Cerebrovascular lesions in infants and children dying after extracorporeal membrane oxygenation

A Systematic Review of Clinical Outcomes After Carotid Artery Ligation Versus Carotid Artery Reconstruction Following Venoarterial Extracorporeal Membrane Oxygenation in Infants and Children

INTRODUCTION

In pediatric and neonatal populations, the carotid artery is commonly cannulated for venoarterial (VA) extracorporeal membrane oxygenation (ECMO). The decision to ligate (carotid artery ligation [CAL]) versus reconstruct (carotid artery reconstruction [CAR]) the artery at decannulation remains controversial as long-term neurologic outcomes remain unknown. The objective of this study was to summarize current literature on clinical outcomes following CAL and CAR after Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO).

METHODS

PubMed (MEDLINE), Embase, Web of Science, and Cochrane databases were searched using keywords from January 1950 to October 2020. Studies examining clinical outcomes following CAL and CAR for VA-ECMO in patients <18 y of age were included. Prospective and retrospective cohort studies, case series, case-control studies, and case reports were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were performed independently by two reviewers. Assessment of risk of bias was performed.

RESULTS

Eighty studies were included and classified into four categories: noncomparative clinical outcomes after CAL (n = 23, 28.8%), noncomparative clinical outcomes after CAR (n = 12, 15.0%), comparative clinical outcomes after CAL and/or CAR (n = 28, 35.0%), and case reports of clinical outcomes after CAL and/or CAR (n = 17, 21.3%). Follow-up ranged from 0 to 11 y. CAR patency rates ranged from 44 to 100%. There was no substantial evidence supporting an association between CAL versus CAR and short-term neurologic outcomes.

CONCLUSIONS

Studies evaluating outcomes after CAL versus CAR for VA-ECMO are heterogeneous with limited generalizability. Further studies are needed to evaluate long-term consequences of CAL versus CAR, especially as the first survivors of pediatric/neonatal ECMO approach an age of increased risk of carotid stenosis and stroke.

Acute Brain Injury in Infant Venoarterial Extracorporeal Membrane Oxygenation: An Autopsy Study

OBJECTIVES

Characterization of the types and timing of acute brain injury in infant autopsy patients after extracorporeal membrane oxygenation.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary-care center.

PATIENTS

Infants supported on extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Clinical and pathologic records were reviewed for infant extracorporeal membrane oxygenation patients who had undergone brain autopsy in a single center between January 2009 and December 2018. Twenty-four patients supported on venoarterial extracorporeal membrane oxygenation had postmortem examination with brain autopsy. Median age at extracorporeal membrane oxygenation initiation was 82 days (interquartile range, 11-263 d), median age at time of death was 20 weeks (interquartile range, 5-44 wk), and median extracorporeal membrane oxygenation support duration was 108 hours (interquartile range, 35-366 hr). The most common acute brain injury found at autopsy was hypoxic-ischemic brain injury (58%) followed by intracranial hemorrhage (29%). The most common types of intracranial hemorrhage were intracerebral (17%), subarachnoid (17%), and subdural (8%). Only five infants (21%) did not have acute brain injury. Correlates of acute brain injury included low preextracorporeal membrane oxygenation oxygen saturation as well as elevated liver enzymes, total bilirubin, and lactate on days 1 and 3 of extracorporeal membrane oxygenation. Gestational age, Apgar scores, birth weight, extracorporeal membrane oxygenation duration, anticoagulation therapy, and renal and hepatic impairments were not associated with acute brain injury.

CONCLUSIONS

Acute brain injury was observed in 79% of autopsies conducted in infants supported on extracorporeal membrane oxygenation. Hypoxic-ischemic brain injury was the most common type of brain injury (58%), and further associations with preextracorporeal membrane oxygenation acute brain injury require additional exploration.

Neuropathology of Congenital Heart Disease in an Inpatient Autopsy Cohort 2000-2017

