Clinical use of an extracorporeal membrane oxygenator in neonatal pulmonary failure

The Story of ECMO

Extracorporeal Circulation in Neonatal Respiratory Failure: A Prospective Randomized Study. By RH Bartlett, DW Roloff, RG Cornell, AF Andrews, PW Dillon, JB Zwischenberger. Pediatrics 1985; 76:479-87. Extracorporeal membrane oxygenation (ECMO) is the use of mechanical devices to replace cardiac and pulmonary function in critical care. In the 1960s, laboratory research showed that extracorporeal circulation could be maintained for days using a membrane oxygenator. In the 1970s, the first clinical trials showed that ECMO could sustain life in severe cardiac and pulmonary failure for days or weeks, leading to organ recovery. From 1980 to 2000, ECMO became standard practice for neonatal and pediatric respiratory and cardiac failure. The critical clinical trial was a prospective randomized trial of ECMO in newborn respiratory failure, published in 1985. This is the classic article reviewed in this publication. This was the first use of a randomized, adaptive design trial to minimize the potential ethical dilemma inherent to clinical trials in which the endpoint is death. Other randomized trials followed, and ECMO is now standard practice for severe respiratory and cardiac failure in all age groups.

Inflight use of extracorporeal membrane oxygenation for severe neonatal respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a heart-lung bypass technique which has been used over the past ten years to support some 300 neonates with life-threatening respiratory failure. It is estimated that, within the constraints of currently accepted treatment criteria, there are between 2,000 and 3,000 neonates born each year within the United States who require this extreme therapeutic measure. Unfortunately, since there are still relatively few medical centres in the country offering this type of support, it is frequently necessary to transport candidate neonates from the hospital of birth to a referral centre. This is generally a tenuous procedure since neonates who are sufficiently ill to require ECMO treatment are commonly poor transport risks. We report the first successful use of an ECMO system designed to be transported to the referring hospital, assembled, and used to support an infant on bypass for a controlled air transport back to the receiving medical centre. The potential for decreasing the morbidity and mortality of selected infants requiring ECMO support by the addition of this capability is discussed.

Neonatal Extracorporeal Membrane Oxygenation: A Review

The history of extracorporeal membrane oxygenation (ECMO) therapy is summarized. The adult and pediatric experiences are described, but emphasis is placed on the development of neonatal ECMO, now an accepted therapy for newborns with severe respiratory failure. The technical aspects of neonatal ECMO are outlined, as are the clinical criteria for its use. Experience at Children's Hospital National Medical Center, Washington, DC, is reported. Promising new technological developments, and their implications for future applications of neonatal ECMO, are presented.

An Economic Analysis of Extracorporeal Membrane Oxygenation

Financial considerations, in concert with clinical effec tiveness, are of increasing importance in the assessment of technological innovations. One such innovation, ex tracorporeal membrane oxygenation (ECMO), is now in use at over twenty centers nationwide to treat new borns with severe, acute lung disease. Use of ECMO therapy for one year at Children's Hospital National Medical Center, Washington, DC, in a population of pa tients with persistent pulmonary hypertension of the newborn (PPHN) is reported, comparing outcome and financial considerations with a similar group of infants treated conventionally prior to ECMO. A historical con trol group of infants with severe PPHN showed that before ECMO was available the survival rate in this criti cally ill population was only 21%. With ECMO, infants with the same clinical characteristics have an 80% chance of survival. Analysis of hospital and physician charges for these two groups (pre-ECMO and ECMO) reveals that ECMO therapy is about 2% less expensive than conventional treatment. When only survivors in each group are compared, ECMO is 43% less costly. These differences are attributable to reductions in aver age length of hospital stay with ECMO therapy, and they are conservative in that they do not take into considera tion the marked economic advantage to society of avert ing unnecessary deaths.

Extracorporeal membrane oxygenation: a breakthrough for respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a method for providing long-term treatment of a patient in a modified heart-lung machine. Desaturated blood is drained from the patient, oxygenated and pumped back to a major vein or artery. ECMO supports heart and lung function and may be used in severe heart and/or lung failure when conventional intensive care fails. The Stockholm programme started in 1987 with treatment of neonates. In 1995, the first adult patient was accepted onto the programme. Interhospital transportation during ECMO was started in 1996, which enabled retrieval of extremely unstable patients during ECMO. Today, the programme has an annual volume of about 80 patients. It has been characterized by, amongst other things, minimal patient sedation. By 31 December 2014, over 900 patients had been treated, the vast majority for respiratory failure, and over 650 patients had been transported during ECMO. The median ECMO duration was 5.3, 5.7 and 7.1 days for neonatal, paediatric and adult patients, respectively. The survival to hospital discharge rate for respiratory ECMO was 81%, 70% and 63% in the different age groups, respectively, which is significantly higher than the overall international experience as reported to the Extracorporeal Life Support Organization (ELSO) Registry (74%, 57% and 57%, respectively). The survival rate was significantly higher in the Stockholm programme compared to ELSO for meconium aspiration syndrome, congenital diaphragmatic hernia in neonates and pneumocystis pneumonia in paediatric patients.

