Gilles Jourdain

Stroke volume and cardiac output evaluation by electrical cardiometry: accuracy and reference nomograms in hemodynamically stable preterm neonates

Objective:To investigate the accuracy of electrical cardiometry (EC) to measure stroke volume (SV) and cardiac output (CO) and to provide gestational age (GA) and birth weight (BW)-based reference data for SV and CO in hemodynamically stable preterm neonates.Study Design:Prospective observational blinded study. Paired measurements of SV and CO on stable preterm infants without any hemodynamic compromise were carried out using EC (SVEC) and echocardiography (SVECHO).Results:Seventy-nine preterm neonates (mean GA: 31±3.2 weeks) were enrolled. A good correlation was found for SV (r=0.743; P<0.0001) and CO (r=0.7; P<0.0001) measured by EC and echocardiography. These correlations remained significant after adjusting for GA, patent ductus arteriosus and type of respiratory support (SV: St.β=0.48, P<0.0001 and CO: St.β=0.69, P<0.0001). Mean biases (and variabilities) were −1.1 (from 0.7 to −2.9) ml and −0.21 (from 0.15 to −0.55) l min−1 for SV and CO, respectively. Local regression shows a tendency for EC to overestimate SV and CO especially at higher values (at about >2 ml and >0.4 l min−1, respectively). Coefficient of variation of SV was 48.9% and 52%, for EC and echocardiography. SV and CO rose with increasing GA and BW following an exponential equation (R2>0.8).Conclusion:Measuring SV and CO with EC in hemodynamically stable preterm infants shows good correlation and variability similar to that of echocardiography. A trend to overestimation exists at highest values, but it is unlikely to be clinically significant. Reference GA and BW-based nomograms for SV and CO are provided.

Outcomes of Preterm Neonates Transferred Between Tertiary Perinatal Centers.

Objective: To verify if preterm neonates transferred between tertiary referral centers have worse outcomes than matched untransferred infants. Design: Cohort study with a historically matched control group. Setting: Two tertiary-level neonatal ICUs. Patients: Seventy-five neonates per group. Interventions: Transfer between tertiary-level neonatal ICUs carried out by a fully equipped transportation team. Measurements and Main Results: We measured in-hospital mortality, frequency of intraventricular hemorrhage greater than 2nd grade, periventricular leukomalacia, necrotizing enterocolitis greater than or equal to grade 2, bronchopulmonary dysplasia, composite outcomes (in-hospital mortality/bronchopulmonary dysplasia, in-hospital mortality/intraventricular hemorrhage > 2nd grade, and bronchopulmonary dysplasia/periventricular leukomalacia/intraventricular hemorrhage > 2nd grade), length of neonatal ICU stay, weight at discharge, and time spent on ventilatory support. Seventy-five similar (except for antenatal steroids administration) neonates were enrolled in each cohort. Cohorts did not differ in mortality, bronchopulmonary dysplasia, intraventricular hemorrhage greater than 2nd grade, periventricular leukomalacia, necrotizing enterocolitis greater than or equal to grade 2, any composite outcomes, neonatal ICU stay, weight at discharge, and duration of respiratory support. Results were unchanged adjusting for antenatal steroids. Conclusions: Neonatal transfer between tertiary-level centers does not impact on clinical outcomes, if performed under optimal conditions.

Basic Hemodynamic Monitoring Using Ultrasound or Electrical Cardiometry During Transportation of Neonates and Infants

Objectives: Electrical cardiometry and heart ultrasound might allow hemodynamic evaluation during transportation of critically ill patients. Our aims were 1) to test feasibility of stroke volume monitoring using electrical cardiometry or ultrasound during transportation and 2) to investigate if transportation impacts on electrical cardiometry and ultrasound reliability. Design: Prospective, pragmatic, feasibility cohort study. Setting: Mobile ICUs specialized for neonatal and pediatric transportation. Patients: Thirty hemodynamically stable neonates and infants. Interventions: Patients enrolled underwent paired stroke volume measurements (180 before/after and 180 during the transfer) by electrical cardiometry (SVEC) and ultrasound (SVUS). Measurements and Main Results: No problems or malfunctioning occurred neither with electrical cardiometry nor with ultrasound. Ultrasound lasted on average 90 (10) seconds, while 45 (15) seconds were needed to instigate electrical cardiometry monitoring. Coefficient of variation was higher for SVUS (before/after: 0.57; during: 0.66) than for SVEC (before/after: 0.38; during: 0.36). Correlations between SVEC and SVUS before/after and during the transfer were r equal to 0.57 and r equal to 0.8, respectively (p always < 0.001). Bland-Altman analysis showed that stroke volume tends to be higher if measured by electrical cardiometry. SVEC measured before (5.5 [2.4] mL), during (5.4 [2.4] mL), and after the transfer (5.4 [2.3] mL) are similar (p = 0.955); same applies for SVUS before (2.6 [1.5] mL), during (2.4 [2] mL), and after (2.9 [2] mL) the transfer (p = 0.268). Conclusions: Basic hemodynamic monitoring is feasible during pediatric and neonatal transportation both with electrical cardiometry and ultrasound. These two techniques show comparable reliability, although stroke volume was higher if measured by electrical cardiometry. The transportation itself does not affect the reliability of stroke volume measurements.