Background As a result of medical and surgical advancements in the management of congenital heart disease (CHD), survival rates have improved substantially, which has allowed the focus of CHD management to shift toward neurodevelopmental outcomes. Previous studies of the neuropathology occurring in CHD focused on cases preceding 1995 and reported high rates of white matter injury and intracranial hemorrhage, but do not reflect improvements in management of CHD in the past 2 decades. The purpose of this study is therefore to characterize the neuropathological lesions identified in subjects dying from CHD in a more-recent cohort from 2 institutions. Methods and Results We searched the autopsy archives at 2 major children's hospitals for patients with cyanotic congenital cardiac malformations who underwent autopsy. We identified 50 cases ranging in age from 20 gestational weeks to 46 years. Acquired neuropathological lesions were identified in 60% (30 of 50) of subjects upon postmortem examination. The most common lesions were intracranial hemorrhage, most commonly subarachnoid (12 of 50; 24%) or germinal matrix (10 of 50; 20%), hippocampal injuries (10 of 50; 20%), and diffuse white matter gliosis (8 of 50; 16%). Periventricular leukomalacia was rare (3 of 50). Twenty-six subjects underwent repair or palliation of their lesions. Of the 50 subjects, 60% (30 of 50) had isolated CHD, whereas 24% (12 of 50) were diagnosed with chromosomal abnormalities (trisomy 13, 18, chromosomal deletions, and duplications) and 16% (8/50) had multiple congenital anomalies. Conclusions In the modern era of pediatric cardiology and cardiac surgery, intracranial hemorrhage and microscopic gray matter hypoxic-ischemic lesions are the dominant neuropathological lesions identified in patients coming to autopsy. Rates of more severe focal lesions, particularly periventricular leukomalacia, have decreased compared with historical controls.

Perinatal arterial ischemic stroke

Perinatal arterial ischemic stroke is a relatively common and serious neurologic disorder that can affect the fetus, the preterm, and the term-born infant. It carries significant long-term disabilities. Herein we describe the current understanding of its etiology, pathophysiology and classification, different presentations, and optimal early management. We discuss the role of different brain imaging modalities in defining the extent of lesions and the impact this has on the prediction of outcomes. In recent years there has been progress in treatments, making early diagnosis and the understanding of likely morbidities imperative. An overview is given of the range of possible outcomes and optimal approaches to follow-up and support for the child and their family in the light of present knowledge.

Serum S100B protein could help to detect cerebral complications associated with extracorporeal membrane oxygenation (ECMO)

BACKGROUND

To investigate if serum S100B protein levels could early detect cerebral complications under treatment extracorporeal membrane oxygenation (ECMO).

METHODS

Serum S100B levels were measured over 5 days in 32 patients with cardiogenic and septic shock, including 15 patients who treated by ECMO and 17 who did not. Cerebral complications included hemorrhage, stroke, encephalopathy with myoclonus, and brain death. Delirium was identified by the positive Confusion Assessment Method in the ICU.

RESULTS

S100B levels were elevated in 24/32 patients (75 %) at ICU admission. Five patients developed cerebral complications (2 hemorrhages with 1 brain death, 1 encephalopathy with myoclonus in the ECMO group and 2 strokes in the non-ECMO group). At day 5, S100B levels were higher in the 5 patients with cerebral complications than in the 27 without cerebral complications, regardless of ECMO (0.426 [0.421, 0.652] vs. 0.102 [0.085, 0.135] μg/L, p = 0.011). S100B levels were also more elevated in 3 patients with than in 12 without cerebral complications associated with ECMO (0.799 [0.325, 0.965] vs. 0.102 [0.09, 0.607] μg/L, p = 0.033). S100B levels were not associated with delirium after sedation withdrawal.

CONCLUSIONS

Measurement serum S100B could be useful to detect cerebral complications in deeply sedated patients associated with ECMO but not for monitoring delirium after sedation withdrawal.

Discrepancies between autopsy and clinical findings among patients requiring extracorporeal membrane oxygenator support

Discrepancy between clinical and autopsy diagnosis in children supported on extracorporeal membrane oxygenation (ECMO) has not been previously described. To assess the utility of autopsy examination in children supported on ECMO and assess discrepancies between premortem and postmortem diagnosis in these patients. Retrospective chart review. General pediatric and cardiac intensive care units (ICUs) in a tertiary children's hospital. The hospital's ECMO database was queried for patients supported on ECMO from 2000 through 2010 who died and underwent autopsy examination. Fifty-four autopsies were performed in 139 nonsurvivors (28%) who required ECMO support in the pediatric and cardiac ICU. Major discrepancies between premortem and postmortem diagnoses were found in 29 patients (53.7%). The commonest missed diagnosis was myocardial infarction that occurred in 16 patients, followed by adrenal hemorrhage in three patients. Five patients with a cardiac diagnosis had both major (type 1 discrepancy) and minor (type 2 discrepancy) discrepancies. Surgical complications were noted in four postmortem study with three of them being class 1 discrepancy. We report significant discrepancy between autopsy and clinical findings among ECMO-supported pediatric patients. Our findings underscore the need for enhanced premorbid surveillance in patients supported on ECMO.

