Prediction of mortality in neonates with congenital diaphragmatic hernia treated with extracorporeal membrane oxygenation

Outcomes after Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia: A Single-Center Experience

Background

Congenital diaphragmatic hernia (CDH) is a rare disease often requiring mechanical ventilation after birth. In severe cases, extracorporeal membrane oxygenation (ECMO) may be needed. This study analyzed the outcomes of patients with CDH treated with ECMO and investigated factors related to in-hospital mortality.

Methods

Among 254 newborns diagnosed with CDH between 2008 and 2020, 51 patients needed ECMO support. At Asan Medical Center, a multidisciplinary team approach has been applied for managing newborns with CDH since 2018. Outcomes were compared between hospital survivors and nonsurvivors.

Results

ECMO was established at a median of 17 hours after birth. The mean birth weight was 3.1±0.5 kg. Twenty-three patients (23/51, 45.1%) were weaned from ECMO, and 16 patients (16/51, 31.4%) survived to discharge. The ECMO mode was veno-venous in 24 patients (47.1%) and veno-arterial in 27 patients (52.9%). Most cannulations (50/51, 98%) were accomplished through a transverse cervical incision. No significant between-group differences in baseline characteristics and prenatal indices were observed. The oxygenation index (1 hour before 90.0 vs. 51.0, p=0.005) and blood lactate level (peak 7.9 vs. 5.2 mmol/L, p=0.023) before ECMO were higher in nonsurvivors. Major bleeding during ECMO more frequently occurred in nonsurvivors (57.1% vs. 12.5%, p=0.007). In the multivariate analysis, the oxygenation index measured at 1 hour before ECMO initiation was identified as a significant risk factor for in-hospital mortality (odds ratio, 1.02; 95% confidence interval, 1.01–1.04; p=0.05).

Conclusion

The survival of neonates after ECMO for CDH is suboptimal. Timely application of ECMO is crucial for better survival outcomes.

The development of multiorgan dysfunction in CDH-ECMO neonates is associated with the level of pre-ECMO support

PURPOSE

Congenital diaphragmatic hernia (CDH) is the most common indication for neonatal extracorporeal membrane oxygenation (ECMO), but mortality remains at 50%. Multiorgan failure can occur in 25% and has been linked to worse outcomes. We sought to examine the factors that would increase the risk of multiorgan dysfunction (MOD).

METHODS

The Extracorporeal Life Support Organization (ELSO) database was used to identify infants with CDH (2000-2015). The primary outcome was MOD, which was defined as the presence of organ failure in ≥2 organ systems. We used a multivariable logistic regression to examine the effect of demographics, pre-ECMO respiratory status, comorbidities, and therapies on MOD.

RESULTS

There were a total of 4374 CDH infants who were treated with ECMO. Overall mortality was 52.4%. The risk models demonstrated that pre-ECMO cardiac arrest (OR 1.458, CI: 1.146-1.861, p = 0.002) and hand-bagging (OR 1.461, CI: 1.094-1.963, p = 0.032) had the strongest association with MOD. In addition, other pre-ECMO indicators of disease severity (pH, HFOV, MAP, 5-min APGAR) and pre-ECMO therapies (bicarb, neuromuscular [NM] blockers) were also associated with MOD.

CONCLUSIONS

The level of pre-ECMO support has a significant association with the development of MOD, and initiation of ECMO prior to arrest seems to be critical to avoid complications.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Comparison of early versus delayed strategies for repair of congenital diaphragmatic hernia on extracorporeal membrane oxygenation

PURPOSE

For the last seven years, our institution has repaired infants with CDH that require ECMO early after cannulation. Prior to that, we attempted to decannulate before repair, but repaired on ECMO if we were unable to wean after two weeks. This study compares those strategies.

METHODS

From 2002 to 2016, 65 infants with CDH required ECMO. 67.7% were repaired on ECMO, and 27.7% were repaired after decannulation. Data were compared between patients repaired ≤5days after cannulation ("early protocol", n=30) and >5days after cannulation or after de-cannulation ("late protocol", n=35). We used Cox regression to assess differences in outcomes between groups.

RESULTS

Survival for the early and late protocol groups was 43.3% and 68.8%, respectively (p=0.0485). For patients that were successfully decannulated before repair, survival was 94.4%. Moreover, the early repair protocol was associated with prolongation of ECMO (16.8±7.4 vs. 12.6±6.8days, p=0.0216). After multivariate regression, the early repair protocol was an independent predictor of both mortality (HR=3.48, 95% CI=1.28-9.45, p=0.015) and days on ECMO (IRR=1.39, 95% CI=1.07-1.79, p=0.012). All bleeding occurred in patients repaired on ECMO (29.5%, 13/44).

CONCLUSIONS

Our data suggest that protocolized CDH repair early after ECMO cannulation may be associated with increased mortality and prolongation of ECMO. However, early repair is not necessarily harmful for those patients who would otherwise be unable to wean from ECMO before repair. Further work is needed to better move towards individualized patient care.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

Level III.

