Increased N-terminal Pro-B-Type Natriuretic Peptide during Extracorporeal Life Support Is Associated with Poor Outcome in Neonates with Congenital Diaphragmatic Hernia

Diagnosis, management and long term cardiovascular outcomes of phenotypic profiles in pulmonary hypertension associated with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a developmental defect of the diaphragm resulting in herniation of viscera into the chest. This condition is characterized by pulmonary hypoplasia, pulmonary hypertension (PH) and cardiac ventricular dysfunction. PH is a key component of the pathophysiology of CDH in neonates and contributes to morbidity and mortality. Traditionally, PH associated with CDH (CDH-PH) is thought to be secondary to increased pulmonary arterial resistance and vasoreactivity resulting from pulmonary hypoplasia. Additionally, there is increasing recognition of associated left ventricular hypoplasia, dysfunction and elevated end diastolic pressure resulting in pulmonary venous hypertension in infants with CDH. Thus, hemodynamic management of these infants is complex and cautious use of pulmonary vasodilators such as inhaled nitric oxide (iNO) is warranted. We aim to provide an overview of different phenotypic profiles of CDH associated PH and potential management options based on current evidence and pathophysiology.

Hemolysis during Venovenous Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia: A Prospective Observational Study

OBJECTIVE

To investigate the incidence of hemolysis and its association with outcome in neonates with congenital diaphragmatic hernia (CDH) requiring venovenous extracorporeal membrane oxygenation (ECMO) treatment using a Medos Deltastream circuit with a DP3 pump, a hilite 800 LT oxygenator system, and a ¼' tubing.

STUDY DESIGN

Plasma free hemoglobin (PFH) was prospectively measured once daily during ECMO using spectrophotometric testing. Patients (n = 62) were allocated into two groups according to presence or absence of hemolysis. Hemolysis was defined as PFH ≥ 50 mg/dL on at least 2 consecutive days during ECMO treatment. Hemolysis was classified as either moderate with a maximum PFH of 50-100 mg/dL or severe with a maximum PFH >100 mg/dL.

RESULTS

Hemolysis was detected in 14 patients (22.6%). Mortality was 100% in neonates with hemolysis compared with 31.1% in neonates without hemolysis (P < .001). In 21.4% hemolysis was moderate and in 78.6% severe. Using multivariable analysis, hemolysis (hazard ratio: 6.8; 95%CI: 1.86-24.86) and suprasystemic pulmonary hypertension (PH) (hazard ratio: 3.07; 95%CI: 1.01-9.32) were independently associated with mortality. Hemolysis occurred significantly more often using 8 French (Fr) cannulae than 13 Fr cannulae (43% vs 17%; P = .039). Cutoff for relative ECMO flow to predict hemolysis were 115 ml/kg/ minute for patients with 8 Fr cannulae (Area under the curve [AUC] 0.786, P = .042) and 100 ml/kg/ minute for patients with 13 Fr cannulae (AUC 0.840, P < .001).

CONCLUSIONS

Hemolysis in CDH neonates receiving venovenous ECMO is independently associated with mortality.

Percutaneous, ultrasound-guided single- and multisite cannulation for veno-venous extracorporeal membrane oxygenation in neonates

AIMS

Extracorporeal membrane oxygenation (ECMO) is a widely used technique to support neonates with severe respiratory failure. Data on percutaneous, ultrasound-guided veno-venous (VV) ECMO cannulation in neonates is still scarce. Aim of this study was to describe our institutional experience with ultrasound-guided percutaneous, VV ECMO cannulation in neonates with severe respiratory failure.

METHODS

Neonates receiving ECMO support at our department between January 2017 and January 2021 were retrospectively identified. Patients receiving VV ECMO cannulation performed by the percutaneous Seldinger technique by single- or multisite cannulation were analyzed.

RESULTS

A total of 54 neonates received ECMO cannulation performed by the percutaneous Seldinger technique. In 39 patients (72%) a 13 French bicaval dual-lumen cannula was inserted and in 15 patients (28%) two single-lumen cannulae were used. Cannulae positioning using the multisite approach was in all cases as desired. The tip of the 13 French cannula was located in the IVC in 35/39 patients, in four patients position was too proximal but did not dislocate during the ECMO run. One (2%) preterm neonate (weight 1.75 kg) developed a cardiac tamponade which was successfully managed with drainage. Median duration of ECMO was 7 days (interquartile range: 5-16 days). Forty-four patients (82%) were successfully weaned from ECMO and in 31/44 (71%) the ECMO cannulae were removed with a delay of 0.9-7.2 days (median 2.8 days) after weaning without noticing complications.

CONCLUSIONS

A correct cannula placement using the ultrasound-guided percutaneous Seldinger technique, for both single- and multisite cannulation, seems feasible in most neonatal patients receiving VV ECMO.