Passive hypothermia (≥35 - <36°C) during transport of newborns with hypoxic-ischaemic encephalopathy

Background Hypothermia initiated in the first six hours of life in term infants with hypoxic ischemic encephalopathy reduces the risk of death and severe neurological sequelae. Our studys principal objective was to evaluate transport predictors potentially influencing arrival in NICU (Neonatal Intensive Care Unit) at a temperature ≥35-<36°C. Methodology/Principal findings A multi-centric, prospective cohort study was conducted during 18 months by the three Neonatal Transport Teams and 13 NICUs. Newborns were selected for inclusion according to biological and clinical criteria before transport using passive hypothermia using a target temperature of ≥35-<36°C. Data on 120 of 126 inclusions were available for analysis. Thirty-three percent of the children arrived in NICU with the target temperature of ≥35-<36°C. The mean temperature for the whole group of infants on arrival in NICU was 35.4°C (34.3–36.5). The median age of all infants on arrival in NICU was 3h03min [2h25min-3h56min]. Three infants arrived in NICU with a temperature of <33°C and eleven with a temperature ≥37°C. Adrenaline during resuscitation was associated with a lower mean temperature on arrival in NICU. Conclusions/Significance Our strategy using ≥35-<36°C passive hypothermia combined with short transport times had little effect on temperature after the arrival of Neonatal Transport Team although did reduce numbers of infants arriving in NICU in deep hypothermia. For those infants where hypothermia was discontinued in NICU our strategy facilitated re-warming. Re-adjustment to a lower target temperature to ≥34.5-<35.5°C may reduce the proportion of infants with high/normothermic temperatures.

Appropriateness of surfactant dosing for preterm babies with respiratory distress syndrome: retrospective cohort study

Poractant-α is the most common surfactant in Europe:1 its recommended dose is 200 mg/kg, according to pharmacokinetic and clinical data.2 We hypothesised that the correct dose is not often followed at the bedside as some clinicians may be tempted to administrate a rounded dose. In fact, a recent multicentre randomised clinical trial has been based on a rounded dose, as the authors acknowledge among the study limitations.3 We conducted a retrospective (2011–2013), population-based, cohort study performed on the formally established neonatal network in Parisian area,4 following Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Eligible babies were fulfilling the following conditions: (1) <37 weeks gestation, (2) respiratory distress syndrome defined as clinical distress needing oxygen and/or continuous positive airway pressure or mechanical ventilation with the typical radiological appearance, (3) surfactant administered in the …

Correction: Passive hypothermia (≥35 - <36°C) during transport of newborns with hypoxic-ischaemic encephalopathy

[This corrects the article DOI: 10.1371/journal.pone.0170100.].

Continuous positive airway pressure delivery during less invasive surfactant administration: a physiologic study

ObjectiveWe sought to investigate the pressure delivery during less invasive surfactant administration, as we hypothesize that it might be reduced.Study designPhysiologic in vitro study in a ventilation lab, using different pressure generators, levels, and leaks in a model of neonatal airways/lung mimicking mechanical characteristics of respiratory distress syndrome. Pressure was measured at the lung and verified in vivo measuring pharyngeal pressure in 19 neonates under same conditions. Data were analyzed using repeated measures-analysis of variance.ResultsPressure delivery in vitro is significantly and variably reduced during minimally invasive surfactant administration: pressure loss is ≈99% and ≈10–97%, during mouth opening and closure, respectively. Pressure loss seems independent from the type of CPAP and interface. In vivo measurements showed similar pressure drops.ConclusionsPressure transmission during minimally invasive surfactant administration is significantly reduced or totally absent. Pressure drop occurs despite the increased airway resistances and the airflow limitation due to the tracheal catheterization, but is independent from the type of pressure generator and interface.