Expanded application of extracorporeal membrane oxygenation in a pediatric surgery practice

OBJECTIVE

To examine the breadth of application and resulting outcomes in a university-based extracorporeal membrane oxygenation (ECMO) program directed by pediatric surgeons.

SUMMARY BACKGROUND DATA

Several randomized control trials have supported the use of ECMO in neonates with respiratory failure. No comparable data exist for older children and young adults who may be afflicted with a variety of uncommon conditions. The indications for ECMO in these patients remain controversial.

METHODS

Patient data were recorded prospectively and reported to the Extracorporeal Life Support Organization. These data were analyzed by indications and outcomes on all patients treated since the inception of the program.

RESULTS

Two hundred sixteen patients were treated with 225 courses of ECMO. Neonates (188 [87%]) outnumbered 28 older patients (aged 6 weeks to 22 years). Overall, 174 patients survived (81%). Sixty-four of 65 (98.5%) neonates with meconium aspiration syndrome survived. ECMO support after heart (3), lung (2), heart-lung (1), and liver (1) transplant yielded a 57% survival to discharge. ECMO also resulted in survival of patients with uncommon conditions, including severe asthma (1), hydrocarbon aspiration (1/2), congestive heart failure due to a cerebral arteriovenous malformation (1), tracheal occlusion incurred during endoscopic stent manipulation (2), meningitis (1), and viral pneumonia (3/5).

CONCLUSIONS

ECMO can potentially eliminate mortality for meconium aspiration syndrome. Survival for other causes of respiratory failure in neonates and older children, while not as dramatic, still surpasses that anticipated with conventional therapy. Moreover, survival of transplant patients has been comparable to that achieved in other children.

MRI, MRA, and neurodevelopmental outcome following neonatal ECMO

Cranial magnetic resonance imaging (MRI) of 31 newborn infants treated with venoarterial cardiopulmonary bypass for severe but reversible respiratory failure, revealed major focal parenchymal lesions in 7 of 31 infants (23%) and demonstrated abnormal enlargement of extra-axial and ventricular cerebrospinal fluid spaces in 16 of 31 (51%). No preferential left versus right lateralization of focal injury was observed in conjunction with right common carotid artery and jugular vein ligation. No statistically significant relationships were found between major brain lesions on MRI scans and the clinical characteristics of the pre-extracorporeal membrane oxygenation (ECMO), ECMO, and post-ECMO course. Major focal brain lesions were significantly associated with an asymmetric cerebrovascular response to carotid ligation of the right versus left middle cerebral arteries as detected by magnetic resonance angiography (P < .05). Enlarged cerebrospinal fluid spaces were not significantly related to the presence of parenchymal MRI lesions, but were associated with lower Bayley neurodevelopmental scores for mental (MDI) and psychomotor evaluations (PDI) at 6 and 12 months (P < .05). It is concluded that asymmetries of cerebral vascular adaptation detected by magnetic resonance angiography after ECMO may be associated with major brain lesions revealed by MRI. Thereafter, the presence of enlarged cerebrospinal fluid spaces on MRI is associated with a poor shortterm developmental outcome.

Extracorporeal membrane oxygenation for cardiac failure after congenital heart operation

Despite continuing improvement in myocardial protection and surgical technique, the repair of complex congenital heart lesions can result in cardiopulmonary compromise refractory to conventional therapy. In a 29-month period, 24 patients (aged 14 hours to 6 years) were treated with extracorporeal membrane oxygenation (ECMO) 28 times for profound cardiopulmonary failure. Four patients required ECMO after each of two cardiopulmonary bypass procedures. Seventeen patients required ECMO to be initiated in the operating room: 12 (71%) were weaned successfully from ECMO, and 8 (47%) survived. Seven patients had ECMO initiated in the intensive care unit: 6 (86%) were weaned, and 5 (71%) survived. Serial echocardiograms demonstrated substantial recovery of cardiac function in 18 of 21 instances (86%) of ventricular failure from myocardial dysfunction. Overall, 18 of 24 patients (75%) were successfully weaned from ECMO including all 4 who underwent 2 ECMO treatments. We conclude that ECMO can successfully salvage children who have serious cardiopulmonary failure immediately after a congenital heart operation and that long-term survival is possible after two ECMO treatments.

