Predicting neonatal morbidity after perinatal asphyxia: a scoring system

Organ Complications of Infants with Hypoxic Ischemic Encephalopathy Before Therapeutic Hypothermia

Hypoxic ischemic encephalopathy (HIE) is a serious neurological complication that may develop in asphyxiated infants. Severity of encephalopathy may vary, and concurrent multiorgan dysfunctions are commonly observed. Analyzing the incidence of such complications according to severity of HIE, and how they correlate with each other, may shape clinical judgment and allow for early intervention. The study included a total of 57 HIE infants, in which 27/57 (47.37%) met Sarnat inclusion criteria for moderate stage II HIE (Group A) and 30/57 (52.63%) for severe stage III HIE (Group B). Both groups were assessed and compared for incidence of kidney dysfunction, liver dysfunction, coagulopathy, qualitative cardiac abnormalities, respiratory-related dysfunction, and bone marrow insufficiency/thrombocytopenia. All assessments were performed before initiation of therapeutic hypothermia. The complications were further assessed for the presence of correlations. Group B experienced significantly higher incidence of kidney dysfunction (A: 2/27 [7.4%] vs. B: 21/30 [70%], p < 0.001), liver dysfunction (A: 14/27 [51.8%] vs. B: 28/30 [93.3%], p < 0.001), and thrombocytopenia (A: 8/27 [29.6%] vs. B 21/30 [70%], p = 0.002) in our study group. Kidney dysfunction and bone marrow insufficiency showed the highest affiliation with other organ systems in both groups, correlating positively with each other as well as HIE severity, cardiac abnormalities, liver dysfunction, and infant death. A total of 8/57 (14%) infant deaths were observed, all originating from grade III severe HIE group (p = 0.003). Multiorgan dysfunction showed a significant difference between HIE severity (A: 12/27 [44.4%] vs. B: 28/30 [93.3%], p < 0.001). A positive correlation was obtained between multiorgan dysfunction, HIE severity, and infant death. Stage III HIE infants are more likely to experience abnormalities in the kidneys, liver, bone marrow as compared with stage II HIE infants. Correlations between organ complications are present, and should be taken into account during clinical assessment of HIE infants. The probability of mortality is higher in stage III HIE infants with observed multiorgan dysfunctions.

[Critical Outcome and Hypoxic Ischemic Encephalopathy - A quality Assurance Issue]

The study evaluates the predictive value of the critical status of a newborn as to the risk of developing hypoxic ischemic encephalopathy (HIE).

METHODS

On the basis of the data set from the perinatal survey in Hesse, Germany, in the year 2016, including 52,122 live births (singleton, 37+0 GA), cases of critical newborns were identified. A conjoined analysis with the data set of the neonatal survey from the identical period provided the basis to evaluate the relationship to cases compromised by HIE.

RESULTS

The incidence of cases with a critical outcome (n=11) and those with HIE (n=29) was low. The sensitivity of the status of the newborn for detecting a risk of HIE was 10.34%. The specificity was 99.98%. The positive predictive value was 27.35%. The negative predictive value was 99.95%. The detailed, confidential single-case analysis indicated the ability to avoid negative outcomes in about one third of cases with a critical status of the newborn (4/11) and HIE (9/29).

DISCUSSION AND CONCLUSION

The likelihood of developing encephalopathy (HIE) increases after a critical outcome after birth. Intensified monitoring of these newborns is justified. A single-case analysis identifies the potential ways to improve perinatal outcomes. Measures of external quality assurance should integrate the analysis of both perinatal and neonatal surveys as a basis for quality management (QM).

Apgar Score Components at 5 Minutes: Risks and Prediction of Neonatal Mortality

BACKGROUND

The Apgar score consists of five components: heart rate, respiratory effort, muscle tone, reflex irritability, and colour. Although the Apgar score has been used for 60 years, the specific contribution of the Apgar score components with respect to risks and prediction of neonatal mortality remains unknown. Likewise, the value of reduced scores (including less than five Apgar score components) has rarely been investigated.

METHODS

In a population-based cohort study of 148 765 liveborn singleton infants in Sweden 2008-2013, we investigated components of Apgar score at 5 min with respect to relative risks and prediction (using ROC curves, sensitivity, and positive predictive values) of neonatal mortality.

RESULTS

Reduced values (0-1) of heart rate, respiratory effort, and colour were independently associated with increased relative risks of neonatal mortality. For the full Apgar score, the sensitivity and positive predictive values of neonatal mortality (cut-off ≤3) were by gestational age: ≤31 weeks: 56.1% and 49.2%; 32-36 weeks: 25.0% and 18.2%; and ≥37 weeks: 35.2% and 9.3%, respectively. When only heart rate and respiratory effort were considered (range 0-4; cut-off ≤2), corresponding values were 66.7% and 34.9%; 37.5% and 13.0%; and 46.3% and 7.6%, respectively.

CONCLUSIONS

A reduced Apgar score has generally the same predictability of neonatal mortality as the full Apgar score. The full Apgar score or reduced scores may be better predictors of neonatal mortality in very preterm infants (≤31 weeks) than in infants with longer gestations.

Urinary Uric Acid/Creatinine Ratio - A Marker For Perinatal Asphyxia

BACKGROUND

Perinatal hypoxia is one of the leading causes of perinatal mortality in developing countries. Both apgar score and arterial blood pH predict the neonatal mortality in asphyxia. Apgar score alone does not predict neurologic outcome and as it is influenced by various factors. This study was conducted to evaluate the utility and sensitivity of urinary uric acid to creatinine ratio (UA/Cr ratio) in asphyxia diagnosis, compared to invasive Arterial Blood Gas (ABG) analysis.

AIM

To assess the urinary uric acid/creatinine ratio as an additional marker for perinatal asphyxia compared with ABG analysis in apgar score monitoring.

MATERIALS AND METHODS

The present case control study was conducted at a teaching hospital in Central Gujarat. Data of 40 healthy newborns and 40 asphyxiated newborns were collected. In absence of regional estimates, a sample of size 39 was required to attain a power of 80% at 5% alpha (type I error) considering a moderate effect size of 0.65. (UA/Cr) ratio was measured from the spot urine sample collected during 24-72 hours of birth. Statistical analysis was performed by Independent t-test, Pearson's correlation coefficient (r) and Receiver Operating Characteristic (ROC) plots.

RESULTS

The mean (UA/Cr ratio) (2.75±0.18 vs 1.78±0.23) is significantly higher in asphyxiated group than in the control group (p<0.0001). Urinary UA/Cr ratio had negative correlation with blood pH (r= -0.27, p=0.18), which was not significant (p>0.05). Urinary UA/Cr ratio with criterion of >2.3 had 100% sensitivity, 100% specificity with AUC of 1 (p<0.0001) had a better predictive value.

CONCLUSIONS

Apgar score is usually reduced in neonates with congenital anomalies and premature neonates. Hence, it is preferable that the clinical diagnosis of asphyxia by apgar scores be supported by other investigations so that early decision can be taken about the level of care the baby needs. pH, lactates and base deficits change with establishment of respiration following resuscitation. However, pH, lactate, base deficit estimations are invasive and need rapid estimations. Non-invasive urinary UA/Cr ratio may be an answer to these issues as it easy, economical and equally efficient.

Impact of transient period of metabolic adaptation on perinatal asphyxia in neonates with intrauterine growth retardation

INTRODUCTION

Temperature, glycemia and respiration make neonatal energy triangle (NET). In growth retardation (IUGR) neonates pathological metabolic adaptation exists in transient neonatal period.

