Extracorporeal membrane oxygenation for cardiac support in children

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) support for cardiac failure has been used in children since 1981 at the Children's Hospital in Pittsburgh. Most children required support after cardiac operations. Recently, however, a larger number of patients with decompensated cardiomyopathy or myocarditis have been supported with ECMO, which was used as a bridge to transplantation in most. METHODS: From 1981 to 1994, 68 children were placed on ECMO for cardiac support. RESULTS: The overall survival for the entire time period was 38%, with the more recent experience survival increased to 47%. In 14 children, ECMO was used as a bridge to transplantation, with 9 children receiving a heart transplant and 7 long-term survivors. Extracorporeal membrane oxygenation has also been used to resuscitate 11 children after sudden cardiac arrest, with a long-term survival of 53%. CONCLUSIONS: We conclude that ECMO support for severe cardiac failure is effective. Patient selection and the use of heart transplantation for intractable heart failure have improved the overall survival.     

Extracorporeal membrane oxygenation for nonneonatal pulmonary and multiple-organ failure

PURPOSE: Extracorporeal membrane oxygenation (ECMO) is an accepted therapy for neonatal pulmonary failure, but its use in older children has been controversial. METHODS: Over 13 years, 55 children (ages, 3 months to 16 years) were treated with venoarterial or venovenous ECMO. The diagnoses were viral, bacterial, or fungal pneumonia (24 patients); hydrocarbon or gastric aspiration (n = 10); adult respiratory distress syndrome (ARDS), sepsis, near drowning (n = 15); pulmonary contusion (n = 2); airway obstruction (n = 3); pulmonary artery foreign body (n = 1). Pre-ECMO blood gas ranges (and means) were PO2, 21 to 100 (n = 44); PCO2, 23 to 125 (n = 72); pH, 6.81 to 7.55 (n = 7.11). RESULTS: All patients received inotropes, and 38 required dialysis or hemofiltration. ECMO was used for 20 to 613 hours (mean, 196 hours). Patient complications included cannulation site hemorrhage (n = 40), renal failure (n = 10), seizures (n = 8), stroke (n = 3), and cerebral hemorrhage (n = 2). Twenty-five patients (45%) survived ECMO, with 21 long-term survivors (10 pneumonia, five aspiration, five ARDS, one pulmonary contusion), five of whom have mild to moderate neurological deficit. Patients with combinations of pulmonary, cardiac, and renal failure, or sepsis did not survive. CONCLUSIONS: ECMO is an invasive technique that can be life saving in the child with isolated respiratory failure, but its usefulness in children with multiorgan failure is less certain.     

The present state of ECMO for newborn infants and children

Venoarterial extracorporeal membrane oxygenation (V-A ECMO) is considered to provide not only lung support but also cardiac assist to acute cardiac or pulmonary failure of the newborn infants and children. However, an excessive "LUNG REST" strategy may lead to myocardial hypoxic damage in patients without PDA or any left-to-right cardiac shunt. The estimation of pulmonary vascular resistance and cardiac contractility, which is independent of preload, afterload and heart rate, is very important for the selection of ECMO, vascular access and weaning strategy from ECMO. Introduction of new ECMO techniques including heparin-coated or FUT-175 infused circuit, ECMO into double-lumen venous cannulas, the other therapies, such as artificial surfactant therapy, high frequency oscillation or inhaled nitric oxide can affect our approaches toward patients with severe cardiorespiratory failure.     

Pediatric ECMO for pulmonary support: experience from 12 cases

Extracorporeal membrane oxygenation (ECMO), which can be described as treatment with a modified heart-lung machine over a prolonged period of time, is used to support patients with life-threatening but potentially reversible lung failure. ECMO by itself does not cure the patient but gives the lungs a chance to rest while awaiting spontaneous or therapeutic healing. The method is well documented in the neonatal age group. In the non-neonatal age group, however, experience is less extensive. This report of the initial result from our hospital with 12 non-neonatal pediatric cases shows high survival and low morbidity. Nine of the 12 patients were able to be weaned from ECMO (75% survival) and 8 of these 9 patients were long-term survivors. Medium time on the ventilator after discontinuation of ECMO was 4 days. At follow-up, all long-term survivors had no signs of neurological or pulmonary sequelae. These encouraging results point to the fact that ECMO should be considered more often in cases of life-threatening but potentially reversible pulmonary failure.     

