use of room air on resuscitation causes less oxidative stress and damage to heart and kidney than pure oxygen.

Comparison of serum cardiac troponin T and creatine kinase MB isoenzyme mass concentrations in asphyxiated term infants during the first 48 h of life

OBJECTIVE

This prospective study aimed to compare serum creatine kinase MB isoenzyme (CK-MB) mass concentrations and cardiac troponin T (cTnT) concentrations during the first 48 h of life in asphyxiated term infants.

METHODS

Serum cTnT and CK-MB mass concentrations of 50 term infants with clinical features of perinatal asphyxia were measured at birth and at 12, 24 and 48 h of age by chemiluminescence immunoassay. These infants were followed up until discharge or death. Cord blood CK-MB and cTnT concentrations of 50 healthy term infants were also assayed.

RESULTS

At birth, asphyxiated infants had significantly higher concentrations of cTnT and CK-MB than controls (P < 0.0001). Serum cTnT of asphyxiated infants with low ejection fraction <60% was significantly higher at 12 and 24 h than those with normal ejection fraction (P < 0.05). Asphyxiated infants with congestive cardiac failure had significantly higher serum cTnT concentration during the first 48 h of life than those without congestive cardiac failure (P <or= 0.04). Serum cTnT concentrations during the first 48 h of life were significantly higher in asphyxiated infants who died than those who survived (P < 0.0001). There was no significant difference in serum CK-MB mass concentrations between asphyxiated infants with and without these complications (P >or= 0.1).

CONCLUSION

Unlike CK-MB, serum cTnT concentrations are significantly higher in asphyxiated infants who die or develop cardiac dysfunction.

Inflammatory chemokine expression in the peripheral blood of neonates with perinatal asphyxia and perinatal or nosocomial infections

AIM

The inflammatory response induced by perinatal infections and asphyxia is considered to participate in neonatal brain damage. Inflammatory responses are characterized by the expression of chemokines. Although chemokine levels have been investigated in healthy newborns, their role during neonatal pathological conditions has not been studied. The aim of our study was to examine chemokine serum levels in asphyxiated and infected neonates.

METHODS

Peripheral blood samples were obtained from perinatally asphyxiated and infected neonates during the first days of life and from neonates who developed nosocomial infections. Serum levels of interleukin-8 (IL-8), interferon-gamma-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), and regulated upon activation, normal T cells expressed and secreted (RANTES) were determined.

RESULTS

In perinatally asphyxiated neonates, IL-8 levels were significantly elevated on the 1st day of life. In perinatally infected neonates, IL-8 and IP-10 levels were significantly increased on the 1st day of life, while RANTES levels were significantly lower and remained so until the 4th day. In nosocomially infected neonates, IL-8, IP-10 and MIP-1alpha levels were significantly increased on diagnosis of infection.

CONCLUSION

The neonatal immune system is able to produce chemokines for the induction of an inflammatory response during perinatal asphyxia and perinatal or nosocomial infections. Blockade of inflammatory chemokines could possibly contribute to the prevention of brain damage.

Early prognostic significance of umbilical cord troponin I in critically ill newborns. Prospective study with a control group

AIM

To determine the value of cord blood cardiac troponin I levels (cTnl) as an early prognostic factor in critically ill newborns, and to compare cord cTnl levels with the prognostic value of the score for neonatal acute physiology (SNAP).

METHODS

Cord arterial samples were collected routinely for blood gas analysis, and cord venous samples for cTnl and cardiac-specific creatine kinase assay. The study group (n=109) comprised critically ill newborns who required mechanical ventilation. The control group (n = 96) comprised newborns who were either completely healthy (n = 48) or were followed in a level I neonatal care unit due to moderate-severity problems.

RESULTS

The critically ill newborns had significantly higher cTnl levels than control babies (median [min-max] 1.4 [0-13] vs. 0 [0-1.8] ng/mL, respectively; P<0.001). In critically ill newborns, non-survivors had significantly higher cTnl levels than survivors (median [min-max] 6.6 [1.3-13.0] vs. 1.3 [0-8.0] ng/mL, respectively; P<0.001). Receiver-operator curve analysis revealed that, compared with SNAP, cTnl was a more sensitive predictor of mortality in critically ill newborns (area under curve=0.96; 95% CI=0.90-1.02).

CONCLUSION

Significantly elevated cord cTnl may be a valuable predictor of mortality in critically ill newborns.

Thrombopoietin level is increased in the serum of asphyxiated neonates: a prospective controlled study

BACKGROUND

Thrombopoietin (TPO) is a growth factor that controls platelet production. Despite the known association of chronic hypoxia and acute asphyxia with hematologic changes, TPO had not been studied in neonatal asphyxia.

OBJECTIVE

To assess TPO concentrations in the serum of asphyxiated and nonasphyxiated neonates, and examine any correlation with the severity of asphyxia.

