Severe congenital diaphragmatic hernia (CDH): a critical analysis of eight years' experience

Developing a new pediatric extracorporeal membrane oxygenation (ECMO) program

OBJECTIVES

We aimed to critically evaluate the effectiveness of a designated ECMO team in our ECMO selection process and patient outcomes in the first 3 years of our low-volume pediatric ECMO program.

METHODS

We conducted a retrospective chart review of patients who received an ECMO consultation between the start of our program in March 2015 and May 2018. We gathered clinical and demographic information on patients who did and did not receive ECMO, and described our selection process. We reflected on the processes used to initiate our program and our outcomes in the first 3 years.

RESULTS

69 patients received consultations, and of those, 50 patients were potential candidates. 19 (38%) of the candidates were ultimately placed on ECMO. There were statistically significant differences in oxygen saturation, paO₂, oxygenation index, A-aDO₂, lactate, and pH between the patients who went on ECMO and who did not. We improved our outcomes from 0% survival to discharge in 2015, to 60% in 2018, with an average of 63% survival to discharge over the first 3 years of our program.

CONCLUSIONS

In a low-volume pediatric ECMO center, having a designated team to assist in the patient selection process and management can help provide safe and efficient care to these patients, and improve patient outcomes. Having a strict management protocol and simulation sessions involving all members of the medical team yields comfort for the providers and optimal care for patients. This study describes our novel structure, processes, and outcomes, which we hope will be helpful to others seeking to develop a new pediatric ECMO program.

First 24-h SNAP-II score and highest PaCO2 predict the need for ECMO in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Early clinical predictors for the use of ECMO in patients with congenital diaphragmatic hernia (CDH) are lacking. We sought to evaluate the first 24-h SNAP-II score and highest PaCO2 as predictors of ECMO support and in-hospital mortality in neonates with CDH.

METHODS

Retrospective review of 47 consecutive neonates with CDH admitted to our institution from January 2007 to December 2010 was performed. Covariates of ECMO use including SNAP-II score and highest PaCO2 within the first 24 h of NICU admission were evaluated.

RESULTS

Of the 47 infants in this study, 24 patients were supported with ECMO. The ECMO group had a higher incidence of pulmonary hypertension, higher PaCO2, and higher 24-h SNAP-II scores. Only the SNAP-II score and not highest PaCO2 predicted mortality following multivariate adjustment.

CONCLUSIONS

The first 24-h SNAP-II score and highest PaCO2 may provide some prognostic value in identifying neonates who undergo ECMO support; however neither measure was independently associated with the use of therapy. Only the SNAP-II score was associated with in-hospital mortality following multivariate adjustment. Additional study is needed to validate these results in a larger data set.

Thoracoscopic repair of congenital diaphragmatic hernia in infancy

BACKGROUND

Minimally invasive surgical techniques, specifically the thoracoscopic approach, have been applied to congenital diaphragmatic hernia (CDH) with varying outcomes from selected centers. The aim of our study was to examine the rate of successful completion and compare outcomes between open and thoracoscopic approaches in CDH repair.

METHODS

We performed a retrospective analysis of infants with CDH repair (From February 2004 to January 2008). Patients were divided into thoracoscopic and open groups, based on operative approach. We analyzed demographic, clinical, and hospitalization characteristics to compare the completion rate and outcomes in these two groups.

RESULTS

Analysis of 31 infants with CDH (14 thorascocopic and 17 open) demonstrated no differences in sex (P = 0.132), age (P = 0.807), birthweight (P = 0.256), weight at operation (P = 0.647), pulmonary hypertension (P = 0.067), preoperative intensive care unit (ICU) days (P = 0.673), ventilator days (P = 0.944), or use of a patch (P = 0.999) between the groups. Seventy-nine percent of thoracoscopic operative approaches were completed successfully. There was a significant difference between the open and thoracoscopic groups with respect to estimated gestational age (39 versus 36.5 weeks; P = 0.006) and operating room time (70 versus 145 minutes; P = 0.004). The total (P = 0.662), ICU (P = 0.889), and postoperative (P = 0.619) length of stay and days on ventilator (P = 0.705), as well as days until initial enteral feeds (P = 0.092), were not significantly different between groups. There were no deaths and no evidence of recurrence, with a mean follow-up of 346 days.