Cardiac arrest before repair or extracorporeal membrane oxygenation cannulation does not increase the mortality rate associated with congenital diaphragmatic hernia

Despite recent advances in the management of high-risk congenital diaphragmatic hernia (CDH), mortality remains high. Deaths occur later because infants with inadequate pulmonary parenchyma are treated aggressively but eventually succumb to respiratory failure. In an attempt to identify absolute predictors of mortality the authors examined retrospectively their experience with CDH to determine if cardiac arrest before repair or initiation of extracorporeal membrane oxygenation (ECMO) invariably increased mortality. The authors reviewed the charts of 119 infants who had high-risk CDH treated between 1981 and 1994. They were divided into two groups: those that suffered cardiopulmonary arrest (CA, n = 21) before CDH repair or ECMO cannulation; and those that did not (NCA, N = 98). The authors compared mortality rate, ventilatory parameters, duration of, and complications on ECMO, as well as length of hospitalization between groups. Twenty-one infants suffered CA before initiation of ECMO support or CDH repair. Three infants (14%) suffered CA before arrival at our institution; seven (33%) after, and 11 (53%) both before and after arrival. There was no difference between the CA and NCA groups in terms of birth weight, gestational age, race and gender mix, or pregnancy and delivery complications. Five-minute Apgar scores were significantly lower in the CA group compared with the NCA group (4.6 v 5.7, P = .04). The CA group also had significantly worse "best postductal" blood gas and ventilatory parameters. There was no significant difference in length of hospitalization, time from admission to ECMO cannulation or CDH repair, or incidence of complications while on ECMO between the two groups. CA cases were more likely to require ECMO support (76% v 48%, P = .02) and to stay on ECMO for a more prolonged period than NCA cases (5.8 v 3.8 days, P = NS). However, there was no significant difference in overall survival between CA and NCA cases (43% v 51%, P = NS). Cardiopulmonary arrest before repair of CDH or ECMO cannulation is not a univariate independent predictor of mortality and therefore should not preclude these high-risk infants from maximum intensive care therapy, including ECMO cannulation.     

Current status of heart assist and replacement in Taiwan

The first clinical application of intraaortic balloon pumps (IABP) in Taiwan was in 1976 to treat post-cardiotomy cardiogenic shock. It is now the most commonly used circulatory assist. From 1991 to 1995, 186 patients received IABP support with an overall mortality rate 41.9%. The male patients had the best survival rate, 67%, after coronary artery bypass grafting. The first extracorporeal membrane oxygenation (ECMO) was in 1987 to treat intractable heart failure caused by severe acute rejection after heart transplantation. Because of poor outcome, patients only received ECMO sporadically during the past years. From November 1994 to November 1995, 30 patients received ECMO support with 50% of them eventually weaned from ECMO and 27% discharged. For short-term support or emergency rescue, ECMO was a good choice. When long-term support was required, the ventricular assist device (VAD) was a more suitable assist. One patient who received Thermedics VAD developed right heart failure and finally died of sepsis and multiple organ failure. VAD should be implanted before the secondary organ failure. The first successful clinical heart transplantation in Taiwan was performed on July 17, 1987. From 1991 to 1995, 102 patients underwent heart transplantation. The operative mortality was 3.9%, and the 1 and 5 year actuarial survival rates were 86 +/- 3% and 77 +/- 5%, respectively. To improve the success rate of clinical heart transplantation, organ donation should be encouraged.     