DESIGN/METHODS

This prospective study was carried out on 32 asphyxiated neonates and 30 control subjects admitted at Cairo University Medical Center. Asphyxia was defined if two of the following were found: (1) Apgar score </=3 at 1 minute or </=6 at 5 minutes, (2) umbilical cord arterial pH </=7.2 combined with base deficit >/=-10 and (3) clinical evidence of perinatal asphyxia. Encephalopathy was classified clinically according to Sarnat's stages during the first day of life. Platelet count and TPO level (pg/ml) were measured at 1st, 3rd and 7th day of life.

RESULTS

: TPO measured on the first day of life did not differ between cases and controls (900.2+/-526.4 vs 726.6+/-441.9 pg/ml, p=0.2). It increased on the 3rd day of life and was significantly higher in asphyxiated infants compared to controls (1291.4+/-627.9 vs 885.5+/-400.3 pg/ml, respectively; p=0.004). This difference remained significant in a logistic regression model controlling for birth weight, sex and mode of delivery (regression coefficient=476.9+/-146.8; p=0.002). In asphyxiated infants (n=32), encephalopathy was classified as mild (n=17), moderate (n=10) and severe (n=5). TPO correlated with the degree of clinical severity on the 7th day of life (r=0.59, p=0.003). TPO did not differ between survivors (n=24) and nonsurvivors (n=8) within the asphyxia group (1197.1+/-596.8 vs 1613.1+/-605.9 pg/ml; p=0.09). Platelet counts correlated negatively with TPO measured on day 1 (r=-0.415; p=0.02), day 3 (r=-0.64; p=0.001) and day 7 (r=-0.562; p=0.007).

CONCLUSIONS

TPO increased and correlated with severity of asphyxia at 3 and 7 days of life. It correlated negatively with the platelet count at all times.

[Clinical values of superoxide dismutase and malondialdehyde detection in cord blood of newborns with fetal distress]

OBJECTIVE

To investigate the relations between intrauterine asphyxia and peroxidation and newborn hypoxic-ischemic encephalopathy (HIE).

METHODS

The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in cord blood of 60 newborns with intrauterine asphyxia during labor (which was divided into two groups, 39 cases with asphyxia in group I, and 21 cases with asphyxia in group II), and in 30 newborns without intrauterine asphyxia (control group) were determined. The levels of SOD and MDA in cord blood of newborns with HIE were compared with those in newborns without HIE. The incidence of HIE was estimated simultaneously.

RESULTS

(1) The levels of SOD were (12,896 +/- 247) U/g Hb in group I, (9846 +/- 268) U/g Hb in group II, (17,282 +/- 134) U/g Hb in control group, significantly lower in the former two groups compared with control group, while the level of SOD in group I was higher than that in group II (P < 0.01). There were nine cases with HIE in groups I and II (HIE group), the level of SOD in these cases was (7486 +/- 245) U/g Hb. There were 51 cases with non-HIE (non-HIE group), the level of SOD in this group was (13,878 +/- 257) U/g Hb. There was significant difference in the level of SOD between HIE and non-HIE groups (P < 0.01). Nineteen cases were in < 30 min group, and the levels of SOD was (17 411 +/- 324) U/g Hb. Twenty-six cases were in 30 - 120 min group, and the levels of SOD was (12,076 +/- 230) U/g Hb. Fifteen cases were in > 121 min group, and the levels of SOD was (9786 +/- 249) U/g Hb. (2) The levels of MDA were (6.3 +/- 0.4) micromol/L in group I, (8.6 +/- 1.5) micromol/L in group II, and (4.1 +/- 0.5) micromol/L in control group, significantly higher in the former two groups compared with control group (P < 0.01). The levels of MDA were (10.6 +/- 0.6) micromol/L in HIE group and (5.1 +/- 0.8) micromol/L in non-HIE group, with significant difference between the two groups (P < 0.01). The levels of MDA were (4.2 +/- 0.3) micromol/L in <or= 30 min group, (7.5 +/- 1.5) micromol/L in 31 - 120 min group and (8.9 +/- 1.5) micromol/L in >or= 121 min group respectively. (3) None of HIE cases were in <or= 30 min group, three cases in 31 - 120 min group, and six cases in >or= 121 min group.

CONCLUSIONS

The results indicate that the incidence of intrauterine asphyxia is closely related to peroxidation, and intrauterine asphyxia may be an important factor in pathogenesis of HIE. The levels of SOD and MDA in cord blood may be regarded as one of the early predictive indexes for HIE.

Restoration of cardiopulmonary function with 21% versus 100% oxygen after hypoxaemia in newborn pigs

OBJECTIVE

To assess the consequences of hypoxaemia and resuscitation with room air versus 100% O(2) on cardiac troponin I (cTnI), cardiac output (CO), and pulmonary artery pressure (PAP) in newborn pigs.

