Neonatal cord blood eucapnic pH: A potential biomarker predicting the need for transfer to the NICU.

INTRODUCTION: The best biomarker for neonatal metabolic acidosis (NMA) and its related complications is still a matter of debate. Umbilical artery (Ua) cord pH is not sufficiently specific, as is lactatemia, while base deficit is considered to offer no added value. From a physiological point of view, the calculated neonatal eucapnic pH is a more specific marker for neonatal metabolic acidosis and may be a better predictor of birth complications of hypoxic origin, because complications related to asphyxia are always preceded by neonatal depression leading to a transfer to a neonatal intensive care unit (NICU) for close monitoring. OBJECTIVE: This study aimed to test the hypothesis that in a group of neonates with significant acidemia, neonatal eucapnic pH (pH euc-n) predicts NICU admission better than the Ua cord pH does. METHODS: From a cohort of 5,392 infants all born at ≥35 weeks' gestation, we identified a group of 30 cases with Ua cord pH <7.0. We calculated the area under the curve (AUC) for pH euc-n and Ua cord pH using the receiver-operating characteristic (ROC) curve and compared the performance of these biological markers in predicting transfer to the NICU. Cut-off points were determined by selecting the best value of the positive likelihood ratio that maximizes the accuracy of prediction. RESULTS: From the 30 newborns diagnosed with significant acidemia, four infants were transferred to the NICU. No case of neonatal encephalopathy was observed. In these infants, the pH euc-n AUC (0.66) was significantly higher than the Ua cord pH AUC (0.44) (P<0.005), with the best pH euc-n cut-off value at 7.11. CONCLUSION: Despite the study limitations, our results suggest that pH euc-n is a better marker than Ua pH for predicting admission to the NICU in newborns with acidemia at birth. These are preliminary results and further investigations are mandatory in larger population samples to confirm these findings and to determine the optimal cut-off value for pH euc-n for the most accurate prediction of a complicated transition to extrauterine life and, potentially, neonatal hypoxic-ischemic encephalopathy.

Field testing of decision coaching with a decision aid for parents facing extreme prematurity.

OBJECTIVE: The objective of this study is to assess and modify an existing decision aid and field-test decision coaching with the modified aid during consultations with parents facing potential delivery at 23 to 24 weeks gestation. STUDY DESIGN: International Patient Decision Aid Standards instrument (IPDASi) scoring deficits, multi-stakeholder group feedback and α-testing guided modifications. Feasibility/acceptability were assessed. The Decisional Conflict Scale was used to measure participants' decisional conflict before (T1) and immediately after (T2) the consultation. RESULTS: IPDASi assessment of the existing aid (score 11/35) indicated it required updated data, more information and a palliative care description. Following modification, IPDASi score increased to 26/35. Twenty subjects (12 pregnancies) participated in field-testing; 15 completed all questionnaires. Most participants (89%) would definitely recommend this form of consultation. Decisional conflict scores decreased (P<0.001) between T1 (52±25) and T2 (10±16). CONCLUSION: Field testing demonstrated that consultations using the aid with decision coaching were feasible, reduced decisional conflict and may facilitate shared decision-making.

Shared decision making for infants born at the threshold of viability: a prognosis-based guideline.

OBJECTIVE: Making prenatal decisions regarding resuscitation of extremely premature infants, based on gestational age alone is inadequate. We developed a prognosis-based guideline. STUDY DESIGN: We followed a five step approach and used the AGREE II framework: (1) systematic review and critical appraisal of published guidelines; (2) identification of key medical factors for decision making; (3) systematic reviews; (4) creation of a multi-disciplinary working group and (5) external consultation and appraisal. RESULT: No published guideline met high-quality appraisal criteria. Survival, neurodevelopmental disability, quality of life of child and parents, and maternal mortality and risk of long-term morbidity were identified as key for quality decision-making. Eighteen stakeholders (including parents) advocated for the incorporation of parents' values and preferences in the process. CONCLUSION: A novel framework, based on prognosis, was generated to guide when early intensive and palliative care may both be offered to expectant parents. Pre-implementation assessment is underway to identify barriers and facilitators to putting in practice.

Neonatal metabolic acidosis at birth: In search of a reliable marker.

OBJECTIVE: A newborn may present acidemia on the umbilical artery blood which can result from respiratory acidosis or metabolic acidosis or be of mixed origin. Currently, in the absence of a satisfactory definition, the challenge is to determine the most accurate marker for metabolic acidosis, which can be deleterious for the neonate. METHODS: We reviewed the methodological and physiological aspects of the perinatal literature to search for the best marker of NMA. RESULTS: Base deficit and pH have been criticized as the standard criteria to predict outcome. The proposed threshold of pathogenicity is not based on convincing studies. The algorithms of various blood gas analyzers differ and do not take into account the specific neonatal acid-base profile. CONCLUSION: Birth-related neonatal eucapnic pH is described as the most pertinent marker of NMA at birth. The various means of calculating this value and the level below which it seems to play a possible pathogenic role are presented.

Body temperature mapping in critically ill newborn infants nursed under radiant warmers during intensive care.

OBJECTIVE: The objectives of this study were to assess (i) the agreement between servo-control temperature (Tfeedback) and rectal temperature (Tre) and (ii) the distribution of regional skin temperatures (Tsk) of neonates nursed under a radiant warmer (RW) in a neonatal intensive care unit. STUDY DESIGN: An observational study of 13 neonates nursed under a RW device set to servo-control mode (Tfeedback set-point: 36.5 °C) who were monitored for Tfeedback, Tre and Tsk at six sites for a period of 105 min. RESULTS: Mean bias for Tfeedback relative to Tre was +0.01 °C, but 95% limits of agreement were ±0.99 °C, and only 66% of Tfeedback values were within the acceptable limits determined a priori (±0.5 °C). Tfeedback was maintained within a range of 1.4 °C (35.9 to 37.3 °C), whereas the range observed for regional skin temperatures spanned from 9.5 °C (27.3 to 36.8 °C; foot) to 4.8 °C (33.1 to 37.9 °C; chest). CONCLUSION: Although Tfeedback is maintained within narrow limits, the level of agreement with Tre is poor. In addition, large fluctuations in regional skin temperatures occur with a consistent caudal-to-rostral temperature gradient, irrespective of Tfeedback.

Accidental overheating of a newborn under an infant radiant warmer: a lesson for future use.

A fully functional radiant warmer induced rapid and continuous increases in regional skin temperatures, heart rate, mean arterial blood pressure and respiratory rate in a newborn patient without corrective action. We report this case of passive overheating to create awareness of the risks associated with regulating radiant heat output based upon a single servo-controlled temperature.