Congenital diaphragmatic hernia: developing a protocolized approach

Risk Factors for Preoperative Pneumothorax in Neonates With Isolated Left-Sided Congenital Diaphragmatic Hernia: An International Cohort Study

BACKGROUND

We aimed to investigate the clinical characteristics and outcomes of patients with isolated left-sided congenital diaphragmatic hernia (CDH) who developed preoperative pneumothorax and determine its risk factors.

METHODS

We performed an international cohort study of patients with CDH enrolled in the Congenital Diaphragmatic Hernia Study Group registry between January 2015 and December 2020. The main outcomes assessed included survival to hospital discharge and preoperative pneumothorax development. The cumulative incidence of pneumothorax was estimated by the Gray test. The Fine and Gray competing risk regression model was used to identify the risk factors for pneumothorax.

RESULTS

Data for 2858 neonates with isolated left-sided CDH were extracted; 224 (7.8%) developed preoperative pneumothorax. Among patients with a large diaphragmatic defect, those with pneumothorax had a significantly lower rate of survival to discharge than did those without. The competing risks model demonstrated that a patent ductus arteriosus with a right-to-left shunt flow after birth (hazard ratio [HR]: 1.78; 95% confidence interval [CI]: 1.21-2.63; p = 0.003) and large defects (HR: 1.65; 95% CI: 1.13-2.42; p = 0.01) were associated with an increased risk of preoperative pneumothorax. Significant differences were observed in the cumulative incidence of pneumothorax depending on defect size and shunt direction (p < 0.001).

CONCLUSIONS

Pneumothorax is a significant preoperative complication associated with increased mortality in neonates with CDH, particularly in cases with large defects. Large diaphragmatic defects and persistent pulmonary hypertension were found to be risk factors for preoperative pneumothorax development.

LEVEL OF EVIDENCE

LEVEL Ⅲ Retrospective Comparative Study.

Congenital diaphragmatic hernia: a narrative review of controversies in neonatal management

The consequences of most hernias can be immediately corrected by surgical repair. However, this isn't always the case for children born with a congenital diaphragmatic hernia. The derangements in physiology encountered immediately after birth result from pulmonary hypoplasia and hypertension caused by herniation of abdominal contents into the chest early in lung development. This degree of physiologic compromise can vary from mild to severe. Postnatal management of these children remains controversial. Although heavily studied, multi-institutional randomized controlled trials are lacking to help determine what constitutes best practice. Additionally, the results of the many studies currently within the literature that have investigated differing aspect of care (i.e., inhaled nitric oxide, ventilator type, timing of repair, role of extracorporeal membrane oxygenation, etc.) are difficult to interpret due to the small numbers investigated, the varying degree of physiologic compromise, and the contrasting care that exists between institutions. The aim of this paper is to review areas of controversy in the care of these complex kids, mainly: the use of fraction of inspired oxygen, surfactant therapy, gentle ventilation, mode of ventilation, medical management of pulmonary hypertension (inhaled nitric oxide, sildenafil, milrinone, bosentan, prostaglandins), the utilization of extracorporeal membrane oxygenation, and the timing of surgical repair.

Update on Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a rare developmental defect of the diaphragm, characterized by herniation of abdominal contents into the chest that results in varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH). Significant advances in the prenatal diagnosis and identification of prognostic factors have resulted in the continued refinement of the approach to fetal therapies for CDH. Postnatally, protocolized approaches to lung-protective ventilation, nutrition, prevention of infection, and early aggressive management of PH have led to improved outcomes in infants with CDH. Advances in our understanding of the associated left ventricular (LV) hypoplasia and myocardial dysfunction in infants with severe CDH have allowed for the optimization of hemodynamics and management of PH. This article provides a comprehensive review of CDH for the anesthesiologist, focusing on the complex pathophysiology, advances in prenatal diagnosis, fetal interventions, and optimal postnatal management of CDH.

Perinatal stabilisation of infants born with congenital diaphragmatic hernia: a review of current concepts

Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidity, mainly due to disrupted lung development related to herniation of abdominal organs into the chest. Pulmonary hypertension is a major contributor to both mortality and morbidity, however, treatment modalities are limited. Novel prenatal and postnatal interventions, such as fetal surgery and medical treatments, are currently under investigation. Until now, the perinatal stabilisation period immediately after birth has been relatively overlooked, although optimising support in these early stages may be vital in improving outcomes. Moreover, physiological parameters obtained from the perinatal stabilisation period could serve as early predictors of adverse outcomes, thereby facilitating both prevention and early treatment of these conditions. In this review, we focus on the perinatal stabilisation period by discussing the current delivery room guidelines in infants born with CDH, the physiological changes occurring during the fetal-to-neonatal transition in CDH, novel delivery room strategies and early predictors of adverse outcomes. The combination of improvements in the perinatal stabilisation period and early prediction of adverse outcomes may mitigate the need for specific postnatal management strategies.

Risk factors for pneumothorax associated with isolated congenital diaphragmatic hernia: results of a Japanese multicenter study

PURPOSE

This study aimed to elucidate the clinical characteristics of neonates with congenital diaphragmatic hernia (CDH) associated with pneumothorax and evaluate the risk factors for the development of pneumothorax.

METHODS

A retrospective cohort study was conducted in the 15 institutions participating in the Japanese CDH Study Group. A total of 495 neonates with isolated CDH who were born between 2011 and 2018 were analyzed in this study.

RESULTS

Among the 495 neonates with isolated CDH, 52 (10.5%) developed pneumothorax. Eighteen (34.6%) patients developed pneumothorax before surgery, while 34 (65.4%) developed pneumothorax after surgery. The log-rank test showed that the cumulative survival rate was significantly lower in patients with pneumothorax than in those without pneumothorax. Univariate analysis revealed significant differences between patients with pneumothorax and those without pneumothorax with regard to the best oxygenation index within 24 h after birth, mean airway pressure (MAP) higher than 16 cmH₂O, diaphragmatic defect size, and need for patch closure. Multiple logistic regression analysis indicated that only the MAP was associated with an increased risk of pneumothorax.

CONCLUSIONS

The cumulative survival rate was significantly lower in isolated CDH patients with pneumothorax than in those without pneumothorax. A higher MAP was a risk factor for pneumothorax in CDH patients.

Initiating resuscitation before umbilical cord clamping in infants with congenital diaphragmatic hernia: a pilot feasibility trial

BACKGROUND

Infants with congenital diaphragmatic hernia (CDH) often experience hypoxaemia with acidosis immediately after birth. The traditional approach in the delivery room is immediate cord clamping followed by intubation. Initiating resuscitation prior to umbilical cord clamping (UCC) may support this transition.

OBJECTIVES

To establish the safety and feasibility of intubation and ventilation prior to UCC for infants with CDH. To compare short-term outcomes between trial participants and matched controls treated with immediate cord clamping before intubation and ventilation.

