[Microvolume dosage of lactate in cord blood for the evaluation of the neonatal well-being].
ABSTRACT A preliminary experience about a new microvolume lactate meter (Lactate Pro) is reported from 200 consecutive term deliveries. Comparison between lactate and pH in umbilical artery revealed a significant negative correlation between the two variables (r=-0.0693; p<0.0001). For the diagnosis of acidosis (pH<7.15) a lactate cutoff value at 6 mmol/l had a sensitivity of 50% and a specificity of 92% in a population with a prevalence of 8%. The study also demonstrated a better correlation between the concentrations of lactate and the base excess from 44 cord blood samples in high risk deliveries (r=0.837; p<0.0001). A lactate value higher than 6mmol/L predicted a metabolic acidosis (BE>- 8 mmol/l) with a sensitivity of 50% and a specificity of 94% from a collective with a prevalence of 16%. Considering the simplicity of the method, lactate measurements in cord blood could be extended to all birth centers for a systematic evaluation of the fetal condition in combination with the APGAR score. According to the minimal sampling volume (5 microliter) and the better prediction of metabolic acidosis this new method could replace the determination of the pH on fetal scalp.
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ABSTRACT: Obstetric litigation is a growing problem in developed countries and its escalating cost together with increasing medical insurance premiums is a major concern for maternity service providers, leading to obstetric practice cessation by many practitioners. Fifty-four to 74 % of claims are based on cardiotocographic (CTG) abnormalities and their interpretation followed by inappropriate or delayed reactions. A critical analysis is performed about the nine criteria identified by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics in their task force on Neonatal Encephalopathy and Cerebral Palsy: four essential criteria defining neonatal asphyxia and five other suggesting an acute intrapartum event sufficient to cause cerebral palsy in term newborns. The importance of placental histologic examination is emphasized in order to confirm sudden catastrophic events occurring before or during labor or to detect occult thrombotic processes affecting the fetal circulation, patterns of decreased placenta reserve and adaptative responses to chronic hypoxia. It may also exclude intrapartum hypoxia by revealing some histologic patterns typical of acute chorioamnionitis and fetal inflammatory response or compatible with metabolic diseases. Magnetic resonance imaging (MRI) of the infant's damaged brain is very contributive to elucidate the mechanism and timing of asphyxia in conjunction with the clinical picture, by locating cerebral injuries predominantly in white or grey matter. Intrapartum asphyxia is sometimes preventable by delivering weak fetuses by cesarean sections before birth, by avoiding some "sentinel" events, and essentially by responding appropriately to CTG anomalies and performing an efficient neonatal resuscitation. During litigation procedures, it is necessary to have access to a readable CTG, a well-documented partogram, a complete analysis of umbilical cord gases, a placental pathology and an extensive clinical work-up of the newborn infant including cerebral MRI. Malpractice litigation in obstetric care can be reduced by permanent CTG education, respect of national CTG guidelines, use of adjuncts such as fetal blood sampling for pH or lactates, regular review of adverse events in Clinical Risk Management (CRM) groups and periodic audits about low arterial cord pH in newborns, admission to neonatal unit, the need for assisted ventilation and the decision-to-delivery interval for emergency operative deliveries. Considering the fast occurrence of fetal cerebral hypoxic injuries, and thus despite an adequate management, many intrapartum asphyxias will not be preventable. Conversely, well-documented hypoxic-ischemic brain insults during the antenatal period do not automatically exclude intrapartum suboptimal obstetric care.Gynécologie Obstétrique & Fertilité 02/2011; 39(3):146-73. · 0.55 Impact Factor
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ABSTRACT: The aim of the present study was (1) to evaluate the relationship between umbilical cord arterial blood lactate and pH, standard base excess (SBE), and actual base excess (ABE) at delivery and (2) to suggest a cut-off level of umbilical cord arterial blood lactate in predicting fetal asphyxia using ROC-curves, where an ABE value less than -12 was used as "gold standard" for significant intrapartum asphyxia. This is a descriptive study of umbilical cord arterial blood samples from 2554 singleton deliveries. The deliveries took place at the Department of Obstetrics and Gynaecology, Hvidovre University Hospital, Copenhagen, Denmark where umbilical cord blood sampling and blood gas analysis is part of the routine assessment of all newborns. We found significant correlations between lactate and pH (r=-0.73), lactate and SBE (r=-0.76), and lactate and ABE (r=-0.83). ROC-curves suggested a lactate cut-off level of 8mmol/l for indicating intrapartum asphyxia. Lactate in arterial umbilical cord blood might be a more direct and accordingly more correct indicator of fetal asphyxia at delivery than pH and SBE (or ABE). Its potential as a predictor of neonatal outcome needs to be evaluated in future studies.European Journal of Obstetrics & Gynecology and Reproductive Biology 08/2008; 139(1):16-20. · 1.84 Impact Factor
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ABSTRACT: The identification of a metabolic acidosis is a key criterion for establishing a causal relationship between fetal perpartum asphyxia and neonatal encephalopathy and/or cerebral palsy. The diagnostic criteria currently used (pH and base deficit or lactatemia) are imprecise and non-specific. The study aimed to determine among a low-risk cohort of infants born at term (n=867), the best diagnostic tool of metabolic acidosis in the cordonal from the following parameters: pH, blood gases and lactate values at birth. The data were obtained from arterial blood of the umbilical cord by a blood gas analyser. The parameter best predicting metabolic analysis was estimated from the partial correlations established between the most relevant parameters. The results showed a slight change in all parameters compared to adult values: acidemia (pH: 7.28±0.01), hypercapnia (56.5±1.59mmHg) and hyperlactatemia (3.4±0.05mmol/L). From partial correlation analysis, pCO2 emerged to be the main contributor of acidemia, while lactatemia was shown to be non-specific for metabolic acidosis. Seven cases (0.81 %) showed a pH less than 7.00 with marked hypercapnia. The correction of this respiratory component by EISENBERG's method led to the eucapnic pH, classifying six out of seven cases as exclusive respiratory acidosis. It has been demonstrated that the criteria from ACOG-AAP for defining a metabolic acidosis are incomplete, imprecise and generating errors in excess. The same is true for lactatemia, whose physiological significance has been completely revised, challenging the misconception of lactic acidosis as a specific marker of hypoxia. It appeared that eucapnic pH was the best way for obtaining a reliable diagnosis of metabolic acidosis. We proposed to adopt a simple decision scheme for determining whether a metabolic acidosis has occurred in case of acidemia less than 7.00.Gynécologie Obstétrique & Fertilité 08/2013; · 0.55 Impact Factor