Although delayed repair with preoperative stabilization using high-frequency oscillatory ventilation (HFOV) has been advocated in neonates with congenital diaphragmatic hernia (CDH), improved survival has not been reported. We compared survival between neonates undergoing delayed repair after prolonged stabilization for more than 48 h using HFOV and those undergoing immediate repair following short stabilization using HFOV in subjects with high-risk CDH. Patient selection was made by two criteria: fetuses with the lung/thorax transverse area ratio (L/T) below 0.26 and neonates who presented with respiratory distress significant enough to require intubation within 6 h after delivery. Selection of the strategies differed by era and medical center. Stabilization failed in 11 of 18 patients with delayed repair and only 7 patients (38.9%) in this group survived, but 18 of 23 patients (78.3%) in the immediate-repair group survived (P < 0.05). Although lower values of Apgar scores, best postductal PO2 (BPtDPO2), gestational weeks, and L/T and more frequent patch repair were observed in the delayed than in the immediate repair group, significant differences in survival among the subpopulations were also observed in the prenatally diagnosed group, including the group with L/T < 0.15 and the group that required ECMO, the group with the best preductal PO2 (BPrDPO2) >/= 100 torr, and the group with BPtDPO2 < 100 torr. These results indicate that prolonged stabilization for more than 48 h using HFOV does not improve survival in patients with high-risk CDH.
Infants with congenital diaphragmatic hernia (CDH) show a wide range of anatomic and physiological abnormalities, making it difficult to compare the efficacy of management protocols between institutions. The purpose of this study was twofold: (1) to analyze the results of treatment of CDH in a large tertiary care pediatric center using conventional mechanical ventilation (CMV) with extracorporeal membrane oxygenation (ECMO) as rescue therapy, and (2) to compare these results with those of a parallel study by a similar large urban center that used high-frequency oscillating ventilation (HFOV) as rescue therapy without ECMO. All patients who had CDH diagnosed within the first 12 hours of life and were referred for treatment before repair (between 1981 and 1994) were included in the analysis (n = 196). CMV was used initially in all patients, with conversion to ECMO for refractory hypoxemia or hypercapnea. Between 1981 and 1984, ECMO was not available. Between 1984 and 1987, ECMO was offered postoperatively. Between 1987 and 1991, ECMO was offered preoperatively. In all three groups, aggressive hyperventilation and alkalosis was the norm. Since 1991, permissive hypercapnia has been used. HFOV was used in three patients as stand-alone therapy with one survivor. Twenty patients died without repair: Ten had other lethal anomalies, eight died before ECMO could be instituted, and two died of ECMO-related complications. Overall, 104 patients (53%) survived and 92 (47%) died. Ninety-eight patients (50%) received ECMO, and 43 (44%) survived. Survivors had significantly higher 1- and 5-minute Apgar scores and higher postductal Po2s than did nonsurvivors. Associated anomalies were present in 39%, who had a significantly lower survival than those with isolated CDH. Antenatal diagnosis and side of the defect had no impact on outcome. Survival was not improved with the institution of ECMO or delayed repair but rose significantly to 69% (84% with isolated CDH, P = .007) with the introduction of permissive hypercapnea. Autopsy results from nonsurvivors showed other lethal anomalies and significant barotrauma as the primary causes of death. Comparisons between the Boston and Toronto series showed similar patient demographics and no significant differences in survival in any time period. The two series differed in the number of associated anomalies, their impact on survival, and in the prognosis of right-sided CDH. From the individual and combined analyses the authors concluded: (1) CMV with ECMO as rescue produced an overall survival in CDH patients equivalent to CMV with HFOV in a parallel series, (2) neither HFOV nor ECMO has significantly improved outcome in CDH patients, (3) institution of permissive hypercapnia has resulted in a significant increase in survival, and (4) the leading causes of death in CDH patients appear to be associated anomalies and pulmonary hypoplasia, which are currently untreatable. Barotrauma, which may contribute in up to 25% of deaths in CDH patients is avoidable.
PURPOSE: The optimal therapy for congenital diaphragmatic hernia (CDH) is evolving. This study analyzes the results of treatment of CDH in a large tertiary care pediatric center using conventional and high-frequency oscillatory ventilation (HFOV) without extracorporeal membrane oxygenation (ECMO) contrasting these with a parallel study from a similar large urban center using conventional ventilation with ECMO.
METHODS: Between 1981 and 1994, 223 consecutive neonates who had CDH diagnosed in the first 12 hours of life were referred for treatment before repair. Conventional ventilation was used with conversion to HFOV for refractory hypoxemia or hypercapnia, and a predicted near 100% mortality rate. ECMO was used in only three patients, all of whom died. A retrospective database was collected. Thirty-one clinical variables were tested for their association with the outcome. Common ventilatory and oxygenation indices were tested for their prognostic capability.