DESIGN

Single-arm, single-site trial of infants with CDH and gestational age ≥36 weeks. Infants were placed on a trolley immediately after birth and underwent intubation and ventilation, with UCC performed after qualitative CO₂ detection. The primary feasibility endpoint was successful intubation prior to UCC. Prespecified safety and physiological outcomes were compared with historical controls matched for prognostic variables using standard bivariate tests.

RESULTS

Of 20 enrolled infants, all were placed on the trolley, and 17 (85%) infants were intubated before UCC. The first haemoglobin and mean blood pressure at 1 hour of life were significantly higher in trial participants than controls. There were no significant differences between groups for subsequent blood pressure values, vasoactive medications, inhaled nitric oxide or extracorporeal membrane oxygenation. Blood gas and oxygenation index values did not differ between groups at any point.

CONCLUSIONS

Intubation and ventilation prior to UCC is safe and feasible among infants with CDH. The impact of this approach on clinically relevant outcomes deserves investigation in a randomised trial.

Avoiding Furosemide Ototoxicity Associated With Single-Ventricle Repair in Young Infants

OBJECTIVE

To reduce bilateral delayed-onset progressive sensory permanent hearing loss using a systems-wide quality improvement project with adherence to best practice for the administration of furosemide.

DESIGN

Prospective cohort study with regular audiologic follow-up assessment of survivors both before and after a 2007-2008 quality improvement practice change.

SETTING

The referral center in Western Canada for complex cardiac surgery, with comprehensive multidisciplinary follow-up by the Complex Pediatric Therapies Follow-up Program.

PATIENTS

All consecutive patients having single-ventricle palliative cardiac surgery at age 6 weeks old or younger.

INTERVENTIONS

A 2007-2008 quality improvement practice change consisted of a Parenteral Drug Monograph revision indicating slow IV administration of furosemide, an educational program, and an evaluation.

MEASUREMENTS AND MAIN RESULTS

The outcome measure was the prevalence of permanent hearing loss by 4 years old. Firth multiple logistic regression compared pre (1996-2008) to post (2008-2012) practice change occurrence of permanent hearing loss, adjusting for confounding variables, including all hospital days, extracorporeal membrane oxygenation, cardiopulmonary bypass time, age at first surgery, dialysis, and sepsis. From 1996 to 2012, 259 infants had single-ventricle palliative surgery at age 6 weeks old or younger, with 173 (64%) surviving to age 4 years. Of survivors, 106 (61%) were male, age at surgery was 11.6 days (9.0 d), and total hospitalization days by age 4 years were 64 (42); 18 (10%) had cardiopulmonary resuscitation and 38 (22%) had sepsis at any time. All 173 (100%) had 4-year follow-up. Pre- to postpractice change permanent hearing loss dropped from 17/100 (17%) to 0/73 (0%) of survivors. On Firth multiple logistic regression, the only variable statistically associated with permanent hearing loss was the pre- to postpractice change time period (odds ratio, 0.03; 95% CI, 0-0.35; p = 0.001).

CONCLUSIONS

A practice change to ensure slow IV administration of furosemide eliminated permanent hearing loss. Centers caring for critically ill infants, particularly those with single-ventricle anatomy or hypoxia, should review their drug administration guidelines and adhere to best practice for administration of IV furosemide.

Congenital diaphragmatic hernia: Impact of contemporary management strategies on perinatal outcomes

OBJECTIVE

This study aims to review temporal changes in perinatal management and 1-year survival outcomes of cases of congenital diaphragmatic hernia (CDH) from 1996 to 2015 in Western Australia (WA).

METHOD

This research is a retrospective study of all cases of CDH in WA from 1996 to 2015 identified from five independent databases within the WA health network. Detailed information pertaining to pregnancy and survival outcomes were obtained from review of maternal and infant medical records.

RESULTS

There were 215 cases of CDH with 164 diagnosed prenatally. Between 1996 and 2010, a decline in live birth rates for CDH-affected pregnancies was observed, reaching a nadir of 5.3 per 10 000 births before increasing to a peak of 9.73 per 10 000 births in 2011-2015. A corresponding decline was seen in the number of pregnancies terminated in the same period from 8.3 to 4.6 per 10 000 births (P = 0.14) and an increase in survival of live births from 38.9% to 81.3% (P = 0.01).

CONCLUSION

The improved overall survival rate in infants with CDH over the last 20 years may have resulted in an increased tendency for women to continue their pregnancy with a concomitant decline in termination rates. Information from this study will help in the counselling of women following prenatal detection of CDH.

Ventilation modalities in infants with congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia are among the more complex patients to support with mechanical ventilation. They have particular features that add to the difficulties already present in the neonatal patient. A ventilation strategy tailored to the patient's underlying physiology rather than mode of ventilation is a crucial issue for clinicians treating these delicate patients.

Treatment Strategies for Congenital Diaphragmatic Hernia: Change Sometimes Comes Bearing Gifts

OBJECTIVE

To report treatment strategies' evolution and its impact on congenital diaphragmatic hernia (CDH) outcome.

DESIGN

Registry-based cohort study using the CDH Study Group database, 1995-2013.

SETTING

International multicenter database.

PATIENTS

CDH patients entered into the registry. Late presenters or patients with very incomplete data were excluded. Patients were divided into three Eras (1995-2000; 2001-2006; 2007-2013).

MAIN OUTCOME MEASURES

Treatment strategies and outcomes. One-way ANOVA, X2 test, and X2 test for trend were used. A Sydak-adjusted p < 0.0027 was considered significant. Prevalence or mean (SE) are reported.

RESULTS

Patients: 8,603; included: 7,716; Era I: 2,146; Era II: 2,572; Era III: 2,998. From Era I to Era III, significant changes happened. Some severity indicators such as gestational age, prevalence of prenatal diagnosis, and inborn patients significantly worsened. Also, treatment strategies such as the use of prenatal steroids and inhaled nitric oxide, age at operation, prevalence of minimal access surgery, and the use of surfactant significantly changed. Finally, length of hospital stay became significantly longer and survival to discharge slightly but significantly improved, from 67.7 to 71.4% (p for trend 0.0019).

CONCLUSION

Treatment strategies for patients registered since 1995 in the CDH Study Group significantly changed. Survival to discharge slightly but significantly improved.

Congenital diaphragmatic hernia, management in the newborn

Congenital diaphragmatic hernia (CDH) in the newborn poses challenges to the multi-disciplinary teams involved in its management. Mortality remains significantly high, despite growing understanding and treatment options. Early intubation of antenatally diagnosed cases is crucial in preventing deterioration and persistent pulmonary hypertension. Early recognition of cases not diagnosed on antenatal scan, with appreciation of differential diagnosis, requires an index of suspicion and imaging. Increasing options and modalities are available, with only modest, if any, survival advantage. Permissive hypercapnea and minimal ventilation have made the most significant impact on survival in modern era. High-frequency oscillatory ventilation (HFOV), inhaled nitric oxide (iNO), treatment of pulmonary hypertension, and ECMO are used in a somewhat stepwise manner for stabilisation. Delayed surgery has become established later in management plan. The impact of individual therapies (e.g. HFOV, iNO, ECMO) on outcome is difficult to ascertain. Little level 1 or 2 evidence exists. Randomised studies and reviews on the role of ECMO have not yet proven any long-term survival benefit. One pilot randomised study of thoracoscopic repair suggests increased acidosis; intraoperative blood gases and CO2 levels should be closely monitored. Monitoring tissue oxygenation should be considered. There is no evidence to suggest the best patch material.

