Pao2 and Mortality in Neonatal Extracorporeal Membrane Oxygenation: Retrospective Analysis of the Extracorporeal Life Support Organization Registry, 2015-2020

OBJECTIVES

Extracorporeal life support can lead to rapid reversal of hypoxemia but the benefits and harms of different oxygenation targets in severely ill patients are unclear. Our primary objective was to investigate the association between the Pao2 after extracorporeal membrane oxygenation (ECMO) initiation and mortality in neonates treated for respiratory failure.

DESIGN

Retrospective analysis of the Extracorporeal Life Support Organization (ELSO) Registry data, 2015-2020.

PATIENTS

Newborns supported by ECMO for respiratory indication were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pao2 24 hours after ECMO initiation (H24 Pao2) was reported. The primary outcome was 28-day mortality. We identified 3533 newborns (median age 1 d [interquartile range (IQR), 1-3]; median weight 3.2 kg [IQR, 2.8-3.6]) from 198 ELSO centers, who were placed on ECMO. By 28 days of life, 731 (20.7%) had died. The median H24 Pao2 was 85 mm Hg (IQR, 60-142). We found that both hypoxia (Pao2 < 60 mm Hg) and moderate hyperoxia (Pao2 201-300 mm Hg) were associated with greater adjusted odds ratio (aOR [95% CI]) of 28-day mortality, respectively: aOR 1.44 (95% CI, 1.08-1.93), p = 0.016, and aOR 1.49 (95% CI, 1.01-2.19), p value equals to 0.045.

CONCLUSIONS

Early hypoxia or moderate hyperoxia after ECMO initiation are each associated with greater odds of 28-day mortality among neonates requiring ECMO for respiratory failure.

High-dose intravenous immunoglobulin versus albumin 4% in paediatric toxic shock syndrome: a randomised controlled feasibility study

PURPOSE

Toxic shock syndrome (TSS) is a rare disease responsible for significant morbidity and mortality. Intravenous immunoglobulin (IG) therapy in paediatric TSS could improve shock and organ failure, but more consistent efficacy and safety data are needed. Our objective was to determine whether a randomised clinical trial (RCT) assessing intravenous IG in TSS in children is feasible.

METHODS

We performed a multicentre, feasibility, double-blind RCT assessing efficacy of high-dose intravenous IG versus albumin 4% (control group) within the first 12 hours of shock onset. Included patients were aged above 1 month and below 18 years with suspected TSS and septic shock. Feasibility was assessed by measuring inclusion rate, protocol compliance and missing data regarding death and the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) Score. Other secondary clinical outcomes were evaluated during hospital stay, at 60 day and 1 year.

RESULTS

28 patients, admitted in 6 paediatric intensive care units during 36 consecutive months and followed for 1 year, received the allocated treatment: 13 in intravenous IG group, 15 in control group. The median age was 10.6 years and the sex ratio was 1. Inclusion rate was above 50%, protocol deviations were below 30% and missing data regarding death and PELOD-2 Score below 10%. No difference concerning secondary clinical outcomes between groups was observed, and more adverse events were reported in the control group.

CONCLUSION

It seems to be feasible to conduct an RCT assessing intravenous IG efficacy and safety in paediatric TSS but must be realised internationally, with choice of a clinically relevant endpoint and a specific design in order to be realistic.

TRIAL REGISTRATION NUMBER

NCT02219165.

Determining Optimal Mean Arterial Blood Pressure Based on Cerebral Autoregulation in Children after Cardiac Surgery

To evaluate the feasibility of continuous determination of the optimal mean arterial blood pressure (opt-MAP) according to cerebral autoregulation and to describe the opt-MAP, the autoregulation limits, and the time spent outside these limits in children within 48 h of cardiac surgery. Cerebral autoregulation was assessed using the correlation coefficient (COx) between cerebral oxygenation and MAP in children following cardiac surgery. Plots depicting the COx according to the MAP were used to determine the opt-MAP using weighted multiple time windows. For each patient, we estimated (1) the time spent with MAP outside the autoregulation limits and (2) the burden of deviation, defined as the area between the MAP curve and the autoregulation limits when the MAP was outside these limits. Fifty-one patients with a median age of 7.1 (IQR 0.7-52.0) months old were included. The opt-MAP was calculated for 94% (IQR 90-96) of the monitored time. The opt-MAP was significantly lower in neonates < 1 month old. The patients spent 24% (18-31) of the time outside of the autoregulation limits, with no significant differences between age groups. Continuous determination of the opt-MAP is feasible in children within the first 48 h following cardiac surgery.

Evolution of Carboxyhemoglobin in Children Supported by Extracorporeal Membrane Oxygenation: An Observational Single-Center Study

Carboxyhemoglobin (COHb) is potentially a novel marker of hemolysis on extracorporeal membrane oxygenation (ECMO) and may be useful as an indicator for circuit-related complication in adults, but little is known about COHb levels in children. An observational single-center study was performed between January 2018 and December 2021. Fifty-eight children were included and COHb levels were obtained along with routine blood gas analysis before, during, and after ECMO support. From the 6th hour of ECMO support, the COHb level increased relative to the pre-ECMO level, with an adjusted mean difference of 0.44 (95% confidence interval [CI], 0.26-0.62; p < 0.001) and remained higher during ECMO run and within 6 hours after weaning ( p < 0.001). Among the 18 children (31%) who experienced at least one circuit-related complication leading to a circuit change, we observed a significant decrease in COHb levels within 24 hours after the circuit change, compared with the 24 hours before (adjusted mean difference, 0.54%; 95% CI, 0.27-0.80; p < 0.001). The maximal daily COHb level was able to predict circuit-related complications within 24 hours following COHb measurement with an area under the receiver operating characteristic (ROC) curve of 0.85 (95% CI, 0.77-0.92; p < 0.001).

