The Role of Imaging During Extracorporeal Membrane Oxygenation in Pediatric Respiratory Failure

Best Practices for Vessel Management in Pediatric Extracorporeal Membrane Oxygenation Cannulation, Decannulation, and Follow-up: A Narrative Review

Extracorporeal membrane oxygenation (ECMO) to support neonates and children with cardiopulmonary failure was first described in the 1970s, since which time its use has expanded to an increasingly complex and heterogenous pediatric population. Despite preserved survival outcomes, complications of ECMO use, including iatrogenic vascular injury, are common. Here, we provide a brief overview of the epidemiology of pediatric ECMO and associated vascular complications; describe common peripheral cannulation equipment and techniques, trends in cannulation and decannulation strategies, and respective incidence of vascular complications; and review existing evidence for best practices in cannula site selection, cannulation technique, decannulation strategies, and management of vascular complications, with the goal of providing a comprehensive review for interventionalists involved in the care of pediatric ECMO patients. Areas of wide practice variation in vessel management-application of vessel-sparing cervical venoarterial cannulation, the use of distal perfusion catheters in femoral arterial cannulation, and best practices for percutaneous single-lumen venovenous cannulation, as examples-areas of focus for future research, and the potential role of vascular surgeons and other subspecialty proceduralists in the care of pediatric ECMO patients are highlighted. LEVEL OF EVIDENCE: V.

Pediatric Neurosonography: Comprehensive Review and Systematic Approach

Neurosonography (NSG) is pivotal for rapid, point-of-care neonatal brain assessment. This review elucidates the comprehensive applications of NSG in pediatric care, emphasizing its role in early diagnosis and management of pathologies affecting the pediatric head-such as scalp lesions, misshapen calvarium, ventricular distortions, and cerebrovascular abnormalities, and its specific role in conditions like hypoxic-ischaemic encephalopathy (HIE) across different neonatal gestational ages. We explore its diagnostic advantage in critical care settings, particularly for infants with stroke risk in sickle cell disease, ECMO-related complications, screening for therapeutic hypothermia, and routine neonatal intensive care unit monitoring. This review discusses the recommendations based on the timing of brain injury (preterm and term) and describes technical considerations that enhance diagnostic accuracy. Ultimately, this article advocates for its incorporation into routine neonatal screening to improve neurodevelopmental outcomes, underscoring its importance in clinical decision-making and long-term management of pediatric brain disorders.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) cannula malposition identified with point-of-care ultrasound

BACKGROUND

Point-of-care ultrasound (POCUS) has become a mainstay in the evaluation of critically ill patients in the intensive care unit (ICU). ECMO patients are susceptible to complications during prolonged ICU stay, including cannula malposition, which has deleterious consequences. Although the literature surrounding utility of ultrasound on ECMO patients is expansive, direct comparison between radiographic imaging versus ultrasound for identification of cannula malposition is lacking.

CASE PRESENTATION

The authors identified four patients with cannula malposition discovered through POCUS that was missed on routine radiographic imaging. Identification and correction of malposition changed their ECMO course.

CONCLUSION

This case series is the first in literature demonstrating that ultrasound may be superior to radiographic images for ECMO cannula malposition. Further investigation into this subject is warranted.

Use of point-of-care ultrasound (POCUS) to monitor neonatal and pediatric extracorporeal life support