Extracorporeal support for intractable cardiorespiratory failure due to meningococcal disease

BACKGROUND: Meningococcal disease is still associated with considerable mortality, despite the use of early antibiotics and management in specialised intensive care units, due principally to early refractory myocardial depression and hypotension as well as severe acute respiratory distress syndrome. Extracorporeal membrane oxygenation (ECMO) is a complex technology that uses a modified "heart-lung" machine to provide temporary cardiac and respiratory support. We reviewed the UK and Australian experience of the use of ECMO in patients with refractory cardiorespiratory failure due to meningococcal disease. METHODS: The records from all 12 known patients supported with ECMO for meningococcal disease in the UK and Australia since 1989 were reviewed. FINDINGS: 12 patients (aged 4 months to 18 years, median 26 months) with meningococcal disease received ECMO over 8 years. In seven patients, ECMO was required early for cardiac support for intractable shock within 36 h of admission to intensive care. In the other five patients, ECMO was indicated for respiratory failure due to severe adult respiratory distress syndrome, which tended to occur later in the disease. The paediatric risk of mortality score ranged from 13 to 40 (median 29, median predicted risk of mortality 72%). Six of the 12 patients required cardiopulmonary resuscitation before ECMO and the other six were deteriorating despite maximal conventional therapy. Overall, eight of the 12 patients survived, with six leading functionally normal lives at a median of 1 year (range 4 months to 4 years) of follow-up. INTERPRETATION: ECMO might be considered to support patients with intractable cardiorespiratory failure due to meningococcal disease who are not responding to conventional treatment.     

Circulatory support with pneumatic paracorporeal ventricular assist device in infants and children

BACKGROUND: Mechanical circulatory support in intractable heart failure in children has been limited to centrifugal pumps and extracorporeal membrane oxygenation: Since 1990 small adult-size pulsatile air-driven ventricular assist devices "Berlin Heart" (VAD) and, since 1992 miniaturized pediatric VAD (12, 15, 25, 30 mL pumps), have been used in our institution. Since 1994 the blood-contacting surfaces of the device system have been heparin-coated. In this report the experiences with VAD support in 28 children are presented. METHODS: In 28 children-ages between 6 days and 16 years-the Berlin Heart VAD has been applied for periods of between 12 hours and 98 days (mean, 16.9 days) aiming at keeping the patient alive and allowing for recovery from shock sequelae until later transplantation or myocardial recovery. There were three groups. Group I: with primary intention of "bridge-to-transplantation" in various forms of cardiomyopathy (n = 13) or chronic stages of congenital heart disease (n = 5). Group II: "Rescue" in intractable heart failure early after corrective surgery for congenital heart disease (n = 4) or in early graft failure after a heart transplantation (n = 1). Group III: "Acute myocarditis" (n = 5) aiming at either myocardial recovery or transplantation. Twelve were brought to the operating room under cardiac massage and 25 had been on the respirator for more than 24 hours. RESULTS: Twelve patients died on the system from sequelae of profound shock-multiorgan failure, sepsis, loss of peripheral circulatory resistance-or from hemorrhagic complications (n = 4) or brain death (n = 1). Thirteen patients (groups I and III) were transplanted after support periods of between 3 and 98 days with 7 long-term survivors living now up to 7.5 years (mean, 4.4 years). Three patients (groups II and III) were weaned from the system with two long-term survivors (both in group III). There were no patients in group II who survived and the "rescue" indication has been discarded for VAD since 1992. Such patients are since treated by extracorporeal membrane oxygenation (ECMO) in our institution. Out of the 8 patients placed on VAD during 1996 and 1997, 7 were successfully supported until transplantation or weaning. Thirteen patients were extubated and mobilized on the system. Whereas with the earlier systems thrombi in the blood pumps were seen in 15 instances and 2 patients suffered from thromboembolic complications, no thrombotic events occurred with the heparin-coated systems. CONCLUSIONS: After accumulating clinical experience and several technical improvements since 1990 the use of the pediatric Berlin Heart VAD has matured into a reliable and safe system to keep patients with otherwise intractable heart failure alive until complete myocardial recovery is reached or transplantation becomes feasible. Whereas heart failure early after cardiac operation is now primarily treated by ECMO, acute myocarditis appears to be a promising precondition for complete cardiac recovery during VAD support.     

Use of glucagon in the treatment of severe contractile insufficiency of the myocardium

Glucagon hydrochloride has been used to treat severe contractile insufficiency of the myocardium. The drug was administered to cardiopathic patients who had been admitted to the intensive care unit. Results in the various groups examined were satisfactory, particularly in cases of patients with valve diseases and with chronic pulmonary heart and cardiac insufficiency recalcitrant to digitalis therapy. No important side-effects were noted.     