Continuous Amplitude-Integrated Electroencephalography During Neonatal and Pediatric Extracorporeal Membrane Oxygenation

PURPOSE

Early prognostication of neurologic outcome in neonates and children supported with extra-corporeal membrane oxygenation (ECMO) is challenging. Amplitude-integrated EEG (aEEG) offers the advantages of continuous monitoring and 24-hours availability at the bedside for intensive care unit providers. The objective of this study was to describe the early electrophysiological background patterns of neonates and children undergoing ECMO and their association with neurologic outcomes.

METHODS

This was a retrospective review of neonates and children undergoing ECMO and monitored with aEEG. Amplitude-integrated EEG was summarized as an aEEG background score determined within the first 24 hours of ECMO and divided in 3-hour periods. Screening for electrical seizures was performed throughout the full ECMO duration. Neurologic outcome was defined by the Pediatric Cerebral Performance Category score at hospital discharge.

RESULTS

Seventy-three patients (median age 79 days [8-660], median weight 4.78 kg [3.24-10.02]) were included in the analysis. Thirty-two patients had a favorable neurologic outcome and 41 had an unfavorable neurologic outcome group at hospital discharge. A 24-hour aEEG background score >17 was associated with an unfavorable outcome with a sensitivity of 44%, a specificity of 97%, a positive predictive value of 95%, and a negative predictive value of 57%. In multivariate analysis, 24-hour aEEG background score was associated with unfavorable outcome (hazard ratio, 6.1; p = 0.001; 95% confidence interval, 2.31-16.24). The presence of seizures was not associated with neurologic outcome at hospital discharge.

CONCLUSIONS

Continuous aEEG provides accurate neurologic prognostication in neonates and children supported with ECMO. Early aEEG monitoring may help intensive care unit providers to guide clinical care and family counseling.

Effectiveness of intraoperative use of dexmedetomidine in reducing the incidence of tachyarrhythmia after congenital cardiac surgery in neonates and infants: a doubly robust method estimation analysis

OBJECTIVES

The antiarrhythmic effects of dexmedetomidine (DEX) have been suggested, but there are controversial reports on the effectiveness of intraoperative use of DEX to reduce the incidence of post operative tachyarrhythmia (POT).

METHODS

From a local ECHSA database, we included patients operated for congenital heart diseases (CHD) under cardiopulmonary bypass within a five-year period (2017-2021), during which intraoperative use of high dose of DEX (1-1.4 µg/kg/h) was implemented. A doubly robust matching estimation of the causal effect of DEX on the incidence of POT was conducted. We combined a multimodal estimation model in patients not exposed to DEX (Disease Risk Score) as well as a regression analysis in a matched cohort for patients exposured to DEX.

RESULTS

From a cohort of 593 surgeries (514 patients) occurring during the study period, doubly matched analysis consisted of the analysis of 426 surgeries conducted under DEX or not (213 per group). The probability of developing POT in patients exposed to DEX was 6.6% (95% CI 0.032-0.099) versus 14.5% (95% CI 0.098-0.193) in the group of patients not exposed to DEX. The doubly robust matched estimation method showed a mean reduction of 8.8% (95% CI -0.137 to -0.023)) of POT when DEX is used for intraoperative anaesthesia.

CONCLUSION

The use of high doses of DEX during anaesthesia for congenital heart surgery in neonates and infants is associated with a moderate but significant reduction of POT.

Population Pharmacokinetics of Levosimendan and its Metabolites in Critically Ill Neonates and Children Supported or Not by Extracorporeal Membrane Oxygenation

BACKGROUND

Levosimendan (LVSMD) is a calcium-sensitizer inotropic and vasodilator agent whose use might have a beneficial effect on the weaning of venoarterial extracorporeal membrane oxygenation (VA-ECMO). In light of LVSMD pharmacological characteristics, we hypothesized that ECMO may induce major pharmacokinetic (PK) modifications for LVSMD and its metabolites.

OBJECTIVE

The aim of this study was to investigate the PK of LVSMD and its metabolites, and to assess the effects of ECMO on PK parameters.

METHODS

We conducted a multicentric, prospective study (NCT03681379). Twenty-seven infusions of LVSMD were performed, allowing for the collection of 255 blood samples. Non-linear mixed-effects modeling software (MONOLIX®) was used to develop a parent-metabolite PK model of LVSMD and its metabolites.

RESULTS

Most patients received a 0.2 µg/kg/min infusion of LVSMD over 24 h. After elimination of non-reliable samples or concentrations below the limit of quantification, 166, 101 and 85 samples were considered for LVSMD, OR-1855 and OR-1896, respectively, of which 81, 53 and 41, respectively, were drawn under ECMO conditions. Parent-metabolite PK modeling revealed that a two-compartment model with first-order elimination best described LVSMD PK. Use of a transit compartment allowed for an explanation of the delayed appearance of circulating OR-1855 and OR-1896, with the latter following a first-order elimination. Patient weight influenced the central volume of distribution and elimination of LVSMD. ECMO support increased the elimination rate of LVSMD by 78%, and ECMO also slowed down the metabolite formation rate by 85% for OR-1855, which in turn is converted to the active metabolite OR-1896, 14% slower than without ECMO. Simulated data revealed that standard dosing may not be appropriate for patients under ECMO, with a decrease in the steady-state concentration of LVSMD and lower exposure to the active metabolite OR-1896.