Cardiac arrest in the ECMO candidate

Extracorporeal membrane oxygenation (ECMO) improves survival in appropriately selected full-term neonates with severe respiratory failure. The clinical course and outcome of infants placed on ECMO after sustaining a cardiac arrest is not known. This study reviews the characteristics and outcome of 10 neonates, identified by retrospective review, placed on ECMO at Children's Hospital Medical Center (CHMC), Cincinnati, OH, after sustaining a cardiac arrest. Long-term survival in this group was 60%, significantly less than the 87% overall ECMO survival in infants at CHMC (P less than .01). Survivors and nonsurvivors in the cardiac arrest group were similar with regard to gestational age, birth weight, Apgar scores, and arterial PO2 prior to cannulation. Nonsurvivors had an ECMO course complicated by progressive multisystem organ failure. Head computed tomography obtained at the time of discharge demonstrated right-sided brain lesions in three of six survivors. Despite these radiographic findings, early clinical follow-up suggests adequate growth and development with no individuals demonstrating a severe neurological deficit. Thus, ECMO can play a role in the resuscitation of neonatal ECMO candidates sustaining cardiac arrest prior to or at the time of cannulation. Early clinical follow-up suggests adequate preservation of neurological function in this extremely high-risk group.

Comparison of six ECMO selection criteria and analysis of factors influencing their accuracy

This study compared six extracorporeal membrane oxygenation (ECMO) selection criteria in 42 neonates and analyzed factors influencing the accuracy of outcome predictions. The sensitivity of the criteria in identifying fatal cases varied from 0.44 to 0.94 and the specificity of predictions of survival ranged from 0.42 to 0.69. The criterion having the highest sensitivity had the lowest specificity and conversely the criterion with the lowest sensitivity had the highest specificity. Overall accuracy of the criteria, as measured by the total number of correct outcome predictions, differed little among the criteria (23/42 to 27/42 correct predictions). Three factors influenced predictive accuracy: 1) a primary diagnosis of congenital diaphragmatic hernia (CDH) was associated with a greater mortality (P less than 0.001) and a significantly higher positive predictive value (PPV) for all criteria (P = 0.0009-0.012) than that seen in patients with other primary diagnoses; 2) calculating the alveolar-arterial oxygen gradient using an assumed, rather than measured barometric pressure, or estimating oxygenation index using a calculated, rather than a measured, mean airway pressure, increased false positive mortality predictions in non-CDH patients; and 3) requiring a peak inspiratory pressure (PIP) of at least 50 cm H2O in the definition of maximal medical management, rather than a PIP of 20-49 cm H2O, significantly increased the PPV for three of four criteria examined (P = 0.02-0.04). Awareness of these factors may facilitate the identification of neonates who need ECMO to survive.

Extracorporeal membrane oxygenation and indications for cardiopulmonary bypass in the neonate

Extracorporeal membrane oxygenation (ECMO) is a rescue technique used for term and near-term neonates who have respiratory failure that is unresponsive to conventional therapy. The complexity of the equipment necessitates intensive training of a specialized team before setting up an ECMO unit. An understanding of the physiology underlying ECMO and the criteria used for patient selection assists the nurse in identifying neonates who might benefit from the technique.

The significance of ductal shunting during extracorporeal membrane oxygenation

The purpose of this study was to evaluate the significance and direction of shunts at the level of the foramen ovale or ductus arteriosus in full-term newborns with neonatal respiratory failure who were placed on extracorporeal membrane oxygenation (ECMO). A decrease in left ventricular dimension was expected when infants were placed on ECMO but did not occur. A left-to-right shunt was demonstrated at the ductal level in nine of 12 infants early in the course of ECMO before pulmonary resistance decreased. Presumably, the lack of change in the left ventricular dimension when infants were placed on bypass was due to a left-to-right shunt at the ductal level with ductal flow replacing the right heart output, being drawn into the bypass circuit.

Advanced techniques in thoracic trauma

Technologic aid is available for the three central problems of hemorrhage, lung damage, and cardiac damage. Autotransfusion, new modes of ventilator support, extracorporeal oxygenation, balloon pumping, and left ventricular assist are available for the trauma patient. The author explains these new devices and their role in thoracic trauma cases.

Doppler echocardiographic evaluation of cardiac performance in infants on prolonged extracorporeal membrane oxygenation