DESIGN

Twenty anaesthetised pigs (12-36 hours; 1.7-2.7 kg) were subjected to hypoxaemia by ventilation with 8% O(2). When mean arterial blood pressure fell to 15 mm Hg, or arterial base excess was < or = -20 mmol/l, resuscitation was performed with 21% (n = 10) or 100% (n = 10) O(2) for 30 minutes, then ventilation with 21% O(2) for 120 minutes. Blood was analysed for cTnI. Ultrasound examinations of CO and PAP (estimated from tricuspid regurgitation velocity (TR-Vmax)) were performed at baseline, during hypoxia, and at the start of and during reoxygenation.

RESULTS

cTnI increased from baseline to the end point (p<0.001), confirming a serious myocardial injury, with no differences between the 21% and 100% O(2) group (p = 0.12). TR-Vmax increased during the insult and returned towards baseline values during reoxygenation, with no differences between the groups (p = 0.11) or between cTnI concentrations (p = 0.31). An inverse relation was found between increasing age and TR-Vmax during hypoxaemia (p = 0.034). CO per kg body weight increased during the early phase of hypoxaemia (p<0.001), then decreased. Changes in CO per kg were mainly due to changes in heart rate, with no differences between the groups during reoxygenation (p = 0.298).

CONCLUSION

Hypoxaemia affects the myocardium and PAP. During this limited period of observation, reoxygenation with 100% O(2) showed no benefits compared with 21% O(2) in normalising myocardial function and PAP. The important issue may be resuscitation and reoxygenation without hyperoxygenation.

Carnitine levels in neonatal hypoxia

BACKGROUND

The aim of this study is to determine carnitine levels in hypoxic-ischemiac neonates.

METHODS

Total and free carnitine levels were measured in 20 normal term neonates and 20 term neonates who were diagnosed as hypoxia-ischemia.

RESULTS

Both total carnitine levels (43.7 +/- 10.0 microg/dl vice 27.8 +/- 11.8 microg/dl, p<0.0001) and free carnitine levels (28.0 +/- 8.8 vice 13.2 +/- 6.8 microg/dl, p<0.0001) were lower in the hypoxic-ischemic group). Additionally acyl/total carnitine ratio was higher in the asphyxic group (0.33 +/- 0.20 vice 0.56 +/- 0.24, p<0.0001).

CONCLUSIONS

The findings of this study show that neonates with hypoxia-ischemia suffer carnitine deficiency.

Serum carnitine levels in newborns with perinatal asphyxia and relation to neurologic prognosis

Neonatal hypoxic encephalopathy is one of the major causes of permanent neurological sequel. This study was conducted to investigate serum total, free and acylcarnitine levels in asphyxiated newborns with or without encephalopathy. Serum total, free and acylcarnitine levels were investigated in 21 newborns with and seven asphyxiated newborns without signs of encephalopathy. The newborns with encephalopathy were further divided into grade 1, 2 and 3 encephalopathy groups. Serum total and acylcarnitine concentrations of the whole encephalopathy group were significantly lower than the non-encephalopathy group (p = 0.042 for both). Serum total and acylcarnitine concentrations of grade 3 encephalopathy group were significantly lower than the non-encephalopathy group (p = 0.014 and p = 0.040, respectively). No significant differences were noticed for free carnitine levels. Total carnitine levels were positively correlated with birth weight and 10th minute apgar score, whereas acylcarnitine levels were found to correlate with cord blood pH and free carnitine levels with birth weight. Cord blood pH, and total carnitine levels were found to be the most significant determinants of the neurological outcome at one year of age. It was emphasized that carnitine deficiency could occur in severely affected asphyxiated newborns and it is related to the outcome at one year of age.

Usefulness of cardiac troponin T and echocardiography in the diagnosis of hypoxic myocardial injury of full-term neonates

BACKGROUND

Perinatal asphyxia constitutes a significant problem influencing neonatal mortality and morbidity.

OBJECTIVES

The aim of the present work was to provide evidence of the usefulness of cardiac troponin T (cTnT) and echocardiographic investigations in the diagnosis of heart damage in full-term infants after intrauterine hypoxia.

MATERIAL AND METHODS

The subjects were 39 asphyxiated and 44 term infants without fetal anoxia. Quantitative determinations of cTnT were performed between 12 and 24 h of life. Two-dimensional Doppler and color Doppler studies were performed at the bedside. We evaluated fractional shortening (FS), cardiac output (CO), cardiac index (CI), tricuspid (TI) and mitral (MI) insufficiency.

RESULTS

Asphyxiated infants presented increased cTnT (mean 0.141+/-0.226 vs. 0.087+/-0.111 ng/ml; p<0.01) and TI (38.5 vs. 11.4% of population; p<0.05) compared to healthy infants. CO, CI and FS remained in the same range.