Extracorporeal membrane oxygenation (ECMO) is an invasive life support technique that requires a blood pump, an artificial membrane lung, and vascular cannulae to drain de-oxygenated blood, remove carbon dioxide, oxygenate, and return it to the patient. ECMO is generally used to provide advanced and prolonged cardiopulmonary support in patients with refractory acute cardiac and/or respiratory failure. After its first use in 1975 to manage a severe form of meconium aspiration syndrome with resultant pulmonary hypertension, the following years were dominated by the use of ECMO to manage neonatal respiratory failure and limited to a few centers across the world. In the 1990s, evidence for neonatal respiratory ECMO support increased; however, the number of cases began to decline with the use of newer pharmacologic therapies (e.g., inhaled nitric oxide, exogenous surfactant, and high-frequency oscillatory ventilation). On the contrary, pediatric ECMO sustained steady growth. Combined advances in ECMO technology and bedside medical management have improved general outcomes, although ECMO-related complications remain challenging. Point-of-care ultrasound (POCUS) is an essential tool to monitor all phases of neonatal and pediatric ECMO: evaluation of ECMO candidacy, ultrasound-guided ECMO cannulation, daily evaluation of heart and lung function and brain perfusion, detection and management of major complications, and weaning from ECMO support.  Conclusion: Based on these considerations and on the lack of specific guidelines for the use of POCUS in the neonatal and pediatric ECMO setting, the aim of this paper is to provide a systematic overview for the application of POCUS during ECMO support in these populations. What is Known: • Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary support for patients with refractory acute cardiac and/or respiratory failure and requires appropriate monitoring. • Point-of-care ultrasound (POCUS) is an accessible and adaptable tool to assess neonatal and pediatric cardiac and/or respiratory failure at bedside. What is New: • In this review, we discussed the use of POCUS to monitor and manage at bedside neonatal and pediatric patients supported with ECMO. • We explored the potential use of POCUS during all phases of ECMO support: pre-ECMO assessment, ECMO candidacy evaluation, daily evaluation of heart, lung and brain function, detection and troubleshooting of major complications, and weaning from ECMO support.

Chest X-ray Interpretation: Detecting Devices and Device-Related Complications

This short review has the aim of helping the radiologist to identify medical devices when interpreting a chest X-ray, as well as looking for their most commonly detectable complications. Nowadays, many different medical devices are used, often together, especially in critical patients. It is important for the radiologist to know what to look for and to remember the technical factors that need to be considered when checking each device's positioning.

Extracorporeal membrane oxygenation (ECMO) in COVID-19 patients: a pocket guide for radiologists

During the coronavirus disease 19 (COVID-19) pandemic, extracorporeal membrane oxygenation (ECMO) has been proposed as a possible therapy for COVID-19 patients with acute respiratory distress syndrome. This pictorial review is intended to provide radiologists with up-to-date information regarding different types of ECMO devices, correct placement of ECMO cannulae, and imaging features of potential complications and disease evolution in COVID-19 patients treated with ECMO, which is essential for a correct interpretation of diagnostic imaging, so as to guide proper patient management.

Residual Lesion Diagnostics in Pediatric Postcardiotomy Extracorporeal Membrane Oxygenation and Its Outcomes

BACKGROUND

To assess the impact of diagnostic procedures in identifying residual lesions during extracorporeal membrane oxygenation (ECMO) on survival after pediatric cardiac surgery.

METHODS

Between January 2012 and December 2017, 74 patients required postcardiotomy ECMO. Patients were retrospectively divided into 2 groups: Group I underwent only echocardiography ([echo only] 46 patients, 62.2%) and group II (echo+) underwent additional diagnostic tests (ie, computed tomography [CT] or cardiac catheterization; 28 patients, 37.8%). Propensity score matching was used to balance the 2 groups by baseline characteristics.

RESULTS

Two equal groups (28 patients in each group) were formed by propensity score matching. Fourteen (50%) patients in the echo-only group and 20 (71%) patients in the echo+ group were successfully weaned from ECMO (P = .17). Four (14.3%) patients survived in the echo-only group and 15 (53.5%) patients survived in the echo+ group (P = .004). Patients in the echo+ group had a lower chance of dying compared to the echo-only group (odds ratio, 0.14.6; 95% CI, 0.039-0.52; P = .003). The residual lesions, which may have served as a mortality factor, were found by autopsy in 8 (40%) patients in the echo-only group, while none were found in the echo+ group (P = .014).