Cardiac performance was evaluated by Doppler echocardiography in 19 infants with persistent pulmonary hypertension before, during and after prolonged extracorporeal membrane oxygenation (ECMO). Systemic arterial pressure was normal before ECMO (67 +/- 12 mm Hg), increased during ECMO (78 +/- 13 mm Hg) and decreased to baseline after ECMO (p less than or equal to 0.01). Heart rate was normal before ECMO and did not change during or after ECMO. The left ventricular shortening fraction was normal before ECMO (37 +/- 11%), decreased after beginning ECMO (25 +/- 11%) and returned to baseline 72 hours after beginning ECMO (p less than or equal to 0.01). Pulmonary arterial and aortic blood flow velocities were normal before ECMO, decreased 30 to 50% during ECMO and increased to baseline 72 hours after beginning ECMO (p less than or equal to 0.01). Stroke volume had an identical trend (p less than or equal to 0.01). Left ventricular velocity of circumferential shortening--an index of contractility--decreased after beginning ECMO (p less than or equal to 0.05). Left ventricular systolic wall stress--an index of systemic afterload--increased after beginning ECMO (p less than or equal to 0.01). A patent ductus arteriosus was present in 13 of 19 infants before ECMO, 16 of 19 infants during ECMO and in none of 19 infants after ECMO. Pulmonary arterial systolic pressure was high before ECMO (72 +/- 25 mm Hg), began to decrease after 48 hours on ECMO (59 +/- 24 mm Hg) and was normal after ECMO (38 +/- 18 mm Hg), p less than or equal to 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical use of extracorporeal membrane oxygenation in the treatment of persistent pulmonary hypertension following surgical repair of congenital diaphragmatic hernia

The clinical use of extracorporeal membrane oxygenation (ECMO) in the treatment of persistent pulmonary hypertension following surgical repair of congenital diaphragmatic hernia is reported on 11 patients. The patients had a total of 13 treatments; two patients had two treatments. During the same period of clinical use, 122 patients were placed on ECMO for all causes. The indications, results, and complications of the use of ECMO for treatment following surgical repair of congenital diaphragmatic hernia are presented. The reversal of persistent pulmonary hypertension is demonstrated. All patients treated by ECMO for congenital diaphragmatic hernia have survived.

To-and-for extracorporeal lung assist (ECLA) through a single catheter-in premature goats as an experimental model of infant respiratory Insufficiency

A new to-and-fro V-V bypass extracorporeal lung assist (ECLA) through a single catheter as a blood access was investigated for its efficacy on six premature goats delivered by Cesarean section at a gestational age of 118 approximately 139 days as an experimental model of infant respiratory insufficiency, then applied to a human premature infant suffering from life threatening barotrauma that had developed from mechanical pulmonary ventilation. The extracorporeal bypass flow and the gas flow to the artificial membrane lung were controlled to keep Pa(O)(2) above 40 mmHg and Pa(CO)(2) within normal limits. The neonate's own lungs were treated with a continuous positive airway pressure of 5 approximately 12 cmH(2)O, apneic oxygenation or IMV. Two goats weighing 1250 g and 700 g died 2 approximately 2.5 hours after birth from severe circulatory distress. However, the other four neonates which were heavier than 2000 g, were successfully weaned from ECLA, and three of these could be weaned from mechanical ventilation as well. A human infant also survived and was weaned from ECLA on the third day.(Tanoue T, Terasaki H, Sadanaga M et al.: To-and-fro extracorporeal lung assist (ECLA) through a single catheter-in premature goats as an experimental model of infant respiratory insufficiency.

Aluminum-containing emboli in infants treated with extracorporeal membrane oxygenation

We found fibrin thrombi or thromboemboli at autopsy in 22 of 23 infants with respiratory failure who had been treated with venoarterial extracorporeal membrane oxygenation (ECMO). In addition, distinctive basophilic aluminum-containing emboli were found in 12 of the infants; the distribution of these emboli was similar to that of the thromboemboli, except that an aluminum-containing embolus was found in a lung in only 1 infant. Sixteen infants had pulmonary thrombi or thromboemboli. We also found friable aluminum-containing concretions adhering loosely to the mixing rods of heat exchangers that had been used to warm the blood flowing through the ECMO circuit; such concretions were not present on unused mixing rods. We propose that these aluminum-containing concretions developed as the silicone coating of the heat exchanger wore away and aluminum metal was exposed to warm, oxygenated blood and that fragments of aluminum-containing concretions formed emboli. This hypothesis is supported by the fact that aluminum-containing emboli were generally not present in the lungs, which are bypassed by ECMO. Although infarcts were found in 16 of the 23 infants, we cannot be certain whether any of the infarcts were caused by the aluminum-containing emboli.