CONCLUSIONS

ECMO altered PK parameters for LVSMD and its metabolites. An infusion of LVSMD over 48 h, instead of 24 h, with a slightly higher dose may promote synthesis of the active metabolite OR-1896, which is responsible for the long-term efficacy of LVSMD. Further trials evaluating ECMO effects using a PK/pharmacodynamic approach may be of interest.

REGISTRATION

ClinicalTrials.gov identifier number NCT03681379.

Semiautomated Regional Citrate Anticoagulation for Continuous Kidney Replacement Therapy: An Observational Study in Young Children

OBJECTIVES

To review use of semiautomated regional citrate anticoagulation (saRCA) for continuous kidney replacement therapy (CKRT) in young children.

DESIGN

Retrospective cohort study.

SETTING

Three independent PICUs.

PATIENTS

All consecutive children weighing less than 11 kg who received CKRT with saRCA from January 2015 to June 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-one children weighing less than 11 kg underwent CKRT with saRCA. The total duration of the CKRT was 2,014 hours, with a total of 64 CKRT sessions. Citrate intoxication occurred in four of 64 CKRT sessions (6%). Citrate intoxication was consistently observed in the few CKRT sessions where the initial lactate concentration was greater than 4 mmol/L or the ratio of replacement fluid flow to citrate flow less than 50%. The rate of unscheduled interruptions of CKRT sessions was 25% (16/64).

CONCLUSIONS

We have used saRCA for CKRT in children weighing less than 11 kg. A strict protocol and intensive training are required to minimize complications.

Evolution du capacitaire et des ressources humaines en réanimation après la première vague de la pandémie COVID-19 : une enquête du Syndicat des Médecins Réanimateurs

La France a connu au printemps 2020 une crise sanitaire sans précédent sur les plans sanitaire et sociétal due à la pandémie de COVID-19. Lors de cette première vague les hôpitaux ont fait face à un afflux important de patients dans les secteurs de Réanimation. Des mesures exceptionnelles ont été mises en place, pour permettre au système de soins de tenir. Au sortir de cette première vague des propositions ont été faites afin d’optimiser l’organisation des Soins Critiques. Dans ce contexte, nous avons mené une enquête auprès des services de Réanimation français en Janvier 2021, destinée à produire un état des lieux. L’objectif principal de cette enquête était de déterminer si les mesures revendiquées par les soignants et affichées par l’exécutif étaient effectives. Nous avons mené une enquête déclarative visant à établir l’état des lieux des lits de Réanimation et des effectifs soignants avant et après la première vague de la pandémie à COVID-19 en France. Nous avons ainsi pu démontré qu’aucun des lits supplémentaires ouverts pendant la première vague épidémique n’a été pérennisé. Plus inquiétant, 13% des 114 services répondeurs soulignent que le ratio d’une infirmière pour 2,5 patients n’est pas respecté par manque de personnels formés et disponibles. Ces éléments confirment qu’à l’heure actuelle, aucune mesure n’a été prise pour améliorer un capacitaire historiquement et conjoncturellement déficitaire. Cette indispensable correction ne pourra s’opérer qu’avec le recrutement, la formation et la stabilisation d’équipes soignantes spécialisées, médicales et paramédicales.

Neurological Outcome According to the Site of Cannulation in Septic Children Supported by Venoarterial Extracorporeal Membrane Oxygenation

The impact of cervical cannulation on neurologic outcome has not been yet studied among children receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the context of severe sepsis or septic shock. A retrospective cohort study was performed using the extracorporeal life support organization (ELSO) registry. A total of 559 children weighing less than 20 kg with a primary or secondary diagnosis of severe sepsis, septic shock or toxic shock syndrome were included between January 1, 2010, and December 31, 2019. Cervical cannulation was performed in 485 children (87%) and central cannulation in 74 children (13%). The prevalence of acute neurologic event (ANE) was 32%, including clinical and/or electroencephalographic seizures, cerebral infarction, cerebral hemorrhage, and/or brain death. In multivariable analysis, we did not find an association between cervical cannulation and greater/lesser odds of ANE during ECMO (adjusted odds ratio [aOR] = 1.39, 95% confidence interval [CI] 0.72-2.65; P = 0.326). Only pre-ECMO acidosis was independently associated with the development of ANE (pH < 6.99; aOR = 2.71, 95% CI 1.34-5.49; P = 0.006; pH 6.99 to <7.12; aOR = 2.57, 95% CI 1.37-4.82; P = 0.003). Thus, the site of cannulation appears not as a modifiable neurologic risk factor in this young septic population.

Frequency of Extracorporeal Membrane Oxygenation Support and Outcomes After Implementation of a Structured PICU Network in Neonates and Children: A Prospective Population-Based Study in the West of France

OBJECTIVES

To describe the frequency and outcomes on the use of extracorporeal membrane oxygenation (ECMO) among critically ill neonates and children within a structured pediatric critical care network in the West of France. To assess the optimality of decision-making process for patients primarily admitted in non-ECMO centers.

DESIGN

Observational prospective population-based study from January 2015 to December 2019.