Improved survival in congenital diaphragmatic hernia with evolving therapeutic strategies

OBJECTIVE: To compare the survival rates for 3 therapeutic eras, each using different treatment strategies for the management of newborns with congenital diaphragmatic hernia (CDH). DESIGN: Retrospective review of all infants with CDH from 1970 through 1997. SETTING: Tertiary care children's hospital. PARTICIPANTS: A total of 203 newborns with CDH. INTERVENTIONS: Extracorporeal membrane oxygenation (ECMO) was performed with arterial and venous cannulation connected to a membrane oxygenatorroller pump perfusion apparatus, using systemic heparinization. Delayed operative therapy involved operative repair 2 to 5 days after birth using preoperative ventilation support only. Since 1970, 203 newborns with CDH were managed in 3 therapeutic eras: era 1 (1970-1983, 102 patients) was immediate CDH repair with postoperative ventilator and pharmacologic support; era 2 (1984-1988, 45 patients) was immediate repair with postoperative ventilator support (18 patients), immediate ECMO with CDH repair on ECMO (4 patients), or immediate repair with postoperative ECMO (23 patients); and era 3 (1989-1997, 56 patients) was immediate ECMO with repair on ECMO (23 patients), immediate repair with postoperative ECMO (9 patients), or delayed (2-5 days) CDH repair (24 patients). MAIN OUTCOME MEASURES: Survival, defined as discharge from the hospital, and morbidity. RESULTS: Survival was 42% (43/102 patients) in era 1, 58% (26/45 patients) in era 2, and 79% (44/56 patients) in era 3 (P<.02 vs eras 1 and 2). In era 3, the survival for immediate ECMO with repair on ECMO was 57% (13/23 patients), 89% (8/9 patients) for immediate repair with postoperative ECMO, and 96% (23/24 patients) for delayed repair. Eight late deaths were caused by pulmonary hypertension (1 death), sudden infant death syndrome (1 death), and other causes (6 deaths). Morbidity in survivors included mild neurologic deficit (5 patients) and pulmonary disease (3 patients). CONCLUSION: These data demonstrate a significant improvement in survival in CDH with preoperative ECMO and with delayed repair with and without ECMO support and suggest that immediate repair of CDH without the availability of ECMO support should be abandoned.     

Improved results in patients who have congenital diaphragmatic hernia using preoperative stabilization, extracorporeal membrane oxygenation, and delayed surgery

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.     

Risk of reoperative valve replacement for failed mitral and aortic bioprostheses

BACKGROUND: One factor influencing the choice of mechanical versus bioprosthetic valves is reoperation for bioprosthetic valve failure. To define its operative risk, we reviewed our results with valve reoperation for bioprosthetic valve failure. METHODS: Records of 400 consecutive patients having reoperative mitral, aortic, or mitral and aortic bioprosthetic valve replacement from January 1985 to March 1997 were reviewed. RESULTS: Reoperations were for failed bioprosthetic mitral valves in 219 patients, failed aortic valves in 153 patients, and failed aortic and mitral valves in 28 patients. Including 26 operations (6%) for acute endocarditis, 153 operations (38%) were nonelective. One hundred nine patients (27%) had other valves repaired or replaced, and 72 (18%) had coronary bypass grafting. The incidence of death in the mitral, aortic, and double-valve groups was respectively, 15 (6.8%), 12 (7.8%), and 4 (14.3%); and the incidence of prolonged postoperative hospital stay (>14 days) was, respectively, 57 (26.0%), 41 (26.8%), and 8 (28.6%). Only 7 of 147 patients (4.8%) having elective, isolated, first-time valve reoperation died. Multivariable predictors (p < 0.05) of hospital death were age greater than 65 years, male sex, renal insufficiency, and nonelective operation; and predictors of prolonged stay were acute endocarditis, renal insufficiency, any concurrent cardiac operation, and elevated pulmonary artery systolic pressure. CONCLUSIONS: Reoperative bioprosthetic valve replacement can be performed with acceptable mortality and hospital stay. The best results are achieved with elective valve replacement, without concurrent cardiac procedures.     