Current Practices in the Management of Congenital Diaphragmatic Hernia Patients Requiring Extracorporeal Membrane Oxygenation: Results of an International Survey of Pediatric Surgeons

INTRODUCTION

There is little consensus on optimal management for congenital diaphragmatic hernia extracorporeal membrane oxygenation (CDH ECMO) patients. Meaningful comparisons of the various approaches have been limited due to the low number of cases in institutions. In addition, the multidisciplinary reliance and rigid institutional framework of ECMO serve to further limit exposure to alternative practices. The goal of this study is to survey the international pediatric surgery community to describe the current practice trends.

METHODS

A survey was electronically distributed to the international pediatric surgical community. The results were evaluated using statistical analysis.

RESULTS

A total of 123 pediatric surgeons completed the survey, of whom 89% work at institutions offering both venoatrial (VA) and venovenous (VV) ECMO. Although 69% perform VA ECMO for CDH, only 46% felt VA was the "optimal method." Among VV proponents, 21% believe the rate of VV to VA conversion to be <5% and 16% believe it to be >30% compared with 0% and 40% in VA proponents. Distribution of timing of repair: 46% post-ECMO repair, 22% early ECMO repair, 15% whenever stabilized on ECMO, and 14% late ECMO repair. Sixty-four percent (71/111) would perform an ECMO CDH repair in the unweanable patient and 27% (30/111) report successful decannulation after repair of a patient who was unweanable on ECMO for 2 weeks. Ninety-two percent do not perform exit-to-ECMO.

CONCLUSION

There are significant practice variations in the management of CDH ECMO. Majority of pediatric surgeons perform VA ECMO in CDH patients; however, a significant percentage of those believe VV to be more optimal. This discrepancy is not accounted for by the VA-only institutions. Although post-ECMO CDH repair is the most common approach, the majority would perform a repair "on ECMO" if the patient was unweanable. In addition, although many pediatric surgeons believe the "last ditch repair" for the unweanable patient to be futile, 27% have reported success. Exit-to-ECMO for CDH remains a minority practice.

Shifting Risks and Conflicting Outcomes-ECMO for Neonates with Congenital Diaphragmatic Hernia in the Modern Era

OBJECTIVES

To update previously described trends for neonates with congenital diaphragmatic hernia (CDH) receiving ECMO with changes in recommendations for care, and to determine how recent advancements in respiratory care have affected this patient population.

STUDY DESIGN

This study is a retrospective review of more than 2500 neonates with CDH who received ECMO listed in the Extracorporeal Life Support Organization (ELSO) registry. Cochran-Armitage and multivariate regression analyses were used to analyze changes in the patient population over time and in mortality-related risk factors.

RESULTS

Almost one-half (48.1%) of the term neonates survived to discharge, representing a 13.8% decline in survival over the past 25 years (P < .0001). Over the past 10 years, the prevalence of respiratory acidosis more than doubled (P < .0001) and the prevalence of major complications increased (P < .001). During the same period, the number of ECMO courses longer than 1 week increased (P < .001), whereas the prevalence of multiple complications (>4) decreased (P < .0001). Surgeries performed on ECMO were associated with worse outcomes than those performed off ECMO. ECMO duration no longer represents a mortality-related risk factor.

CONCLUSIONS

Survival rates for neonates with CDH receiving ECMO have continued to drop in the modern era. Although the safety of ECMO has improved over the last decade, the number of patients experiencing significant respiratory acidosis has more than doubled-increasing the risk of intracranial hemorrhage and overall mortality. The evidence for permissive hypercapnia remains mixed; nonetheless, we believe that the risks outweigh the rewards in this patient population.

Risk factors for postoperative mortality in congenital diaphragmatic hernia: a single-centre observational study

BACKGROUND

The management of congenital diaphragmatic hernia (CDH) is a major challenge. The mortality is dependent on associated malformations, the severity of pulmonary hypoplasia, pulmonary hypertension and iatrogenic lung injury associated with aggressive mechanical ventilation. The aims of the study were to investigate the mortality over time in a single paediatric surgical centre, to compare the results with recent reports and to define the risk factors for mortality.

METHODS

The medical records of infants with CDH from two time periods: 1995-2005 and 2006-2016 were reviewed. Cox regression was used for statistical analysis.

RESULTS

The study included 113 infants. The mortality rate was significantly decreased in the later time period, compared to the earlier, 4.4 and 17.9%, respectively. At the early time period five patients (7.5%) were treated with ECMO and in the later time period ECMO was used in three patients (6.5%). The mortality in ECMO-treated patients was 50% in both time periods. Prenatal diagnosis, intrathoracic liver, low Apgar score and low birth weight were defined as independent risk factors for mortality.

CONCLUSION

Despite no significant differences in the incidence of independent risk factors and the use of ECMO between the two time periods, mortality decreased over time. The mortality was lower than previously reported. The results indicate that there are many important factors involved in a successful outcome after CDH repair. Large multicentre studies are necessary to define those critical factors and to determine optimal treatment strategies.