RESULTS: Apgar scores, birth weight, right-sided defects, pneumothorax, total ventilatory time, and the use of high frequency oscillatory ventilation were the only variables associated with outcome. A modified ventilatory index and postductal A-aDo2 were strong prognostic indicators. From 1981 to 1984 surgery was performed on an emergency basis. Since 1985 surgery was deferred until stabilization had been achieved. This resulted in a shift in the mortality from postoperative to preoperative with no change in total survival. HFOV did not alter the overall survival. Results of autopsies performed (70%) showed significant pulmonary hypoplasia and barotrauma as the primary causes of death. The survival was 54.7%.
CONCLUSION: Conventional ventilation with HFOV produced equal survival to conventional ventilation with ECMO in two comparable series. Pulmonary hypoplasia was the principle cause of death. This continued high mortality at both centers suggests that new therapies are required to improve outcomes.
Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia. The pulmonary vascular bed may be extremely reactive to various stimuli, and in the treatment it is important to avoid pulmonary vasospasm. The strategy in our institution since 1990 has involved a prolonged preoperative stabilization with gentle mechanical ventilation. Pressures have been kept as low as possible, and slight hypercarbia has been accepted. Peak inspiratory pressures exceeding 35 cm H2O have been avoided. Extracorporeal membrane oxygenation (ECMO) has been used according to standard inclusion criteria. Nitric oxide and high-frequency oscillation have been added to the therapeutic modalities during the study period. When the patient was considered stabilized, surgical repair was undertaken after a delay of 24 to 96 hours. In patients on ECMO who could not be decannulated, surgical repair was undertaken while on ECMO. From 1990 through 1995, 52 patients were admitted with a diagnosis of CDH. Forty-three of these were risk group patients presenting with respiratory distress within 6 hours after birth. A total of 48 patients survived (survival rate 92%), and 39 of the risk group patients (survival rate 91%). There were only four hospital deaths, all with contraindications to ECMO. It is suggested that the adopted protocol is beneficial in the treatment of CDH and that the fraction of patients who have pulmonary hypoplasia incompatible with life is smaller than previously believed.
Delayed surgery has become widely accepted in the management of congenital diaphragmatic hernia after comparing outcomes only with historical retrospective controls. It was the aim of this study to compare early and delayed hernia repair in a randomized prospective clinical trial. Fifty-four infants were randomized to receive either early repair (within 4 hours of admission) or delayed repair (more than 24 hours after birth). The survival rate was higher for the delayed group (57% v 46%), but the difference was not significant (difference: -11; 95% confidence limits: -37.5, 15.5). There were no significant differences between the two groups with respect to length of hospital stay, ventilator dependency, or survival time. Recorded preoperative risk factors were similar for the two groups. Eight infants in the delayed repair group died without having undergone surgery. The optimum time for surgery still needs clarification.
BACKGROUND: Since November 1992, operative repair in neonates with congenital diaphragmatic hernia (CDH) at this institution was delayed until respiratory insufficiency had resolved.
METHODS: A retrospective analysis was performed (n = 33) comparing delayed repair with our previously reported institutional experience with immediate repair from January 1988 to October 1992 (n = 66). Infants with severe genetic defects or moribund conditions or who were premature were not considered candidates for repair or extracorporeal life support (ECLS), but they were included in the survival analysis. Survival was defined as hospital discharge. Data were compared with an independent t test or Pearson chi-squared test.
RESULTS: Mean age at repair was 8.9 +/- 4.5 days (range, 3 to 20 days). Eleven infants in the study group were placed on ECLS (33% versus 68% in the comparison group; p = 0.001). Six of these infants survived (55% versus 58% in the comparison group; p = 0.846). Of these survivors, one patient was repaired while on ECLS, and the remainder underwent repair after decannulation from ECLS. All 20 of the remaining candidates for repair survived without need for ECLS. Overall survival was 79% versus 56% in the comparison group (p = 0.027).
CONCLUSIONS: Our current data suggest that very delayed repair of newborns with CDHs is associated with an increase in the overall survival and a decrease in the use of ECLS when compared with previous experience at this institution.
This report suggests that stabilization of the intrauterine to extrauterine transitional circulation combined with a respiratory care strategy that avoids pulmonary overdistension, takes advantage of inherent biological cardiorespiratory mechanics, and very delayed surgery for congenital diaphragmatic hernia results in improved survival and decreases the need for extracorporeal membrane oxygenation (ECMO). This retrospective review of a 10-year experience in which the respiratory care strategy, ECMO availability, and technique of surgical repair remained essentially constant describes the evolution of this method of management of congenital diaphragmatic hernia.
