Venoarterial Extracorporeal Life Support for Neonatal Respiratory Failure: Indications and Impact on Mortality

Cannulation approach and mortality in neonatal ECMO

OBJECTIVE

Identify associations between cannulation approach and mortality in neonates who received ECMO support for respiratory failure.

STUDY DESIGN

A retrospective analysis of neonates receiving ECMO for respiratory indications at a single quaternary-referral NICU. Associations between cannulation approach and mortality were assessed after adjustment for Neo-RESCUERS score. Cox Proportional Hazards (CPH) model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for each variable and outcome.

RESULTS

Among 244 neonates, overall survival was 88%, with 71% undergoing VV cannulation. After adjusting for Neo-RESCUERS score, VA cannulation was associated with higher mortality during ECMO when compared with VV cannulation (HR 4.189, 95% CI 1.480-11.851, P = 0.0069). Disease-specific comparisons revealed no statistical difference in Neo-RESCUERS score between VA and VV cohorts; however, VA cannulation was associated with higher ECMO mortality for neonates with congenital diaphragmatic hernia (50% vs. 5.5%, Χ² = 8.5965, P = 0.0034) and PPHN (20% vs. 1.8%, Χ² = 9.1047, P = 0.0025) when compared with VV cannulation.

CONCLUSION

VA cannulation was associated with increased mortality in neonates while on ECMO for respiratory failure, which was independent of illness severity.

Management of the CDH patient on ECLS

Congenital diaphragmatic hernia (CDH) is the most common indication for respiratory extracorporeal life support (ECLS) in neonates. The survival rate of CDH neonates treated with ECLS is 50%, and this figure has remained relatively stable over the last few decades. This is likely because the current population of CDH neonates who require ECLS have a higher risk profile [1]. The management of neonates with CDH has evolved over time to emphasize postnatal stabilization, gentle ventilation, and multi-modal treatment of pulmonary hypertension. In order to minimize practice variation, many centers have adopted CDH-specific clinical practice guidelines, however care is not standardized between different centers and outcomes vary [3]. The purpose of this review is to summarize our current understanding of issues central to the care of neonates with CDH treated with ECLS and specifically highlight how the use of the Extracorporeal Life Support Organization (ELSO) data have added to our understanding of CDH.

Comparison of the predictive ability of lactate and central venous blood gas in pediatric venoarterial mode extracorporeal membrane oxygenation outcome

BACKGROUND

This study aims to compare lactate and central venous blood gas in the prediction of outcome in pediatric venoarterial mode extracorporeal membrane oxygenation (V-A ECMO).

METHOD

This was a retrospective observational study conducted on patients undergoing V-A ECMO care in the pediatric intensive care unit of a tertiary medical center in Taiwan. Patients under 18 years of age undergoing V-A ECMO from January 2009 to April 2019 were included in this study.

RESULTS

This study consisted of 47 children who received V-A ECMO with an overall weaning rate of 66.0%. The mean age was 5.5 years and mean ECMO duration was 11.6 days. Successful weaning group had significantly lower lactate levels at initial (58.7 ± 47.0 mg/dL vs. 108.0 ± 55.3 mg/dL, p = 0.003), 0-12 h (37.8 ± 29.0 mg/dL vs. 83.5 ± 60.0 mg/dL, p Z 0.001), and 12-24 h (29.4 ± 26.9 mg/dL vs. 69.1 ± 59.1 mg/dL, p = 0.003) after ECMO initiation; however, the central venous blood gas including pH, HCO₃, CO₂, base excess (BE), and O₂ saturation showed no significant difference. The favorable outcome group had significantly lower lactate levels at 0-12 h (32.8 ± 26.3 mg/dL vs. 71.3 ± 53.3 mg/dL, p = 0.005), and 12-24 h (20.7 ± 10.2 mg/dL vs. 61.9 ± 53.5 mg/dL, p = 0.002); however, the HCO₃ levels (26.2 ± 4.5 mmol/L vs. 22.9 ± 6.8 mmol/L, p = 0.042) and BE (2.2 ± 5.4 vs. 2.2 ± 8.5, p = 0.047) were significantly higher at 12-24 h. In multivariate logistic regression, 12-24 h lactate value was an independent factor for unfavorable outcomes (p = 0.015, odds ratio [OR] = 1.1) with the best cut-off value of 48.6 mg/dL (sensitivity 48%, specificity 100%).

CONCLUSION

Lactate has better outcome prediction than central venous blood gas in pediatric V-A ECMO. The lactate value 12-24 h after ECMO initiation was an independent factor for unfavorable outcomes.

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.

The role of ECMO in the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the most common indication for extra-corporeal membrane oxygenation (ECMO) for neonatal respiratory failure. CDH management is evolving with advanced prenatal diagnostic imaging modalities. The risk profiles of infants receiving ECMO for CDH are shifting towards higher risk. Many clinicians are developing and following clinical practice guidelines to standardize and optimize the care of CDH neonates. Despite these efforts, there are significant differences in the practice patterns among ECMO centers as to how and when they choose to initiate ECMO for CDH, when they believe repair is safe, as well as many other nuances that are based on center experience or style. The purpose of this report is to summarize our current understanding of the new and recent developments regarding management of infants with CDH managed with ECMO.

