Inotrope Needs in Neonates Requiring Extracorporeal Membrane Oxygenation for Respiratory Failure

Mortality Prediction in Newborns With Persistent Pulmonary Hypertension: A Comparison of Four Illness Severity Scores

OBJECTIVE

This study aimed to compare the accuracy of four neonatal illness severity scores for predicting mortality in persistent pulmonary hypertension of the newborn (PPHN).

STUDY DESIGN

This retrospective study included neonates diagnosed with PPHN between 2013 and 2022. The illness severity scores of four commonly used tools were completed for each infant: the Clinical Risk Index for Babies-II (CRIB-II), the Score for Neonatal Acute Physiology-Perinatal Extension version II (SNAPPE-II) in the first 12 h after admission and maximum oxygenation index (OI) and Vasoactive-Inotropic score (VIS) during the first 24 h (OI24max and VIS24max), 48 h (OI48max and VIS48max), and 72 h (OI72max and VIS72max) after admission. We constructed a receiver operating characteristic (ROC) curve to assess the discrimination and accuracy of the scores and determine the cutoff values for predicting mortality.

RESULTS

We enrolled 146 neonates (131 survivors and 15 nonsurvivors). The CRIB-II, SNAPPE-II, maximum OI, and VIS were significantly higher in nonsurvivors than in survivors. An OI72max score of 41 showed the highest accuracy in predicting mortality (area under the ROC curve [AUC] of 0.88) with an OI48max score of 31 (AUC: 0.86) and VIS72max score of 430 (AUC: 0.80) showing good accuracy. The best CRIB-II and SNAPPE-II cutoff scores for predicting mortality were 4 (AUC: 0.74) and 32 (AUC: 0.84), respectively.

CONCLUSIONS

The most accurate illness severity score for predicting mortality was OI72max score of 41. However, the OI48max, SNAPPE-II, and VIS72max scores also showed good accuracy. Mortality prediction using these scores can guide early management and close monitoring.

Fluid Flow Analysis of Neonatal Dual-Lumen Cannulas for Venovenous Extracorporeal Membrane Oxygenation

Hemolysis persists as a common and serious problem for neonatal patients on extracorporeal membrane oxygenation (ECMO). Since the cannula within the ECMO circuit is associated with hemolysis-inducing shear stresses, real-world internal fluid flow measurements are urgently needed to understand the mechanism and confirm computational estimates. This study appears to be the first experimental study of fluid flow inside commercial ECMO dual-lumen cannulas (DLCs) and first particle image velocimetry (PIV) visualization inside a complicated medical device. The internal geometries of four different opaque neonatal DLCs, both atrial and bicaval positioning geometries each sized 13 Fr and 16 Fr, were replicated by three-dimensional printing clear lumen scaled-up models, which were integrated in a circuit with appropriate ECMO flow parameters. PIV was then used to visualize two-dimensional fluid flow in a single cross section within the models. An empirical model accounting for shear stress and exposure time was used to compare the maximum expected level of hemolysis through each model. The maximum measured peak shear stress recorded was 16±2 Pa in the top arterial bicaval 13 Fr model. The atrial and 16 Fr cannula models never produced greater single-pass peak shear stress or hemolysis than the bicaval and 13 Fr models, respectively, and no difference was found in hemolysis at two different flow rates. After 5 days of flow, small DLC-induced hemolysis values for a single pass through each cannula were modeled to linearly accumulate and caused the most severe hemolysis in the bicaval 13 Fr DLC. Engineering and clinical solutions to improve cannula safety are proposed.

Fetal MRI mediastinal shift angle and respiratory and cardiovascular pharmacological support in newborns with congenital diaphragmatic hernia

In newborns with congenital diaphragmatic hernia (CDH), the mediastinal shift caused by the herniated organs negatively affects lung development. Assessment of the fetal magnetic resonance imaging (MRI) mediastinal shift angle (MSA) was shown to have an inverse correlation with the total fetal lung volume (TFLV), being associated with neonatal survival. However, a possible association with postnatal morbidity has never been investigated. We hypothesize that the degree of the mediastinal shift could be associated with higher respiratory and cardiocirculatory impairment, requiring intensive treatments and extended hospitalization in survivors. We retrospectively consider a cohort of isolated, left-sided CDH, for whom we calculated the MSA and the observed/expected (O/E) TFLV at fetal MRI. We performed a data collection regarding inotropic or vasoactive support, treatment with pulmonary vasodilators, mechanical ventilation, and length of stay. General linear models were performed. The MSA and O/E TFLV were inversely correlated (Pearson's coefficient - 0.65, p < 0.001), and deceased patients showed higher MSA values then survivors (p = 0.011). Among survivors, an increase in MSA was associated with longer pharmacological treatments (dobutamine: p = 0.016; dopamine: p = 0.049; hydrocortisone: p = 0.003; nitric oxide: p = 0.002; sildenafil: p = 0.039; milrinone: p = 0.039; oxygen: p = 0.066), and mechanical ventilation (p = 0.005), with an increasing trend in the length of hospitalization (p = 0.089).Conclusion: The MSA indirectly reflects lung hypoplasia and is associated with a higher neonatal intensity of cares. However, further studies are needed to consolidate the results.Trial registration: The study is an exploratory post hoc analysis of the registered NeoAPACHE protocol at ClinicalTrials.gov with the identifier NCT04396028. What is Known: • In congenital diaphragmatic hernia, the lung size, liver position, and defect side are the most common prenatal prognostic parameters used in clinical practice for morbidity and mortality prediction. • Lung hypoplasia, strictly associated with lung size, is estimated by observed/expected lung to head ratio and observed/expected total fetal lung volume with prenatal ultrasound and fetal magnetic resonance imaging, respectively. What is New: • A new, faster, more straightforward, and less operator-dependent tool to assess CDH severity could be the mediastinal shift angle calculation with fetal magnetic resonance imaging. • Postnatal clinical severity, considered as a postnatal cardiovascular and respiratory impairment that indirectly reflects lung hypoplasia, is associated with an increased mediastinal shift angle calculation.