CONCLUSIONS

We found cTnT to be the most useful among accessible diagnostic tools used in post-hypoxic heart damage in neonates. The data from our relatively small population study suggest a cTnT value of >0.1 ng/ml as a reliable marker of myocardial injury in neonates. Further study should be performed to generate a receiver-operator characteristic curve to discover what the cut-off level should be.

Low adjusted serum ionized calcium concentration shortly after birth predicts poor outcome in neonatal hypoxic-ischemic encephalopathy

AIM

Hypoxic-ischemic reperfusion injury causes either necrosis or apoptosis, and the influx of ionized calcium into cells is the major cause of both types of cell death. The aim of this study was to investigate whether or not the serum ionized calcium concentration in neonates with hypoxic-ischemic encephalopathy (HIE) could be used to predict their outcome.

METHODS

Serum samples were obtained shortly after birth from 20 HIE neonates who had not urinated or received treatment with calcium. Serum ionized calcium concentrations were adjusted for pH using a correction formula. Twelve neonates without any disease were selected as a control. The results were compared between nine HIE neonates who made a full recovery, 11 who died or had neurologic deficits, and 12 normal neonates.

RESULTS

Considered together, the two HIE groups had lower serum ionized calcium concentrations (1.05 +/- 0.10 mmol/L) than the control group (1.22 +/- 0.07 mmol/L; P < 0.0001). Moreover, serum ionized calcium concentrations in the group with the poor outcome (0.99 +/- 0.07 mmol/L) were lower than those in the group that made a full recovery (1.13 +/- 0.06 mmol/L; P=0.0016).

CONCLUSIONS

The serum ionized calcium concentrations shortly after birth were significantly lower in neonates with HIE who had a poor outcome. Low concentrations may reflect multiple organ damage, particularly involving the brain.

Clinical risk management in newborn and neonatal resuscitation

This chapter aims to provide an overview of aspects of risk management as they might be applied to the practice of resuscitation of the newborn using general principles of risk management and specific standards where they apply. Section 1 considers the matter of hazard and risk and how they may be classified. Figures are presented to provide a clinical perspective on resuscitation with a discussion on the hierarchy of clinical risks operating upon the baby. Section 2 centres on a discussion of those aspects that operate to modify the risks to the baby during a resuscitation, including environmental considerations (location, clinical setting and equipment); staffing issues (establishment, competency, induction and training) and logistics (process, communication and documentation). Section 3 debates the place of cord gases in the context of the diagnosis of perinatal hypoxaemia.

Adrenomedullin increases in term asphyxiated newborns developing intraventricular hemorrhage

OBJECTIVES

Adrenomedullin (AM) is a newly discovered vasodilator peptide that participates in the regulation of cerebral blood flow. The aim of this study was to investigate whether circulating AM was increased in infants with prenatal asphyxia who developed intraventricular hemorrhage (IVH).

DESIGN AND METHOD

: A case-control study was performed on 40 full-term asphyxiated newborns: 20 developed IVH (group A) and 20 did not (group B). Forty term healthy newborns represented the control group. Biochemical laboratory parameters, neurological patterns, cerebral ultrasound scanning, and Doppler velocimetry were assessed at 12 and 72 h from birth. Plasma AM concentration was measured at 12 h from birth by means of a specific RIA.

RESULTS

AM levels were significantly higher in group A (20.2 +/- 5.2 fmol/ml) than in group B (8.4 +/- 2.1 fmol/ml) or controls (9.3 +/- 2.6 fmol/ml). In asphyxiated newborns, AM concentration was correlated with middle cerebral artery PI value only in group B.

CONCLUSIONS

Increased concentration of AM at 12 h from birth in asphyxiated newborns who later developed IVH suggests that this peptide may participate in the loss of cerebral vascular autoregulation in response to hypoxia and could be useful to discriminate, among newborns at risk, those with an adverse neurological outcome.

Value of nucleated red blood cells in predicting severity and outcome of perinatal asphyxia

The objective of the study was to assess nucleated red blood cell counts in cord blood in a group of asphyxiated infants, and to determine its predictive value for short-term outcome. A prospective case control study was undertaken on cord blood samples collected from fifty six term neonates with perinatal asphyxia and an equal number of normal appropriately matched controls for cord blood pH and nucleated RBC counts. Babies were followed up in nursery till discharge. Statistical analysis employed were ANOVA test, logistic and linear regression analysis. There was a significant increase in the number of nucleated red blood cells in cases as compared to controls. Low Apgar, cord blood pH and neonatal outcome correlated well with nucleated RBC counts. Nucleated red blood cell count at birth is a useful predictor of severity and short-term outcome of perinatal asphyxia.

Midazolam and amplitude-integrated EEG in asphyxiated full-term neonates

AIM

In the present, prospective study, the relation between the levels of midazolam, its two active metabolites--1-hydroxy-midazolam (OH-midazolam) and 1-hydroxy-midazolam-glucuronide (glu-midazolam)--and the aEEG were examined.