CONCLUSIONS

In our early experience, the thoracoscopic approach for congenital diaphragmatic hernia repair was completed in 80% of our patient population with minimal exclusion criteria. Further study, with larger sample sizes, is needed to ascertain differences in outcomes, such as length of stay and initiation of enteral feeding.

Predictors and statistical models in congenital diaphragmatic hernia

Despite advances in intensive care, congenital diaphragmatic hernia (CDH) maintains a risk of death >35%. Mortality predictors have been claimed, using logistic regression. When the outcome of interest is rare (i.e. <20%), the odds ratio, measured by logistic regression, is approximately equal to the relative risk, calculated by log-binomial model. However, for common events, the odds ratio misleads the exposition risk. The aims are to identify independent predictors of mortality in high-risk CDH, using the log-binomial model and disclose if the exposition risks could differ applying in comparison the logistic regression. Details of 113 consecutive high-risk CDH neonates, baseline demographics and disease features were collected retrospectively. Log-binomial model and logistic regression were applied and compared. Overall mortality rate was 41.6% (47/113). The log-binomial model identified preoperative pneumothorax (pnx), birth weight < or = 2,500 g and liver herniation as independent mortality predictors; female gender, an advanced gestational age and a PaO(2) > or = 90 mmHg as protective factors. Using logistic regression, liver herniation and birth weight did not maintain the significance. The exposition risks for pnx, female gender and gestational age were overestimated. The odds ratio measured by logistic regression overestimated the exposition risks. Since the mortality rate is confirmed to be >20% and the exposition risks, measured by logistic regression, are misleading, the log-binomial model should be consider in CDH binary outcome studies. According to the mortality predictors identified, making every effort to plan delivery at term and lowering the risk of pnx could improve the outcome.

Ex utero intrapartum treatment with extracorporeal membrane oxygenation for severe congenital diaphragmatic hernia

PURPOSE

The purpose of this study was to determine whether ex utero intrapartum treatment with extracorporeal membrane oxygenation (EXIT to ECMO) is a reasonable approach for managing patients antenatally diagnosed with severe congenital diaphragmatic hernia (CDH).

METHODS

A 6-year retrospective review was performed on fetuses with severe CDH (liver herniation and a lung/head ratio <1.4, percentage of predicted lung volume <15, and/or congenital heart disease). Fourteen of the patients underwent EXIT with a trial of ventilation. Fetuses with poor preductal oxygen saturations despite mechanical ventilation received ECMO before their delivery. Maternal-fetal outcomes were analyzed.

RESULTS

There were no maternal-reported complications. Three babies passed the ventilation trial and survived, but 2 of them required ECMO within 48 hours. The remaining 11 fetuses received ECMO before their delivery. Overall survival after EXIT-to-ECMO was 64%. At 1-year follow-up, all survivors had weaned off supplemental oxygen, but 57% required diuretics and/or bronchodilators.

CONCLUSION

This is the largest reported experience using EXIT to ECMO in the management of severe CDH. The EXIT-to-ECMO procedure is associated with favorable survival rates and acceptable pulmonary morbidity in fetuses expected to have a poor prognosis under conventional management.

Fetal lung volume estimated by 3-dimensional ultrasonography and magnetic resonance imaging in cases with isolated congenital diaphragmatic hernia

OBJECTIVE

To assess the agreement of 3-dimensional ultrasonography and magnetic resonance imaging in estimating fetal lung volume in cases with isolated congenital diaphragmatic hernia.

METHODS

Fetal lung volume was measured in 11 cases of congenital diaphragmatic hernia (10 left and 1 right) by 3-dimensional ultrasonography and magnetic resonance imaging. These examinations were performed during the same week. The operators were blinded to each other's results. Intraclass correlation was used to evaluate the agreement between 3-dimensional ultrasonography and magnetic resonance imaging estimations of the ipsilateral, contralateral, and total fetal lung volume. A Bland-Altman graph was plotted to detect possible discordant observations.

RESULTS

The global intraclass correlation coefficient between magnetic resonance imaging and 3-dimensional ultrasonographic measurement of fetal lung volume was 0.94 (95% confidence interval, 0.78-0.98) with no outliers observed on the Bland-Altman plot.

CONCLUSIONS

There is a good agreement between 3-dimensional ultrasonography and magnetic resonance imaging for fetal lung volume estimation in cases with congenital diaphragmatic hernia.