Postoperative junctional ectopic tachycardia

PURPOSE: To report the management of junctional ectopic tachycardia after cardiac surgery in an infant. Postoperatively, the patient suffered profound cardiac decompensation secondary to the accelerated rhythm and required extracorporeal membrane oxygenation (ECMO) for haemodynamic support. CLINICAL FEATURES: A 14-day-old, 3.5 kg boy exhibited junctional ectopic tachycardia after cardiopulmonary bypass. Left atrial pressure was 25-28 mmHg. No impact on the tachycardia was seen after rapid overdrive atrial pacing or after 20 micrograms fentanyl i.v., 45 micrograms digitalis, 100 mg magnesium or procainamide (loading dose 15 mg, then 30 mg.kg-1.min-1). Active cooling decreased the nasopharyngeal temperature to 35.2 degrees C, when the heart rate decreased below 180 bpm with a left atrial pressure of 8-10 mmHg. Dopamine (2 micrograms.kg-1.min-1) and dobutamine (5 micrograms.kg-1.min-1) were added to improve the cardiac output. Sodium nitroprusside (0.25 to 1 microgram.kg-1.min) maintained the systolic pressure < 100 mmHg. On arrival in ICU, heart rate increased to 200 bpm. The patient received cardiac massage for severe hypotension 75 min after surgery. Emergency ECMO was instituted for circulatory support. Procainamide, digoxin, dopamine, dobutamine, sodium nitroprusside and hypothermia were continued. Sinus rhythm resumed on the first postoperative day, but procainamide and induced hypothermia at 34 degrees C were maintained for 36 hr after normalization of the rhythm to prevent recurrence of the tachycardia. Total duration of ECMO was three and a half days. Recovery was uneventful. CONCLUSION: The use of ECMO, as a first line of defence, is suitable for the emergency support of patients with JET because of the ease of support of circulation and precise control of hypothermia.     

Inhaled nitric oxide in congenital hypoplasia of the lungs due to diaphragmatic hernia or oligohydramnios

OBJECTIVE: We determined whether inhaled nitric oxide (NO) could improve systemic oxygenation in human neonates with hypoplastic lungs. METHODS: A multicenter nonrandomized investigation was performed to study the efficacy of short-term NO inhalation. Inhaled NO was administered at 80 ppm to nine neonates without evidence of structural cardiac disease by echocardiography. Lung hypoplasia was due to congenital diaphragmatic hernia (CDH) in eight patients and to oligohydramnios in one patient. A total of 15 trials of NO inhalation were performed in these nine patients. Eight trials in seven patients were performed before extracorporeal membrane oxygenation ((ECMO); one patient had two trials) and seven trials were performed in five patients after decannulation from ECMO (two patients had two trials each). RESULTS: NO inhalation before ECMO did not change postductal PaO2 (42 +/- 3 mmHg vs 42 +/- 4 mmHg), oxygen saturation (SpO2; 89% vs 88%) or oxygenation index (31 +/- 4 cm H2O/torr vs 31 +/- 4 cm H2O/torr) for the group. All patients required ECMO support, which lasted from 5 to 17 days (mean 9). After decannulation from ECMO, NO inhalation increased postductal PaO2 from a median of 56 mm Hg (range 41 to 94) to a median of 113 mm Hg (range 77 to 326), P < .05. It decreased the oxygenation index from a median of 23 cm H2O/torr (range 11 to 7) to a median of 11 cm H2O/torr (range 4 to 21), P < .05. It increased SpO2 from 91% to 96% (P < .05) and pH from 7.48 +/- .03 to 7.50 +/- .03. CONCLUSION: In our patients with hypoplastic lungs, inhaled NO was effective only after ECMO. This could be due to maturational changes such as activating the endogenous surfactant system. Inhaled NO may be effective in neonates with hypoplastic lungs who have recurrent episodes of pulmonary hypertension after ECMO, even if they were previously unresponsive.     