PS-145 Preterm Infants Transportation Between Tertiary Care Centres (tcc) Within First Hours Of Life: Restrospective Cohort Study

Introduction Regionalization in perinatal care improved neonatal survival for 2 decades. Perinatal transport is known to be a bad prognostic factor for preterm neonates born in second level centres. No data exist for babies born in TCC who had to be transferred to other TTC. We evaluate short term clinical outcomes of preterm infants transferred between TCC. Methods We retrospectively analysed all neonates aged ≤32 weeks gestation transferred before 6 h of life from the South Paris University Hospitals to another TCC. Transfer was due to organisational problems. Control group consisted of neonates born the month before or after the cases and matched for gestational age, birth weight and CRIB-II. Simple linear and logistic regressions were used for analysis. Results We included 60 cases and 60 controls. The two groups were similar for basic clinical characteristics. No difference in clinical features (RDS, infection related respiratory failure, air leaks, hypotension) were present between the groups (Table 1). Early outcomes (IVH, periventricular leucomalacy, NEC, BPD and NICU stay) rates were not influenced by the transfer transport ((Table 1) Abstract PS-145 Table 1 Conclusions Perinatal transfer for preterm babies born in a TCC is not a negative prognostic factor. It is conceivable that optimal care in delivery room is a keystone for better outcome.

PS-021 Electrical Cardiometry Stroke Volume Evaluation In Nicu: Comparison With Functional Echocardiography

Background Evaluation of cardiac output in neonates might be difficult because of the complexity and risks of invasive classical procedures. New systems like electrical cardiometry (EC: Osypka Medical, Berlin, Germany and La Jolla, California, USA) have been proposed but few data are available in neonates. We investigated stroke volume (SV) using EC in term and preterm infants. Methods Eligible patients were neonates admitted to the NICU and undergoing echocardiography for any clinical reasons, without congenital heart disease. We measured SV with EC and echocardiography, within 10 min. Measurements were repeated 6 times by the same operator to calculate repeatability before and after echocardiography. Data have been compared with correlation and Bland-Altman analysis. Results 59 neonates were enrolled, allowing 150 paired measurements. Mean gestational age and birth weight were 33.9 ± 3.4 wks and 1988 ± 823 g, respectively. Results of Pearson correlation and Bland-Altman analysis for the whole population were (r = 0.611; p < 0.001) and (mean error [echo-EC] -1.35 mL [95% CI: -6.55 mL ± 3.85 ml]), respectively. Correlation is maintained even with PDA (r = 0.627; p < 0.001). Gestational age seems to do not influence the correlation between EC and echo (Partial correlation coefficient r = 0.36; p < 0.0001). Repeatability (coefficient of variation) was 46% for EC and 52% for echocardiography. There was no difference in SV measured by EC after 10 min (3.76 ± SD vs 3.78 ± SD; p = 0.56, Wilcoxon test). Conclusions EC is feasible, reproducible and quick. It could be an useful tool for continuous monitoring and haemodynamic evaluation in neonates. EC is particularly interesting for the clinical management of preterm neonates.

PO-0488 Non-invasive Haemodynamic Monitoring Using Electrical Cardiometry In Neonates During Respiratory Procedures

Background Electrical cardiometry (EC: Osypka Medical, Berlin, Germany and La Jolla, California, USA) is a new non-invasive technique for haemodynamic monitoring of neonates. No data are available for preterm babies during respiratory procedures, such as elective extubation or chest physiotherapy. We designed this study to clarify if these procedures have any haemodynamic consequences. Abstract PO-0488 Figure 1 Methods We assessed stroke volume (SV), cardiac output (CO), contractility index (ICON) and heart rate (HR) with EC before and after 5, 10, 15, 30 and 60 min from elective extubation or physiotherapy sessions with accelerated expiratory flow [Demont B et al , Physiotherapy 2007;93:12–16]. Functional echocardiography has been performed by the same operator before and after 60 min from the above-described respiratory procedures. Infants with congenital heart disease were not eligible. Results Eleven (for physiotherapy) and thirteen (for extubation) preterm infants were enrolled. Gestational age and birth weight were 29.2 ± 0.5 wks and 1313 ± 915 g, respectively. Fig.1 shows trends of SV, CO, ICON and HR before and after the procedures: no differences were noticed (p = 0.318 for SV; p = 0.559 for CO; p = 0.23 for ICON;p = 0.78 for HR, Friedman test). No differences were found analysing separately extubation and physiotherapy groups. Conclusions No haemodynamic changes are visible during elective extubation or chest physiotherapy in preterm infants. These preliminary results deserve further evaluation studying cerebral oxygenation with NIRS.