Life-threatening intrathoracic complications during treatment with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) has been successful (greater than 80% survival) in 35 centers in greater than 900 newborns with severe respiratory failure having an estimated mortality of greater than 80% on conventional management. During the last 3 years we have treated 79 newborns with 74 survivors (94%). Their diagnoses included meconium aspiration, persistent fetal circulation, respiratory distress syndrome, congenital diaphragmatic hernia, and sepsis. Seven patients (9%) had life-threatening intrathoracic complications requiring emergent intervention while on ECMO: tension hemothorax (3), tension pneumothorax (2), and pericardial tamponade (2). Pericardial tamponade and tension hemothorax and pneumothorax show a similar pathophysiology of increasing intrapericardial pressure and decreasing venous return. Perfusion is initially maintained by the nonpulsatile flow of the ECMO circuit before further decrease in venous return results in decreasing ECMO flow and progressive hemodynamic deterioration. Each of the seven patients demonstrated a clinical triad that includes increasing PaO2 and decreasing peripheral perfusion (as evidenced by decreasing pulse pressure and decreasing SvO2) followed by decreasing ECMO flow with progressive deterioration. The diagnoses were confirmed by transillumination, chest x-ray, or cardiac echocardiogram. Initial emergent placement of a percutaneous drainage catheter was temporizing in all seven cases. However, four patients required emergent thoracotomy for definitive treatment while still on ECMO. All seven patients were weaned from ECMO and are short-term survivors (6 months to 3.5 years). As use of ECMO for newborn severe respiratory failure increases, responsible physicians must be familiar with life-threatening intrathoracic complications and appropriate treatment strategies.

Extracorporeal membrane oxygenation following repair of congenital diaphragmatic hernias

From 1981 through 1986, 8 newborns with congenital diaphragmatic hernia required herniorrhaphy in the first 8 hours of life. Extracorporeal membrane oxygenation (ECMO) was employed in 7 after they met local criteria predictive of 95% mortality. These criteria were an alveolar-postductal arterial oxygen gradient greater than 600 mm Hg for 12 hours or hemodynamic instability. Four of these 7 patients had unremitting hypoxemia after herniorrhaphy (no "honeymoon" period), 3 of whom survived. One additional patient died, producing a mortality of 29%. ECMO used for 68 to 241 hours (mean, 163 hours) provided reliable oxygenation in all. Deaths resulted from disseminated intravascular coagulation and bleeding, and bleeding and pulmonary failure after ligation of a patent ductus arteriosus. Complications occurred in 6 patients and included bleeding (3), hernia recurrence (3), and air embolism (1). Follow-up ranging from 1 year to 6 years after discharge of the 5 survivors shows normal growth and development in 4. The reported mortality without ECMO following congenital diaphragmatic herniorrhaphy in the first 8 hours of life ranges between 60 and 80%. While bleeding may present problems, survival of newborns with refractory hypoxemia after diaphragmatic repair has improved with ECMO.

Development of extrauterine fetal incubation system using extracorporeal membrane oxygenator

Despite the recent progress in perinatal medicine, it is still difficult to manage the extremely immature newborn. A new extrauterine incubation system has been developed using 14 goat fetuses. The goat fetus is surrounded by artificial amniotic fluid and is connected to an extracorporeal membrane oxygenator. The blood is drained from the umbilical arteries and returned to the umbilical vein. The perfused blood is recirculated and ventilated with a mixture of O2, N2, and CO2 gases to obtain a PO2 of 30-35 mm Hg and a PCO2 of 30-35 mm Hg in the umbilical venous blood. Fetal heart rate, blood pressure, electroencephalogram, and several movement parameters are continuously recorded by the polygraph. With this system, the fetuses can be kept under fairly stable physiological conditions for periods up to 165 h. This improved system might therefore become a useful method to manage the ill fetuses and newborns.

Extracorporeal membrane oxygenation in pediatric respiratory failure

ECMO is capable of safely supporting respiration and circulation in newborns with severe respiratory failure and a moribund clinical presentation. The results thus far suggest that term infants with respiratory failure are the best candidates for ECMO, with a survival rate of 83 per cent. Infants under 35 weeks' gestation have a very high incidence of intracranial hemorrhage. Consequently, we do not currently accept them for ECMO treatment. The outcome of the survivors is largely determined by the clinical condition before ECMO and by major complications. Research must be directed toward cost effectiveness, timing and earlier use, alternative vascular access, cannula and circuit design, and expanded indications.

Extracorporeal membrane oxygenation (ECMO) in neonatal respiratory failure. 100 cases

Extracorporeal membrane oxygenation (ECMO) was used in the treatment of 100 newborn infants with respiratory failure in three phases: Phase I (50 moribund patients to determine safety, efficacy, and risks); Phase II (30 high risk patients to compare ECMO to conventional ventilation); and Phase III (20 moderate to high risk patients, the current protocol). Seventy-two patients survived including 54% in Phase I, 90% in Phase II, and 90% in Phase III. The major complication was intracranial bleeding, which occurred in 89% of premature infants (less than 35 weeks) and 15% of full-term infants. Best survival results were in persistent fetal circulation (10, 10 survived), followed by congenital diaphragmatic hernia (9, 7 survived), meconium aspiration (44, 37 survived), respiratory distress syndrome (26, 13 survived), and sepsis (8, 3 survived). There were seven late deaths; in follow-up, 63% are normal or near normal, 17% had moderate to severe central nervous system dysfunction, and 8% had severe pulmonary dysfunction. ECMO is now used in several neonatal centers as the treatment of choice for full-term infants with respiratory failure that is unresponsive to conventional management. The success of this technique establishes prolonged extracorporeal circulation as a definitive means of treatment in reversible vital organ failure.