Neurologic complications of cardiac surgery and interventional cardiology

A wide array of neurologic complications can occur in relation to cardiac surgical procedures, most of which are transient and do not result in permanent sequelae. Specific neurologic insults can occur depending on the type of cardiac procedure and are an important cause of morbidity and mortality. Neurologists practicing in the hospital setting as well as outpatient neurologists should be familiar with the cardiac surgical procedures currently available. Prompt identification of neurologic deficits is important in order to plan an appropriate systematic evaluation and initiate possible treatments in a timely manner. This chapter provides a comprehensive overview of all facets of neurologic complications after cardiac surgical procedures.

Cerebral microbleeds after use of extracorporeal membrane oxygenation in children

Cerebral microbleeds (CMB) on gradient-recalled echo (GRE) magnetic resonance imaging (MRI) are rarely seen in children, yet have been described following vascular procedures in adults. Extracorporeal membrane oxygenation (ECMO) has been associated with vascular injury and neurological events in children, but there have been no reports to date of GRE MRI findings in children treated with ECMO. We reviewed MRI scans for all vascular neurology consultations in children treated with ECMO at an academic medical center over a 5-year period. In 6 of 12 cases, GRE was acquired as others were unstable or had contraindications to MRI. All 6 of 6 (100%) GRE cases (mean age 2.1 years, 7 female, 5 male) demonstrated CMB. CMB were multiple (>3 lesions), situated in cortical or lobar regions, with a striking predominance (5/6 cases) for the right carotid distribution. Other than CMB, no cases demonstrated intracranial hemorrhage. CMB may be noted on GRE MRI after ECMO and may reflect vascular damage from gaseous emboli.

Symmetrical peripheral gangrene in four pediatric cardiac surgery patients receiving extracorporeal membrane oxygenation

Symmetrical peripheral gangrene (multilimb ischemia without large artery occlusion) is a rare condition usually associated with disseminated intravascular coagulation, hemodynamic compromise, and/or sepsis. However, it has not been described in patients on extracorporal membrane oxygenation (ECMO). Over a 5 year period, four pediatric patients developed symmetrical peripheral gangrene on ECMO after cardiac surgery. They subsequently died and came to autopsy. History, physical examination, and laboratory studies were examined. Gross and microscopic autopsy material was reviewed. Patients were 11 days to 13 years old. Extracorporal membrane oxygenation duration was 11-22 days, and limb ischemia began 2-4 days before death. Three patients had rapid onset, with ischemia developing in <48 hours. In the fourth, ischemic changes began as focal lesions and gradually spread. Two patients were septic. Three had evidence of other end-organ damage. Pressors were used in 3 patients before the limb ischemia. Autopsies disclosed ischemic changes involving all limbs, with confluent ecchymoses. In a detailed examination in 1 case, large arteries of the extremities were patent. Involved skin and soft tissue showed bland fibrin thrombi in the microcirculation, with tissue necrosis and hemorrhage. This report describes the first 4 cases of symmetrical peripheral gangrene complicating ECMO. The 4 pediatric patients all had recent surgery for congenital cardiac disease, and all had significant exposure to ECMO prior to developing limb ischemia. Symmetrical peripheral gangrene is an unusual complication of ECMO that may arise in the setting of disseminated intravascular coagulation, sepsis, or other hemostatic and/or hemodynamic imbalance.

Extracorporeal Membrane Oxygenation in 108 Patients with Low Cardiac Output – a Single-Center Experience

Background

For short-term ventricular and pulmonary support the extracorporeal membrane oxygenation (ECMO) system using the Bio-Medicus centrifugal pump (Medtronic®, Minneapolis, MN, USA) was applied in 108 patients with cardiac low-output.

Methods

From December 1996 to July 2006 the ECMO was implanted in 108 patients (73 adult, mean age: 49.3±18.0 yrs and 35 children, mean age: 1.3 ± 2.7 yrs) with mostly postcardiotomy cardiac low output. The surgical procedures included congenital heart surgery (n=35), heart transplantation (HTx) (n=21), coronary artery bypass operation (CABG) and/or valvular operation (n=33), other operations (n=6) and 13 patients with ECMO support for bridge to recovery.