Successful primary use of VVDL+V ECMO with cephalic drain in neonatal respiratory failure

OBJECTIVE

To describe the use of double-lumen venovenous (VVDL) extracorporeal membrane oxygenation (ECMO) with cephalic draining cannula (VVDL+V) as a primary approach for all neonatal respiratory diagnoses and to compare our single-center experience with data as collected in the Extracorporeal Life Support Organization (ELSO) database.

STUDY DESIGN

We retrospectively reviewed all cases of ECMO for neonatal respiratory failure performed in the neonatal intensive-care unit at a large referral children's hospital, the Children's Healthcare of Atlanta at Egleston (CHOA-E). Comparisons were then made to neonatal respiratory ECMO data retrieved from the ELSO database.

RESULTS

At CHOA-E 162 of 189 cases were completed with the VVDL+V approach. Survival in the VVDL+V cohort was 89.1% versus 68.7% from ELSO, P<0.001. For those complications considered, the overall risk of complication favored the CHOA-E VVDL+V group as compared with ELSO (odds ratio (OR) 0.71 (0.52-0.7)) as did the risk of neurologic complications (OR 0.29, (0.15-0.58)), including intracranial hemorrhage (OR 0.39 (0.18-0.97), P=0.011).

CONCLUSION

The VVDL+V approach can be used successfully as the primary approach for ECMO for neonatal respiratory failure of various etiologies and in this single-center cohort this approach was associated with improved survival and lower rates of complication as compared with the ELSO database.

Persistent hypercarbia after resuscitation is associated with increased mortality in congenital diaphragmatic hernia patients

BACKGROUND

Within congenital diaphragmatic hernia (CDH) care, there have been attempts to identify clinical parameters associated with patient survival, including markers of postnatal pulmonary gas exchange. This study aimed to identify whether postnatal pulmonary gas exchange parameters correlated with CDH patient survival.

METHODS

A retrospective review was performed of isolated CDH neonates treated at a single institution from 1/2007 to 12/2013. Patient demographics, prenatal imaging, and postnatal clinical parameters, including arterial blood gas values within the first 24hours of life, were collected.

RESULTS

Seventy-four patients with isolated CDH were identified. Fifty-seven had fetal MRI. Overall, 30-day patient survival was 85%. Sixteen infants (22%) required ECMO within 24hours. Mean initial PaCO2 in nonsurvivors was higher, and infants who remained hypercarbic postresuscitation (72±19mmHg) had a worse prognosis than those who resuscitated to a normal PaCO2 (39±1.6mmHg) (p<0.001). Prenatal fetal lung volumes measured by MRI were not strongly correlated with PaCO2 levels.

CONCLUSION

CDH nonsurvivors are unable to maintain sufficient pulmonary gas exchange during the first 24hours of resuscitation. Furthermore, prenatal fetal lung volumes are weakly correlated with actual pulmonary gas exchange. These data may be useful for patient counseling during the resuscitative phase of CDH care.

Optimal timing of congenital diaphragmatic hernia repair in infants on extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a vital pre-operative adjunct for the stabilization of patients with severe congenital diaphragmatic hernia (CDH) that develop cardiorespiratory failure. The optimal timing of diaphragmatic repair in patients with CDH that require ECMO remains controversial. This article offers a review of the data available addressing the risks and outcomes of patients who require ECMO support with regard to timing of repair.

Stability prior to surgery in Congenital Diaphragmatic Hernia: is it necessary?

BACKGROUND

Delaying surgery for infants with CDH until they achieve clinical stability is common practice. Stability, however, is inconsistently defined, and many infants fail to reach pre-established criteria. We sought to determine if infants undergoing surgery without meeting pre-established criteria could achieve meaningful survival.

METHODS

All infants in the CAPSNet database were analyzed (2005-2010). Patients undergoing operative repair were divided into two groups based on whether they met strict (FiO2<0.40, conventional ventilation, preductal saturation >92%, no inotropes or vasodilators), or lenient (FiO2 <0.60, conventional ventilation, preductal saturation >88%, no vasodilators) criteria. Univariate analyses were performed comparing characteristics of those who survived after surgery (N=273) with those who did not (N=21).

RESULTS

294 patients (85%) survived to surgery. Predictors of post-operative survival included prenatal liver position (p=0.003), preoperative oxygen requirements (p=0.008), preoperative inotropes (p<0.0001), and non-conventional ventilation (p=0.004). Infants meeting strict criteria had increased survival (99%; p<0.0001). Infants meeting lenient criteria constituted 70% of survivors. Nearly one-third of survivors met neither strict nor lenient criteria.

CONCLUSIONS

Infants with CDH can achieve good survival even when criteria for pre-operative stability are not met. We suggest that all infants should be repaired even if lenient criteria for ventilatory, inotrope, or vasodilator requirements are not achieved.