Alteration in diaphragmatic function during cardiac insufficiency: potential pharmacology modulation

Respiratory muscle dysfunction has been demonstrated in several clinical situations including chronic respiratory disease, such as chronic obstructive pulmonary disease, as well as cardiac insufficiency. In the latter case, respiratory muscle dysfunction has been demonstrated in acute situation (cardiogenic shock) and in chronic cardiac insufficiency. In the former case, it has been shown in an animal model that respiratory muscle dysfunction could influence markedly the outcome of cardiogenic shock. In chronic cardiac insufficiency histologic, biochemical and contractile abnormalities of the respiratory muscles have been demonstrated in an animal model as well as in humans. These alterations may account, at least in part, for the sensation of dyspnea that these patients encountered. Finally, several pharmacological agents such as angiotensin-converting enzyme inhibitors have been shown to restore muscle abnormalities observed during chronic cardiac insufficiency.     

Experimental antitumour activity of S 16020-2 in a panel of human tumours

OBJECTIVE: To compare the effects of inhaled nitric oxide (NO) and extracorporeal membrane oxygenation (ECMO) on oxygenation, hemodynamics, and lymphatic drainage in an oleic acid lung injury model in sheep. DESIGN: Prospective, randomized study. SETTING: Animal research laboratory. ANIMALS: Thirty female sheep, weighing 35 to 40 kg. INTERVENTIONS: Acute lung injury was induced by central venous injection of oleic acid (0.5 mL/kg body weight). A chronic lymph fistula had been prepared through a right thoracotomy 3 days before the experiment. Animals were assigned randomly to the NO group (n = 14) or the ECMO group (n = 16). When a lung injury score of > 2.5 was achieved, the animals were given NO in dosage increments of 2, 5, 10, 20, and 40 parts per million (ppm), or placed on ECMO with an FIO2 of 0.21 (ECMO-21) and then 1.0 (ECMO-100) at the oxygenator. Mechanical ventilator parameters were kept constant to isolate the effects of NO and ECMO on systemic and pulmonary hemodynamics, cardiac output, oxygenation parameters, lymph/plasma protein ratio, and lymph flow. Measurements and calculations were performed after 1 hr at each individual step of NO concentration or FIO2. MEASUREMENTS AND MAIN RESULTS: In the ECMO group, PVRI and MPAP did not change and were significantly different from the NO group. In the NO group, there was a dose-dependent decrease in venous admixture, maximal at 10 ppm NO and decreasing from 40 +/- 6% to 23 +/- 10% (p < .05). This decrease was significantly different from the ECMO group, where there was no change. There was a significant increase in PaO2/FIO2 in the NO group, maximal at 10 ppm NO (84 +/- 11 to 210 +/- 90, p < .05), but a greater increase in PaO2/FIO2 on ECMO-21 (81 +/- 14 to 265 +/- 63) and a further increase on ECMO-100 (398 +/- 100) (p < .05). The lymph/plasma protein ratio remained unchanged in both groups after induction of lung injury by oleic acid. However, lymph flow decreased by 11 +/- 6% in the NO group, whereas it increased by 14 +/- 17% in the ECMO group (p < .05). CONCLUSIONS: In an oleic acid-induced sheep model of acute lung injury, there were significant differences between the effects of NO and ECMO on acute pulmonary hypertension, hypoxemia, hypercarbia, and lymph flow. NO significantly decreases pulmonary hypertension, whereas pulmonary hemodynamics were not substantially affected by ECMO. Both interventions reversed hypoxemia, but ECMO did so to a greater degree, and only ECMO improved hypercarbia. Only NO decreased lymph flow, possibly as an effect of decreased microvascular filtration pressure. This study did not attempt to evaluate the impact of these interventions on ventilatory requirements, barotrauma, or outcome. However, this model suggests that NO therapy may moderate pulmonary hypertension and improve lymph flow in acute lung injury. Clinical studies are needed to assess whether NO therapy might be beneficial in treatment of severe acute lung injury in older children and adults.     