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.

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.

Impact of our new protocol on the outcome of the neonates with congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Congenital diaphragmatic hernia (CDH) remains a defiant challenge for pediatric surgeons. Since 2003, we developed a new protocol aiming for the better outcome. In this study, the usefulness of our new protocol was evaluated.

MATERIALS AND METHODS

Forty-six neonates with CDH at the age of less than 24 h were divided into two groups based on the difference of era and treatment protocols. In Group 1, 15 patients were treated between 1997 and 2002 and 31 patients were treated between 2003 and 2011 in Group 2. In the latter group, a new protocol was introduced focusing on the prevention of lung edema as well as lung injury by steroid administration and on the stabilization of cardiopulmonary function using continuous D-mannitol infusion. The survival rate and the postoperative intubation period (POIP) were compared between the two groups.

RESULTS

The overall survival rate was significantly increased from 53 % (8/15) to 81 % (25/31) (p < 0.05). In isolated CDH, the survival rate was increased from 58 to 93 %. The average POIP was remarkably shortened from 39.0 to 4.4 days (p < 0.01).

CONCLUSION

Our new protocol remarkably improved the survival rate and shortened the period of mechanical ventilation in neonates with CDH.

Recent advances in the management of congenital diaphragmatic hernia

PURPOSE OF REVIEW

Congenital diaphragmatic hernia (CDH) is a rare developmental defect resulting in variable degrees of lung and pulmonary vasculature hypoplasia. Whereas many high-volume centers have recently reported increased survival rates, this has not been the collective trend. One potential explanation for this is inconsistent perinatal care among centers.

RECENT FINDINGS

Significant efforts have been made to identify prenatally those fetuses that will be most severely affected. A number of radiologic features have shown promise for achieving this goal as well as identifying fetuses that may benefit from prenatal intervention. When CDH is antenatally diagnosed, early referral to a tertiary center is recommended. Centers that routinely use postnatal management protocols have demonstrated improved overall survival rates including increased survival in high-risk CDH patients.

SUMMARY

As a result of advancements in perinatal care, more severely affected newborns with CDH are now surviving. These patients may experience a number of associated morbidities which affect not only their health but overall quality of life. A multidisciplinary approach to the long-term care of these patients will allow early identification and management of these morbidities.

Permissive hypercapnia in the management of congenital diaphragmatic hernia: our institutional experience

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a potentially lethal anomaly associated with pulmonary hypoplasia and persistent pulmonary hypertension. Permissive hypercapnia is a strategy designed to reduce lung injury from mechanical ventilation in infants. It has been shown to be a potentially superior method of ventilator management for patients with CDH. In 2001, the Divisions of Neonatology and Pediatric Surgery at the University of Virginia Children's Hospital established permissive hypercapnia as the management strategy for treatment of CDH. We hypothesized that permissive hypercapnia would be associated with improved outcomes in this patient population.

STUDY DESIGN

This retrospective review compares outcomes of infants treated for CDH in the extracorporeal membrane oxygenation (ECMO) era before and after initiation of permissive hypercapnia at a single institution. Outcomes were compared using univariate statistical analysis.

RESULTS

Ninety-one patients were available for analysis and were divided into 2 groups: 42 (Group 1) treated before and 49 (Group 2) treated after implementation of permissive hypercapnia. Survival was higher in Group 2 (85.8% vs 54.8%; p = 0.001; relative risk [RR] 3.17). Morbidity was lower in Group 2 and approached statistical significance (65.3% vs 83.3%; p = 0.052). Patients in Group 2 were repaired later, had a lower rate of ECMO use, and were extubated earlier. There was no difference in hospital stay.

CONCLUSIONS

The use of permissive hypercapnia for infants with CDH was associated with decreased mortality, a longer period of ventilation before repair with a shorter period of ventilation after repair, a lower rate of ECMO use, and no lengthening of hospital stay. Permissive hypercapnia remains the standard of care for ventilation of infants with CDH at our institution.

Impact of prenatal evaluation and protocol-based perinatal management on congenital diaphragmatic hernia outcomes

BACKGROUND/PURPOSE

Although intuitive, the benefit of prenatal evaluation and multidisciplinary perinatal management for fetuses with congenital diaphragmatic hernia (CDH) is unproven. We compared the outcome of prenatally diagnosed patients with CDH whose perinatal management was by a predefined protocol with those who were diagnosed postnatally and managed by the same team. We hypothesized that patients with CDH undergoing prenatal evaluation with perinatal planning would demonstrate improved outcome.

METHODS

Retrospective chart review of all patients with Bochdalek-type CDH at a single institution between 2004 and 2009 was performed. Patients were stratified by history of perinatal management, and data were analyzed by Fisher's Exact test and Student's t test.

RESULTS

Of 116 patients, 71 fetuses presented in the prenatal period and delivered at our facility (PRE), whereas 45 infants were either outborn or postnatally diagnosed (POST). There were more high-risk patients in the PRE group compared with the POST group as indicated by higher rates of liver herniation (63% vs 36%, P = .03), need for patch repair (57% vs 27%, P = .004), and extracorporeal membrane oxygenation use (35% vs 18%, P = .05). Despite differences in risk, there was no difference in 6-month survival between groups (73% vs 73%).

CONCLUSIONS

Patients with CDH diagnosed prenatally are a higher risk group. Prenatal evaluation and multidisciplinary perinatal management allows for improved outcome in these 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.

Protocolized approach to the management of congenital diaphragmatic hernia: benefits of reducing variability in care

PURPOSE

Variable approaches to the care of infants with congenital diaphragmatic hernia (CDH) by multiple providers may contribute to inconsistent care. Our institution developed a comprehensive evidence-based protocol to standardize the management of CDH infants. This report reviews patient outcomes before and after the implementation of the protocol.

METHODS

Retrospective chart review of CDH infants managed with individualized care (preprotocol group, January 1997-December 2001, n = 22) or on the protocol (Protocol group, January 2002-July 2009, n = 47). Survival and other categorical variables were compared by chi(2) analysis, and continuous variables were compared using 1-sided analysis of variance analysis, with significance defined as P < .05.

RESULTS

Survival to discharge was significantly greater in the Protocol group (40/47; 85%) than the preprotocol group (12/22; 52%; P = .006), although mean gestational age, mean birth weight, and expected survival were not statistically different between the 2 groups. The use of supportive therapies, including high-frequency jet ventilation, inhaled nitric oxide, and extracorporeal life support, was similar between groups as well.