Dynamics of pulmonary hypertension severity in the first 48 h in neonates with prenatally diagnosed congenital diaphragmatic hernia

Introduction

Pulmonary hypertension (PH) is one of the major contributing factors to the high morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH). The severity and duration of postnatal PH are an established risk factor for patient outcome; however, the early postnatal dynamics of PH have not been investigated. This study aims to describe the early course of PH in CDH infants, and its relation to established prognostic markers and outcome measures.

Methods

We performed a monocentric retrospective review of neonates with prenatally diagnosed CDH, who received three standardized echocardiographic examinations at 2-6 h, 24, and 48 h of life. The degree of PH was graded as one of three categories: mild/no, moderate, or severe PH. The characteristics of the three groups and their course of PH over 48 h were compared using univariate and correlational analyses.

Results

Of 165 eligible CDH cases, initial PH classification was mild/no in 28%, moderate in 35%, and severe PH in 37%. The course of PH varied markedly based on the initial staging. No patient with initial no/mild PH developed severe PH, required extracorporeal membrane oxygenation (ECMO)-therapy, or died. Of cases with initial severe PH, 63% had persistent PH at 48 h, 69% required ECMO, and 54% died. Risk factors for any PH included younger gestational age, intrathoracic liver herniation, prenatal fetoscopic endoluminal tracheal occlusion (FETO)-intervention, lower lung to head ratio (LHR), and total fetal lung volume (TFLV). Patients with moderate and severe PH showed similar characteristics, except liver position at 24- (p = 0.042) and 48 h (p = 0.001), mortality (p = 0.001), and ECMO-rate (p = 0.035).

Discussion

To our knowledge, this is the first study to systematically assess the dynamics of PH in the first postnatal 48 h at three defined time points. CDH infants with initial moderate and severe PH have a high variation in postnatal PH severity over the first 48 h of life. Patients with mild/no PH have less change in PH severity, and an excellent prognosis. Patients with severe PH at any point have a significantly higher risk for ECMO and mortality. Assessing PH within 2-6 h should be a primary goal in the care for CDH neonates.

Echocardiographic Assessment of Pulmonary Hypertension in Neonates with Congenital Diaphragmatic Hernia Using Pulmonary Artery Flow Characteristics

Background: Assessment of pulmonary hypertension (PH) is essential in neonates with congenital diaphragmatic hernia (CDH). Echocardiography is widely established to quantify PH severity, but currently used parameters have inherent limitations. The aim of our study was to investigate the prognostic utility of the index of the pulmonary artery acceleration time to the right ventricular ejection time (PAAT:ET) in CDH neonates assessed using echocardiography. Methods: PAAT:ET values were prospectively measured in CDH neonates on admission, on day of life (DOL) 2 and DOL 5−7. Optimal cut-off values to predict mortality and need for ECMO were calculated and PAAT:ET values were compared between non-ECMO survivors, ECMO-survivors, and ECMO-non-survivors. Results: 87 CDH neonates were enrolled and 39 patients required ECMO therapy. At baseline, PAAT:ET values were significantly lower in ECMO patients compared to non-ECMO patients (p < 0.001). ECMO survivors and ECMO non-survivors had similar values at baseline (p = 0.967) and DOL 2 (p = 0.124) but significantly higher values at DOL 5−7 (p = 0.003). Optimal PAAT:ET cut-off for predicting ECMO was 0.290 at baseline and 0.310 for predicting non-survival in patients on ECMO at DOL 5−7. Conclusion: PAAT:ET is a feasible parameter for early risk assessment in CDH neonates.

The heart in congenital diaphragmatic hernia: Knowns, unknowns, and future priorities

There is growing recognition that the heart is a key contributor to the pathophysiology of congenital diaphragmatic hernia (CDH), in conjunction with developmental abnormalities of the lung and pulmonary vasculature. Investigations to date have demonstrated altered fetal cardiac morphology, notably relative hypoplasia of the fetal left heart, as well as early postnatal right and left ventricular dysfunction which appears to be independently associated with adverse outcomes. However, many more unknowns remain, not least an understanding of the genetic and cellular basis for cardiac dysplasia and dysfunction in CDH, the relationship between fetal, postnatal and long-term cardiac function, and the impact on other parts of the body especially the developing brain. Consensus on how to measure and classify cardiac function and pulmonary hypertension in CDH is also required, potentially using both non-invasive imaging and biomarkers. This may allow routine assessment of the relative contribution of cardiac dysfunction to individual patient pathophysiological phenotype and enable better, individualized therapeutic strategies incorporating targeted use of fetal therapies, cardiac pharmacotherapies, and extra-corporeal membrane oxygenation (ECMO). Collaborative, multi-model approaches are now required to explore these unknowns and fully appreciate the role of the heart in CDH.