CONCLUSIONS

The autopsies of patients who died despite postcardiotomy ECMO support showed that in 40% of cases that had been investigated by echo only, residual lesions that had not been detected by echocardiography were present. The cardiac catheterization and CT during ECMO are effective and safe for identifying residual lesions. Early detection and repair of residual lesions may increase the survival rate of pediatric cardiac patients on ECMO.

Point-of-care ultrasound for the evaluation of venous cannula position in neonatal extracorporeal membrane oxygenation

OBJECTIVE

To assess the ability of point-of-care ultrasound (POCUS) to identify venous cannula position in neonates on extracorporeal membrane oxygenation (ECMO) and compare with conventional imaging.

STUDY DESIGN

Retrospective review of 37 infants on ECMO with 51 POCUS studies between January 2017 and October 2019. Studies were reviewed for identification of venous cannula location and compared with plain radiography and echocardiography. Kappa statistic and predictive values were calculated.

RESULTS

Venous cannula tip position was identified in 90% of POCUS studies. Fifty percent of the cannula tips were malpositioned. Plain radiography, the most commonly used method for evaluating tip position, showed poor agreement (57%) with POCUS (kappa 0.13). There was substantial agreement (89%) between echocardiography and POCUS (kappa 0.78).

CONCLUSION

This study provides preliminary evidence that POCUS is more accurate than plain radiography for the evaluation of ECMO venous cannula position. Adoption of this practice may prevent potentially catastrophic ECMO complications.

Neonatal Head Ultrasound: A Review and Update-Part 2: The Term Neonate and Analysis of Brain Anomalies

Neonatal head ultrasound has a key role in triaging neonates with antenatal imaging or postnatal clinical concerns. This article will discuss key features of various intracranial pathologies of concern in term infants. It will also illustrate various congenital malformations.

Portable CT Pulmonary Angiogram in an Infant on Veno-Arterial Extracorporeal Membrane Oxygenation in the Pediatric Intensive Care Unit

PURPOSE

Computed tomography (CT) has been shown to change management in children on extracorporeal membrane oxygenation (ECMO). Although techniques have been described to transport these critically ill patients to the CT suite in the radiology department, transport out of the intensive care setting is not without risk, and using portable CT is a practical alternative. However, obtaining a CT pulmonary angiogram (CTPA) in a patient on veno-arterial (VA) ECMO presents unique challenges due to bypass of the cardiopulmonary system, which may lead to suboptimal opacification of the pulmonary arteries.

METHODS

We describe a method to obtain a diagnostic CTPA study in an infant on VA ECMO in the intensive care unit using portable CT. Our solution involved temporary withholding ECMO and using the venous cannula to deliver a compact contrast bolus to the right atrium to adequately opacify the pulmonary arteries. Special attention was given to the delivery of the contrast bolus, which was given by hand injection, to ensure it coincided with image acquisition and minimized the time ECMO was withheld.

RESULTS

We were able to successfully obtain a diagnostic CTPA study in an infant on VA ECMO in the intensive care unit using portable CT.

CONCLUSION

This case demonstrates that in select instances CTPA in infants on VA ECMO can be achieved using a portable CT system.

Intrapulmonary Percussive Ventilation as an Airway Clearance Technique during Venoarterial Extracorporeal Life Support in an Infant with Pertussis

Initiation of extracorporeal life support (ECLS) is often followed by complete opacification of pulmonary parenchyma and volume loss. The optimal mechanical ventilator management and lung recruitment strategy of a pediatric patient requiring extracorporeal membrane oxygenation is not known. We present a case of a 4-week old infant who developed a severe pertussis infection requiring ECLS. The severity of his illness and pertussis infection-associated intraluminal bronchiole obstruction made medical management challenging. In addition to lung protection ventilator strategies and bronchoscopy, intrapulmonary percussive ventilation was initiated to facilitate lung recruitment. This was associated with precipitous incremental improvement in lung compliance and eventual liberation from venoarterial ECLS.