PATIENTS AND METHODS

Fifteen full-term neonates with seizures due to hypoxic-ischaemic encephalopathy admitted to our NICU were included. Midazolam (loading dose 0.05 mg/kg in 10 min, maintenance dose 0.15 mg/kg/h) was used as an add-on anti-convulsant after phenobarbital and lidocaine because of continuing seizures. Amplitude-integrated EEG background pattern was scored at the start of midazolam and at the time of blood sampling as continuous normal voltage (CNV), discontinuous normal voltage (DNV), burst suppression (BS), continuous low voltage (CLV) or flat trace (FT). Serum levels of midazolam, OH-midazolam and glu-midazolam were measured at least 8 h after the start with HPLC.

RESULTS

In 11/15 patients, seizures were abolished with the addition of midazolam. In the remaining patients, seizure frequency was reduced in one and unchanged in three. Amplitude-integrated EEG background pattern at the start of midazolam was CNV in two, DNV in six, BS in five and CLV in two. Moderate, temporary suppression of the aEEG background pattern lasting less than 2 h was seen in four neonates. Amplitude-integrated EEG at midazolam sampling was CNV in two, DNV in seven, CLV in two and FT in four. Serum levels of midazolam ranged from 0.10 to 1.76 mg/l, OH-midazolam from 0.05 to 0.28 mg/l and glu-midazolam from 0.85 to 4.36 mg/l.

CONCLUSIONS

A brief and moderate suppression of the aEEG background pattern immediately after midazolam was seen in four neonates for less than 2 h. Suppression at a later time point, i.e. after more than 8 h of midazolam infusion, was demonstrated almost exclusively in neonates with a poor background pattern, and therefore these patterns appear to be determined mainly by the severity of hypoxic-ischaemic encephalopathy.

Neuron-specific enolase as a marker of the severity and outcome of hypoxic ischemic encephalopathy

The aim of this study was to evaluate serum concentrations of neuron-specific enolase (NSE) as a marker of the severity of hypoxic ischemic encephalopathy (HIE) and to elucidate the relation among the concentrations of NSE, grade of HIE and short-term outcome. Forty-three asphyxiated full-term newborn infants who developed symptoms and signs of HIE (Group 1) and 29 full-term newborn infants with meconium-stained amniotic fluid but with normal physical examination (Group 2) were studied with serial neurological examination, Denver developmental screening test (DDST), electroencephalogram and computerized cerebral tomography (CT) for neurological follow-up. Thirty healthy infants were selected as the control group. In the patient groups, two blood samples were taken to measure NSE levels, one between 4 and 48 h and the other 5-7 days after birth. Serum NSE levels were significantly higher in infants with HIE compared to those infants in Group 2 and control group. The mean serum concentrations of the second samples decreased in all groups studied but they were significantly higher in Group 1 compared to those in Group 2. Serum NSE concentrations of initial samples were significantly higher in patients with stage III HIE than in those with stages II and I. The sensitivity and specificity values of serum NSE as a predictor of HIE of moderate or severe degree (cut-off value 40.0 microg/l) were 79 and 70%, respectively, and as a predictor of poor outcome (cut-off value 45.4 microg/l) were calculated as 84 and 70%, respectively. The predictive capacity of serum NSE concentrations for poor outcome seems to be better than predicting HIE of moderate or severe degree. However, earlier and/or CSF samples may be required to establish serum NSE as an early marker for the application of neuroprotective strategies.

[Fetal monitoring intra partum with cardiotocography and fetal blood sampling analysis and its possible influence on the C-section rate]

In times of rising c-section rates worldwide the obstetricians feel a big responsibility in avoiding a secondary c-section for non-reassuring fetal heart rate. No other experimental method has been established beside the gold standard (cardiotocography and fetal blood sampling) in daily routine until today. The two cases presented demonstrate the fallibility of the "gold standard" in predicting fetal asphyxia and why methodology with better positive predictive value is needed.

Protection of newborn organism against effect of oxidative stress

OBJECTIVE

The aim of the present study was to investigate influence of oxidative stress on newborn organism, in terms of the dynamics of malondialdehyde (MDA) concentration changes and of the activities of selected antioxidants in asphyxial newborns on the 1st and 5th day of life.

METHOD

In the group of 62 preterm and term asphyxial newborns, characterized by the presence of asphyxial criteria and admitted within 24 hours of life, the plasma concentration of MDA and level of total antioxidant status (TAS) were followed.

RESULTS

Dynamic changes of MDA signalized active process of lipoperoxidation (LP) and values of TAS were decreased in comparison with the capacity of adult patients.

[The significance of parameters of the acid-base status, blood gas and blood lactate level for the adequate resuscitation and prognosis in newborns with very low birth weight]

The aim of this prospective study was to optimize the resuscitation guidelines for VLBW and ELBW premature newborns, to improve their life prognosis and to minimize the permanent complications of the perinatal asphyxia.