AIM

The of this study was to examine the occurrence of pathological NET and check its impact on perinatal asphyxia during the transient period in IUGR neonates.

MATERIAL AND METHODS

One hundred and fifty-nine neonates with IUGR were classified into - early preterm, late preterm and term neonates. By the presence of hypothermia, hypoglycemia and hypoxia in the first hour after birth neonates were classified into: group of pathological NET, group of unstable NET and group of stable NET. We analyzed distribution per body mass, gestational age, type of IUGR, gender and the frequency of perinatal asphyxia between the groups.

RESULTS

The late preterm neonates were the most frequent in the group of pathological NET. Perinatal asphyxia was diagnosed in 52 (32.7%) neonates, with highest frequency in the group of pathological NET. Univariate binary logistic regression analysis showed that pathological NET in neonates with IUGR is significant predictor for perinatal asphyxia occurrence (OR = 8.57; CI = 4.05-18.12; p < 0.001 R² = 0.27).

CONCLUSION

Poor metabolic adaptation in neonates with IUGR in the first hour after birth is significant risk factor for the perinatal asphyxia.

Serum NGAL and copeptin levels as predictors of acute kidney injury in asphyxiated neonates

Background

Acute kidney injury (AKI) is the most common complication of perinatal asphyxia. Recent research indicates that serum neutrophil gelatinase-associated lipocalin (NGAL) is an early marker for AKI, but there are the lacks of data about its use in term neonates with perinatal asphyxia.

Methods

A prospective cohort study was conducted on 43 term neonates. Umbilical cord blood and 24 h after birth serum NGAL, copeptin, creatinine, and molality were measured in all asphyxiated and controls neonates.

Results

During the study period, 8 of asphyxiated nenates (18.6 %) suffered from AKI, while 35 newborns have no signs of AKI and 30 healthy infants. We did not observe any differences in creatinine and copeptin levels, as well as serum osmolality in all three investigated groups (AKI, no-AKI, and controls) in cord blood, and 24 h after birth. Serum NGAL levels in umbilical cord blood were significantly higher in the AKI group (174.3 ng/mL) compared with no-AKI (88.5 ng/mL, p = 0.01) and control groups (28.5 ng/mL, p < 0.001), and 24 h after birth (respectively, AKI 152.5 ng/mL vs no-AKI 74.9 ng/mL, p = 0.02 vs controls 39.1 ng/mL, p < 0.001). NGAL concentration showed a strong negative correlation to umbilical artery pH (Rho = −0.42, p = 0.04), base excess (Rho = −0.31, p = 0.03), and Apgar score in 1st min (Rho = −0.41, p = 0.02) and 5th min of life (Rho = −0.20, p = 0.001). ROC curve analysis demonstrated a good predictive value for NGAL levels (>140.7 ng/mL) which allows to diagnose AKI in asphyxiated patients with 88.9 % sensitivity (95 % CI 75–95 %) and 95.0 % specificity (95 % CI 76–99 %).

Conclusion

NGAL seems to be a promising marker, even in subclinical AKI in neonates, due to its high specificity, but copeptin did not meet expectations.

The value of serum pro-oxidant/antioxidant balance in the assessment of asphyxia in term neonates

OBJECTIVE

Asphyxia is a major cause of disabilities in term-born infants. Here we have explored the value in HIE (hypoxic-ischemic-encephalopathy) of using a combination of serum pro-oxidant/antioxidant balance (PAB) assay for predicting the prognosis of asphyxia.

METHOD

Ninety term neonates with asphyxia were enrolled and followed up for two years. Serum PAB, demographic/biochemical characteristics of mothers, and their neonates were determined. The Denver II test was used to assess outcomes.

RESULTS

Of the 90 asphyxiated neonates, 47 (52.2%) had a normal outcome and 43 babies (47.8%) had abnormal outcome. Serum PAB levels in neonates with normal and abnormal outcomes were 17.1 ± 9.23 and 48.27 ± 41.30 HK, respectively. A combination of HIE intensity and PAB, compared to other indicators, had a higher predictive-value (95.2%) for outcomes in asphyxiated babies.

CONCLUSION

We demonstrate that PAB in combination with HIE grade may have a better predictive value for the prognosis of asphyxiated babies and predicting future neurologic problems in asphyxiated term infants.

Risk factors associated with neonatal deaths: a matched case-control study in Indonesia

Background

Similar to global trends, neonatal mortality has fallen only slightly in Indonesia over the period 1990–2010, with a high proportion of deaths in the first week of life.

Objective

This study aimed to identify risk factors associated with neonatal deaths of low and normal birthweight infants that were amenable to health service intervention at a community level in a relatively poor province of Indonesia.

Design

A matched case–control study of neonatal deaths reported from selected community health centres (puskesmas) was conducted over 10 months in 2013. Cases were singleton births, born by vaginal delivery, at home or in a health facility, matched with two controls satisfying the same criteria. Potential variables related to maternal and neonatal risk factors were collected from puskesmas medical records and through home visit interviews. A conditional logistic regression was performed to calculate odds ratios using the clogit procedure in Stata 11.

Results

Combining all significant variables related to maternal, neonatal, and delivery factors into a single multivariate model, six factors were found to be significantly associated with a higher risk of neonatal death. The factors identified were as follows: neonatal complications during birth; mother noting a health problem during the first 28 days; maternal lack of knowledge of danger signs for neonates; low Apgar score; delivery at home; and history of complications during pregnancy. Three risk factors (neonatal complication at delivery; neonatal health problem noted by mother; and low Apgar score) were significantly associated with early neonatal death at age 0–7 days. For normal birthweight neonates, three factors (complications during delivery; lack of early initiation of breastfeeding; and lack of maternal knowledge of neonatal danger signs) were found to be associated with a higher risk of neonatal death.

Conclusion

The study identified a number of factors amenable to health service intervention associated with neonatal deaths in normal and low birthweight infants. These factors include maternal knowledge of danger signs, response to health problems noted by parents in the first month, early initiation of breastfeeding, and delivery at home. Addressing these factors could reduce neonatal deaths in low resource settings.

A scoring system for early prognostic assessment after neonatal seizures

OBJECTIVE

The aim of this study was to devise a scoring system that could aid in predicting neurologic outcome at the onset of neonatal seizures.

METHODS

A total of 106 newborns who had neonatal seizures and were consecutively admitted to the NICU of the University of Parma from January 1999 through December 2004 were prospectively followed-up, and neurologic outcome was assessed at 24 months' postconceptional age. We conducted a retrospective analysis on this cohort to identify variables that were significantly related to adverse outcome and to develop a scoring system that could provide early prognostic indications.

RESULTS

A total of 70 (66%) of 106 infants had an adverse neurologic outcome. Six variables were identified as the most important independent risk factors for adverse outcome and were used to construct a scoring system: birth weight, Apgar score at 1 minute, neurologic examination at seizure onset, cerebral ultrasound, efficacy of anticonvulsant therapy, and presence of neonatal status epilepticus. Each variable was scored from 0 to 3 to represent the range from "normal" to "severely abnormal." A total composite score was computed by addition of the raw scores of the 6 variables. This score ranged from 0 to 12. A cutoff score of > or =4 provided the greatest sensitivity and specificity.

CONCLUSIONS

This scoring system may offer an easy, rapid, and reliable prognostic indicator of neurologic outcome after the onset of neonatal seizures. A final assessment of the validity of this score in routine clinical practice will require independent validation in other centers.