PATIENTS

Neonates over 34 weeks of gestational age, weighing more than 2,000 g and children under 15 years and 3 months old admitted in one of the 10 units belonging to a Regional Pediatric Critical Care Network.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eight-thousand one hundred eighty-nine children and 3,947 newborns were admitted within one of the 10 units of the network over the study period. Sixty-five children (8.1% [95% CI, 6.2-10‰]) and 35 newborns (9.4% [95% CI, 6.4-12%]) required ECMO support. Of these patients, 31 were first admitted to a non-ECMO center, where 20 were cannulated in situ (outside the regional ECMO center) and 11 after transfer to the ECMO regional center. Cardiogenic shock, highest serum lactate level, and cardiac arrest prior to first phone call with the regional ECMO center were associated with higher rate of in situ cannulation. During the study period, most of the patients were cannulated for underlying cardiac issue (42/100), postoperative cardiac surgery instability (38/100), and pediatric (10/100) and neonatal (10/100) respiratory distress syndrome. Patients primarily admitted in non-ECMO centers or not had similar 28-day post-ICU survival rates compared with those admitted in the referral ECMO center (58% vs 51%; p = 0.332). Pre-ECMO cardiac arrest, ECMO, and lower pH at ECMO onset were associated with lower 28-day post-ICU survival.

CONCLUSIONS

Our local results suggest that a structured referral network for neonatal and pediatric ECMO in the region of Western France facilitated escalation of care with noninferior (or similar) early mortality outcome. Our data support establishing referral networks in other equivalent regions.

Impact of Arterial Carbon Dioxide and Oxygen Content on Cerebral Autoregulation Monitoring Among Children Supported by ECMO

BACKGROUND

Cerebral autoregulation (CA) impairment is associated with neurological complications among children supported by extracorporeal membrane oxygenation (ECMO). Severe variations of arterial CO₂ (PaCO₂) and O₂ (PaO₂) tension after ECMO onset are common and associate with mortality and poor neurological outcome. The impact of gas exchange on CA among critically ill patients is poorly studied.

METHODS

Retrospective analysis of data collected prospectively from 30 children treated with veno-arterial or veno-venous ECMO in the PICU of Nantes University Hospital, France. A correlation coefficient between the variations of regional cerebral oxygen saturation (rSO₂) and the variations of mean arterial blood pressure (MAP) was calculated as an index of CA (cerebral oxygenation reactivity index, COx). Cox-MAP plots were investigated allowing determining lower limit of autoregulation (LLA) and upper limit of autoregulation (ULA) limits of autoregulation. Age-based normal blood pressure was used to adjust the MAP, LLA, and ULA data from each patient and then reported as percentage (nMAP, nLLA, and nULA, respectively). RSO₂, COx, nMAP, nLLA, and nULA values were averaged over one hour before each arterial blood gas (ABG) sample during ECMO run.

RESULTS

Thirty children (median age 4.8 months [Interquartile range (IQR) 0.7-39.1], median weight 5 kg [IQR 4-15]) experiencing 31 ECMO runs were included in the study. Three hundred and ninety ABGs were analyzed. The highest values of COx were observed on day 1 (D1) of ECMO. The relationship between COx and PaCO₂ was nonlinear, but COx values tended to be lower in case of hypercapnia compared to normocapnia. During the whole ECMO run, a weak but significant correlation between PaCO₂ and nULA was observed (R = 0.432, p = 0.02). On D1 of ECMO, this correlation was stronger (R = 0.85, p = 0.03) and a positive correlation between nLLA and PaCO₂ was also found (R = 0.726, p < 0.001). A very weak negative correlation between PaO₂ and nULA was observed within the whole ECMO run and on D1 of ECMO (R =  -0.07 p = 0.04 and R =  -0.135 p =  <0.001, respectively). The difference between nULA and nLLA representing the span of the autoregulation plateau was positively correlated with PaCO₂ and negatively correlated with PaO₂ (R = 0.224, p = 0.01 and R =  -0.051, p = 0.004, respectively).

CONCLUSIONS

We observed a complex relationship between PaCO₂ and CA, influenced by the level of blood pressure. Hypercapnia seems to be globally protective in normotensive or hypertensive condition, while, in case of very low MAP, hypercapnia may disturb CA as it increases LLA. These data add additional arguments for very cautiously lower PaCO₂, especially after ECMO start.

Outcome analysis of a conservative approach to diaphragmatic paralysis following congenital cardiac surgery in neonates and infants: a bicentric retrospective study

 

OBJECTIVES

Diaphragmatic paralysis following congenital cardiac surgery is associated with significant morbidity and mortality. Spontaneous recovery of diaphragmatic function has been described, contrasting with centres providing early diaphragmatic plication. We aimed to describe the outcomes of a conservative approach, as well as to identify factors associated with a failure of the strategy.

METHODS

This is a retrospective study of patients admitted after cardiac surgery and suffering unilateral diaphragmatic paralysis within 2 French Paediatric Cardiac Surgery Centers. The conservative approach, defined by the prolonged use of ventilation until successful weaning from respiratory support, was the primary strategy adopted in both centres. In case of unsuccessful evolution, a diaphragmatic plication was scheduled. Total ventilation time included invasive and non-invasive ventilation. Diaphragm asymmetry was defined by the number of posterior rib segments counted between the 2 hemi-diaphragms on the chest X-ray after cardiac surgery.

RESULTS

Fifty-one neonates and infants were included in the analysis. Patients' median age was 12.0 days at cardiac surgery (5.0-82.0), and median weight was 3.5 kg (2.8-4.9). The conservative approach was successful for 32/51 patients (63%), whereas 19/51 patients (37%) needed diaphragm plication. There was no difference in patients' characteristics between groups. Respiratory support prolonged for 21 days or more and diaphragm asymmetry more than 2 rib segments were independently associated with the failure of the conservative strategy [odds ratio (OR) 6.9 (1.29-37.3); P = 0.024 and OR 6.0 (1.4-24.7); P = 0.013, respectively].