RESULTS

The newborns were divided in 2 groups: main group--28 ELBW and 55 VLBW infants born from 01.10.01 to 30.06.02; and control group--52 ELBW and 78 VLBW infants, born in year 2000 in "Maichin dom". More intensive resuscitation was given to the VLBW newborns in the mean group--58% of them were intubated and ventilated in Delivery room (DR) infants compared with 40% from the controls. In the ELBW groups the rate of the assisted ventilation (AV) remains high (85% and 82%) but more often we insufflated Surfactant for prophylaxis of the RDS (71% compared with 52% in the controls). This, as well as the precisely monitoring of the early postnatal adaptation--pulsoxymetry, parameters of acid-base status (ABS) and homeostasis, resulted in significantly reduction of the mortality rate in ELBW infants from 46% to 18%. We found a reduction of the severe neurological injuries and high degree retinopathy of prematurity too. We evaluated the lactate values and the ABS parameters in blood from umbilical artery (u.a.) and from arterial blood 1 hour after birth. We found out that the low lactate levels in u.a. didn't correlate with the degree of the metabolic acidosis (pH and BE). Correlation between high lactate levels in u.a, low pH and BE were found predominantly in newborns with significant intrauterine retardation and chronic placental insufficiency. Levels > 5.0 mmol/l 1h after birth and the persistence of the metabolic acidosis despite an adequate resuscitation determinated in principle bad outcome and severe complications.

CONCLUSIONS

The adequate DR resuscitation under strict monitoring of the cardio-pulmonary adaptation and the prophylactic Surfactant application improve the survival rate and the prognosis of the ELBW newborns. The persistence of high lactate levels in combination with a metabolic acidosis and intrauterine retardation are bad prognostic criteria for outcome.

Postnatal lactate as an early predictor of short-term outcome after intrapartum asphyxia

OBJECTIVES

To compare the predictive value of pH, base deficit and lactate for the occurrence of moderate-to-severe hypoxic ischaemic encephalopathy (HIE) and systemic complications of asphyxia in term infants with intrapartum asphyxia.

STUDY DESIGN

We retrospectively reviewed the records of 61 full-term neonates (> or =37 weeks gestation) suspected of having suffered from a significant degree of intrapartum asphyxia from a period of January 1997 to December 2001. The clinical signs of HIE, if any, were categorized using Sarnat and Sarnat classification as mild (stage 1), moderate (stage 2) or severe (stage 3). Base deficit, pH and plasma lactate levels were measured from indwelling arterial catheters within 1 hour after birth and thereafter alongwith every blood gas measurement. The results were correlated with the subsequent presence or absence of moderate-to-severe HIE by computing receiver operating characteristic curves.

RESULTS

The initial lactate levels were significantly higher (p=0.001) in neonates with moderate-to-severe HIE (mean+/-SD=11.09+/-4.6) as compared to those with mild or no HIE (mean+/-SD=7.1+/-4.7). Also, the lactate levels took longer to normalize in these babies. A plasma lactate concentration >7.5+/-mmol/l was associated with moderate-or-severe HIE with a sensitivity of 94% and specificity of 67%. The sensitivity and negative predictive value of lactate was greater than that of the pH or base deficit.

CONCLUSIONS

The highest recorded lactate level in the first hour of life and serial measurements of lactate are important predictors of moderate-to-severe HIE.

Effect of perinatal asphyxia on thyroid-stimulating hormone and thyroid hormone levels

AIM

To compare serum concentrations of thyroid hormones--T4, T3, free T4 (FT4) and reverse T3 (rT3)--and thyroid-stimulating hormone (TSH) found in the umbilical cord blood of term newborns with and without asphyxia and those found in their arterial blood collected between 18 and 24 h after birth. A further aim of the study was to assess the association between severity of hypoxic-ischemic encephalopathy and altered thyroid hormone and TSH levels, and between mortality and FT4 levels in the arterial blood of newborns between 18 and 24 h of life.

METHODS

A case-control study was carried out. The case group comprised 17 term newborns (Apgar score < or = 3 and < or = 5 at the first and fifth minutes; umbilical cord blood pH < or = 7.15) who required bag and mask ventilation for at least one minute immediately after birth. The control group consisted of 17 normal, term newborns (Apgar score > or = 8 and > or = 9 at the first and fifth minutes; umbilical cord blood pH > or = 7.2). Cord blood and arterial blood samples were collected immediately after birth and 18 to 24 h after birth, respectively, and were used in the blood gas analysis and to determine serum concentrations of T4, T3, FT4, rT3 and TSH by radioimmunoassay. All newborns were followed-up until hospital discharge or death.