Neonatal resuscitation in low-resource settings: what, who, and how to overcome challenges to scale up?

BACKGROUND

Each year approximately 10 million babies do not breathe immediately at birth, of which about 6 million require basic neonatal resuscitation. The major burden is in low-income settings, where health system capacity to provide neonatal resuscitation is inadequate.

OBJECTIVE

To systematically review the evidence for neonatal resuscitation content, training and competency, equipment and supplies, cost, and key program considerations, specifically for resource-constrained settings.

RESULTS

Evidence from several observational studies shows that facility-based basic neonatal resuscitation may avert 30% of intrapartum-related neonatal deaths. Very few babies require advanced resuscitation (endotracheal intubation and drugs) and these newborns may not survive without ongoing ventilation; hence, advanced neonatal resuscitation is not a priority in settings without neonatal intensive care. Of the 60 million nonfacility births, most do not have access to resuscitation. Several trials have shown that a range of community health workers can perform neonatal resuscitation with an estimated effect of a 20% reduction in intrapartum-related neonatal deaths, based on expert opinion. Case studies illustrate key considerations for scale up.

CONCLUSION

Basic resuscitation would substantially reduce intrapartum-related neonatal deaths. Where births occur in facilities, it is a priority to ensure that all birth attendants are competent in resuscitation. Strategies to address the gap for home births are urgently required. More data are required to determine the impact of neonatal resuscitation, particularly on long-term outcomes in low-income settings.

Magnesium sulfate in severe perinatal asphyxia: a randomized, placebo-controlled trial

OBJECTIVE

The goal was to study whether postnatal magnesium sulfate infusion could improve neurologic outcomes at discharge for term neonates with severe perinatal asphyxia.

METHODS

Forty term (> or =37 weeks of gestation) neonates with severe perinatal asphyxia were studied in a prospective, longitudinal, placebo-controlled trial. Patients were assigned randomly to receive either 3 doses of magnesium sulfate infusion at 250 mg/kg per dose (1 mL/kg per dose) 24 hours apart (treatment group) or 3 doses of normal saline infusion (1 mL/kg per dose) 24 hours apart (placebo group). Both groups also received supportive care according to the unit protocol for perinatal asphyxia.

RESULTS

In the treatment group, moderate encephalopathy was present in 35% (7 of 20) of the patients and severe encephalopathy in 65% (13 of 20) of patients at admission. In the placebo group, 40% (8 of 20) of patients had moderate encephalopathy and 60% (12 of 20) of patients had severe encephalopathy. The mean serum magnesium concentration in the treatment group remained at > or =1.2 mmol/L for 72 hours after the first infusion. At discharge, 22% (4 of 18) of infants in the treatment group had neurologic abnormalities, compared with 56% (10 of 18) of infants in the placebo group. Also, neuroimaging (head computed tomography) performed on day 14 yielded abnormal findings for fewer infants in the treatment group than in the placebo group (16% vs 44%). Infants in the treatment group were more likely to be receiving oral feedings (sucking) at discharge than were those in the placebo group (77% vs 37%). Good short-term outcomes at discharge occurred for 77% of the patients in the treatment group, compared with 37% of the patients in the placebo group.

CONCLUSION

Postnatal magnesium sulfate treatment improves neurologic outcomes at discharge for term neonates with severe perinatal asphyxia.

Acute kidney injury in critically ill newborns: what do we know? What do we need to learn?

Outcomes in critically ill neonates have improved over the past three decades, yet high residual mortality and morbidity rates exist. Acute kidney injury (AKI) is not just an innocent by-stander in the critically ill patient. Research on incidence and outcomes of AKI in the critically ill neonatal population is scarce. The objective of this publication is to (a) review original articles on the short- and long-term outcomes after neonatal AKI, (b) highlight key articles on adults and children with AKI in order to demonstrate how such insights might be applied to neonates, and (c) suggest clinical research studies to fill the gaps in our understanding of neonatal AKI. To date, observational studies suggest high rates of AKI and poor outcomes in critically ill neonates. Neonates with AKI are at risk of developing chronic kidney disease and hypertension. Large prospective studies are needed to test definitions and to better understand risk factors, incidence, independent outcomes, and mechanisms that lead to poor short- and long-term outcomes. Early biomarkers of AKI need to be explored in critically ill neonates. Infants with AKI need to be followed for sequelae after AKI.

N-acetylcysteine improves the hemodynamics and oxidative stress in hypoxic newborn pigs reoxygenated with 100% oxygen

Neonatal asphyxia may lead to cardiac and renal complications perhaps mediated by oxygen free radicals. Using a model of neonatal hypoxia-reoxygenation, we tested the hypothesis that N-acetylcysteine (NAC) would improve cardiac function and renal blood flow. Eighteen piglets (aged 1-4 days old, weighing 1.4-2.2 kg) were anesthetized and acutely instrumented for continuous monitoring of pulmonary and renal artery flow (cardiac index [CI] and renal artery flow index [RAFI], respectively) and mean blood pressure. Alveolar hypoxia was induced for 2 h, followed by resuscitation with 100% oxygen for 1 h and 21% oxygen for 3 h. Animals were randomized to sham-operated, hypoxic control, and NAC treatment (i.v. bolus of 150 mg/kg given at 10 min of reoxygenation followed by 100 mg/kg per h infusion) groups. Myocardial and renal tissue glutathione content and lipid hydroperoxide levels were assayed, and histology was examined. After 2 h of hypoxia, all animals were acidotic (pH 6.96 +/- 0.04) and in cardiogenic shock with depressed renal blood flow. Upon reoxygenation, CI and RAFI increased but gradually deteriorated later. The NAC treatment prevented the decreased CI, stroke volume, mean blood pressure, systemic oxygen delivery, RAFI, and renal oxygen delivery at 2 to 4 h of reoxygenation observed in hypoxic controls (versus shams, all P < 0.05). The myocardial and renal tissue glutathione content was significantly higher in the NAC treatment group (versus controls). The CI and RAFI at 4 h of reoxygenation correlated with the tissue glutathione redox ratio (r = 0.5 and 0.6, respectively, P < 0.05). There were no significant differences in heart rate, pulmonary artery pressure, systemic oxygen uptake, and tissue lipid hydroperoxide levels between groups. No histologic injury was found in the heart or kidney. In this porcine model of neonatal hypoxia and 100% reoxygenation, NAC improved cardiac function and renal perfusion, with improved tissue glutathione content.

Use of umbilical cord blood gas analysis in the assessment of the newborn

Analysis of paired arterial and venous specimens can give insights into the aetiology of acidosis in the newborn

Threshold of metabolic acidosis associated with neonatal encephalopathy in the term newborn

OBJECTIVE

To determine the threshold of metabolic acidosis associated with neonatal encephalopathy (NE) in the term newborn.

METHODS

Term patients were included on the basis of abnormal hemodynamic, respiratory or neurological signs still persisting 30 min after birth. Base deficit (BD30) was measured in arterial blood between the 30th and the 45th min of life and correlated with the occurrence of NE during the first days of life using receiver operating characteristics (ROC) methodology.

RESULTS

Moderate or severe NE occurred in 26% of patients whose BD30 was higher than 10 mmol/L and in 79% of patients whose BD30 was higher than 18 mmol/L. No infants developed moderate or severe NE when BD30 was less than 10 mmol/L. The apex of ROC curve related to moderate or severe NE corresponds to a BD30 of 14 mmol/L. At this threshold, the sensitivity of BD30 is 73.2% and the specificity 82%.