CONCLUSIONS

Since the implementation of a management protocol for infants with CDH, survival has improved significantly compared with expected survival and preprotocol controls. Reduction in the variability of care through use of an evidence-based protocol may improve the survival of CDH infants.

Preliminary observations of the use of high-frequency jet ventilation as rescue therapy in infants with congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Congenital diaphragmatic hernia (CDH) is associated with mortality of 10% to 50%. Several investigators have reported outcomes from centers using high-frequency oscillatory ventilation in their management of CDH, but there are no recent reports on use of high-frequency jet ventilation.

METHODS

During the study period from January 2001 until August 2007, infants with CDH who were cared for at Duke University Medical Center received high-frequency jet ventilation as a rescue mode of high-frequency ventilation. We compared actual survival with predicted survival for infants treated only with conventional ventilation vs those rescued with high-frequency jet ventilation after failing conventional ventilation.

RESULTS

Survival for the 16 infants that received high-frequency jet ventilation was predicted to be 63%; actual survival was 75%. Survival for the 15 infants that received only conventional ventilation was predicted to be 83%; actual survival was 87%. We observed no significant survival benefit for high-frequency jet ventilation, 8.0% (95 confidence interval, -22.0% to 38.1%; P = .59).

CONCLUSIONS

Although our sample size was small, we conclude with consideration of the absolute results, the degree of illness of the infants, and the biologic plausibility for the intervention that high-frequency jet ventilation is an acceptable rescue ventilation mode for infants with CDH.

Congenital diaphragmatic hernia: current status and review of the literature

Treatment of congenital diaphragmatic hernia (CDH) challenges obstetricians, pediatric surgeons, and neonatologists. Persistent pulmonary hypertension (PPHT) associated with lung hypoplasia in CDH leads to a high mortality rate at birth. PPHT is principally due to an increased muscularization of the arterioles. Management of CDH has been greatly improved by the introduction of prenatal surgical intervention with tracheal obstruction (TO) and by more appropriate postnatal care. TO appears to accelerate fetal lung growth and to increase the number of capillary vessels and alveoli. Improvement of postnatal care over the last years is mainly due to the avoidance of lung injury by applying low peak inflation pressure during ventilation. The benefits of other drugs or technical improvements such as the use of inhaled nitric oxide or extracorporeal membrane oxygenation (ECMO) are still being debated and no single strategy is accepted worldwide. Despite intensive clinical and experimental research, the treatment of newborn with CDH remains difficult.

Ventilation and spontaneous breathing at birth of infants with congenital diaphragmatic hernia

OBJECTIVE

To describe the interaction of spontaneous breaths, manual ventilation, and tidal volumes (V(T)) during stabilization of infants with congenital diaphragmatic hernia (CDH) in the delivery room.

STUDY DESIGN

We studied infants with CDH receiving respiratory support at birth. Airway pressure, flow, and volume were measured, and each breath or inflation was analyzed. Each V(T) was classified as a manual inflation, a spontaneous breath, or a spontaneous breath coinciding with manual inflation on the basis of the timing of the pressure and flow waves.

RESULTS

Twelve infants had 2957 breaths suitable for analysis, with spontaneous breathing in 11 infants (92%). The mean (+/-SD) proportion of manual inflations was 41% (+/-24%), spontaneous breaths 43% (+/-25%), spontaneous but coinciding with manual inflation 16% (+/-12%). V(T) was significantly different for spontaneous breaths (3.8 +/- 1.9 mL/kg), spontaneous breaths coinciding with manual inflation (4.7 +/- 2.5 mL/kg), and manual inflations alone (2.6 +/- 1.6 mL/kg).

CONCLUSIONS

Most infants with CDH breathed spontaneously, and manual ventilation was mostly asynchronous. We observed large differences in tidal volumes between spontaneous breaths, manual inflations, or where these coincided, with manual inflations having the lowest V(T). Monitoring the respiratory pattern of these infants could improve respiratory support.

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.

Postnatal management and long-term outcome for survivors with congenital diaphragmatic hernia

Significant advances in the postnatal management of patients with congenital diaphragmatic hernia (CDH) have resulted in a remarkable improvement in survival rates over the past two decades. The success of current postnatal management of CDH patients has rendered fetal intervention to be limited to the most severe cases, and the role for prenatal treatment of CDH patients remains unclear. The adoption of lung-preserving strategies including high-frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) have improved CDH outcomes especially in those patients with significant ventilatory or circulatory compromise. Survival rates of up to 90% are being reported in some high-volume centers. However, the increased survival in CDH patients has been accompanied by an increase in neurological, nutritional and musculoskeletal morbidity among the long-term survivors. This has resulted in the need to provide resources for the long-term follow-up and support of this patient population. In this article, the postnatal management strategies and primary and secondary outcomes of high-volume international pediatric surgical centers will be reviewed. Finally, the role of a multidisciplinary management team for the follow-up of long-term CDH survivors will be discussed.

Cesarean delivery and its impact on the anomalous infant

Although cesarean deliveries frequently are performed for anomalous fetal conditions, available data do not always support a fetal benefit from this delivery management. The literature on cesarean delivery for anomalous infants reports insufficient information on comorbid neonatal conditions, so these complications are unknown in this population of newborns. In a minority of cases, a cesarean delivery is reasonable to prevent dystocia or optimize outcome. Areas for future investigation include prospective, randomized, controlled trials of prelabor cesarean compared with vaginal deliveries for myelomeningocele and anterior abdominal wall defects. The rarity of other lesions likely precludes randomized controlled trials.

Elective cesarean section: its impact on neonatal respiratory outcome

Physiologic events in the last few weeks of pregnancy coupled with the onset of spontaneous labor are accompanied by changes in the hormonal milieu of the fetus and its mother, resulting in preparation of the fetus for neonatal transition. Rapid clearance of fetal lung fluid is a key part of these changes, and is mediated in large part by transepithelial sodium reabsorption through amiloride-sensitive sodium channels in the alveolar epithelial cells, with only a limited contribution from mechanical factors and Starling forces. This article discusses the respiratory morbidity associated with elective cesarean section, the physiologic mechanisms underlying fetal lung fluid absorption, and potential strategies for facilitating neonatal transition when infants are delivered by elective cesarean section before the onset of spontaneous labor.

Clinical correlations and pulmonary function at 8 years of age after severe neonatal respiratory failure

OBJECTIVES

The aim of this study was to determine the pulmonary sequelae of severe neonatal respiratory failure.