Results

The mean supporting time was 5.1±5.6 days. Overall, 30-day-survival was 40.2%. Best survival rates were seen after congenital heart surgery (24/35, 65.7%) and after HTx (9/21, 42.9%); the worst rates were in the group of CABG and/or valvular operations (5/33, 15.2%), only ECMO support (3/13, 23.1%) and other operations (1/6, 16.7%). Fifty-four patients died while supported by ECMO, 15 were weaned from ECMO but died in hospital, 39 patients were weaned and survived. Causes of death were multi-organ failure (40.6%), bleeding (23.2%), persistent cardiac low output (21.7%), thrombembolic events (8.7%), and graft failure (5.8%). Markers for adverse outcome were identified as older age, high body weight, increased AST/GOT levels, and lower thrombocyte count in adults; and as higher levels of serum creatinine in pediatric patients.

Conclusions

ECMO support showed best results in pediatric patients after congenital heart surgery and in patients after HTx in contrast to multimorbid, older patients with often irreversible myocardial damage.

Laboratory and clinical predictors of thrombosis and hemorrhage in 29 pediatric extracorporeal membrane oxygenation nonsurvivors

Extracorporeal membrane oxygenation (ECMO) is a life-saving therapy for infants and children with cardiac and respiratory failure. However, thrombosis and hemorrhage are common complications. To determine clinical and laboratory predictors of thrombosis and hemorrhage resulting from ECMO, records and slides were reviewed from 29 consecutive autopsies from 2004 through 2008 of pediatric patients who received ECMO at our institution. Laboratory results, including prothrombin time, activated partial thromboplastin time, platelet count, fibrinogen level, and activated clotting time, were analyzed, as was heparin dosing. Thrombosis and hemorrhage were very common, with 1 or both seen in 86% of patients. Sixty-nine percent had thrombosis, and 52% had hemorrhage after ECMO initiation, including intracranial hemorrhage in 33% of the patients in whom brain examination was permitted. Hemorrhage and thrombosis coexisted in 31% of patients. Thrombosis was significantly more common in patients with congenital cardiac disease. Duration of ECMO therapy, being on ECMO at death, sepsis, and patient age and sex did not predict hemorrhage or thrombosis at autopsy. Laboratory tests were poor predictors of thrombosis and hemorrhage, with no correlation between these complications and prothrombin time, partial thromboplastin time, platelet count, fibrinogen level, activated clotting time, or heparin dose. In conclusion, thrombosis and hemorrhage continue to be frequent complications among patients who die during or after ECMO therapy. Patients with congenital cardiac disease appear especially susceptible to thrombosis on ECMO. Prothrombin time, partial thromboplastin time, platelet count, fibrinogen level, activated clotting time, and heparin dose are poor predictors of thrombosis or hemorrhage for pediatric patients who die after ECMO.

Outcomes of perinatal arterial ischemic stroke and cerebral sinovenous thrombosis

Perinatal stroke can result in cerebral palsy, cognitive impairment, epilepsy, and sensory deficits. While some children only experience one type of disability, severe disabilities often cluster together. Death associated with perinatal stroke is rare, and often associated with other comorbidities. Clinical and radiographic factors can help predict outcome, but additional as-yet unknown factors appear to contribute to outcome as well. Rehabilitation can ameliorate deficits, and advances in rehabilitation technology and in adult stroke rehabilitation offer promise to pediatric perinatal stroke patients.

Neonatal arterial ischemic stroke and sinovenous thrombosis associated with meningitis

This series describes 5 neonates with meningitis associated with arterial ischemic stroke or cerebral sinovenous thrombosis identified from a tertiary children's hospital perinatal stroke database. A retrospective chart review was performed to collect data on clinical presentations, type of meningitis, radiographic and electroencephalographic findings, neonatal intensive care unit course and complications, additional risk factors associated with stroke, and outcomes. The proportion of arterial ischemic stroke and sinovenous thrombosis in the database associated with meningitis was calculated. Neonates came to medical attention because of seizures (2), hydrocephalus (1), and behavior changes (2). The median age of presentation was birth (range, 0-18 days). Meningitis was bacterial in 4 and viral in 1. The median time from symptom onset to identification of the causative organisms of meningitis was 16.8 days (range, 13-23 days) and from symptom onset to diagnosis of stroke was 11 days (range, 4-18 days). One child had arterial ischemic stroke. Four had cerebral sinovenous thrombosis. One child died in the neonatal intensive care unit. Outcome data were available for 3 of the 4 surviving children; all had some degree of neurological deficit. All 5 of the neonates described had risk factors for perinatal thrombosis or embolization in addition to meningitis. Meningitis is associated with 1.6% (1/63) of cases of arterial ischemic stroke and 7.7% (4/52) of cases of cerebral sinovenous thrombosis in our perinatal stroke database. Further work is needed to clarify when infarction occurs during meningitis and which children are at highest risk.