Prostanoids in bronchoalveolar lavage fluid do not predict outcome in congenital diaphragmatic hernia patients

Vasoactive prostanoids may be involved in persistent pulmonary hypertension (PPH) in infants with a congenital diaphragmatic hernia (CDH). We hypothesized that increased levels of prostanoids in bronchoalveolar lavage (BAL) fluid would predict clinical outcome. We measured the concentrations of 6-keto-prostaglandin F_1α (6-keto-PGF_1α), thromboxane B₂ (TxB₂), protein, albumin, total cell count, and elastase-α1-proteinase-inhibitor complex in BAL fluid of 18 CDH patients and of 13 control subjects without PPH. We found different concentrations of prostanoids in BAL fluid of CDH patients with PPH: infants with a poor prognosis had either high levels of both 6-keto-PGF_1α and TxB₂ compared to controls, or high levels of 6-keto-PGF_1α only. TxB₂ levels showed a large variability in all CDH patients irrespective of outcome. We conclude that prostanoid levels in BAL fluid do not predict clinical outcome in CDH patients.

Predictors of survival in congenital diaphragmatic hernia patients requiring extracorporeal membrane oxygenation: CNMC 15-year experience

OBJECTIVE

To review outcomes of patients with congenital diaphragmatic hernia (CDH) requiring extracorporeal membrane oxygenation (ECMO) at a level IIIC neonatal intensive care unit and to determine if pre-ECMO respiratory status can help predict mortality.

STUDY DESIGN

A single-center retrospective chart review was conducted on all infants with CDH treated with ECMO in the past 15 years. Demographic and clinical information, including pre-ECMO ventilatory and blood gas data, was collected. Differences between survivors and non-survivors were evaluated using independent samples t-/Mann-Whitney U-and Fisher's exact/chi (2)-tests for continuous and categorical data, respectively. Cox regression analysis was performed to evaluate predictors of survival while controlling for covariates. Significant predictors were further explored with receiver operating characteristic (ROC) curve and Kaplan-Meier survival analysis.

RESULT

Overall survival of the population of 62 patients treated with ECMO was 50%. Survivor and non-survivors were similar in birth weight, gestational age, gender, race and Apgar scores. Approximately 80% of patients in both groups had a left-sided defect. Less than half of patients were prenatally diagnosed in either group. Patients in the non-survivor group had associated anomalies (42 vs 23% for survivors) but this was not statistically significant (P=0.303). Non-survivors were more likely to be put on ECMO earlier, stay on ECMO longer and be operated upon later. On pre-ECMO blood gas analyses, survivors had higher pH and PaO(2), and lower oxygenation index and PaCO(2) compared with non-survivors. After controlling for covariates, a lower minimum PaCO(2) and side of defect were the only independent predictors of survival. ROC curve for minimum pre-ECMO PaCO(2) had a significant area under the curve (0.72, P=0.003). Survival was 27% in babies unable to achieve a pre-ECMO PaCO(2) <60 mm Hg whereas no patients survived if their lowest pre-ECMO PaCO(2) was >70 mm Hg.

CONCLUSION

Minimum achievable pre-ECMO PaCO(2) is an independent predictor of survival in patients with CDH requiring ECMO life support. These data provide useful prognostic information for counseling families and may facilitate direction of care in extreme cases where the degree of pulmonary hypoplasia may be incompatible with life.

Early repair of congenital diaphragmatic hernia on extracorporeal membrane oxygenation

BACKGROUND

Timing of repair of congenital diaphragmatic hernia (CDH) in babies that require stabilization on extracorporeal membrane oxygenation (ECMO) remains controversial. Although many centers delay operation until physiologic stabilization has occurred or ECMO is no longer needed, we repair soon after ECMO has been initiated. The purpose of this study is to determine if our approach has achieved acceptable morbidity and mortality.

METHODS

Charts of live-born babies with CDH treated at our institution between 1993 and 2007 were retrospectively reviewed. Data were then compared with The Congenital Diaphragmatic Hernia Study Group and Extracorporeal Life Support Organization registries.

RESULTS

Forty-eight (39%) patients required ECMO Thirty-four of these 48 neonates were cannulated before operative repair. Venoarterial ECMO was used exclusively. The mean (SD) time of repair from cannulation was 55 (21) hours. Survival for this subset of patients was 71%. Three patients (8.8%) who underwent repair on ECMO experienced surgical site hemorrhage that required intervention.

CONCLUSION

Early repair of CDH in neonates on ECMO can be accomplished with acceptable rates of morbidity and mortality.

Timing of delivery and survival rates for infants with prenatal diagnoses of congenital diaphragmatic hernia

OBJECTIVES

The goal of the study was to test the hypothesis that infants with known congenital diaphragmatic hernias born at early term gestation (37-38 weeks) rather than later (39-41 weeks) had greater survival rates and less extracorporeal membrane oxygenation use. Primary outcomes were survival to hospital discharge or transfer and extracorporeal membrane oxygenation use. METHODS; A retrospective cohort study of term infants with prenatal diagnoses of congenital diaphragmatic hernia was performed with the Congenital Diaphragmatic Hernia Study Group Registry of patients with congenital diaphragmatic hernias who were treated between January 1995 and December 2006.