STUDY DESIGN

This was a multicenter, prospective study. Fifty-four survivors of neonatal respiratory failure (oxygenation indices >25 on two occasions), completed pulmonary function testing at 8 years of age. Thirty-one (57%) received extracorporeal membrane oxygenation (ECMO). Pulmonary outcome was based on spirometry and lung volume data. Pulmonary outcome for each diagnostic and treatment group is reported as mean and as percent predicted. Individually subjects were also classified based on spirometry, as either normal, obstructed (defined as forced expiratory volume (FEV(1)) in 1 sec:forced vital capacity (FVC) of <80 % predicted, or with reduced FVC (FCV of <80% predicted) with normal FEV(1)/FVC. Risk for adverse outcome was determined using univariate analysis.

RESULTS

Mean FVC, FEV(1) and FEV(25-75) were reduced in the total cohort. The reduction was greatest in the subgroup with CDH and the group treated with ECMO. Assessed individually, 54% of subjects had normal spirometry and lung volumes, 19% airflow obstruction, and 27% reduced FVC. Poorer pulmonary outcome was linked to ECMO, congenital diaphragmatic hernia (CDH), birth weight for gestational age <10th percentile, duration of hospitalization, or need for prolonged supplemental oxygen.

CONCLUSION

Neonates with severe respiratory failure due to CDH or needing ECMO and small for gestation are at increased risk of poorer pulmonary outcome and require close follow-up.

Congenital diaphragmatic hernia: a systematic review and summary of best-evidence practice strategies

OBJECTIVES

Recent reports suggest that specific care strategies improve survival of infants with congenital diaphragmatic hernia (CDH). This review presents details of care from centers reporting high rates of survival among CDH infants.

STUDY DESIGN

We conducted a MEDLINE search (1995 to 2006) and searched all citations in the Cochrane Central Register of Controlled Trials. Studies were included if they contained reports of >20 infants with symptomatic CDH, and >75% survival of isolated CDH.

RESULT

Thirteen reports from 11 centers met inclusion criteria. Overall survival, including infants with multiple anomalies, was 603/763 (79%; range: 69 to 93%). Survival for isolated CDH was 560/661 (85%; range: 78 to 96%). The frequency of extracorporeal membrane oxygenation (ECMO) use for isolated CDH varied widely among reporting centers 251/622 (40%; range: 11 to 61%), as did survival for infants with isolated CDH placed on ECMO: 149/206 (73%; range: 33 to 86%). There was no suggestion of benefit from use of antenatal glucocorticoids given after 34 weeks gestation or use of postnatal surfactant. Low mortality was frequently attributed to minimizing lung injury and adhering to center-specific criteria for ECMO.

CONCLUSION

Use of strategies aimed at minimizing lung injury, tolerance of postductal acidosis and hypoxemia, and adhering to center-specific criteria for ECMO were strategies most consistently reported by successful centers. The literature lacks randomized clinical trials of these or other care strategies in this complex patient population; prospective studies of safety and long-term outcome are needed.

Mechanical ventilation strategies in the management of congenital diaphragmatic hernia

Most infants with congenital diaphragmatic hernia (CDH) require respiratory support. The goal of this report is to present an overview of mechanical ventilation strategies in the management of infants with CDH. The anatomic and physiologic limitations in the lungs of infants with diaphragmatic hernia make decisions on the best strategy and use of mechanical ventilation challenging. We will briefly review lung development in infants with CDH, identifying factors that provide a basis for lung protection strategies. Background on the use of specific mechanical ventilation modes and the rationale for each are provided. Finally, we review mechanical ventilation practices described in published case series of successful CDH management, with a brief review of additional treatments, including inhaled nitric oxide and extracorporeal membrane oxygenation. Although details of a single specific best strategy for mechanical ventilation for CDH infants cannot be identified from current literature, a lung protection ventilation approach, regardless of the device used, appears to reduce mortality risk.

Efficacy of protocolized management for congenital diaphragmatic hernia. a review of 100 cases

A review of 100 consecutive cases of congenital diaphragmatic hernia (CDH) treated at our institute focusing on the efficacy of protocolized management (PM) was conducted. Of the 100 cases, 14 who became symptomatic more than 24 h after birth, and seven with fatal anomalies (four cardiac and three chromosomal) were excluded, leaving 79 subjects for this study. Of these, 41 were diagnosed prenatally (PD). Subjects were divided into four groups. Group I: No PD, no PM (n = 34), Group II: No PD, PM (n = 4), Group III: PD, no PM (n = 21), and Group IV: PD, PM (n = 20). PM includes criteria for planned delivery, use of high frequency oxygenation, nitric oxide, echocardiography (EC), and a medication schedule. Overall survival rates for Groups I, II, III, and IV were 73.5% (25/34), 75% (3/4), 38.1% (8/21), and 70.0% (14/20), respectively. Survival rates were higher when PM was used: 70.8% (Groups II, IV) versus 60.0% (Groups I, III). Survival rates were significantly lower if diagnosed prenatally (PD+): 53.7% (Groups III, IV) versus 73.7% (Groups I, II) (P < 0.01). However, in PD+ groups, survival was significantly higher if PM was used (P < 0.05). PM significantly reduced length of hospital stay (35.5 vs. 52.0 days: P < 0.05). EC was found to be a predictor for survival while post-ductal AaDO(2) was not. In 17 cases with cardiac anomalies, PM did not affect survival. Our study suggests that use of PM for prenatally diagnosed CDH cases is associated with improved outcome, although the components of PM need to be tested in prospective trials to determine their true value.

Respiratory transition in infants delivered by cesarean section

One of the biggest challenges a newborn faces after birth is the task of making a smooth transition to air breathing. This task is complicated by the fact that fetal lungs are full of fluid which must be cleared rapidly to allow for gas exchange. Respiratory morbidity as a result of failure to clear fetal lung fluid is not uncommon, and can be particularly problematic in some infants delivered by elective cesarean delivery (ECS). Given the high rates of cesarean deliveries in the USA and worldwide, the public health and economic impact of morbidity in this subgroup is considerable. Whereas the occurrence of birth asphyxia, trauma, and meconium aspiration is reduced by elective Cesarean delivery, the risk of respiratory distress secondary to transient tachypnea of the newborn, surfactant deficiency, and pulmonary hypertension is increased. It is clear that physiologic events in the last few weeks of pregnancy coupled with the onset of spontaneous labor are accompanied by changes in the hormonal milieu of the fetus and its mother, resulting in preparation of the fetus for neonatal transition. Rapid clearance of fetal lung fluid is a key part of these changes, and is mediated in large part by transepithelial Na reabsorption through amiloride-sensitive Na channels in the alveolar epithelial cells, with only a limited contribution from mechanical factors and Starling forces. This chapter discusses the physiologic mechanisms underlying fetal lung fluid absorption and explores potential strategies for facilitating neonatal transition when infants are delivered by ECS before the onset of spontaneous labor.

Intratracheal administration of sildenafil and surfactant alleviates the pulmonary hypertension in newborn piglets

OBJECTIVE

To study systemic and pulmonary effects of low-dose sildenafil with surfactant in newborn piglets with pulmonary hypertension (PHT) induced by thromboxane A(2) analog (U46619).