CONCLUSION

The threshold of metabolic acidosis that provides the best combination of sensitivity and specificity in relation to the occurrence of moderate or severe NE was a BD30 higher than 14 mmol/L. Significant birth asphyxia should be considered if BD30 exceeds 10 mmol/L.

Theophylline for renal function in term neonates with perinatal asphyxia: a randomized, placebo-controlled trial

OBJECTIVE

To study whether prophylactic theophylline can reduce the incidence and/or severity of renal failure in term infants with perinatal asphyxia.

STUDY DESIGN

Term neonates with severe perinatal asphyxia were randomized to receive a single dose of either theophylline (study group, n = 40) or placebo (control group, n = 30) during the first hour of life. Daily weight, output/input ratio, 24-hour fluid intake, and urine volumes were recorded during the first 5 days of life. Those infants with asphyxial renal failure were followed up for 1 year.

RESULTS

The incidence of severe renal dysfunction was increased in the control group. Creatinine clearance was higher and excretion of beta 2 microglobulin (beta2M) was lower in the theophylline group. Conversely, the glomerular filtration rate was lower in the control group. In infants with renal failure, serum creatinine and creatinine clearance returned to normal in the neonatal period, and the increased beta2M excretion normalized by age 6 weeks.

CONCLUSIONS

A single dose of theophylline within the first hour of birth in term neonates with perinatal asphyxia results in a significant decrease in serum creatinine level and urinary excretion of beta2M, along with an increase in creatinine clearance.

Combination of early perinatal factors to identify near-term and term neonates for neuroprotection

OBJECTIVE

To determine early predictors of abnormal outcome at > or =24 months' age in neonates at risk for hypoxic-ischemic brain injury.

STUDY DESIGN

A prospective cohort study with developmental follow-up of > or =24 months. Infants were selected based on risk factors, and neurologic outcome was determined. Variables affecting the outcome were evaluated with univariate and multivariate methods, and a scoring system was devised to predict adverse outcome.

RESULTS

A total of 41 infants born > or =35 weeks' gestational age with possibility of hypoxic-ischemic insult were enrolled. In all, 39 (95%) had known outcomes, of whom 17 (48%) had an abnormal neurologic outcome, including five deaths. The variables within the first hour of life correlating with the adverse outcome were 1- and 5-minute Apgar scores, intubation in the delivery room and cord/initial base-deficit > or =20 mmol/l. A scoring system was derived based on significant variables, and a score > or =5 had a 90% positive predictive value for abnormal outcome. Seizures, multiorgan failure and abnormal imaging studies were also significantly associated with abnormal outcome.

CONCLUSIONS

The proposed scoring system, being highly predictive of outcome at 24 months' age, may be potentially useful in selecting subjects for preventive or therapeutic interventions to prevent or minimize neurologic morbidity due to hypoxic brain injury.

Factors predictive of seizures and neurologic outcome in perinatal depression

To identify which early clinical variables are predictive of outcome in newborns with perinatal depression, we prospectively examined newborns with persistently abnormal neurologic examinations at 48 hours and (1) arterial pH </= 7.15, (2) 5-minute Apgar </= 5, (3) requirement for positive pressure ventilation in the delivery room, or (4) fetal heart rate monitoring abnormalities. Eighty-four such infants completed neurodevelopmental assessment at 1 year. Five-minute Apgar (P = 0.0064), arterial pH (P = 0.0065) and base excess (P = 0.0003), neonatal encephalopathy grade at 48 hours and 7 days (both P = 0.0001), EEG at 48 hours and 7 days (both P = 0.0001), cranial ultrasound (US) at 48 hours (P = 0.0013) and 7 days (P = 0.0002), and the occurrence of neonatal seizures (P = 0.0001) all correlated significantly with developmental outcome, whereas fetal heart rate monitoring, mode of delivery, and presence of the non-neurologic hypoxic-ischemic encephalopathy syndrome did not. In the multivariate analysis, a combination of the 48-hour EEG and 48-hour cranial ultrasound provided the best model to predict developmental outcome, and a point system to predict developmental outcome based on these two variables is proposed.

Discriminant function of perinatal risk that predicts early neonatal morbidity: its validity and reliability

BACKGROUND

This study aimed to identify significant perinatal risk factors associated with neonatal morbidity to construct a scoring system to aid in distinguishing between healthy and ill neonates. Validity and reliability of the scoring system were determined.

METHODS

We conducted a screening test and used logistic regression to analyze data from a cohort of 387 neonates and to determine the relationship between risk factors and morbidity. Twenty nine factors of perinatal risk were studied. Logistic regression and discriminant analysis were performed to assess risk for morbidity. This system was developed and validated prospectively on 238 new neonates.

RESULTS

Risk factors that demonstrated association with morbidity by logistic regression were chronic maternal illness, premature rupture of membranes (PROM), amniotic fluid, low Apgar score at 5 min, obstetric trauma, hypertension, neonatal resuscitation, breathing pattern at 6 h after delivery, birth weight, and gestational age. Discriminant function obtained from discriminant analysis had sensitivity of 68% and specificity of 93%, while positive and negative predictive values were 88 and 86%, respectively. Area below receiver operating characteristic (ROC) curve was 0.86 (standard error [SE]: 0.02). In the validity study, these values were maintained without significant differences. Kappa statistic between two physicians was calculated at 0.84 (p < 0.001).

CONCLUSIONS

Evidence indicated that discriminant function is a useful tool to assess initial neonatal risk, allowing pediatricians to predict morbidity prior to discharge of neonates.

Long-term developmental outcome of asphyxiated term neonates

Asphyxia remains one of the main causes of later disability in term infants. Despite many publications identifying possible predictors of outcome in this population of interest, little is known of the long-term developmental outcome of asphyxiated term neonates. Observational studies have largely focused on short-term outcomes, with an emphasis on significant neurologic sequelae and intellectual impairments. This article reviews the literature that has described the developmental outcome of asphyxiated term newborns. As part of this review, we have also highlighted the evolution of the definition of asphyxia and delineated appropriate markers that should be used in future research on this population.

A randomized, double-blind, placebo-controlled trial of the effects of prophylactic theophylline on renal function in term neonates with perinatal asphyxia

BACKGROUND

The kidney is the most damaged organ in asphyxiated full-term infants. Experiments in rabbits and rats have shown that renal adenosine acts as a vasoconstrictive metabolite in the kidney after hypoxemia and/or ischemia, contributing to the fall in glomerular filtration rate (GFR) and filtration fraction. Vasoconstriction produced by adenosine can be inhibited by the nonspecific adenosine receptor antagonist, theophylline. Gouyon and Guignard performed studies in newborn and adult rabbits subjected to normocapnic hypoxemia. Their results clearly showed that the hypoxemia-induced drop in GFR could be avoided by the administration of low doses of theophylline.

OBJECTIVE

This study was designed to determine whether theophylline could prevent and/or ameliorate renal dysfunction in term neonates with perinatal asphyxia.

SETTING

Buenos Aires, Argentina.