RESULTS

Among 628 term infants at 37 to 41 weeks of gestation who had prenatal diagnoses of congenital diaphragmatic hernia and were free of major associated anomalies, early term birth (37 vs 39-41 weeks) and greater birth weight were associated independently with survival, whereas black race was related inversely to survival. Infants born at early term with birth weights at or above the group mean (3.1 kg) had the greatest survival rate (80%). Among infants born through elective cesarean delivery, infants born at 37 to 38 weeks of gestation, compared with 39 to 41 weeks, had less use of extracorporeal membrane oxygenation (22.0% vs 35.5%) and a trend toward a greater survival rate (75.0% vs 65.8%).

CONCLUSIONS

The timing of delivery is an independent, potentially important factor in the consideration of elective delivery for infants diagnosed prenatally as having congenital diaphragmatic hernias. Among fetuses with prenatally diagnosed congenital diaphragmatic hernias and without major associated anomalies, early term delivery may confer advantage.

Identifying neonates at a very high risk for mortality among children with congenital diaphragmatic hernia managed with extracorporeal membrane oxygenation

PURPOSE

The purpose of this study was to identify mortality risk factors in children with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO) and generate a prediction score for those at a very high risk for mortality.

METHODS

Data on first ECMO runs of all neonates with CDH, between January 1997 and June 2007, were obtained from the Extracorporeal Life Support Organization registry (N = 2678). The data were split into "training data (TD)" (n = 2006) and "validation data" (n = 672). The primary outcome analyzed was in-hospital mortality. Modified Poisson regression was used for analyses.

RESULTS

Overall in-hospital mortality among 2678 neonates (males, 57%; median age at ECMO, 1 day) was 52%. The univariate and multivariable analyses were performed using TD. An empirically weighted mortality prediction score was generated with possible scores ranging from 0 to 35 points. Of 69 who scored 14 or higher in the TD, 62 died (positive predictive value [PPV], 90%), of 37 with 15 or higher, 35 died (PPV, 95%), of 23 with 16 or higher, 22 died (PPV, 96%). A cut-off point of 15 was chosen and was tested using the separate validation dataset. In validation data, the cut-off point 15 had a PPV of 96% (23 died of 24).

CONCLUSION

Scoring 15 or higher on the prediction score identifies neonates with CDH at a very high risk for mortality among those managed with ECMO and could be used in surgical decision making and counseling.

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.

Predictors of outcome in patients with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation

BACKGROUND

The role of extracorporeal membrane oxygenation (ECMO) in patients with congenital diaphragmatic hernia is still evolving. The use of ECMO is invasive with potential complications during instrumentation for cannulation and heparinization. There are no reliable predictors of outcome in patients requiring ECMO. We aimed to identify (a) the factors that could predict outcome and (b) the incidence and relation of complications during ECMO to outcome.

METHODS

"Pre" ECMO (age, sex, birth weight, blood gasses, and ventilator settings) and "on" ECMO variables (mode of ECMO, use of nitric oxide, surfactant, liquid ventilation, inotropes, timing of repair, and complications on ECMO) were analyzed to identify predictors of outcome.

RESULTS

Fifty-two patients were included. The overall survival was 58%. Mean duration of ECMO (181 +/- 120 vs 317 +/- 156 hours, P = .001), use of nitric oxide (6 vs 10, P = .049), and renal complications (4 vs 14; P < .001) differed between survivors and nonsurvivors. The survival of patients requiring ECMO support for more than 2 weeks is significantly lower than that of patients requiring ECMO support for less than 2 weeks (18% vs 68%, P = .005). Multiple logistic regression revealed ECMO duration of 2 weeks or more and renal complications to be associated with mortality.

CONCLUSION

No pre-ECMO variable could be identified as predictor of mortality. Prolonged duration of ECMO and renal complications on ECMO were independently associated with mortality.

Congenital diaphragmatic hernia: a simplified postnatal predictor of outcome

BACKGROUND/PURPOSE

The incidence of congenital diaphragmatic hernia (CDH) approximates 1 in 3000 births, with mortality rates up to 50%. The ability to accurately and easily predict the outcomes of these infants could be a valuable management tool. The purpose of this study was to develop and validate a simplified clinical method for predicting survival outcomes in infants born with CDH.

METHODS

The Wilford Hall/Santa Rosa clinical prediction formula (WHSR(PF) = highest PaO2 - highest PCO2) was generated from arterial blood gas values obtained during the initial 24 hours of life, but before surgical repair or extracorporeal membrane oxygenation, in a local group of infants with CDH identified by prospective and retrospective review. The WHSR(PF) was validated using a comparative group from the Congenital Diaphragmatic Hernia Study Group (CHDSG). Bivariate, multivariable, and area under the receiver operating curve (AUC) analysis was performed using SigmaStat and SPSS statistical programs (SPSS, Chicago, Ill).