DESIGN/METHODS

Piglets (1-3 days, 1.7-2.5 kg) were mechanically ventilated and prepared for the continuous measurement of mean systemic and pulmonary arterial pressures (MAP and PAP, respectively), heart rate and pulmonary artery flow (as cardiac output). Following stabilization, PHT was induced by intravenous U46619 infusion (0.2-0.8 microg/kg/min) for 120 min. Piglets were randomized for intratracheal administration of surfactant (BLES, 4 ml/kg) with saline (n=6) or sildenafil (0.05 mg/kg, n=6) given after 60 min of U46619 treatment. Temporal changes of hemodynamic measurements were analyzed by two-way ANOVA.

RESULTS

There was progressive PHT induced by U46619 (161% of baseline), with increased PAP and pulmonary vascular resistance and decreased cardiac output. Surfactant and sildenafil combined improved PAP along with reduced pulmonary vascular resistance. Cardiac output was higher with surfactant and sildenafil combined than surfactant alone. No significant changes in heart rate, stroke volume, MAP and systemic vascular resistance were observed. Ratio of PAP:MAP was lowered with surfactant and sildenafil combined. Systemic oxygen consumption was not different between groups but the oxygen extraction ratio was higher than baseline in surfactant alone (P<0.05).

CONCLUSIONS

Adding low-dose sildenafil to surfactant is effective in alleviating the progressive PHT developed in newborn piglets induced by thromboxane A(2). Intratracheal sildenafil may be a useful therapeutic adjunct to critically ill neonates with PHT.

Corticosteroids for fetuses with congenital diaphragmatic hernia: can we show benefit?

BACKGROUND AND PURPOSE

Prenatal corticosteroids have been used in fetuses with congenital diaphragmatic hernia (CDH). We tested the utility of steroids by 2 methods.

METHODS

Mothers carrying fetuses with CDH were randomized to 3 weekly doses of betamethasone or placebo starting at 34 weeks. Patients were followed until death or discharge. In a separate cohort study, the CDH Registry was used to compare infants who received prenatal steroids to those who had not.

RESULTS

Thirty-four patients were enrolled at 7 centers, with 32 completing the trial. There were 15 placebo and 17 steroid patients. There was no difference in survival, length of stay, duration of ventilation, or oxygen use at 30 days. For the cohort study, we looked at infants older than 34 weeks who were born after October 2000 when data on prenatal steroids were collected. There were 1093 patients; 390 were evaluable, with 56 receiving steroids. There was no difference in survival, length of stay, ventilator days, or oxygen use at 30 days.

CONCLUSION

Neither the trial nor the CDH Registry suggest that late prenatal corticosteroids benefit fetuses with CDH. More than 1700 mothers and fetuses would need to be enrolled in a trial to show a 10% improvement in survival. It is unlikely that late steroids offer benefit to most fetuses with CDH.

Physiology of fetal lung fluid clearance and the effect of labor

Respiratory morbidity in near term (> or =34 and <37 weeks) infants delivered spontaneously or by elective cesarean section (ECS) has been well documented in the literature, and accounts for a significant number of admissions to intensive care units among these neonates. Given the high rates of near-term deliveries in the USA and worldwide, the public health and economic impact of morbidity in this subgroup is considerable. Causes of respiratory distress include transient tachypnea of the newborn (TTNB), surfactant deficiency, pneumonia, and pulmonary hypertension. There is considerable evidence that physiologic events in the last few weeks of pregnancy coupled with the onset of spontaneous labor are accompanied by changes in the hormonal milieu of the fetus and its mother, resulting in rapid maturation and preparation of the fetus for delivery and neonatal transition. A surge in endogenous steroids and catecholamines accompanies term gestation and spontaneous vaginal delivery, and is responsible for some of the maturational effects. Rapid clearance of fetal lung fluid clearance plays a key role in the transition to air breathing. The bulk of this fluid clearance is mediated by transepithelial sodium reabsorption through amiloride-sensitive sodium channels in the alveolar epithelial cells with only a limited contribution from mechanical factors and Starling forces. Disruption of this process can lead to retention of fluid in air spaces, setting the stage for alveolar hypoventilation. When infants are delivered near-term, especially by cesarean section (repeat or primary) before the onset of spontaneous labor, the fetus is often deprived of these hormonal changes, making the neonatal transition more difficult. This chapter discusses the physiologic mechanisms underlying fetal lung fluid absorption and explores potential strategies for facilitating neonatal transition.

Evidence-based management of infants with congenital diaphragmatic hernia

The mortality rate associated with congenital diaphragmatic hernia (CDH) varies widely between centers and remains relatively high despite widespread use of new therapeutic modalities. Many of these have been implemented without properly controlled studies. Over the past 10 to 15 years, only 9 randomized trials enrolling a total of approximately 250 infants with CDH have been published. The limited evidence available suggests that better outcomes are observed by delivering infants with CDH at experienced centers, by delaying surgical repair until hemodynamic and respiratory stability is achieved, and by the judicious utilization of nonaggressive mechanical ventilation and permissive hypercapnea. Other therapeutic modalities, such as high frequency oscillatory ventilation, inhaled nitric oxide, and ECMO, may provide additional advantages for selected infants. There is a dire need to establish networks of centers that manage enough infants with CDH, to conduct appropriately sized randomized trials that can answer some of the critical questions about the management and long-term outcome of these infants.

Is surfactant therapy beneficial in the treatment of the term newborn infant with congenital diaphragmatic hernia?

OBJECTIVES

To determine the impact of surfactant replacement on survival, need for extracorporeal membrane oxygenation (ECMO), and chronic lung disease in term infants with prenatally diagnosed congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Prenatally diagnosed infants born at > or =37 weeks' gestation with immediate distress at delivery and no other major congenital anomalies, who were enrolled in the CDH Registry, were analyzed. For univariate analysis, chi 2 tests were used for categoric variables and unpaired t tests for nominal variables. Multiple logistic regression was used to calculate adjusted odds ratios.

RESULTS

Eligible infants (n = 522) were identified. Demographic variables were similar between the surfactant-treated (n = 192) and nonsurfactant-treated (n = 330) groups, with the exception of race (white, 88.0% vs 71.2%; P =.0007). The use of ECMO and incidence of chronic lung disease were higher (59.8 vs 50.6, P =.04; 59.9 vs 47.6, P =.0066) and survival lower in the surfactant-treated cohort (57.3 vs 70.0, P =.0033). Adjusted logistic regression for use of ECMO, survival, and chronic lung disease resulted in odds ratios inconsistent with an improved outcome associated with surfactant use.

CONCLUSIONS

This analysis shows no benefit associated with surfactant therapy for term infants with a prenatal diagnosis of isolated CDH.