Multisite Veno-Venous Cannulation for Neonates and Nonambulatory Children

OBJECTIVES

Neonates with respiratory failure are ideally supported with veno-venous rather than veno-arterial extracorporeal membrane oxygenation due to the reduced rate of neurologic complications. However, the proportion of neonates supported with veno-venous extracorporeal membrane oxygenation is declining. We report multisite veno-venous extracorporeal membrane oxygenation, accessing the neck, returning to the inferior vena cava via the common femoral vein in neonates and children less than 10 kg.

DESIGN

Retrospective case series with 1 year minimum follow-up.

PATIENTS

Patients less than 10 kg supported with veno-venous extracorporeal membrane oxygenation accessing the jugular and returning to the femoral vein.

SETTING

A 30-bed pediatric intensive care delivering extracorporeal membrane oxygenation to approximately 20 children annually.

INTERVENTIONS

Veno-venous extracorporeal membrane oxygenation accessing the jugular and returning to the femoral vein was delivered using two single lumen cannulae.

MEASUREMENTS AND MAIN RESULTS

January 2015 to August 2019, 11 patients underwent veno-venous extracorporeal membrane oxygenation accessing the jugular and returning to the femoral vein with median weight of 3.6 kg (interquartile range 2.8-6.1 kg), and median corrected gestational age of 13 days (interquartile range, 2-175 d). The smallest patient weighed 2.1 kg. Seven patients had comorbidities. Extracorporeal membrane oxygenation was technically successful in all patients with median flows of 126 mL/kg/min (interquartile range, 120-138 mL/kg/min) and median arterial oxygenation saturation of 94% (interquartile range, 91-98%) at 24 hours. Nine survived to home discharge, and two were palliated. Common femoral vein occlusion was observed in all patients on ultrasound post decannulation. There was no clinical or functional deficit in the cannulated limb at follow-up, a minimum of 1 year post extracorporeal membrane oxygenation.

CONCLUSIONS

Veno-venous extracorporeal membrane oxygenation accessing the jugular and returning to the femoral vein was performed safely in patients under 10 kg with the smallest patient weighing 2.1 kg. Although occlusion of the common femoral vein was observed in patients post decannulation, subsequent follow-up demonstrated no clinical implications. We challenge current practice that veno-venous extracorporeal membrane oxygenation accessing the jugular and returning to the femoral vein cannot be performed in nonambulatory patients and suggest that this strategy is preferred over veno-arterial extracorporeal membrane oxygenation in infants requiring extracorporeal membrane oxygenation for respiratory failure.

Venovenous versus venoarterial extracorporeal membrane oxygenation among infants with hypoxic-ischemic encephalopathy: is there a difference in outcome?

OBJECTIVE

Our hypothesis was that among infants with hypoxic-ischemic encephalopathy (HIE), venoarterial (VA), compared to venovenous (VV), extracorporeal membrane oxygenation (ECMO) is associated with an increased risk of mortality or intracranial hemorrhage (ICH).

DESIGN/METHODS

Retrospective cohort analysis of infants in the Children's Hospitals Neonatal Database from 2010 to 2016 with moderate or severe HIE, gestational age ≥36 weeks, and ECMO initiation <7 days of age. The primary outcome was mortality or ICH.

RESULTS

Severe HIE was more common in the VA ECMO group (n = 57), compared to the VV ECMO group (n = 53) (47.4% vs. 26.4%, P = 0.02). VA ECMO was associated with a significantly higher risk of death or ICH [57.9% vs. 34.0%, aOR 2.39 (1.08-5.28)] and mortality [31.6% vs. 11.3%, aOR 3.06 (1.08-8.68)], after adjusting for HIE severity.

CONCLUSIONS

In HIE, VA ECMO was associated with a higher incidence of mortality or ICH. VV ECMO may be beneficial in this population.

Venoarterial to venovenous extracorporeal life support conversion in pediatric acute respiratory distress syndrome

In patients with pediatric acute respiratory distress syndrome (PARDS) and hemodynamic compromise who need venoarterial (VA) extracorporeal life support (ECLS), we have adopted a strategy to promote early VA-to-venovenous (VV) conversion since 2018. A single-center retrospective review was performed of all 22 patients who underwent ECLS for PARDS from 2008 to 2019. Variables were analyzed to determine factors affecting initial cannulation mode and in-hospital mortality. Outcomes were compared between before and after 2018. Of the 22 patients, 9 patients underwent initial VA-support. Small patient size and severe cardiopulmonary compromise prior to ECLS favored initial VA- over VV-support. Lactate level and vasoactive inotrope score at 24 hours post-ECLS initiation predicted in-hospital mortality. After 2018, all five patients with initial VA-support were converted to VV-support at 4.4 ± 1.3 days post-ECLS initiation without complications. In-hospital mortality decreased after 2018 (3/9) compared with before (10/13) (p = 0.041) despite longer ECLS run time (723.4 ± 384.2 vs 286.5 ± 235.1 hours, p = 0.003). The number of ECLS-related complications per ECLS 1000 run hours decreased after 2018 (7.2 ± 4.2 vs 46.9 ± 66.5, p = 0.063). Our strategy to promote early VA-to-VV conversion may be worth further evaluation in larger cohort studies.