Pulmonary hypertension postventricular septal defect repair treated by extracorporeal membrane oxygenation

Severe pulmonary hypertension complicating the correction of congenital cardiac defects is an unusual cause of early postoperative mortality. We present a case of a nine-month-old infant who developed paroxysmal pulmonary hypertension associated with severe hypoxemia after the successful repair of a large perimembranous ventricular septal defect (VSD). The pulmonary hypertension was refractory to all medical and pharmacologic therapy but was successfully treated with extracorporeal membrane oxygenation (ECMO). On ECMO, pharmacologic support was removed, pulmonary artery pressure reduced, and ECMO support withdrawn. To date, ECMO has been applied to pulmonary hypertension of the newborn, neonatal respiratory insufficiency, and for primary cardiac pump failure. Our experience with this case leads us to believe it is an effective therapy for acute pulmonary hypertension occurring after the repair of congenital cardiac anomalies.

Extracorporeal membrane oxygenation experience at the University of Pittsburgh

Between January, 1981, and May, 1985, 33 infants suffering from acute cardiorespiratory failure were treated with extracorporeal membrane oxygenation (ECMO) when all other forms of conventional management had failed. Only the patients with respiratory failure that was thought to be reversible were treated. Prolonged conventional respiratory management (more than five days) was considered a contraindication to ECMO support because of irreversible damage to the lungs caused by the barotrauma associated with conventional ventilation. Eighteen of the 33 patients (54%) survived and were discharged from the hospital. Patients with congenital diaphragmatic hernia had a high incidence of fatal bleeding complications (8 of 14). Good results were obtained in the newborns with persistent fetal circulation and meconium aspiration syndrome. We conclude that ECMO markedly improves the survival of newborns with severe respiratory failure who would have a mortality close to 100% with conventional respiratory management.

Dense pulmonary opacification in neonates treated with extracorporeal membrane oxygenation

Chest radiographic findings in three neonates with respiratory failure secondary to meconium aspiration treated with extracorporeal membrane oxygenation (ECMO) are described. The degree of pulmonary opacification on the chest radiographs failed to correlate with the patients' clinical status as measured by the arterial oxygen levels but correlated well with the peak airway pressure (PAP) and continuous positive airway pressure (CPAP) settings on the mechanical ventilator. Because a variable portion of the arterial blood oxygenation is performed by the extracorporeal membrane oxygenator and unusually large fluctuations in airway pressure settings can occur in these patients while on ECMO, it is important to realize that the chest radiograph may not be an accurate predictor of the patients' clinical status.

Improving survival in the treatment of congenital diaphragmatic hernia

Thirty-two infants were treated for congenital diaphragmatic hernia at our institution from 1979 to 1984. Eight were in no or minimal distress at birth and had operative intervention when they were more than 24 hours old; survival was 100%. The remaining 24 neonates required immediate intubation and ventilation followed by operation at less than 12 hours of age. Overall survival was 54%; survival was 31% (4 of 13 patients, Group 1) in the first three years of the series and 82% (9 of 11 patients, Group 2) in the last three years (p less than 0.001). Apgar score, gestational age, birth weight, and incidence of associated congenital heart disease were equal for the two groups (all, p greater than 0.05). The two groups also were examined with reference to alveolar-arterial oxygen differences P(A-a)O2 and mean airway pressure (MAP). The best preoperative P(A-a)O2 was greater than 600 mm Hg for 7 neonates in Group 1 and 6 in Group 2, and survival was 0% and 71%, respectively (p less than 0.001). Infants with a postoperative MAP of 13 cm H2O or greater had a higher mortality (100% in Group 1 and 50% in Group 2, p greater than 0.05). Our treatment protocol was studied to determine those methods related to improved survival. Sodium bicarbonate infusion was used earlier in Group 2 as a prophylaxis against persistent fetal circulation (PFC) (p greater than 0.05). The incidence of severe PFC dropped from 85 to 54% (p greater than 0.05). Higher ventilator rates rather than pressures were used to achieve equally effective ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal membrane oxygenation for newborn respiratory failure

Respiratory failure is the leading cause of death in the newborn. Conventional therapy is very successful with 80% of infants weaned from ventilatory support. For neonates with severe respiratory failure, unresponsive to maximal medical therapy, extracorporeal membrane oxygenation (ECMO) offers an alternative means of management. Venoarterial bypass is achieved by cannulating the right atrium via the internal jugular vein and the aortic arch via the right common carotid artery. A 5-inch roller pump is used to circulate the blood through a 0.4 or 0.8 m2 silicone membrane lung. Management includes heparinization, intravenous alimentation, antibiotic coverage, and reduction of FiO2 and airway pressure. Thirty infants aged 12 to 186 hours were placed on ECMO. Each met strict criteria designed to predict greater than 90% mortality. Time on bypass ranged from 37 to 250 hours. Success, defined by weaning from ECMO and ventilatory support, was achieved in 23. Twenty-one remain alive; 18 have excellent outcome with normal growth and development although follow-up is short (1 to 19 mos). These results corroborate reports from the pioneers of the technique and further support the use of ECMO for neonates with respiratory failure unresponsive to conventional therapy.