Neonatal detection of developmental dysplasia of the hip (DDH)

Congenital diaphragmatic hernia (CDH) may be associated with other anomalies, most frequently cardiovascular in nature. Despite fetal echocardiography, diagnosis of an accompanying cardiac malformation often is not made until after birth and sometimes not until after extracorporeal membrane oxygenation (ECMO) has been instituted. Aortic coarctation associated with CDH may occur as an isolated, surgically correctable malformation or it may be a component of the usually fatal left heart "hypoplasia" or "smallness" syndrome. The authors present two cases of aortic coarctation associated with CDH requiring ECMO that illustrate the management challenges of these coincident diagnosis. In one case, the accompanying coarctation was suspected and required precannulation angiography for confirmation, whereas in the other case, the diagnosis of coarctation was not made until after ECMO cannulation. Depending on its anatomic location and severity, an aortic coarctation associated with life-threatening CDH may limit the physiological efficacy of venoarterial ECMO. Furthermore, arterial cannulation for extracorporeal support requires that flow through the remaining carotid artery be maintained during aortic reconstruction, which may prove difficult for lesions best treated by subclavian flap angioplasty. When the diagnosis of coincident aortic coarctation and CDH is suspected or proven before institution of extracorporeal support, serious consideration should be given to venovenous bypass, because this may provide better postductal oxygenation and facilitate aortic repair with the option of left carotid artery inflow occlusion.     

Accidental administration of racemic adrenaline. Three life-threatening cases after intravenous injection in children

The inhalation of racemic adrenalin is an important part of the treatment of inflammatory airway obstruction in children. In Norway during the last few years there have been several cases of adrenal solutions intended only for inhalation being accidentally administered as intravenous injections. The solution for inhalation contains an adrenalin concentration 110 times greater than the adrenalin intended for emergency use (0.1 mg/ml). The instant consequences of intravenous injections of inhalation adrenalin include arterial hypertension followed by hypotension, cardiac ischemia and cardiac insufficiency, pulmonary oedema, and respiratory failure and the need for artificial ventilation. The clinical picture in the three patients we describe was very dramatic. The injected doses were 0.16-1.1 mg l-adrenalin per kg body weight. All children survived without sequelae. In order to reduce the risk of accidentally administering intravenous injections of adrenalin intended for inhalation a set of guidelines is being proposed.     

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

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

Venovenous extracorporeal membrane oxygenation in newborn infants using the umbilical vein as a reinfusion route

PURPOSE: The authors report on four neonates treated with venovenous (VV) extracorporeal membrane oxygenation (ECMO) using the umbilical vein as a reinfusion route. METHODS: From 1994 to 1997, 26 instances VV-ECMO in neonates have been carried out at our neonatal center for the treatment of severe respiratory and cardiac failure. Among them, 22 patients could be treated with VV-ECMO mainly using 15F double-lumen catheter (DLC), adding the cephalic drainage using another catheter. In the remaining four cases, however, attempts to insert the DLC into the right internal jugular vein failed because the vein was too small or technical problems. For such instances, two catheters were cannulated into the right atrium and the cephalic portion of the right internal jugular vein, respectively. These two venous catheters were connected to the drainage route of ECMO circuit with a "Y" connector. Then, the umbilical vein was cannulated with 10F or 8F catheter, which was connected to the reinfusion route of ECMO to return the oxygenated blood to the infant. RESULTS: The median age at which ECMO was initiated was 18 hours, and the median ECMO course was 72 hours. The liver function tests were slightly and transiently worsened in two patients during VV perfusion, (in one patient serum glutamic-oxaloacetic transaminase [SGOT] elevated to 76 IU/L and serum glutamic-pyruvic transaminase [SGPT] to 49 IU/L, and in another patient SGOT elevated to 56 IU/L and SGPT remained in normal range). Preumbilical cannula pressures were measured in two patients. In a patient who used 10F umbilical cannula, the preumbilical maximum pressure was 43 mm Hg at 250 mL/min of ECMO flow. In another with an 8F catheter, it was 72 mm Hg at 180 mL/min of ECMO flow. All of the patients survived without any neurological complications. CONCLUSIONS: If the right internal jugular vein would not accommodate the DLC, VV-ECMO using the umbilical vein as a infusion route could be selected.