STUDY DESIGN

We randomized 51 severe asphyxiated term infants to receive intravenously a single dose of either theophylline (8 mg/kg; study group: n = 24) or placebo (control group: n = 27) during the first 60 minutes of life. The 24-hour fluid intake and the urine volumes formed were recorded during the first 5 days of life. Daily volume balances (water output/input ratio and weights) were determined. Severe renal dysfunction was defined as serum creatinine elevated above 1.50 mg/dL, for at least 2 consecutive days after a fluid challenge, or rising levels of serum creatinine (.3 mg/dL/day). The GFR was estimated during the second to third days of life by endogenous creatinine clearance (mL/minute/1.73 m2) and using Schwartz's formula: GFR (mL/minute/1.73 m2) =.45 x length (cm)/plasma creatinine (mg/100 mL) during the first 5 days of life. Tubular performance was assessed as the concentration of beta2-microglobulin (beta2M) determined by enzyme immunoassay, on the first voided urine 12 hours after theophylline administration. The statistical analysis for the evaluation of the differences between the groups was performed with Student's t and chi(2) tests as appropriate.

RESULTS

During the first day of life, the 24-hour fluid balance was significantly more positive in the infants receiving placebo compared with the infants receiving theophyline. Over the next few days, the change in fluid balance favored the theophyline group. Significantly higher mean plasma values were recorded in the placebo group from the second to the fifth days of life. Severe renal dysfunction was present in 4 of 24 (17%) infants of the theophylline group and in 15 of 27 (55%) infants of the control group (relative risk:.30; 95% confidence interval:.12-.78). Mean endogenous creatinine clearance of the theophylline group was significantly increased compared with the creatinine clearance in infants receiving placebo (21.84 +/- 7.96 vs 6.42 +/- 4.16). The GFR (estimated by Schwartz's formula) was markedly decreased in the placebo group. Urinary beta2M concentrations were significantly reduced in the theophylline group (5.01 +/- 2.3 mg/L vs 11.5 +/- 7.1 mg/L). Moreover, 9 (33%) patients of the theophylline group versus 20 (63%) infants of the control group had urinary beta2M above the normal limit (<.018). There was no difference in the severity of the asphyxia between infants belonging to the theophylline and control groups in regards of Portman's score. Except for renal involvement, a similar frequency of multiorganic dysfunction, including neurologic impairment, was observed in both groups. The theophylline group achieved an average serum level of 12.7 microg/mL (range: 7.5-18.9 microg/mL) at 36 to 48 hours of live versus traces (an average serum level of .87 microg/mg) in the placebo group.

CONCLUSIONS

Our data suggest that prophylactic theophylline, given early after birth, has beneficial effects on reducing the renal dysfunction in asphyxiated full-term infants. (ABSTRACT TRUNCATED)

Selection of babies for intervention after birth asphyxia

Based on animal experiments, the therapeutic window for neonates with signs of perinatal hypoxia-ischaemia is probably less than 6 h, and early selection of patients is of utmost importance. In term neonates, fetal heart rate and blood flow patterns, the Apgar score, and other clinical scoring systems are insufficient to select patients for intervention, whereas umbilical artery pH<7.0 combined with umbilical arteriovenous differences in PCO(2), lactate/pyruvate ratios in cord blood, and CSF interleukin-1beta have a better predictive value. At present, neurophysiological methods such as (amplitude-integrated) EEG and evoked potentials have the best predictive value. In preterm neonates, lactate/pyruvate and uric acid measurements in cord blood, as well as neurophysiology appear to be helpful to predict brain injury, and might be used to select patients for intervention.

Acute fetal asphyxia and permanent brain injury: a retrospective analysis of current indicators

OBJECTIVE

To determine whether a term neonate who has had sufficient intrapartum asphyxia to produce persistent brain injury will manifest the following four criteria: profound acidemia (arterial pH <7.00), an APGAR score < or =3 for 5 min or longer, seizures within 24 h of birth, and multiorgan system dysfunction.

METHODS

Singleton, liveborn, neurologically impaired neonates > or =37 weeks gestation who lived at least 6 days and had sufficient documentation of current intrapartum asphyxia criteria were retrospectively analyzed. Of these infants, solely neonates with acute fetal asphyxia due to a sudden prolonged FHR deceleration that lasted until delivery from a catastrophic event, e.g., uterine rupture, cord prolapse, were included. Organ system dysfunction was defined by separate criteria for each organ system. Dysfunction in one or more was defined as multiorgan system dysfunction.

RESULTS

Of the 292 eligible infants in the registry, 47 satisfied the entry criteria. In these 47 neonates, 10 (21%) satisfied all 4 criteria for intrapartum asphyxia.

CONCLUSIONS

Our retrospective study suggests that currently used indicators to define permanent fetal brain injury are not valid.

Long-term effects of neonatal hypoglycemia on brain growth and psychomotor development in small-for-gestational-age preterm infants

OBJECTIVE

To investigate the effects of neonatal hypoglycemia on physical growth and neurocognitive function.

STUDY DESIGN

A systematic detection of hypoglycemia (<2.6 mmol/L or 47 mg/dL) was carried out in 85 small-for-gestational-age preterm neonates. Prospective serial evaluations of physical growth and psychomotor development were performed. Retrospectively, infants were grouped according to their glycemic status.

RESULTS

The incidence of hypoglycemia was 72.9%. Infants with repeated episodes of hypoglycemia had significantly reduced head circumferences and lower scores in specific psychometric tests at 3.5 years of age. Hypoglycemia also caused reduced head circumferences at 18 months and lower psychometric scores at 5 years of age. Infants with moderate recurrent hypoglycemia had lower scores at 3.5 and 5 years of age compared with the group of infants who had 1 single severe hypoglycemic episode.

CONCLUSION

Recurrent episodes of hypoglycemia were strongly correlated with persistent neurodevelopmental and physical growth deficits until 5 years of age. Recurrent hypoglycemia also was a more predictable factor for long-term effects than the severity of a single hypoglycemic episode. Therefore repetitive blood glucose monitoring and rapid treatment even for mild hypoglycemia are recommended for small-for-gestational-age infants in the neonatal period.

Neonatal neurological examination as a predictor of neuromotor outcome at 4 months in term low-Apgar-score babies in Zimbabwe

The predictive value of the neonatal neurological examination (NNE) adapted from Prechtl, was investigated in 139 term Zimbabwean infants born with an Apgar score of five or less at 5 min. At 4 months, seven infants had died and 13 were lost to follow-up, leaving 119 infants to undergo the Infant Motor Screen (IMS). Eighty-eight infants were diagnosed as normal, six as suspect and 25 as abnormal at screening. The sensitivity, specificity, positive predictive value and negative predictive value of the NNE were 94%, 55%, 42% and 96%, respectively. Seventeen (14%) infants had developed microcephaly at 4 months and 13 (77%) of them scored abnormal on the IMS. Twenty-three of the 48 (48%) infants who had convulsions within 48 h of birth, were diagnosed as abnormal (P < 0.0001). The NNE proved to be very sensitive in detecting neurodevelopmental abnormalities in the neonatal period and the five abnormal syndromes derived from the NNE were able to correctly identify 94% of the abnormal infants.

Prospective validation of a scoring system for predicting neonatal morbidity after acute perinatal asphyxia

OBJECTIVE

To prospectively validate a previously reported scoring system for identifying the near-term infant at risk for the multiple organ system sequelae of acute perinatal asphyxia.

STUDY DESIGN

Prospective observational study.

SETTING

Three Denver teaching hospitals, each providing comprehensive obstetric care.

SUBJECTS

Newborn infants of 36 weeks or more gestation.

INTERVENTION

None.

STATISTICAL ANALYSIS

Chi-squared analysis with Fisher's exact test.