RESULTS

As initially developed from the local data, the WHSR(PF) had a positive predictive value (PPV) of 82%, a negative predictive value of 88% and AUC of 0.87. When validated against the CDHSG data, the positive predictive value was 83%, negative predictive value was 66%, and AUC 0.79. Area under the receiver operating curve analysis by the previously published CDHSG predictive equation was 0.76.

CONCLUSION

This novel formula is an easy to apply clinical tool with similar or better predictive abilities compared to previous methods of predicting survival in infants born with CDH. Currently, no method appears to have sufficient clinical accuracy for predicting the outcome of an individual infant with CDH. Further studies are indicated.

Long-term outcome following extracorporeal membrane oxygenation for congenital diaphragmatic hernia: the UK experience

OBJECTIVE

We evaluated the long-term outcome of neonates receiving extracorporeal membrane oxygenation (ECMO) for congenital diaphragmatic hernia (CDH). Study design A retrospective review of all 73 neonates with CDH supported with ECMO in the United Kingdom between 1991 and 2000, with follow-up to January 2003. Information was from hospital charts and from communication with family doctors and pediatricians. Median follow-up period for survivors was 67 months.

RESULTS

46 infants (63%) were weaned from ECMO, 42 (58%) survived to hospital discharge, and 27 (37%) survived to age 1 year or more. A higher birth weight, higher 5-minute Apgar score, and postnatal diagnosis were "pre-ECMO" predictors of long-term survival. Comorbidity was common in long-term survivors: 13 (48%) had respiratory symptoms, 16(59%) had gastrointestinal problems, and 6 (19%) had severe neurodevelopmental problems. Only 7 children were free of significant neurodevelopmental deficit and required no further medical or surgical intervention.

CONCLUSION

Using the current referral criteria, ECMO can be used to support the sickest neonates with CDH. However, there is significant mortality in the first year of life, and long-term physical and neurodevelopmental morbidity remains in the majority of survivors.

Survival in early- and late-term infants with congenital diaphragmatic hernia treated with extracorporeal membrane oxygenation

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a malformation of the diaphragm that allows bowel to enter the thoracic cavity, resulting in pulmonary hypoplasia and pulmonary hypertension. Approximately 50% of CDH patients are treated with extracorporeal membrane oxygenation (ECMO). The optimal gestational age for delivery of term infants with CDH at high risk for requiring ECMO is not known. The goal of this study was to compare survival of infants with CDH receiving ECMO born early term (38 0/7-39 6/7 weeks' gestation) with those born late term (40 0/7-41 6/7 weeks' gestation). Changes in survival rates of term infants and the factors associated with these changes were assessed over the 25 years that ECMO has been available.

DESIGN

Retrospective cohort study of infants with CDH treated with ECMO.

DATA SOURCES

The Extracorporeal Life Support Organization registry of patients treated at active Extracorporeal Life Support Organization centers from April 1976 through June 2001.

ANALYSIS

Survival and clinical predictors of survival were compared between infants born early term (38 0/7-39 6/7 weeks' gestation) and infants born late term (40 0/7-41 6/7 weeks' gestation). Changes in survival rates over time and factors associated with survival were evaluated.

RESULTS

Among full-term infants with CDH treated with ECMO, late-term compared with early-term delivery was associated with improved survival (63% vs 53%). Among full-term survivors of ECMO, late-term infants spent less time on ECMO (181 vs 197 hours) and less time in the hospital (60 vs 67 days). In multivariate analysis, greater birth weight, higher 5-minute Apgar score, higher arterial pH and PCO(2) <50 torr before ECMO, and absence of a prenatal diagnosis of CDH were associated with survival. Since the late 1980s, survival of infants with CDH requiring ECMO decreased from 63% to 52%. The decreased survival rate was associated with increased rates of prenatal diagnosis, early-term delivery, lower birth weight, longer ECMO runs, and more frequent complications on ECMO.

CONCLUSIONS

Among term infants with CDH receiving ECMO, late-term delivery compared with early-term delivery is associated with improved survival, shorter ECMO duration, shorter hospital length of stay, and fewer complications on ECMO. These data suggest that, at least for the approximately 50% of CDH patients treated with ECMO, outcomes for infants with CDH may be improved by delay of elective delivery until 40 completed weeks of gestation.

Current and emerging treatment for congenital diaphragmatic hernia

Management of congenital diaphragmatic hernia has changed dramatically over the past couple of decades. Until the early 1980s, it was felt that the abdominal contents should be returned to the abdomen as soon as possible to allow the lungs to expand. It is now known that it is not the defect that causes respiratory distress, but the infant's hypoplastic lungs and accompanying pulmonary hypertension. Advances in treatment and technology have contributed to changes in management. Ultrasonography now allows for early prenatal detection. Prenatal treatment modalities include in utero tracheal ligation and maternal antenatal steroids. Postnatal modalities have expanded to include permissive hypercapnia, high-frequency ventilation, inhaled nitric oxide, pharmacologic support, exogenous surfactant, and extracorporeal membrane oxygenation. Liquid ventilation and lobar lung transplantation have also been tried. In spite of these advances, the overall survival rate remains about 63 percent.