The CDH Study Group and advances in the clinical care of the patient with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) occurs in 1 of every 2000 to 4000 births and accounts for 8% of all major congenital anomalies. Recurrence risk for a subsequent pregnancy is estimated at 2%. The mortality rate for CDH when diagnosed antenatally, varies with fetal age and with the presence or absence of hydramnios and degree of pulmonary hypoplasia. The prognosis has improved dramatically in recent years, primarily due to advances in neonatal and surgical interventions. Neonatal survival rates with an antenatal diagnosis now exceed 80% in some centers. Treatment for infants with CDH reflects other pediatric surgical problems in that a majority of the clinical research that shapes treatment is retrospective in nature. Because CDH is a relatively rare disease, using a compilation of cases, such as the CDH database provides, greatly aids our understanding of this disease process. Moreover, the application of a quality assessment scale provides the practitioner with a knowledge base to critically evaluate the published retrospective data.

Surfactant does not improve survival rate in preterm infants with congenital diaphragmatic hernia

BACKGROUND

Use of exogenous surfactant in congenital diaphragmatic hernia (CDH) patients is routine in many centers. The authors sought to determine the impact of surfactant use in the premature infant with CDH.

METHODS

Data on liveborn infants with CDH from participating institutions were collected prospectively. Surfactant use and timing and outcome data were analyzed retrospectively. The authors evaluated the prenatal diagnosis patients as well. The outcome variable was survival to discharge. Odds ratios with confidence intervals were calculated.

RESULTS

Five hundred ten infants less than 37 weeks' gestation were entered in the CDH registry. Infants with severe anomalies (n = 80) were excluded. Information on surfactant use was available for 424 patients. Infants receiving surfactant (n = 209) had a greater odds of death than infants not receiving surfactant (n = 215, odds ratio, 2.17, 95% CI: 1.5 to 3.2; P <.01). In prenatally diagnosed infants with immediate distress, there was a trend toward worse survival rates among those receiving surfactant at 1 hour (52 patients) versus those that did not (93 patients; odds ratio, 1.93, 95% CI: 0.96 to 3.9; P <.07).

CONCLUSIONS

Surfactant, as currently used, is associated with a lower survival rate in preterm infants with CDH. The use of surfactant replacement in premature infants with CDH can be recommended only within the context of a randomized clinical trial.

Congenital diaphragmatic hernia: a survey of practice in Scandinavia

There is no consensus on the treatment of congenital diaphragmatic hernia (CDH), and practice seems to vary between centres. The main purpose of the present study was to survey current practice in Scandinavia. Thirteen paediatric surgical centres serving a population of about 22 million were invited, and all participated. One questionnaire was completed at each centre. The questionnaire evaluated management following prenatal diagnosis, intensive care strategies, operative treatment, and long-term follow-up. Survival data (1995-1998) were available from 12 of 13 centres. Following prenatal diagnosis of CDH, vaginal delivery and maternal steroids were used at eight and six centres, respectively. All centres used high-frequency oscillation ventilation (HFOV), nitric oxide (NO), and surfactant comparatively often. Five centres had extracorporeal membrane oxygenation (ECMO) facilities, and four centres transferred ECMO candidates. The majority of centres (7/9) always tried HFOV before ECMO was instituted. Surgery was performed when the neonate was clinically stable (11/13) and when no signs of pulmonary hypertension were detected by echo-Doppler (6/13). The repair was performed by laparotomy at all centres and most commonly with nonabsorbable sutures (8/13). Thoracic drain was used routinely at seven centres. Long-term follow-up at a paediatric surgical centre was uncommon (3/13). Only three centres treated more than five CDH patients per year. Comparing survival in centres treating more than five with those treating five or fewer CDH patients per year, there was a tendency towards better survival in the higher-volume centres (72.4%) than in the centres with lower volume (58.7%), p =0.065.

Impact of a current treatment protocol on outcome of high-risk congenital diaphragmatic hernia

BACKGROUND

There is considerable debate regarding the optimal management of congenital diaphragmatic hernia (CDH) in high-risk infants (those cases presenting with respiratory distress within 2 hours of birth or those diagnosed prenatally). The aim of this study was to analyze patient outcomes using a new treatment protocol for CDH in a tertiary care non-extracorporeal membrane oxygenation (ECMO) neonatal unit.

METHODS

The records of 78 consecutive neonates with CDH presenting to Bambino Gesù Children's Hospital from 1996 to 2001 were analyzed retrospectively. Of these infants, 70 high-risk patients were identified (prenatal diagnosis or respiratory distress requiring intubation and assisted ventilation within 2 hours after birth), regardless of associated anomalies, medical condition on presentation, or degree of pulmonary hypoplasia. A prenatal diagnosis was made in 46 of 70 (66%) patients. Associated lethal malformations were present in 6 of the children (8.5%). The patients were placed in 3 historical groups: group 1, 19 patients from 1996 to 1997, group 2, 22 patients from 1998 to 1999, and group 3, 29 patients from 2000 to 2001. In the first 2 groups, a new protocol was introduced using inhaled nitric oxide (iNO) and high-frequency oxygen ventilation (HFOV). In the third group, gentle ventilation and permissive hypercarbia were also used routinely. Mortality and severe morbidity--defined as O2 requirement at discharge, need for a tracheostomy, neurologic impairment, or bilateral hearing loss-were evaluated when the patients were at 6 months old. Univariate analysis was performed.

RESULTS

The 3 groups were comparable with respect to predictive risk factors such as side of hernia, prenatal diagnosis, polyhydramnios, stomach and liver in the thorax, associated lethal malformations, and patch. Overall survival rate significantly increased from 47% (9 of 19) in group 1 and 50% (11 of 22) in group 2 to 90% (26 of 29) in group 3 (P =.02). None of the 19 patients in group 1 had severe morbidity compared with 2 of 22 (9%) patients in group 2 and 2 of 29 (7%) patients in group 3. Hearing loss was observed in 4 patients. Mortality rate and preoperative pneumothorax significantly decreased in group 3 compared with groups 1 and 2 (P =.03 and P =.00, respectively).

CONCLUSIONS

(1) The application of new treatment protocol for CDH, using gentle ventilation and permissive hypercarbia, produced a significant increase in survival with concomitant decrease in morbidity. (2) The rate of pneumothorax was significantly decreased by the introduction of permissive hypercarbia and gentle ventilation. (3) As more infants survive CDH without the use of ECMO, severe long-term sequelae of CDH can be recognized in these children.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia occurs in approximately 1 in every 2500 live births and is associated with a reported mortality of almost 35% in live-born patients and a higher mortality when in utero deaths are counted. Ventilator-induced lung injury, pulmonary hypoplasia, and other associated anomalies account for the high death rate. Numerous adjunctive measures have been used to treat these patients. Inhaled vasodilators (nitric oxide), intravenous vasodilators, and fetal therapy have no proven benefit. While animal models of congenital diaphragmatic hernia are surfactant deficient, controversy remains over the use of surfactant in infants. There has been no clinical trial showing any clear benefit with the use of exogenous surfactant in these patients. Similarly, prenatal corticosteroids show some improvements in animal models, but again, there is a complete absence of supportive data to show benefit in humans. Mechanical ventilator strategies that limit ventilator-induced lung injury by avoiding hyperventilation and lung over inflation are the strategies currently in use that have been associated with improved survival. Long-term follow-up of these patients is quite important since gastroesophageal reflux, developmental delay, chronic lung disease, and chest wall deformity are all seen with increased frequency in these children.