RESULTS

Gestational age, birthweight, sex, size for gestational age, mode of delivery and skin color (white and non-white) were similar for both groups. No differences were found in mean levels of cord blood TSH, T4, T3 and FT4 between the groups. In the samples collected 18 to 24 h after birth, mean levels of TSH, T4, T3 and FT4 were significantly lower in the asphyxiated group than in the control group. Mean concentrations of arterial TSH, T4 and T3 between 18 and 24 h of life were lower than concentrations found in the cord blood analysis in asphyxiated newborns, but not in controls. In addition, asphyxiated newborns with moderate/severe hypoxic-ischemic encephalopathy presented significantly lower mean levels of TSH, T4, T3 and FT4 than those of controls. None of the asphyxiated newborns with FT4 > or = 2.0 ng/dl died; 6 out of the 11 asphyxiated newborns with FT4 < 2.0 ng/dl died.

CONCLUSIONS

Serum concentrations of TSH, T4, T3 and FT4 are lower in asphyxiated newborns than in normal newborns between 18 and 24 h of life; this suggests central hypothyroidism secondary to asphyxia. Asphyxiated newborns with moderate/severe hypoxic-ischemic encephalopathy present a greater involvement of the thyroid function and consequently a greater risk of death.

Predictive value of brain-specific proteins in serum for neurodevelopmental outcome after birth asphyxia

Brain-specific proteins have been used to detect cerebral injury after birth asphyxia. Previous investigations suggest that serum protein S-100beta, brain-specific creatine kinase (CK-BB), and neuron-specific enolase (NSE) are capable of identifying patients with a risk of developing hypoxic-ischemic encephalopathy. Whether detection of elevated serum concentrations of these proteins reflects long-term neurodevelopmental impairment remains to be investigated. We examined serum protein S-100beta, NSE, and CK-BB at 2, 6, 12, and 24 h after birth in 29 asphyxiated infants and 20 control infants. Neurodevelopmental follow-up examinations were performed at 20 mo of age using the German revision of the Griffiths scales for developmental assessment. Elevated concentrations of serum protein S-100beta, NSE, and CK-BB within 24 h after asphyxia did not correlate with long-term neurodevelopmental delay. We conclude that serum protein S-100beta, NSE, and CK-BB, sampled on the first day of life, is of limited value in predicting severe brain damage after birth asphyxia.

Effects of gestational age and prenatal and perinatal events on the coagulation status in premature infants

OBJECTIVE

To study prospectively the effects of prematurity and perinatal events on the coagulation status of premature infants.

PATIENTS AND MAIN OUTCOME MEASURES

Blood samples from premature infants born before 37 gestational weeks were taken for analysis of coagulation factors II, V, VII, and X and platelet count.

RESULTS

A total of 125 premature infants, 71 boys, were studied at the median postnatal age of 40 minutes (range 12-100). The lowest median activities of coagulation factors II, V, VII, and X and the platelet count were observed, as expected, in infants (n = 21) born at 24-27 weeks gestation. Twin B (n = 14) had lower median activities of coagulation factors II, V, VII, and X than twin A. Infants with evidence of mild asphyxia (Apgar score at 5 minutes < 7 or cord pH < 7.26) had significantly (p < 0.05) lower levels of coagulation factors II, V, VII, and X and platelet counts than infants without asphyxia. Infants who were small for gestational age (SGA) had significantly (p < 0.05) lower levels of coagulation factors V and VII and platelet counts than infants of appropriate size for gestational age. Other prenatal and perinatal variables examined (sex, maternal hypertension and/or pre-eclampsia, antenatal steroid use, mode of delivery, Apgar scores) did not show any significant associations with coagulation status, which may be explained by the small number of infants studied.

CONCLUSIONS

The data strongly suggest that there are distinct differences in specific coagulation tests in different patient populations, which could assist in the identification of extremely preterm, SGA, or asphyxiated preterm infants who may be susceptible to haemorrhagic problems perinatally.

Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns

OBJECTIVE

To determine normal level of nucleated red blood cells (NRBC) per 100 white blood cells (WBC) in cord blood of term non-asphyxiated newborns and to investigate variations in NRBC counts in perinatal asphyxia.

METHODS

A total of 75 cases were studied. Levels of NRBC per 100 WBC in umbilical venous blood were compared between 26 asphyxiated newborns (group I) and 49 non-asphyxiated newborns (group II). Correlation with neonatal outcome was also evaluated.

RESULTS

The mean (+/-S.D.) NRBC per 100 WBC level in umbilical blood of newborns in group I was 16.5+/-6.4, range 3-25; whereas that in group II was 8.6+/-7.01, range 1-26. This difference was statistically significant (P<0.001). A statistically significant negative correlation existed between NRBC level and markers of acute intrapartum asphyxia, Apgar score and umbilical arterial pH (r=-0.50, P<0.001 and r=-0.48, P<0.001, respectively). Positive correlation was demonstrated with evidence of chronic antepartum asphyxia, presence of pregnancy induced hypertension and intrauterine growth restriction (r=2.66, P=0.02). A high NRBC count in umbilical blood correlated with poor early neonatal outcome.