OUTCOME

Scores consisting of graded abnormalities in fetal heart rate monitoring, umbilical arterial base deficit, and 5-minute Apgar score were calculated by the research nurse after admission of the infant to the nursery (range of possible scores, 0 to 9). A second nurse, blinded to these data, prospectively followed the newborn's hospital course for multiple organ system morbidity.

RESULTS

Three thousand two hundred thirty-eight newborns were studied; 366 required neonatal intensive care unit admission. Eleven newborns had a score > or = 6 (mean umbilical artery pH = 6.98, base deficit = 17.1 mEq/L). Morbidities in these 11 newborns included seizures (2), hypoxic-ischemic encephalopathy (5), respiratory distress (9), hypotension (7), renal dysfunction (9), hypoglycemia/hypocalcemia (4), and thrombocytopenia or disseminated intravascular coagulopathy (3). The odds ratio (OR) and 95% confidence interval (CI) for newborns admitted to the neonatal intensive care unit with a score > or = 6 for having multiple organ system morbidity, defined as three or more affected organ systems, was 38.5 (95% CI, 9.2 to 127.8). The scoring system showed a stronger relationship with multiple organ system morbidity than did isolated individual indicators commonly used to identify asphyxia calculated on the same subjects: for those with pH < 7.00, OR 24 (95% CI, 6.4 to 94.1); base deficit > or = 10 mEq/L, OR 4.5 (95% CI, 1.9 to 10.3), and 5-minute Apgar score < or = 3, OR 7.4 (95% CI, 1.3 to 38.1).

CONCLUSION

This scoring system, encompassing both immediate intrapartum and postpartum measures and acid-base status proximate to the time of delivery, is useful for rapidly identifying the term and near-term newborn at risk for multiple organ system morbidity after acute perinatal asphyxia.

Predicting the outcome of postasphyxial hypoxic-ischemic encephalopathy within 4 hours of birth

OBJECTIVE

To build models that predict severe adverse outcome within 4 hours of birth in patients with postasphyxial hypoxic-ischemic encephalopathy. The goal was to develop models for selecting patients for therapeutic trials of neuroprotective medications.

STUDY DESIGN

Retrospective cohort study with follow-up to a minimum age of 12 months of 164 "outborn" term infants admitted to a tertiary neonatal intensive care unit, and 14 "inborn" term infants in the two tertiary perinatal centers in a regionalized setting. After performing univariate screening tests, multivariate models of association between risk factors and "severe adverse outcome" (death or major neurosensory impairment) were constructed.

RESULTS

Of 178 infants with postasphyxial hypoxic-ischemic encephalopathy of defined severity admitted consecutively between 1985 and 1992, 48 died, 40 survived with major neurosensory impairment, and 13 were lost to follow-up. The important predictors of severe adverse outcome in the first 4 hours were delayed onset of breathing, administration of chest compressions, and seizures. At 60 minutes of age, based on predicted probabilities of > 0.50, the sensitivity of the predictive model was 85% and specificity 68%. The parameter estimates of the predictive models are reported.

CONCLUSIONS

Age of onset of breathing, administration of chest compressions, and age of onset of seizures were the most important variables predictive of adverse outcome in this study. Although fairly sensitive and specific, these predictive models should be applied with caution. To build more accurate models, a template for the conduct of a large, multicenter prospective study is provided.

The value of a scoring system for hypoxic ischaemic encephalopathy in predicting neurodevelopmental outcome

A numeric scoring system for the assessment of hypoxic ischaemic encephalopathy during the neonatal period was tested. The value of the score in predicting neurodevelopmental outcome at 1 y of age was assessed. Forty-five infants who developed hypoxic ischaemic encephalopathy after birth were studied prospectively. In addition to the hypoxic ischaemic encephalopathy score all but two infants had at least one cranial ultrasound examination. Thirty-five infants were evaluated at 12 months of age by full neurological examination and the Griffiths Scales of Mental Development. Five infants were assessed at an earlier stage, four who died before 6 months of age and one infant who was hospitalized at the time of the 12 month assessment. Twenty-three (58%) of the infants were normal and 17 (42%) were abnormal, 16 with cerebral palsy and one with developmental delay. The hypoxic ischaemic encephalopathy score was highly predictive for outcome. The best correlation with outcome was the peak score; a peak score of 15 or higher had a positive predictive value of 92% and a negative predictive value of 82% for abnormal outcome, with a sensitivity and specificity of 71% and 96%, respectively. For the clinician working in areas where sophisticated technology is unavailable this scoring system will be useful for assessment of infants with hypoxic ischaemic encephalopathy and for prognosis of neurodevelopmental outcome.

Clinicopathological correlations in postasphyxial organ damage: a donor organ perspective

OBJECTIVES

1) To assess pathology in the heart, kidneys, lungs, liver, and intestine in babies dying of postasphyxial hypoxic ischemic encephalopathy (HIE), and their suitability for organ transplantation. 2) To analyze the correlation between in vivo clinical markers of collateral organ damage and autopsy findings.

STUDY DESIGN

Retrospective cohort study of 58 infants who died of postasphyxial HIE and had autopsies during 1985 to 1994. Collateral organ damage was evaluated clinically and pathologically, and the results compared.

RESULTS

Severe pathological changes were observed in 6% to 62% of the five organs studied; 59% of the four major organs had either minor or no pathology. The sensitivity of the clinical predictors ranged from 69% to 100%, and specificity from 50% to 97%.

CONCLUSIONS

The organs of newborns dying of severe HIE may be suitable for use as donor organs; predictions of their suitability were most accurate for liver, kidney, and lungs, and least accurate for the heart.

Neonatal complications in newborns with an umbilical artery pH < 7.00

OBJECTIVE

Our purpose was to determine the significance of an umbilical artery pH < 7.00 in relation to neonatal morbidity and mortality.

STUDY DESIGN

Between 1986 and 1993 acid-base assessment of the umbilical artery was performed routinely in 10,699 deliveries. In a retrospective cohort study 84 nonanomalous neonates with an umbilical artery pH < 7.00 were individually matched with 84 neonates with an umbilical artery pH > 7.24. Matched variables included year of delivery, gender, parity, maternal age, delivery mode, fetal presentation, gestational age, and birth weight. Differences in morbidity between the two groups during the neonatal period (until 28 days after delivery) were investigated.

RESULTS

Neonates with an umbilical artery pH < 7.00 versus > 7.24 showed significant differences in the following: neonatal condition directly post partum; neurologic, respiratory, cardiovascular, and gastrointestinal complications; and neonatal intensive care unit admissions. No significance was found in renal dysfunction and mortality rate. The proportion of premature infants (< 37 weeks) was 17% in both groups. In the acidotic group a 1-minute Apgar score < or = 3 and a 5-minute Apgar score < 7 was predictive for neonatal complications.

CONCLUSIONS

Severe intrapartum asphyxia, quantified by an umbilical artery pH < 7.00, poses a threat to the neonate's health.