Successful Establishment of the First Neonatal Respiratory Extracorporeal Membrane Oxygenation (ECMO) Program in the Middle East, in Collaboration With Pediatric Services

Background: Extracorporeal membrane oxygenation (ECMO) is a complex life-saving support for acute cardio-respiratory failure, unresponsive to medical treatment. Starting a new ECMO program requires synergizing different aspects of organizational infrastructures and appropriate extensive training of core team members to deliver the care successfully and safely. Objectives: To describe the process of establishing a new neonatal ECMO program and to evaluate the program by benchmarking the ECMO respiratory outcomes and mechanical complications to the well-established Extracorporeal Life Support Organization (ELSO) registry data. Materials and Methods: We reviewed the processes and steps involved in planning and setting up the new ECMO program. To assess the success of the ECMO implementation program, we retrospectively reviewed data of clinical outcomes and technical complications for the first 11 patients who have received ECMO therapy for respiratory indications since program activation (July 2018-May 2020). We analyzed mechanical complications as a tool to measure infrastructures and our effective training for the core team of ECMO specialists. We also looked at all clinical complications and benchmarked these numbers with the last 10 years of ELSO registry data (2009-2019) in the corresponding categories for comparison. Chi-square test was used to compare, and outcomes are presented in percentage; a p-value of <0.05 is considered significant. Results: A total of 27 patients underwent ECMO in the hospital, out of which 11 (six neonatal and five pediatric) patients had acute respiratory failure treated with venovenous (VV) ECMO or veno-arterial (VA) ECMO over a 22-month period. We had a total of 3,360 h of ECMO run with a range from 1 day to 7 weeks on ECMO. Clinical outcomes and mechanical complications are comparable to ELSO registry data (no significant difference); there were no pump failure, oxygenator failure, or pump clots. Conclusions: Establishing the ECMO program involved a multisystem approach with particular attention to the training of ECMO team members. The unified protocols, equipment, and multistep ECMO team training increased staff knowledge, technical skills, and teamwork, allowing the successful development of a neonatal respiratory ECMO program with minimal mechanical complications during ECMO runs, showing a comparable patient flow and mechanical complications.

Outcomes of neonates with listeriosis supported with extracorporeal membrane oxygenation from 1991 to 2017

BACKGROUND

Listeriosis may cause severe disease in fetuses and neonates. The outcomes of critically ill neonates with early-onset listeriosis requiring extracorporeal membrane oxygenation (ECMO) from 1975 to 1991 have been reported.

OBJECTIVE

To update the characteristics and outcomes of neonates with listeriosis supported by ECMO.

STUDY DESIGN

Retrospective study of neonates with culture-proven listeriosis reported to the Extracorporeal Life Support Organization Registry between 1991 and 2017. Comparisons were made between this cohort and the case series from 1975-1991.

RESULTS

Twenty-two neonates had culture-proven Listeria monocytogenes infection and required ECMO support. Eight-six percent survived to discharge, compared with 67% in the previous cohort (p = 0.2). The median ECMO duration was 131 h, compared with 209 h in the previous cohort (p = 0.1). Nonsurvivors had a significantly lower pre-ECMO pH (6.91 vs 7.31, p = 0.0006).

CONCLUSION

The survival of neonates with listeriosis supported with ECMO is high, supporting the use of ECMO as rescue therapy for this condition.

Inotrope Needs in Neonates Requiring Extracorporeal Membrane Oxygenation for Respiratory Failure

OBJECTIVE

To evaluate how inotropic requirements in neonates with respiratory failure are affected by extracorporeal membrane oxygenation (ECMO) mode and whether high requirements predict mortality.

STUDY DESIGN

This retrospective chart review included all neonates undergoing ECMO for primary respiratory failure from 2010 to 2016 at a single institution. The vasoactive inotropy score (VIS) was calculated as described in the literature. Data were analyzed with descriptive statistics and univariate analyses.

RESULTS

Of the 110 identified neonates, 96 underwent venovenous (VV) (87%), 11 (10%) venoarterial, and 3 (3%) converted from VV to venoarterial. The median precannulation VIS score was 33.02 for patients who underwent VV compared with 28.93 for venoarterial (P = .25) and 15 for infants converted. VIS decreased dramatically by 4 hours of ECMO in both groups. The VIS before cannulation was similar in survivors and nonsurvivors, but was significantly higher in nonsurvivors after 24 hours of ECMO (median VIS, 12 [IQR, 8-25] vs 8 [IQR, 3.0-14.5]; P = .035) and at decannulation (10 [IQR, 7-19] vs 3 [IQR, 0-7]; P < .001).

CONCLUSIONS

Neonates with respiratory failure can be successfully managed on VV ECMO even with considerable vasoactive requirements. Vasoactive requirement after 24 hours of ECMO was predictive of mortality.