Long-term follow-up of infants and children treated with extracorporeal membrane oxygenation (ECMO): a preliminary report

Extracorporeal Membrane Oxygenation (ECMO) has been used clinically as a life-saving treatment modality in infants and children who are dying of respiratory insufficiency. From 1973 to 1980 47 children less than 10 years of age were treated in a study to determine the feasibility and effectiveness of ECMO in the pediatric population. Despite a predicted mortality of 90% or greater, 24 patients survived. Eighteen of those patients have been seen in long-term follow-up. Thirteen patients (72%) demonstrate basically normal growth and development. Five patients (28%) have definite handicaps which are severe in two. Despite ligation of one common carotid artery and systemic heparinization, the risk of intracranial hemorrhage and/or neurodevelopmental problems appears to be no higher in this ECMO group and may even be lower than in the high-risk population treated with conventional therapy. The incidence of chronic respiratory problems, especially bronchopulmonary dysplasia, is zero in this group of patients. Only one patient (4%) has a defect that lateralizes to the right hemisphere which may have been affected by ligation of the carotid artery. Further study is required; however, it appears that ECMO offers life-saving intervention without increasing morbidity in select children with severe respiratory insufficiency.

Venovenous perfusion in ECMO for newborn respiratory insufficiency. A clinical comparison with venoarterial perfusion

Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in the treatment of newborns less than 1 week of age and greater than 2000 gm birthweight with respiratory failure resistant to current medical and surgical management. While VA ECMO supports the heart as well as the lungs, it has the disadvantage of requiring carotid artery ligation and the possibility of perfusing air bubbles or particles into the arterial tree. We have treated 11 newborns with respiratory failure with venovenous (VV) ECMO returning the oxygenated blood to a cannula in the distal iliac vein. We compared these patients with 16 patients treated during the same period of time with VA ECMO. Three of the 11 VV patients required conversion to VA ECMO because of inadequate oxygenation and unstable hemodynamic situations. Ten of the 11 VV patients survived. Eleven of the 16 VA patients survived. The better survival in these patients treated with VV ECMO is attributed to their more favorable initial condition compared to patients treated with VA ECMO. The disadvantages of VV ECMO include a longer operative time to place the cannulas, groin wound problems, and persistent leg swelling along with the necessity to convert some patients to VA ECMO. Although this experience demonstrates that newborns with severe respiratory failure can be supported with VV ECMO, the complications and lack of practical advantages over VA lead us to recommend VA ECMO for routine clinical use at present.

The early evaluation of survivors after extracorporeal membrane oxygenation for neonatal pulmonary failure

Excluding mortality data, there is little information regarding patients' development after extra corporeal membrane oxygenation (ECMO). In six of nine neonates surviving ECMO for predictably fatal pulmonary failure, examination 15 to 21 months afterward showed (1) physical growth and development, normal in six; (2) chest x-ray, normal pulmonary parenchyma; (3) average arterial blood gases, PO2 80, Pco2 35, pH 7.35; (4) echocardiogram, normal, without evidence of pulmonary hypertension; (5) cerebrovascular dopplers, normal ophthalmic artery flow in five patients, retrograde in one; (6) CT scan, EEG, neurologic survey, normal in five, cerebral atrophy in one patient who had an air embolus during decannulation; (7) psychologic examination, normal in all. This early evaluation of ECMO survivors should encourage its further application in those newborns who would otherwise die.

Alveolar-arterial oxygen gradients versus the Neonatal Pulmonary Insufficiency Index for prediction of mortality in ECMO candidates