CONCLUSIONS

The conservative approach was successful for 63% of the patients. We identified risk factors associated with the strategy's failure.

Monocytic Human Leukocyte Antigen DR Expression in Young Infants Undergoing Cardiopulmonary Bypass

BACKGROUND

Monocytic human leukocyte antigen DR (mHLA-DR) expression levels have been reported to be a marker of immunosuppression and a predictor of sepsis and mortality. There are, however, scant data regarding mHLA-DR monitoring in young infants after cardiopulmonary bypass. Our objectives were to investigate the kinetics of mHLA-DR expression and to determine whether mHLA-DR levels are associated with healthcare-associated infection (HAI) after cardiopulmonary bypass in young infants.

METHODS

mHLA-DR levels were analyzed by flow cytometry using a standardized method in 49 infants (<3 months old) with congenital heart disease before and after cardiopulmonary bypass. Results are expressed as the number of anti-HLA-DR antibodies per cell (AB/c).

RESULTS

Postoperative mHLA-DR expression was reduced in all infants. Eleven patients (22%) developed HAI, and 4 patients (8%) died during the 30-day follow-up. mHLA-DR expression was significantly lower on postoperative day 4 in the HAI group compared with those who without HAI (3768 AB/c [range, 1938-6144] vs 13,230 AB/c [range, 6152-19,130], P = .014). Although mHLA-DR expression was associated with postoperative severity, mHLA-DR ≤4500 AB/c in the first 72 hours among patients with higher postoperative severity (extracorporeal membrane oxygenation and/or corticoids and/or delayed closure of sternum) was associated with occurrence of HAI in the univariate analysis (odds ratio, 6.3; 95% confidence interval, 1.0-38.7; P = .037).

CONCLUSIONS

Cardiopulmonary bypass induces a profound decrease in mHLA-DR expression in young infants. Among patients with higher postoperative severity, low level of mHLA-DR in the early postoperative period is associated with the development of HAI.

Right watershed cerebral infarction following neck cannulation for veno-arterial extracorporeal membrane oxygenation in pediatric septic shock: a case series

Children supported by extracorporeal membrane oxygenation present a high risk of neurological complications. Although carotid cannulation is known to be associated with neurologic injury, conflicting data exist with regard to the predominance of right- or left-sided lesions. We describe here two infants requiring veno-arterial extracorporeal membrane oxygenation for septic shock who encountered right watershed infarction ipsilateral to carotid artery cannulation. Hemodynamic failure seems to be the most probable underlying mechanism. The asymmetry of transcranial Doppler metrics in one case and the low right regional cerebral oxygen saturation value observed soon after right cannulation in both cases suggest an insufficient cerebral collateral flow compensation. The risk of ipsilateral watershed injury should be considered before cervical cannulation, notably in the context of sepsis and an evaluation of the cerebral collateral blood flow before and just after cannulation may be interesting in order to identify infants with higher risk of ipsilateral ischemic lesions.

Neonatal and pediatric ECMO organization in France: A national survey

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) in France has increased since the H1N1 pandemic in 2009. By contrast, neonatal and pediatric ECMO support in France was known to be limited to a few centers offering congenital cardiac surgery. The purpose of this survey conducted in 2017 was to identify the neonatal and pediatric ECMO centers in France as well as networks existing between ECMO and non-ECMO centers.

RESULTS

Seventy-two neonatal or pediatric intensive care unit medical directors answered the survey (84% of the centers surveyed). Twenty were identified as ECMO centers, defined as a unit able to start ECMO with its own resources. ECMO centers ranged from 470,000 to 1,180,000 inhabitants (neonates or children under 18). Thirteen of them (65%) reported that they were affiliated with a congenital cardiac surgery department. A total of 187 patients were supported with ECMO in these centers in 2016. Only six of these centers estimated an activity greater than 15 cases per year over the last 5 years. Nearly 30% of ECMO runs were indicated before or after congenital heart surgery. Four of the ECMO centers offered off-site facilities (mobile team). Non-ECMO centers are likely to be neonatal intensive care units. Nine of them (18.7%) declared knowing an ECMO center that provided mobile care with predefined organization, 11 (22.9%) reported knowing an ECMO center providing a mobile activity without predefined organization, nine (18.%), and 18 (37.5%) ICUs declared they knew of the existence of an ECMO program but did not report any possibility of mobile care or any procedure for transfer.

CONCLUSIONS

Of the centers reporting the highest case volumes, four offered mobile ECMO abilities. Well-organized networks for the most severe neonates and children were not identified in France.

Structural Basis for Properdin Oligomerization and Convertase Stimulation in the Human Complement System

Properdin (FP) is a positive regulator of the immune system stimulating the activity of the proteolytically active C3 convertase C3bBb in the alternative pathway of the complement system. Here we present two crystal structures of FP and two structures of convertase bound FP. A structural core formed by three thrombospondin repeats (TSRs) and a TB domain harbors the convertase binding site in FP that mainly interacts with C3b. Stabilization of the interaction between the C3b C-terminus and the MIDAS bound Mg2+ in the Bb protease by FP TSR5 is proposed to underlie FP convertase stabilization. Intermolecular contacts between FP and the convertase subunits suggested by the structure were confirmed by binding experiments. FP is shown to inhibit C3b degradation by FI due to a direct competition for a common binding site on C3b. FP oligomers are held together by two sets of intermolecular contacts, where the first is formed by the TB domain from one FP molecule and TSR4 from another. The second and largest interface is formed by TSR1 and TSR6 from the same two FP molecules. Flexibility at four hinges between thrombospondin repeats is suggested to enable the oligomeric, polydisperse, and extended architecture of FP. Our structures rationalize the effects of mutations associated with FP deficiencies and provide a structural basis for the analysis of FP function in convertases and its possible role in pattern recognition.