[Congenital hernia of the diaphragm. A retrospective study of 123 cases recorded in the Neonatal Medicine Department, URHC in Lille between 1985 and 1996]

BACKGROUND

During the last ten years, new therapeutic strategies have been used in order to improve the management of congenital diaphragmatic hernia (CDH). CDH is associated with pulmonary hypoplasia, abnormal pulmonary vascular reactivity and pulmonary immaturity. Between 1985 and 1990, mechanical hyperventilation and early surgery were provided systematically. Since 1991, the management of CDH in our institution has involved a preoperative stabilization with exogenous surfactant replacement, gentle ventilation, high-frequency oscillation, nitric oxide or extracorporeal membrane oxygenation.

PURPOSE

To analyse the impact of the new therapeutic strategy on the survival and outcome of newborns with CDH.

METHODS

Retrospective review of all infants with CDH admitted to our institution from 1985 through 1996. Mortality and morbidity were compared between period I (1985-1990) and period II (1991-1996).

RESULTS

Between 1985 and 1996, 123 neonates were admitted to our Neonatal Department. Nine of them had another severe congenital malformation and were excluded from the study. Survival was 23% (12/52) in period I and 56% (35/62) in period II (p < 0.001). In period II, complications were more frequent among survivors in whom an extracorporeal membrane oxygenation was required (13 infants): bronchopulmonary dysplasia 77% (10/13), gastroesophageal reflux 61% (8/13), and hypotrophy 61% (8/13).

CONCLUSION

These data demonstrate a significant improvement in survival in CDH since the implementation of new therapeutic modalities. Nevertheless, a significant morbidity exists among the infants who survive a severe respiratory failure.

A population-based study of congenital diaphragmatic hernia: impact of associated anomalies and preoperative blood gases on survival

BACKGROUND/PURPOSE

Although neonatal care has improved over the past 20 years, mortality rate with congenital diaphragmatic hernia (CDH) remains 50% to 60%, possibly reflecting differences in management or selection biases. The authors determined the incidence, outcome, effect of coexisting anomalies, and prognostic indicators for neonates with CDH in a single inborn population older than 13 years.

METHODS

Forty-three neonates with CDH, those symptomatic within the first 6 hours of life, were identified using a validated neonatal database and diagnosis coding data from medical records among 180,643 live inborn neonates delivered at Parkland Memorial Hospital between 1983 and 1995. Charts were reviewed for prenatal history, demographic variables, presence of coexisting malformations, preoperative arterial blood gases, surgical findings, and outcome. Survival to hospital discharge was the primary outcome variable.

RESULTS

The incidence of CDH was 1 in 4,200 live births; overall survival rate was 51%. Thirty-two (74%) neonates underwent surgical repair, often at less than 8 hours of life; postoperative mortality rate was 31%. Eighteen (42%) had coexisting major anomalies or chromosomal abnormalities. Eighty percent of neonates with isolated CDH survived, whereas 89% with CDH and associated defects died. Nonsurvivors had lower birth weights and Apgar scores, were more acidotic, and had more severe respiratory compromise. When best preoperative pH was > or = 7.25 or PaCO2 < or = 50 mm Hg, 80% of neonates survived.

CONCLUSION

In this inborn population-based review of neonatal CDH between 1983 and 1995, the best predictors of survival were the presence or absence of other anomalies and the best preoperative PaCO2 and pH.

Does extracorporeal membrane oxygenation improve survival in neonates with congenital diaphragmatic hernia? The Congenital Diaphragmatic Hernia Study Group

BACKGROUND/PURPOSE

The benefit of extracorporeal membrane oxygenation (ECMO) in improving survival of neonates with congenital diaphragmatic hernia (CDH) has never been clearly demonstrated. This may be due to comparisons made between treatment groups of unequal illness severity and the low statistical power of analyses from previous studies. The authors analyzed the data from the multicenter CDH registry to determine if ECMO improves survival in CDH neonates with a high risk of mortality.

METHODS

A total of 730 neonates were enrolled in the CDH Registry from January 1995 to November 1997. Of these, 632 neonates had a complete data set and were eligible for ECMO by the weight criterion of greater than 2.0 kg. Multivariate logistic regression analysis was used to assess mortality risk for each neonate based on previously validated independent predictors of survival: birth weight and 5-minute Apgar. Five quintile groups were defined based on increasing predictive mortality risk. Multivariate logistic regression and chi2 analyses with birth weight, Apgar score at 5 minutes, and predictive mortality risk as covariates were then performed to assess survival benefit of ECMO compared with conventional therapy alone. Patient survival rate was defined as survival to discharge from hospital.