BACKGROUND: Congenital diaphragmatic hernia (CDH) continues to have a high mortality rate (24 to 57 percent) despite changing management schemes, which include extracorporeal membrane oxygenation (ECMO) for treatment of associated persistent pulmonary hypertension of the newborn.
STUDY DESIGN: The medical records of 123 acutely symptomatic newborns with CDH treated from 1972 to 1994 were retrospectively reviewed. Patients were divided into three groups to compare historical treatment modalities: group 1, no ECMO available; group 2, postoperative ECMO if necessary; and group 3, delayed repair with preoperative ECMO if necessary. The blood gas values, alveolar-arterial oxygen gradient (A-aDO2), mean airway pressure (MAP), and oxygenation (OI) and ventilation indices (VI) prior to treatment were compared between survivors and nonsurvivors. Chi-square and Student's t tests were used to determine statistical significance.
RESULTS: The overall survival rate was 41 percent: 27 percent in group 1, 45 percent in group 2, and 39 percent in groups 3. If those who were not candidates for ECMO were excluded from analysis, the survival rate improved to 35 percent in group 1, 51 percent in group 2, and 50 percent in group 3. No published prognostic scoring system, such as arterial blood gas values, A-aDO2 gradient, MAP, OI, or VI consistently distinguished survivors from nonsurvivors. Extracorporeal membrane oxygenation decreased the mortality rate of patients having large defects.
CONCLUSIONS: Prognostic scoring systems do not predict which patients with CDH should be treated. Extracorporeal membrane oxygenation has improved survival in newborns with CDH who present in early respiratory distress. There is no advantage or disadvantage to using ECMO prior to repair of CDH.
Stabilization and delayed operation for patients with congenital diaphragmatic hernia (CDH) is now widely accepted. When preoperative extracorporeal membrane oxygenation (ECMO) is needed, most centers have CDH repaired on ECMO to minimize the risk of postoperative deterioration. The authors adopted a policy of weaning from ECMO before repair in an effort to avoid hemorrhagic risks. They reviewed their experience with CDH patients who required ECMO for stabilization before repair but for whom post-ECMO repair was planned. The records of all high-risk CDH patients with a gestational age of at least 34 weeks were reviewed. Eighteen patients were identified. None of the eight who were stabilized and operated on without ECMO required bypass postoperatively; all survived. Ten were placed on bypass, nine for stabilization before repair. Of the nine, seven (78%) were weaned from ECMO to conventional ventilation. Repair of the diaphragmatic defect was performed an average of 3.8 days later; none of these patients had severe pulmonary hypertension postoperatively, and all survived. Two could not be weaned before repair, one of whom had a complex congenital heart defect. This patient died. The other patient had repair on ECMO because of intrathoracic gastric volvulus. Severe blood loss prompted decannulation, and the patient died. One patient who was placed on bypass was transferred 10 days after having had repair elsewhere (at 4 hours of age). Pulmonary hypertension did not resolve, and the postmortem examination showed alveolar capillary dysplasia, with focal misalignment of the pulmonary vessels.(ABSTRACT TRUNCATED AT 250 WORDS)
Although delayed repair with preoperative stabilization using high-frequency oscillatory ventilation (HFOV) has been advocated in neonates with congenital diaphragmatic hernia (CDH), improved survival has not been reported. We compared survival between neonates undergoing delayed repair after prolonged stabilization for more than 48 h using HFOV and those undergoing immediate repair following short stabilization using HFOV in subjects with high-risk CDH. Patient selection was made by two criteria: fetuses with the lung/thorax transverse area ratio (L/T) below 0.26 and neonates who presented with respiratory distress significant enough to require intubation within 6 h after delivery. Selection of the strategies differed by era and medical center. Stabilization failed in 11 of 18 patients with delayed repair and only 7 patients (38.9%) in this group survived, but 18 of 23 patients (78.3%) in the immediate-repair group survived (P < 0.05). Although lower values of Apgar scores, best postductal PO2 (BPtDPO2), gestational weeks, and L/T and more frequent patch repair were observed in the delayed than in the immediate repair group, significant differences in survival among the subpopulations were also observed in the prenatally diagnosed group, including the group with L/T < 0.15 and the group that required ECMO, the group with the best preductal PO2 (BPrDPO2) >/= 100 torr, and the group with BPtDPO2 < 100 torr. These results indicate that prolonged stabilization for more than 48 h using HFOV does not improve survival in patients with high-risk CDH.