Complex Compound Inheritance of Lethal Lung Developmental Disorders Due to Disruption of the TBX-FGF Pathway

Primary defects in lung branching morphogenesis, resulting in neonatal lethal pulmonary hypoplasias, are incompletely understood. To elucidate the pathogenetics of human lung development, we studied a unique collection of samples obtained from deceased individuals with clinically and histopathologically diagnosed interstitial neonatal lung disorders: acinar dysplasia (n = 14), congenital alveolar dysplasia (n = 2), and other lethal lung hypoplasias (n = 10). We identified rare heterozygous copy-number variant deletions or single-nucleotide variants (SNVs) involving TBX4 (n = 8 and n = 2, respectively) or FGF10 (n = 2 and n = 2, respectively) in 16/26 (61%) individuals. In addition to TBX4, the overlapping ∼2 Mb recurrent and nonrecurrent deletions at 17q23.1q23.2 identified in seven individuals with lung hypoplasia also remove a lung-specific enhancer region. Individuals with coding variants involving either TBX4 or FGF10 also harbored at least one non-coding SNV in the predicted lung-specific enhancer region, which was absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies. The occurrence of rare coding variants involving TBX4 or FGF10 with the putative hypomorphic non-coding SNVs implies a complex compound inheritance of these pulmonary hypoplasias. Moreover, they support the importance of TBX4-FGF10-FGFR2 epithelial-mesenchymal signaling in human lung organogenesis and help to explain the histopathological continuum observed in these rare lethal developmental disorders of the lung.

Enhance quality care performance: Determination of the variables for establishing a common database in French paediatric critical care units

Selected variables for the French Paediatric Intensive Care registry.

RATIONALE, AIMS, AND OBJECTIVES

Providing quality care requires follow-up in regard to clinical and economic activities. Over the past decade, medical databases and patient registries have expanded considerably, particularly in paediatric critical care medicine (eg, the Paediatric Intensive Care Audit Network (PICANet) in the UK, the Australian and New Zealand Paediatric Intensive Care (ANZPIC) Registry in Australia and New Zealand, and the Virtual Paediatric Intensive Care Unit Performance System (VPS) in the USA). Such a registry is not yet available in France. The aim of this study was to determine variables that ought to be included in a French paediatric critical care registry.

METHODS

Variables, items, and subitems from 3 foreign registries and 2 French local databases were used. Items described each variable, and subitems described items. The Delphi method was used to evaluate and rate 65 variables, 90 items, and 17 subitems taking into account importance or relevance based on input from 28 French physicians affiliated with the French Paediatric Critical Care Group. Two ratings were used between January and May 2013.

RESULTS

Fifteen files from 10 paediatric intensive care units were included. Out of 65 potential variables, 48 (74%) were considered to be indispensable, 16 (25%) were considered to be optional, and 1 (2%) was considered to be irrelevant. Out of 90 potential items, 62 (69%) were considered to be relevant, 23 (26%) were considered to be of little relevance, and 5 (6%) were considered to be irrelevant. Out of 17 potential subitems, 9 (53%) were considered to be relevant, 6 (35%) were considered to be of little relevance, and 2 (12%) were considered to be irrelevant.

CONCLUSIONS

The necessary variables that ought to be included in a French paediatric critical care registry were identified. The challenge now is to develop the French registry for paediatric intensive care units.

HLA-DR expression in neonates after cardiac surgery under cardiopulmonary bypass: a pilot study

Monocyte HLA-DR expression has been reported as a marker of immunosuppression and a predictor of sepsis development. However, to date, there is no report on monocyte HLA-DR monitoring exclusively in neonates (< 28 days of life) who underwent cardiac surgery under cardiopulmonary bypass (CPB), which have a high risk of nosocomial infection. In this pilot study, we studied nine neonates with a diagnosis of congenital heart disease requiring surgery under CPB. There was a significant reduction in monocyte HLA-DR expression for the first two postoperative days, as compared to preoperatively (p = 0.004). Moreover, neonates who displayed an episode of NI had a dramatically lower HLA-DR expression at day 4, as compared to neonates without NI (4257 AB/c [2220–5895] vs 14,947 AB/c [9858–16,960]; p = 0.04). Our preliminary results could indicate that HLA-DR expression may be a useful biomarker of immunosuppression-induced secondary infection after CPB in neonates.

Physiological effects of invasive ventilation with neurally adjusted ventilatory assist (NAVA) in a crossover study

Background

Neurally Adjusted Ventilatory Assist (NAVA) is a mode of assisted mechanical ventilation that delivers inspiratory pressure proportionally to the electrical activity of the diaphragm. To date, no pediatric study has focused on the effects of NAVA on hemodynamic parameters. This physiologic study with a randomized cross-over design compared hemodynamic parameters when NAVA or conventional ventilation (CV) was applied.