CONCLUSIONS

The level of NRBC per 100 WBC correlates both with acute as well as chronic antepartum asphyxia. Further, it can be used as a reliable index of early neonatal outcome.

[Perinatal asphyxia, known topic, new diagnostic prospects--advisability of troponin T in perinatal medicine]

Perinatal asphyxia is a major topic in neonatology. It has a high impact on neonatal mortality and morbidity and neurological and intellectual development of the infant. Hypoxia triggers compensatory mechanisms in the fetus and the newborn aimed to sustain adequate oxygen transport to the vital organs. Long periods of hypoxia and poor perfusion cause failure of mentioned compensative mechanisms and lead to irreversible damage in tissues. No clear-cut physiologic parameters exist which allow for an early identification of neonatal infants who are either at risk to develop brain damage or posthypoxic heart failure. In the above paper authors demonstrate new possibilities in diagnosis of perinatal asphyxia. They present cardiac troponin T, a thin filament contractile protein as a highly specific and sensitive marker of myocardial injury and hypoxia.

[Relationship among serum cortisol and insulin and blood glucose in the asphyxiated neonates]

OBJECTIVE

To explore the dynamic change of serum cortisol and insulin levels, and their relation with blood glucose concentration in asphyxiated neonates.

METHODS

The levels of serum cortisol and insulin at d1,d3 and d7 of birth were measured by radioimmunoassay and the concentration of blood glucose was measured with glucose oxidase method in 43 asphyxiated neonates.

RESULTS

The levels of serum cortisol at d 1, d 3 and d 7 of birth were gradually decreased (P<0.01). At d1, the incidence of hyperinsulism (>20 mIU/L) was 60.5%. The level of serum insulin reached normal level (<or=20 mIU/L) at d 3. At d 1, the level of serum cortisol was positively related with the level of blood glucose (r=0.432, P<0.01), the ratio of serum insulin and cortisol in hypoglycemia group (0.71+/-0.71) was significantly higher than that in normal blood glucose group (0.19+/-0.36, P<0.01). The incidence of hypoglycemia in hyperinsulism group was markedly higher than that in normal serum insulin group (P<0.05).

CONCLUSION

There are temporary hyperinsulism in asphyxiated neonates. Hypoglycemia in asphyxiated neonates is related with hyperinsulism and low serum cortisol level.

[Blood ammonia and transaminases in full term infants suffering from perinatal asphyxia]

AIMS

To find hepatic markers of perinatal asphyxia.

PATIENTS AND METHODS

Variations in blood ammonia during the first week of life and in transaminase in serum during the first 48 hours were analysed in four groups of newly born infants (NBI): Group I or control, in which 65 NBI were included, with suspected unconfirmed infection and no other pathologies; Group II, made up of 15 NBI with loss of foetal well being (LFW) with no posterior neurological clinical features; Group III, consisting of 27 NBI with LFW criteria and mild hypoxic ischemic encephalopathy (HIE); and Group IV, with 25 NBI with LFW criteria and mild HIE according to Amiel s criteria.

RESULTS

The average blood ammonia values in full term infants remain steady during the first week of life (87.66 21.69 mg/dL), as occurs in infants with LFW but without HIE (89.08 24.69 mg/dL) and in those with mild HIE (89.08 20.75 mg/dL). In moderate HIE, the blood ammonia level rises until the third day (108.55 7.04 mg/dL) and then drops back to the initial values (p= 0.0045). When grouped by days, these values show significant differences (p= 0.04), with higher values in Group IV. The NBI with HIE presented higher levels of transaminases, especially of AST (GOT) (p= 0.000001), and this increase is proportional to its gravity. No relation was found between values of blood ammonia and transaminases.

CONCLUSIONS

Both blood ammonia and transaminases can be considered to be perinatal asphyxia markers.

Non protein bound iron as early predictive marker of neonatal brain damage

Of the approximately 130 million births worldwide each year, four million infants will suffer from birth asphyxia and, of these, one million will die and a similar number will develop serious sequelae. Before being able to develop effective interventions, a better understanding of the pathophysiological mechanisms leading to brain injury and an early identification of babies at high risk for brain injury are required. This study tests the predictivity of traditional and new markers of foetal oxidative stress in relation to neurodevelopmental outcome in 384 newborn infants. The results indicate plasma non protein bound iron as the best early predictive marker of neurodevelopmental outcome, with 100% sensitivity and 100% specificity for good neurodevelopmental outcome at 0-1.16 micro mol/l, and for poor neurodevelopmental outcome at values >15.2 micro mol/l. The number of children with values between 1.16 and 15.2 were 195. Common use of this predictive marker in neonatology units will improve the ability of clinicians to identify those newborn babies who will develop neurodisability.