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.

Surfactant levels after reversible tracheal occlusion and prenatal steroids in experimental diaphragmatic hernia

BACKGROUND/PURPOSE

In normal lungs, fetal tracheal occlusion (TO) induces lung growth but decreases the number of type II cells; this is remedied if TO is released (TR) before delivery. In the current study, the effects of TO with or without TR on pulmonary structure and surfactant were assessed in the ovine model in which lung hypoplasia was induced by creation of a diaphragmatic hernia (CDH).

METHODS

A left-sided CDH was created in fetal lambs at 80 days gestation; TO was done at 108 days; and TR at 129 days. All ewes were given 1 dose of glucocorticoids at 135 days. At 136 days, the fetus was delivered. Lung weight to body weight ratio, mean terminal bronchiole density, type II cell density, bronchoalveolar lavage fluid (BAL) phosphatidylcholine (PC), BAL surfactant protein A (SP-A) and B (SP-B), and lung tissue SP-A and SP-B were assessed in CDH, CDH with TO, CDH with TO and TR, and controls.

RESULTS

CDH lungs were hypoplastic and structurally immature, but had increased type II cell density. TO with or without TR caused lung growth with normalization of lung parenchymal architecture and type II cell density. Although the BAL SP-A and BAL SP-B were similar in all 4 groups, the BAL PC was low in CDH with or without TO or TR. Also, lung tissue SP-B levels were low in CDH with or without TO or TR. However, lung tissue SP-A levels were normal in CDH, but low in CDH with TO with or without TR.

CONCLUSIONS

Despite the finding that lung morphology was improved in CDH with TO with or without TR animals, surfactant content and composition remained abnormal. Although surfactant secreted early by the fetus into alveolar spaces contained normal levels of BAL SP-A and BAL SP-B, the low levels of BAL PC and low lung tissue stores of SP-B indicate that these experimental lambs may experience respiratory insufficiency soon after birth. This implies that prophylactic surfactant at birth might be beneficial for CDH.

Congenital diaphragmatic hernia: where are we and where do we go from here?

The infant born with congenital diphragmatic hernia (CDH) remains one of the most complex patients to manage. Pulmonary hypoplasia and immaturity of the CDH lung are well recognized as the definitive limitation leading to the high mortality rates. Based on the knowledge that CDH is more a physiological disease than a surgical disease, we have shifted our management strategy from immediate repair to delayed repair and stabilization. The associated pulmonary hypertension and right-to-left shunt are common and rarely the cause of death and as such may be largely ignored. Extracorporeal membrane oxygen has been shown to salvage some of the most severely affected neonates. Other advanced and experimental respiratory therapies merit investigation in properly conducted prospective randomized multi-center trials. Survivors of CDH have predictable pulmonary, gastrointestinal and nutritional problems which, when identified and treated early, are correctable. CDH survival is close to 90% at most advanced centers. Uniform standards for CDH management do not exist however. Therefore a minimal set of practice standards should be developed from evidenced-based scientific review.

Congenital diaphragmatic hernia: a meta-analysis of mortality factors

PURPOSE

The aim of this study was to review all available studies reported in the English-language literature from 1975 through 1998, and by meta-analysis assess the importance of prenatal diagnosis, associated malformations, side of hernia, timing of surgery, and study population on mortality rates in patients with congenital diaphragmatic hernia (CDH).

METHODS

One-hundred-two studies were identified, and 51 studies (2,980 patients) fulfilled the prespecified inclusion criteria. Studies were grouped according to study population into: (I) fetuses diagnosed prenatally; (II) neonates admitted to a treatment center; and (III) population-based studies.

RESULTS

Pooled total mortality rate was significantly higher in category I than in category III (75.6% v 58.2%, P < .001). Pooled hidden postnatal mortality rate (deaths before admittance to a treatment center) in population-based studies was 34.9%. Prenatally diagnosed patients in both category II and III had significantly higher mortality rates than those diagnosed postnatally. Mortality rates were significantly higher among CDH infants with associated major malformations compared with isolated CDH in all 3 categories. An increased mortality rate in right-sided CDH was found in category II and III.

CONCLUSIONS

Prenatal diagnosis of CDH, presence of associated major malformations, and the study population have a major influence on mortality rate. The very high mortality rate in studies of fetuses with a prenatal diagnosis of CDH should be taken into account in prenatal counselling.

Neonatal acute respiratory failure

Acute respiratory failure is the most common problem seen in the preterm and term infants admitted to neonatal intensive care units. In preterm infants, the most common cause of acute respiratory failure is respiratory distress syndrome caused by surfactant deficiency. Acute respiratory failure in term and near term infants is usually a result of meconium aspiration syndrome, sepsis, pulmonary hypoplasia, and primary pulmonary hypertension of the newborn. The response to various methods of treatment may vary, depending on the severity of respiratory failure and the cause of the acute respiratory failure. We reviewed the evidence for efficacy and current utilization of newer treatment modalities, including exogenous surfactant administration, high frequency ventilation, inhaled nitric oxide therapy, antenatal steroids for the prevention of respiratory distress syndrome, and use of postnatal steroids for the prevention of chronic lung disease.

Prolonged use of pancuronium bromide and sensorineural hearing loss in childhood survivors of congenital diaphragmatic hernia

Sensorineural hearing loss (SNHL) is a significant neurologic morbidity in survivors of neonatal congenital diaphragmatic hernia (CDH), with a reported incidence of up to 60%. In a historical cohort study of 37 neonates with CDH, we investigated the use of pancuronium bromide (PB) and common ototoxic drugs during the neonatal period and their relationship to SNHL in childhood survivors. Survivors with SNHL (n = 23) had significantly higher cumulative dose of PB administered during the neonatal illness than survivors without SNHL (n = 14). The cumulative dose and duration of PB use significantly correlated (r = 0.66-0.81) and independently predicted (adjusted r (2) = 0.42-0.64) the greatest intensity (in decibels) and the widest band (lowest frequency in hertz) loss of SNHL. No differences were identified between survivors with and without SNHL regarding demographic and neonatal characteristics (including oxygenation and ventilation variables and the cumulative dose and duration of therapy with aminoglycosides, vancomycin, and furosemide), although survivors with SNHL had received a modestly higher cumulative dose of ethacrynic acid than survivors without SNHL. Although we show that prolonged administration of PB during the neonatal period is associated with SNHL in childhood survivors of CDH, further multicenter studies are required to investigate the possible etiologies of SNHL in this high-risk population.