Methods

After a baseline period, infants received NAVA and CV in a randomized order during two consecutive 30-min periods. During the last 10 min of each period, respiratory and hemodynamic parameters were collected. No changes in PEEP, FiO₂, sedation or inotropic doses were allowed during these two periods. The challenge was to keep minute volumes constant, with no changes in blood CO₂ levels and in pH that may affect the results.

Results

Six infants who had undergone cardiac surgery (mean age 7.8 ± 4.1 months) were studied after parental consent. Four of them had low central venous oxygen saturation (ScvO₂ < 65 %). The ventilatory settings resulted in similar minute volumes (1.7 ± 0.4 vs. 1.6 ± 0.6 ml/kg, P = 0.67) and in similar tidal volumes respectively with NAVA and with CV. There were no statistically significant differences on blood pH levels between the two modes of ventilation (7.32 ± 0.02 vs. 7.32 ± 0.04, P = 0.34). Ventilation with NAVA delivered lower peak inspiratory pressures than with CV: -32.7 % (95 % CI: -48.2 to –17.1 %, P = 0.04). With regard to hemodynamics, systolic arterial pressures were higher using NAVA: +8.4 % (95 % CI: +3.3 to +13.6 %, P = 0.03). There were no statistically significant differences on cardiac index between the two modes of ventilation. However, all children with a low baseline ScvO₂ (<65 %) tended to increase their cardiac index with NAVA compared to CV: 2.03 ± 0.30 vs. 1.91 ± 0.39 L/min.m² (median ± interquartile, P = 0.07).

Conclusions

This pilot study raises the hypothesis that NAVA could have beneficial effects on hemodynamics in children when compared to a conventional ventilatory mode that delivered identical PEEP and similar minute volumes.

Trial registration

ClinicalTrials.gov Identifier: NCT01490710. Date of registration: December 7, 2011.

Neonatal Marfan Syndrome: Report of a Case with an Inherited Splicing Mutation outside the Neonatal Domain

We report a child and her mother affected by Marfan syndrome. The child presented with a phenotype of neonatal Marfan syndrome, revealed by acute and refractory heart failure, finally leading to death within the first 4 months of life. Her mother had a common clinical presentation. Genetic analysis revealed an inherited FBN1 mutation. This intronic mutation (c.6163+3_6163+6del), undescribed to date, leads to exon 49 skipping, corresponding to in-frame deletion of 42 amino acids (p.Ile2014_Asp2055del). FBN1 next-generation sequencing did not show any argument for mosaicism. Association in the same family of severe neonatal and classical Marfan syndrome illustrates the intrafamilial phenotype variability.

Regional citrate anticoagulation for pediatric CRRT using integrated citrate software and physiological sodium concentration solutions

BACKGROUND

In continuous renal replacement therapy (CRRT), regional citrate anticoagulation offers an attractive alternative to heparinization, especially for children with a high bleeding risk.

METHODS

We report on a new management approach to CRRT using integrated citrate software and physiological sodium concentration solutions. Convective filtration was performed with pre-filter citrate anticoagulation using an 18 mmol/L citrate solution and a post-filter replacement fluid. The citrate flow rate was automatically adjusted to the blood flow rate by means of integrated citrate software. Similarly, calcium was automatically infused into children to maintain their blood calcium levels within normal range.

RESULTS

Eleven CRRT sessions were performed (330 h) in seven critically ill children aged 3-15 years (extreme values 15-66 kg). Disease categories included sepsis with multiorgan dysfunction (n = 2) and hemolytic uremic syndrome (n = 5). Median effluent dose was 2.1 (extreme values 1.7-3.3) L/h/1.73 m2. No session had to be stopped because of metabolic complications. Calcium levels, both in the circuits and in the circulating blood of the children, remained stable and secure.

CONCLUSIONS

Regional citrate anticoagulation can be used in children with a body weight of >15 kg using integrated citrate software and commercially available solutions with physiological sodium concentrations in a safe, effective and convenient procedure.

[Severe shock after protamine infusion in a neonate undergoing cardio pulmonary bypass]

Shock after protamine infusion are rare. We report here the case of a 6-day-old boy having presented severe and recurring hypotensions after protamine infusions during cardiac surgery under cardio pulmonary bypass. The physiopathology of these reactions is complex and, in the presented case, involved mechanism may not be anaphylactic.

Antenatal phosphodiesterase 4 inhibition restores postnatal growth and pulmonary development in a model of chorioamnionitis in rabbits

Chorioamnionitis is implicated in the pathophysiology of bronchopulmonary disease, and the associated inflammatory response is responsible for adverse effects on alveolar development. The aim of this work was to analyze the effects of a phosphodiesterase 4 (PDE4)-selective inhibitor, rolipram (a modulator of the inflammatory response), in an experimental model of chorioamnionitis on pulmonary development and on the processes of infection and inflammation. Rabbit mothers were assigned to four groups: 1) saline serum inoculation (controls); 2) Escherichia coli intrauterine inoculation (C+); 3) rolipram infusion (R+); and 4) E. coli inoculation + rolipram infusion (C+R+). High rates of morbility and mortality were noticed in mothers and pups (5 of 13 pregnant rabbits in groups with rolipram). Alveolar development, inflammation, and infection were analyzed in pups at day 0 and day 5. At day 0, in the context of chorioamnionitis, rolipram significantly decreased birth weight (p < 0.01) relative to that of controls (p < 0.05). At day 5, weight normalized in group C+R+ but not in group C+ relative to controls (p < 0.001); moreover, alveolar airspace volume was preserved in group C+R+ but not in group C+ (p < 0.05). Interstitial volume decreased in group C+ versus controls (p < 0.05) but was preserved in group C+R+. Specific alveolar area was not significantly modified by rolipram. No significant difference was found concerning bronchoalveolar lavage cellularity, and all blood cultures remained sterile. In this model of impaired alveologenesis, rolipram significantly preserved specific alveolar density. However, PDE4 inhibition induced antenatal fetal demise and growth retardation.