Autopsy findings in patients on postcardiotomy extracorporeal membrane oxygenation (ECMO)

OBJECTIVES

To assess the clinical sensitivity of causes of death, concomitant diseases and postoperative complications including thromboembolic events in ECMO patients.

METHODS

Between January 2000 and December 2004 154/202 patients (76.2%) died after postcardiotomy ECMO circulatory support. Autopsy was performed in 78 (50.6%) consecutive patients. Clinical and post-mortem data were prospectively recorded and compared concerning causes of death and postoperative complications including venous and arterial thromboembolisms and significant comorbidities.

RESULTS

Mean age was 62.1+/-11.3 years, ejection fraction was 43.4+/-17.3%. 39.7% were emergency operations including acute coronary syndrome in 25.6% and preoperative cardiogenic shock in 28.2%. Successful ECMO weaning rate was 43.6%. Mean postoperative survival was 11.3 days. Premortem unknown concomitant diseases were found in 63 patients (80.8%) with clinical relevance in 9 patients (11.5%). Clinically unrecognized postoperative complications were found in 59 patients (75.6%) including acute cerebral infarction (n=7), acute bowel ischemia (1), intestinal perforation (3), pneumonia (4), venous thrombus formation (25) and systemic thromboembolic events (24). Clinically based causes of death were cardiac in 62.8%, multi-organ failure in 10.3%, cerebral in 5.1%, respiratory in 10.3%, fatal pulmonary embolism in 2.6%, technical in 5.1%, and others in 3.8%. Unexpected causes of death were found by autopsy in 22 patients (28.2%) including myocardial infarction (n=5), acute heart failure (4), fatal pulmonary embolism (2), pneumonia (2), ARDS (1), lung bleeding (1), fatal cerebrovascular event (4) and multiorgan failure (3).

CONCLUSIONS

In ECMO patients major discrepancies between clinical and post-mortem examination were found. The true incidence of thromboembolic events is highly underestimated by clinical evaluation.

AE. Hemorrhagic stroke in children

Hemorrhagic stroke accounts for approximately half of stroke in childhood. Unlike arterial ischemic stroke, there are no consensus guidelines to assist in the evaluation and treatment of these children. This article reviews the literature on the evaluation, treatment, etiology, and neurologic outcome of hemorrhagic stroke in children. Important differences between pediatric and adult hemorrhage are highlighted, as treatment guidelines for adults may not be applicable in all cases. Required future research and potential therapies are also discussed.

Extracorporeal life support

Extracorporeal life support (ECLS) denotes the use of prolonged extracorporeal cardiopulmonary bypass in patients with acute, reversible cardiac or respiratory failure. As technology has advanced, organ support functions other than gas exchange, such as liver, renal, and cardiac support, have been provided by ECLS, and others, such as immunologic support, will be developed. The future of ECLS will include improvements in devices accompanied by circuit simplification and auto-regulation. Such enhancements in technology will allow application of ECLS to populations currently excluded from such support; for example, thromboresistant circuits will eliminate the need for systemic anticoagulation and lead to the use of this technique in premature newborns. As the ECLS technique becomes safer and simpler, and as morbidity and mortality are minimized, criteria for application of ECLS will be relaxed. New approaches to ECLS, such as pumpless arteriovenous bypass, the artificial placenta, arteriovenous CO(2) removal (AVCO(2)R), and intravenous oxygenators (IVOX), will become more commonly applied. Such advances in technology will allow broader and more routine application of ECLS for lung and other organ system failure.

Histopathological features of open lung biopsies in children treated with extracorporeal membrane oxygenation (ECMO)

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become an established treatment for severe respiratory distress in a range of pediatric conditions. This study describes the histopathological features in a series of 22 children receiving ECMO therapy in whom open lung biopsy was carried out.

AIMS

To describe the histopathological features of open lung biopsies in children receiving ECMO therapy.

STUDY DESIGN

Retrospective review of clinical material.

SUBJECTS

Children receiving ECMO therapy in whom open lung biopsy was carried out.

RESULTS

In those investigated in infancy, open lung biopsy allowed a definite diagnosis to be made of the underlying condition in more than 90% of cases. In older children, the histopathological changes were more non-specific and, although providing useful clinical information, a definitive diagnosis could often not be made. In about a quarter of cases, there are additional pathological features, which may be related to ECMO treatment, such as significant intra-alveolar haemorrhage, but ECMO does not in itself impair the diagnostic usefulness of open lung biopsy in these selected patients.