Metabolic acidosis and fetal reserve

Dr Bailey, Director of the National Institute of Neurological Diseases and Blindness, Bethesda, Maryland, introduced the 1956 symposium on 'Neurological and psychological deficits of asphyxia neonatorum' by saying. 'Medical research in regard to cerebral palsy and other neurological disabilities has been relatively neglected. For a truly comprehensive attack on this problem we must focus a sharper scientific search for greater knowledge of those adverse biological factors which operate in the perinatal period. The proper point of departure in such a search is through controlled animal observations, for which purpose monkeys are best suited' (Windle, 1958). Our understanding of the significance of asphyxia is built on the foundation of the laboratory research that has followed upon this initiative. Laboratory studies in fetal monkeys and fetal lambs have clearly demonstrated that the fetus can initially compensate for an asphyxial insult and protect the vital organs. However, if the hypoxaemia progresses to a severe metabolic acidosis and cardiovascular decompensation with hypotension, brain damage will occur. There is a growing body of clinical evidence that supports the contention that the human fetus responds in a similar manner. The varied nature of hypoxic and ischaemic insults has been well demonstrated in animal studies. Total anoxia and isolated cerebral ischaemia are uncommon events in the human fetus. The common insult, particularly during labour, is a degree of hypoxia present over a variable period of time. This is fortunate in that such insults are associated with a period of fetal compensation that may last several hours, during which time a diagnosis of a developing metabolic acidosis can be made. This is the clinician's window of opportunity, when a definitive diagnosis of an asphyxial insult can be made and if necessary intervention made before the threshold of decompensation has been reached. A consensus on the threshold of decompensation has yet to be achieved. However, there is a growing body of evidence that the threshold is in the range of an umbilical artery base deficit of 12-16 mmol/l. Since the aim of the obstetrician during labour is the prevention of asphyxial morbidity and mortality, the determination of this threshold is important to provide criteria for clinical action. A blood gas and acid-base assessment with the determination of a metabolic acidosis is the best measure of an asphyxial insult that may be of clinical significance. The definition of the threshold of metabolic acidosis requiring intervention will continue to be clarified with future clinical research. However, there are many factors that will influence the fetal response to an asphyxial insult, which may require that a range of threshold be acknowledged. The effect upon the fetus will be influenced by whether the asphyxial event is the first or the last of a series of asphyxial episodes, and the duration of the asphyxial episode. The characteristics of the fetus, i.e. maturity (pre-term versus term), and fetal growth small for gestational age (SGA) or appropriate for gestational age (AGA) may influence the fetal response to an asphyxial insult. Improved understanding of these issues will provide a better rationale for clinical management.

Comments on past and present situation of intensive monitoring of the fetus during labor

Modern intensive monitoring of the fetus during labor affords the opportunity for the greatest possible safety to the infant, whilst at the same time dispensing with unnecessary operations to terminate labor which can be dangerous for the mother and her child. Developments over the past 28 years, since cardiotocography has been in clinical use, have unfortunately also been accompanied by confusion and mistakes. We think that there are two main reasons for this: I. Many who use cardiotocography have not assessed its efficiency correctly. Heart rate pattern with all their variations have too often been regarded as the only diagnostic criteria for the determination of fetal hypoxia. However this procedure only allows a rough selection of actually endangered fetuses. In more than 50% of the cases with a suspicious or pathologic cardiotocogram there is no concrete clinical evidence of manifest danger of hypoxia. II. Investigations concerning the practical importance of monitoring the fetus during labor were often not based on actual clinical indications. Attempts were made to prove that continuous electronic monitoring of the fetal heart rate could be replaced by simple traditional auscultation. Furthermore due to failure to appreciate the real efficiency of cardiotocography, this truly excellent method was in fact blamed for the faults arising from wrong interpretation, instead of underlining the lack of logic of the investigators concerned. After all, several prospective studies, that have examined the efficiency of various monitoring strategies, demonstrate the shortcomings of these techniques in the clinical setting and have shown them to have no relevance in every practice. Presently the most suitable way to monitor the fetus during labor is to combine cardiotocography with a biochemical method. At the moment fetal blood analysis is the most suitable test to be performed in cases where the cardiotocogram is not normal. Then the role of fetal blood analysis is to find out whether in fact a danger of hypoxia is threatened or not. Today the most urgent task when monitoring the fetus during labor is not so much to reduce the number of cases of cerebral palsy since these are seldom caused by intrapartum asphyxia. The major objective is now recognised to be to prevent early morbidity of the fetus, newborn, and the consequences that flow from this. The excellent results of combined intensive monitoring of the fetus during labor are particularly well illustrated by the intrapartum mortality in our hospital during different periods when monitoring practice has been progressively and methodically improved by stages. During the period when monitoring consisted of simple auscultation used on its own, the intrapartum mortality was 0.56%. After the introduction of fetal blood analysis--at that time cardiotocography did not yet exist--the mortality sank to 0.32%. During the first ten years of cardiotocography combined with fetal blood analysis the mortality reduced further to 0.17%, and during the following 13 years it reached to a minimal level of 0.4%. Finally, in this review, other aspects are commented on such as oximetry. Oximetry, presently used as pulse oximetry, as an additional biochemical method will possibly be incorporated as the third method of monitoring the fetus during labor. Oximetry could also be used as an automatic alarm system in the labor ward when fetal O2 levels drop below a particular limit to draw the attention of the staff to the case concerned. Up to now this has not been convincingly achieved with the use of cardiotocography.

Nonoliguric and oliguric acute renal failure in asphyxiated term neonates

The purpose of this study was to determine the prevalence and types of acute renal failure in asphyxiated full-term neonates and to evaluate the accuracy of an asphyxia morbidity score in predicting acute renal failure. Neonates admitted to one institution from 1990 through 1993 with a gestational age > or = 36 weeks and 5-min Apgar score < or = 6, without congenital malformations or sepsis, were studied retrospectively for acute renal failure in the 1st week of life. Acute renal failure was defined as serum creatinine > 1.5 mg/dl (133 mumol/l) with normal maternal renal function. Nonoliguric renal failure was defined as renal failure with urine output > 1 ml/kg per hour after the 1st day. An asphyxia morbidity scoring system was used to distinguish severe from moderate asphyxia. The score ranged from 0 to 9 and was based upon fetal heart rate, Apgar score at 5 min, and base deficit in the 1st h of life. The score for severe asphyxia was defined as 6-9 and for moderate asphyxia as 1-5. Sixty-six neonates fulfilled study criteria. Acute renal failure was present in 20 of 33 (61%) infants with severe asphyxia scores and 0 of 33 with moderate asphyxia scores (P < 0.0001). Acute renal failure was nonoliguric in 12 of 20 (60%), oliguric in 5 of 20 (25%) and anuric in 3 of 20 (15%). In conclusion 1) acute renal failure occurred in 61% of infants with severe asphyxia, 2) acute renal failure associated with severe asphyxia was predominantly nonoliguric and 3) an asphyxia morbidity score, which can be determined at 1 h of age, predicted acute renal failure in full-term infants with 100% sensitivity and 72% specificity.

Multiple organ involvement in perinatal asphyxia

OBJECTIVES

(1) To evaluate the frequency and spectrum of severity of multisystem dysfunction after perinatal asphyxia and (2) to analyze the relationship between the clinical and biochemical markers of perinatal asphyxia and multiorgan involvement.

STUDY DESIGN

Seventy-two consecutive term newborn infants with perinatal asphyxia were studied prospectively. Systematic neurologic, renal, pulmonary, cardiac, and gastrointestinal evaluations were performed. Involvement of each organ was classified as moderate or severe.