Respiratory support by neurally adjusted ventilatory assist (NAVA) in severe RSV-related bronchiolitis: a case series report

Background

Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation controlled by diaphragmatic electrical signals. The electrical signals allow synchronization of ventilation to spontaneous breathing efforts of a child, as well as permitting pressure assistance proportional to the electrical signal. NAVA provides equally fine synchronization of respiratory support and pressure assistance varying with the needs of the child. NAVA has mainly been studied in children who underwent cardiac surgery during the period of weaning from a respirator.

Case presentation

We report here a series of 3 children (1 month, 3 years, and 28 days old) with severe respiratory distress due to RSV-related bronchiolitis requiring invasive mechanical ventilation with a high level of oxygen (FiO₂ ≥50%) for whom NAVA facilitated respiratory support. One of these children had diagnosis criteria for acute lung injury, another for acute respiratory distress syndrome.

Establishment of NAVA provided synchronization of mechanical ventilatory support with the breathing efforts of the children. Respiratory rate and inspiratory pressure became extremely variable, varying at each cycle, while children were breathing easily and smoothly. All three children demonstrated less oxygen requirements after introducing NAVA (57 ± 6% to 42 ± 18%). This improvement was observed while peak airway pressure decreased (28 ± 3 to 15 ± 5 cm H₂O). In one child, NAVA facilitated the management of acute respiratory distress syndrome with extensive subcutaneous emphysema.

Conclusions

Our findings highlight the feasibility and benefit of NAVA in children with severe RSV-related bronchiolitis. NAVA provides a less aggressive ventilation requiring lower inspiratory pressures with good results for oxygenation and more comfort for the children.

Betamethasone worsens chorioamnionitis-related lung development impairment in rabbits

Although chorioamnionitis and glucocorticoids (GC) are both known to have potential adverse effects on alveolar development, the use of GC is generalized because of their demonstrated benefits in premature newborns. The objective of this study was to analyze the cumulative effects of GC and chorioamnionitis on lung development and infectious process. In a model of ESCHERICHIA COLI chorioamnionitis controlled by antibiotics, pregnant rabbits were randomized among five groups: (1) E. COLI infection alone, (2) infection plus one betamethasone injection (0.1 mg.kg(-1)), (3) infection plus two betamethasone injections, (4) betamethasone alone, (5) control. Lung morphometric analysis, bronchoalveolar lavage, and bacteriologic tissue cultures were performed after spontaneous delivery. In the context of chorioamnionitis, one betamethasone treatment significantly decreased birth weight and lung volume versus controls (30 ± 1.40 versus 52.40 ± 2.54 g, and 1.92 ± 0.67 versus 2.15 ± 0.74 cm(3), respectively, p < 0.05). Two betamethasone treatments significantly decreased specific alveolar area (279.8 ± 46 cm(2)/100 g versus 510.90 ± 54.1 cm(2)/100 g), specific interstitium volume (0.98 ± 0.09 cm(3)/100 g versus 1.78 ± 0.16 cm(3)/100 g), and specific elastin fiber length (57.4 ± 10.5 versus 183.6 ± 8.1 cm/100 g). These results suggest that glucocorticoid treatment might represent an additional risk factor for lung development in the instance of prenatal infection.

[Genetic polymorphisms and infections]

Recent studies have shown that genetic variants, responsible for the different human response when facing an infectious risk, concerned the genes of proteins involved in either recognition of the infectious agent, in the inflammatory cascade, or in the coagulation process. For example, some studies clearly demonstrated that if a twin was affected by an infectious disease, the risk of infection by the same agent for the other twin was significantly higher in homozygote than in heterozygote twins. In Caucasians, a punctual mutation of the TLR2 cytosol was proved to block the response to bacterial lipoproteins and to some Gram positive bacteria and could be responsible for a greater susceptibility to septic shock. Several polymorphisms of the tlr4 gene have been involved in the onset of septic shock in postsurgery infection due to Gram(-) bacilli. Paradoxically, these variants seemed to protect against legionellosis. In pediatrics, polymorphisms of tlr4 were also clearly identified as risk factors for meningococcemia of severe bronchiolitis due to the respiratory syncytial virus (RSV) in children under 2 years of age. A polymorphism of the TLR5 receptor gene, which creates a stop codon and which is responsible for a nonfunctionality of the receptor was associated with the onset of severe legionellosis. Analysing the functions of these genetic polymorphisms in the onset of sepsis will open the way to a lot of research on specific treatments focused on genetic abnormalities.

Umbilical cord blood procalcitonin and C reactive protein concentrations as markers for early diagnosis of very early onset neonatal infection

Procalcitonin (PCT) and C reactive protein (CRP) concentrations in umbilical cord blood of 197 neonates were measured to evaluate their value as markers of infection. Sixteen of the neonates were infected. The sensitivity, specificity, and negative and positive predictive values were respectively 87.5%, 98.7%, 87.5%, and 98.7% for PCT and 50%, 97%, 67%, and 94% for CRP. Serum PCT in cord blood seems to be a useful and early marker of antenatal infection.