CONCLUSION

Open lung biopsy provides clinically useful information in infants receiving ECMO therapy. The histopathological changes may be complex and represent both the effects of ECMO and progression of the underlying disease.

Cerebral intravascular oxygenation correlates with mean arterial pressure in critically ill premature infants

OBJECTIVES

Premature infants experience brain injury, ie, germinal matrix-intraventricular hemorrhage (GMH-IVH) and periventricular leukomalacia (PVL), in considerable part because of disturbances in cerebral blood flow (CBF). Because such infants are susceptible to major fluctuations in mean arterial blood pressure (MAP), impaired cerebrovascular autoregulation would increase the likelihood for the changes in CBF that could result in GMH-IVH and PVL. The objectives of this study were to determine whether a state of impaired cerebrovascular autoregulation could be identified reliably and conveniently at the bedside, the frequency of any such impairment, and the relation of the impairment to the subsequent occurrence of severe GMH-IVH and PVL.

PATIENTS AND METHODS

To monitor the cerebral circulation continuously and noninvasively, we used near-infrared spectroscopy (NIRS) to determine quantitative changes in cerebral concentrations of oxygenated hemoglobin (HbO(2)) and deoxygenated hemoglobin (Hb) from the first hours of life. Our previous experimental study showed a strong correlation between a measure of cerebral intravascular oxygenation (HbD), ie, HbD = HbO(2) - Hb, determined by NIRS, and volemic CBF, determined by radioactive microspheres. We studied 32 very low birth weight premature infants (gestational age: 23-31 weeks; birth weight: 605-1870 g) requiring mechanical ventilation, supplemental oxygen, and invasive blood pressure monitoring by NIRS from 1 to 3 days of age. MAP measured by arterial catheter pressure transducer and arterial oxygen saturation measured by pulse oximetry were recorded simultaneously. The relationship of MAP to HbD was quantitated by coherence analysis.

RESULTS

Concordant changes (coherence scores >. 5) in HbD and MAP, consistent with impaired cerebrovascular autoregulation, were observed in 17 of the 32 infants (53%). Eight of the 17 infants (47%) developed severe GMH-IVH or PVL or both. Of the 15 infants with apparently intact autoregulation, ie, coherence scores <.5, only 2 (13%) developed severe ultrasonographic lesions. Thus, for the entire study population of 32 infants, 8 of the 10 with severe lesions exhibited coherence scores >.5.

CONCLUSIONS

We conclude that NIRS can be used in a noninvasive manner at the bedside to identify premature infants with impaired cerebrovascular autoregulation, that this impairment is relatively common in such infants, and that the presence of this impairment is associated with a high likelihood of occurrence of severe GMH-IVH/PVL.

Coagulopathic-induced membrane dysfunction during extracorporeal membrane oxygenation: a case report

This paper describes an unusual complication of membrane dysfunction during extracorporeal membrane oxygenation (ECMO) for treatment of neonatal respiratory distress. A 2.8-kg term infant presented to our facility in severe respiratory distress and was diagnosed with primary pulmonary hypertension. After routine priming of the extracorporeal circuit, the patient was placed on veno-arterial ECMO with 8 F arterial and 12 F venous cannulae. Transfusion criteria were established which included trigger values of the following: platelet count 100,000/microliters, fibrinogen 150 mg/dl, haematocrit 40%. The ECMO course was uneventful until approximately the 132nd hour on support when the patient developed a consumptive coagulopathy, as evidenced by 55-60% reductions in both platelet count and fibrinogen concentrations, despite transfusion therapy. Total autogeneic blood product transfusion during the first 120 h of ECMO averaged 4.4 +/- 2.2 ml/h, while the transfusion rate for the final 35 h was 7.8 +/- 3.5 ml/h. Coinciding with this rise in transfusion requirements was an increase in transmembrane pressure from 0.29 to 1.52 mmHg/ml blood flow. The patient was separated from ECMO after 175 h due to a continuing coagulopathy and haemothorax. The patient was then treated with nitric oxide therapy before succumbing on the twelfth postoperative day due to refractory respiratory failure. The circuit was dissected and significant clots found in both the venous bladder and oxygenator. In addition, approximately one-third of the membrane compartment had a 'fused' circumferential pattern of dessicated clot which interrupted blood path continuity. In conclusion, this report describes an unusual complication of the ECMO oxygenator that occurred during long-term extracorporeal life support which most likely resulted from a coagulopathy.