Current selection criteria necessary for intelligent application of extracorporeal membrane oxygenation (ECMO) in hypoxic neonates remains controversial. Both the Neonatal Pulmonary Insufficiency Index (NPII) and serial alveolar-arterial oxygenation gradient measurements (A-a)Do2 have been recommended. Accordingly, an analysis of 50 consecutive severely hypoxic neonates was undertaken to assess the predictive value of (A-a)Do2 determinations and NPII in discriminating survivors from non-survivors. These infants with meconium aspiration syndrome (MAS), congenital diaphragmatic hernia (CDH), or persistent pulmonary hypertension of the newborn (PPHN) required maximum mechanical ventilation for hypoxia. Pharmacologic manipulation of pulmonary vascular resistance was attempted in 83%. If postductal (A-a)Do2 remained greater than or equal to 620 torr despite 12 hours of maximum medical therapy, mortality was 100%; however, 35% of nonsurvivors were unfortunately excluded. (A-a)Do2 greater than or equal to 600 torr for 12 hours demonstrated 93.8% mortality, and only 12% of all mortalities were thus excluded. Among nonsurvivors successfully hyperventilated, the NPII could not predict mortality. Ideal selection criteria must exclude those who would otherwise survive without ECMO, yet allow early accurate identification of the neonate certain to die. It would appear that serial (A-a)Do2 determinations best permit this identification and thus orderly application of ECMO.

Creation and repair of diaphragmatic hernia in the fetal lamb: lung development and morphology

Left-sided diaphragmatic hernias were created in 26 lambs at about 78 days' gestation and repaired at 106 to 124 days' gestation. Nine of these lambs were delivered at term and lived much longer than the nonrepaired lambs delivered at term. The normal development of the fetal lamb lung is compared and contrasted with the development of the lung after creation of a diaphragmatic hernia and also with the changes in morphology resulting from in-utero repair. Creation of a diaphragmatic hernia resulted in marked delay in the development of alveoli and at term the lung had small, thick-walled terminal air-spaces with few capillaries and no true alveoli when compared with the thin-walled alveoli in normal lungs. Another striking feature was an apparent increase in the frequency of type II alveolar cells in diaphragmatic hernia lungs. In-utero repair of the diaphragmatic hernia resulted in a more normal appearance with true alveoli developing by term, although capillaries appeared to be less numerous and type II cells more numerous than in normal lungs. Surprisingly, there appears to be little difference between the left and right lungs in lambs with diaphragmatic hernia.

Creation and repair of diaphragmatic hernia in the fetal lamb: techniques and survival

Diaphragmatic hernias were created in 54 fetal lambs at 72 to 82 days gestation via a left thoracotomy. The diaphragmatic hernia was repaired in 30 lambs at 106 to 123 days gestation, and 14 of these lambs subsequently aborted. The majority of those surviving to term were delivered for survival. Four lambs with an unrepaired diaphragmatic hernia were intensively resuscitated at delivery and their diaphragmatic hernias repaired; survival in these lambs ranged from 20 minutes to 89 hours. Nine lambs with repaired diaphragmatic hernia were resuscitated following delivery; survival times ranged from one hour, 45 minutes to 123 days, with three lambs surviving to be sacrificed at 43, 62, and 123 days. Three of the lambs that died before sacrifice, died of causes unrelated to their lung function. These results show that in-utero repair of the diaphragmatic hernia in the fetal lamb results in improved survival. We feel, however, that direct application of these results in humans would be premature.

The mortality of congenital diaphragmatic hernia. Is total pulmonary mass inadequate, no matter what?

Much progress has been made over the past 20 years in neonatal surgery, but the mortality rate in cases of congenital diaphragmatic hernia (CDH) for babies presenting in the early hours of life has remained high. We have reviewed our experience with special reference to 40 autopsied patients. Hypoplastic lungs were seen in all patients. When the ratio of observed combined lung weight to the expected combined lung weight is calculated, the result is 0.33 +/- 0.17 when the expected lung weights are calculated from the babies' birth weight; and 0.36 +/- 0.17 when the expected lung weights are calculated from the gestational age. In all patients with high ratios, extensive pneumonia was confirmed. Those patients with pneumonia were eliminated from the calculations. We cannot state unequivocably that hypoplasia of both lungs is the cause of death in all patients with CDH. We can affirm that, in our experience, hypoplasia is present and is probably a major factor in the high mortality rate.

Venovenous extracorporeal membrane oxygenation in neonates with respiratory failure

Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in support of neonates with respiratory failure but requires right common carotid artery ligation. While no short-term neurologic complications have resulted from neonatal carotid ligation, late complications may occur. For both VA ECMO and venovenous (VV) ECMO, blood is drained from the right atrium via a right internal jugular cannula, oxygenated by a membrane lung, and returned to the patient. VV ECMO spares the carotid by perfusing the oxygenated blood into a vein. VV ECMO gave total respiratory support to three neonates with respiratory failure and each infant survived. In comparison with three similar VA ECMO patients, the VV patients required higher ECMO circuit flow rates and had lower systemic arterial Po2s. Length of time on ECMO, length of hospital stay, and neurologic outcome were similar in the VV and VA patients. Differences among the patients were related to their primary disease rather than to the mode of ECMO support. The VV patients had cannulation of the femoral vein for perfusion of oxygenated blood. Late complications may occur from femoral vein ligation as well as from carotid ligation so long-term follow-up is needed to assess these two ECMO techniques.