RESULTS

Involvement of one or more organs occurred in 82% of the infants; the central nervous system (CNS) was most frequently involved (72%). Severe CNS injury (7 infants) always occurred with involvement of other organs, although moderate CNS involvement was isolated in 14 infants. Renal involvement occurred in 42%, pulmonary in 26%, cardiac in 29%, and gastrointestinal in 29% of the infants; 15% neonates had renal failure and 19% had respiratory failure. The Apgar scores at 1 and 5 minutes were the only perinatal factors related to the number of organs involved and the severity of involvement; the Apgar score at 5 minutes had the stronger independent association. No relationship or organ dysfunction was found with the umbilical cord arterial blood pH, meconium-stained amniotic fluid, umbilical cord abnormalities, presentation, or type of delivery.

CONCLUSIONS

Our findings indicate that the Apgar score at 5 minutes, in infants who have other criteria for asphyxia, is the perinatal marker that may best identify infants at risk of organ dysfunction.

Neonatal urinary uric acid/creatinine [correction of ceratinine] ratio as an additional marker of perinatal asphyxia

The diagnosis and evaluation of perinatal asphyxia can be problematic and objective means of assessing its severity are lacking. To study the validity of urinary uric acid as a marker of the degree of perinatal asphyxia, the ratio of urinary uric acid to creatinine (UA/Cr) in urine specimens obtained after birth was measured in two groups of infants. Eighteen term infants with Apgar scores < or = 5 at 5 min and/or an umbilical cord blood pH < or = 7.2, and a base deficit > or = 12 meq/l were compared to 50 healthy controls. The severity of the perinatal asphyxia was determined by using an ASPHYXIA SCORE. The UA/Cr was higher in the asphyxiated group when compared to controls. (2.06 +/- 1.12, vs. 0.64 +/- 0.48; P < 0.001). Within the perinatal asphyxia group, a significant correlation was found between the UA/Cr ratio and the asphyxia score. (r = 0.86, P < 0.01).

CONCLUSION

Infants with perinatal asphyxia have a significantly higher urinary UA/Cr ratio. This may be used as an indicator of the severity of perinatal asphyxia.

Newborn complications after intrapartum asphyxia with metabolic acidosis in the term fetus

OBJECTIVES

Our purpose was to determine the newborn complications after respiratory or metabolic acidosis at delivery and to demonstrate the characteristics of an asphyxial insult predictive of these complications.

STUDY DESIGN

Fifty-nine term fetuses with metabolic acidosis were matched with 59 fetuses with normal blood gas measures at delivery. Fifty-one fetuses with respiratory acidosis were also examined. A complication score expressed the magnitude of newborn complications during the 10 days after delivery.

RESULTS

Newborn complications were not increased after respiratory acidosis. Newborn complications after metabolic acidosis increase in frequency and severity with the increasing severity and duration of the metabolic acidosis. Thirty-two of the 59 newborns in the metabolic acidosis group had a high complication score. The index values predictive of high scores were the duration of the metabolic acidosis and the Apgar score at 1 minute.

CONCLUSIONS

Intrapartum fetal asphyxia with a severe metabolic acidosis accounts for complications in all newborn systems. The probability of a high complication score increases from 14% with favorable index values to 85% with unfavorable index values.

Diagnosis of severe birth asphyxia and early prediction of neonatal neurological outcome in term asphyxiated newborns

Ten indicators available during the first two hours of life, such as clinical criteria of neonatal distress and postnatal arterial blood gases, were compared with the neonatal neurological course in sixty full term newborns with significant birth asphyxia in order to test their value for the diagnosis and the short-term prognosis of severe birth asphyxia. Birth asphyxia was defined as severe when it was followed by symptoms of moderate or severe post-asphyxial encephalopathy. We calculated a sensitivity lower than fifty percent for clinical criteria such as delay in establishing regular respiration and Apgar scores. It was clear that normal delay in establishing regular respiration and normal Apgar scores do not exclude severe birth asphyxia. Arterial pH and base deficit at thirty minutes of life were found to be the best criteria for the diagnosis of severe birth asphyxia, but lacked positive predictive value. The best predictive tool for the short-term neurological prognosis of birth asphyxia was a single score established at 30 minutes of life and based on the evaluation of consciousness, respiration and neonatal reflexes. Some aspects of the pathophysiology of birth asphyxia and the rationale for treatment of post-asphyxial metabolic acidosis are discussed.

Measuring Illness Severity in Newborn Intensive Care

Measurement of illness severity has found increasing use in adult and pediatric intensive care research over the past decade. The development of illness severity indices for neonatal intensive care has lagged because birth weight has served as an excellent proxy for illness severity. However, a number of recent studies have shown marked variation in survival and morbidity among neonatal intensive care units (NICUs) despite birth weight adjustment, making clear the need for neonatal illness severity scoring. We discuss advantages and disadvantages of the 4 types of scoring systems used in adult intensive care—diagnosis, risk-factor, therapeutic, and physiological—and review their applications in adult and pediatric ICU research. Criteria for score design, as well as standards for validation and performance, are enumerated. The 30 neonatal scores fall in 5 major categories: obstetric risk, general use pediatric scores, predictors of developmental outcome, bronchopulmonary dysplasia risk, and acute mortality risk. Few have been adequately validated on large, concurrent independent samples. The most promising scores are those that measure acute physiological derangement on admission. Potential applications for these new illness severity scores are discussed.

The increase of yellow skin colour beyond that of serum bilirubin: a proposed indicator of risk for bilirubin encephalopathy in the newborn

Forty-seven newborn infants with 1 min Apgar score < 7 were studied. On the third postnatal day the following measurements were made: yellow skin colour, serum bilirubin concentration, reserve albumin concentration and plasma pH. Given the bilirubin concentration and the regression curve between the yellow skin colour and the bilirubin concentration, delta-TcB was calculated as the difference between measured yellow skin colour and the expected yellow skin colour. There was a negative correlation between delta-TcB and Apgar score (P = 0.003), pH (P = 0.026) and reserve albumin concentration (P = 0.045). Fourteen of the included newborns had central nervous system symptoms in the days just following birth. A tendency towards higher delta-TcB was noted in this group (P = 0.08). The results suggest that further study of delta-TcB determination as a tool in the assessment of the icteric newborn infant is justified.

Timing of brain insults in severe neonatal encephalopathies with isoelectric EEG

In a neonatal intensive care unit of a large obstetric hospital, 20 neonates (7 preterm, 9 term, 4 postterm) with at least one isoelectric recording were treated over a 6-year period. Seventy-four EEGs were obtained in this cohort, including 36 isoelectric recordings. Seven infants in this group had evidence of a predominant antepartum component of a pathologic process based on placental, postmortem examination findings, or clinical history. Of the 16 placentas available for review, chronic lesions were observed in 13 of 16 specimens, including villitis, infarction, dysmaturity, and thrombosis. Seven of 9 patients with postmortem neuropathologic examinations had evidence of chronic lesions, principally neuronal necrosis, infarction, and microcalcifications. An additional 10 infants had evidence of an antepartum contribution to a pathologic process that continued into either the intrapartum or neonatal periods, based on maternal and/or neonatal medical factors. Clinical findings supportive of antepartum insults included intrauterine growth retardation, antepartum hemorrhage, abnormal antepartum fetal heart rate patterns, and maternal medical complications. Three patients had either intrapartum- or neonatal-onset of injury. Clinical signs of severe encephalopathy, however, were present in the immediate postnatal period in most patients (18 of 20; 90%). Assessment of clinical and pathologic information on neonates with isoelectric EEGs may estimate the timing of brain injury to the antepartum period, as opposed to, or in addition to, the labor and delivery periods. A neonate who suffered brain injury before parturition may be neurologically depressed after birth with absence of electrocerebral activity on EEG.