RESULTS

When analyzing all 632 neonates, ECMO neonates (n = 289) had a decidedly lower survival rate (52.9% v 77.3%, P< .001) than non-ECMO neonates (n = 343) without standardizing for the degree of illness. However, when taking into account the patients' predictive mortality risk, ECMO was associated with improved survival in the neonates with mortality risk < or = 80% (P < .05). Furthermore, ECMO was shown to be a positive independent predictor of survival when accounting for the covariates of birth weight, 5-minute Apgar, and mortality risk (P < .05).

CONCLUSIONS

ECMO significantly improves survival rates for those CDH neonates with a predictive mortality risk > or = 80%. Generally, the more critically ill the patient with CDH, the more marked the survival benefit obtained.

Does extracorporeal membrane oxygenation benefit neonates with congenital diaphragmatic hernia? Application of a predictive equation

The overall survival of neonates with congenital diaphragmatic hernia (CDH) remains poor despite the advent of extracorporeal membrane oxygenation (ECMO). Attempts at accurately predicting survival have been largely unsuccessful. The purpose of this study was twofold: (1) to identify independent predictors of survival from a cohort of CDH neonates treated at the authors' institution when ECMO was not available and combine them to form a predictive equation, and (2) to apply the equation prospectively in a cohort of CDH neonates, treated at the same institution when ECMO was available, to determine whether ECMO improves outcome. From the clinical data of 62 CDH neonates treated at the authors' center by the same team of university neonatologists and pediatric surgeons between 1983 and 1993 (before ECMO availability), 15 preoperative and seven operative variables were selected as potential independent predictors. When subjected to multivariate, stepwise logistic regression analysis, four variables were identified as statistically significant (P < .05), independent predictors of survival: (1) ventilatory index (VI), (2) best preoperative PaCO2, (3) birth weight (BW), and (4) Apgar score at 5 minutes. When combined via logistic regression analysis, the following predictive equation was formulated: P (probability of survival to discharge) = [1 + e(x)]-1 where x = 4.9 - 0.68 (Apgar) - 0.0032 (BW) + 0.0063 (VI) + 0.063 (PaCO2). Applying a standard cut-off rate of survival at less than 20%, the equation yielded a sensitivity of 94% and a specificity of 82% in identifying the correct outcome of patients treated with conventional ventilatory management. The overall survival rate was 66%. Since the availability of ECMO at the center, 32 CDH neonates were treated using the same conventional ventilatory treatment and surgical repair by the same university staff. The overall survival rate was 69%. The predictive equation was applied prospectively to all neonates to determine predicted outcome, but was not used to decide the treatment method. Eighteen neonates received conventional therapy alone; 16 of 18 survived (89%). Fifteen of the 16 patients who survived had their outcomes predicted correctly (94%). Fourteen neonates did not respond to conventional therapy and required ECMO; 6 of 14 survived (43%). Six of the eight patients predicted to survive, lived (75%). All six patients predicted to die, died despite the addition of ECMO therapy (100%). The mean hospital cost, per ECMO patient who died, was $277,264.75 +/- $59,500.71 (SE). An odds ratio analysis, using the four independent predictors to standardize for degree of illness, was performed to assess the risk associated with adding ECMO therapy. The result was 1.25 (P = 0.75). Although the cohort was not large enough to eliminate significant beta error, the data strongly suggested no advantage of ECMO. At this center, absolute survival rates for neonates with CDH have not been significantly altered since ECMO has become available (66% v 69%). The authors conclude that the predictive equation remains an accurate measurement of survival at their center even when ECMO is used as a salvage therapy. The method of creating a predictive equation may be applied at any institution to determine the potential outcome of CDH neonates and assess the effect of ECMO, or other salvage therapies, on survival rates.

Prenatal glucocorticoids improve pulmonary morphometrics in fetal sheep with congenital diaphragmatic hernia

PURPOSE

Prenatal glucocorticoids reverse pulmonary immaturity in rodents with pharmacologically induced congenital diaphragmatic hernia (CDH). The authors applied quantitative stereologic morphometric techniques to test whether these effects could be reproduced in large animals (sheep) with surgically created CDH.

METHODS

Diaphragmatic hernias were created surgically in fetal lambs at gestational day 80. The fetuses were treated with intravenous cortisol (n = 6) or normal saline control (n = 5) from days 133 to 135. Lungs distended at 15 cm pressure from each group were harvested at day 136, processed histologically, and studied by brightfield microscopy at 400 x using a 42-point equidistant counting grid. Ten morphometric parameters (Mean +/- SEM) were measured by point-counting 60 fields/lung, and analysis of variance was performed.

RESULTS

The CDH-cortisol-treated lungs showed striking significant maturational improvements when compared with lungs of CDH-normal saline controls by seven of ten morphometric parameters.

CONCLUSIONS

(1) Prenatal glucocorticoids accelerate lung maturity in fetal lambs with CDH by seven quantitative morphometric parameters. (2) The observation that prenatal glucocorticoid therapy improves measures of maturity for both CDH rodent and sheep models encourages proceeding with a Phase I human clinical trial in ultrasound-confirmed CDH.