Venous Cannula Positioning in Arterial Deoxygenation During Veno-Arterial Extracorporeal Membrane Oxygenation-A Simulation Study and Case Report

Venoarterial extracorporeal membrane oxygenation (VA‐ECMO) is indicated in reversible life‐threatening circulatory failure with or without respiratory failure. Arterial desaturation in the upper body is frequently seen in patients with peripheral arterial cannulation and severe respiratory failure. The importance of venous cannula positioning was explored in a computer simulation model and a clinical case was described. A closed‐loop real‐time simulation model has been developed including vascular segments, the heart with valves and pericardium. ECMO was simulated with a fixed flow pump and a selection of clinically relevant venous cannulation sites. A clinical case with no tidal volumes due to pneumonia and an arterial saturation of below 60% in the right hand despite VA‐ECMO flow of 4 L/min was described. The case was compared with simulation data. Changing the venous cannulation site from the inferior to the superior caval vein increased arterial saturation in the right arm from below 60% to above 80% in the patient and from 64 to 81% in the simulation model without changing ECMO flow. The patient survived, was extubated and showed no signs of hypoxic damage. We conclude that venous drainage from the superior caval vein improves upper body arterial saturation during veno‐arterial ECMO as compared with drainage solely from the inferior caval vein in patients with respiratory failure. The results from the simulation model are in agreement with the clinical scenario.

Echocardiography for adult patients supported with extracorporeal membrane oxygenation

Venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) support is increasingly being used in recent years in the adult population. Owing to the underlying disease precipitating severe respiratory or cardiac failure, echocardiography plays an important role in the management of these patients. Nevertheless, there are currently no guidelines on the use of echocardiography in the setting of ECMO support. This review describes the current state of application of echocardiography for patients supported with both VA and VV ECMO.

Radiographic appearances of uncommon paediatric implants and devices

As childhood survival of chronic illness improves, long-term implanted devices will be encountered more frequently in routine radiology. In our paediatric tertiary referral hospital, we have come across several types of implanted devices that were not confidently recognised or identified by front-line staff and were often only identified by discussion with the patient, family or clinical team. This pictorial review highlights the appearance of nonvascular devices on paediatric radiographs in order to help clinicians identify the most frequent complications and to improve awareness of these important devices.

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.

Chest computed tomography in children undergoing extra-corporeal membrane oxygenation: a 9-year single-centre experience

We retrospectively reviewed the imaging findings, indications, technique and clinical impact in children who had undergone chest CT while undergoing extra-corporeal membrane oxygenation (ECMO). Radiology and ECMO databases were searched to identify all 19 children who had undergone chest CT (20 scans in total) while on ECMO at our institution between May 2003 and May 2012. We reviewed all CT scans for imaging findings. Chest CT is performed in a minority of children on ECMO (4.5% in our series). Timing of chest CT following commencement of ECMO varied among patient groups but generally it was performed earlier in the neonatal group. Clinically significant imaging findings were found in the majority of chest CT scans. Many scans contained several findings, with most cases demonstrating parenchymal or pleural abnormalities. Case examples illustrate the spectrum of imaging findings, including underlying pathology such as necrotising pneumonia and severe barotrauma, and ECMO-related complications such as tension haemothoraces and cannula migration. The results of chest CT led to a change in patient management in 16 of 19 children (84%). There were no adverse events related to patient transfer. An understanding of scan technique and awareness of potential findings is important for the radiologist to provide prompt and optimal image acquisition and interpretation in appropriate patients.

A novel echocardiographic imaging technique, intracatheter echocardiography, to guide veno-venous extracorporeal membrane oxygenation cannulae placement in a validated ovine model

Background

Echocardiography plays a fundamental role in cannulae insertion and positioning for extracorporeal membrane oxygenation (ECMO). Optimal access and return cannulae orientation is required to prevent recirculation. The aim of this study was to compare a novel imaging technique, intracatheter echocardiography (iCATHe), with conventional intracardiac echocardiography (ICE) to guide placement of ECMO access and return venous cannulae.

Methods

Twenty sheep were commenced on veno-venous ECMO (VV ECMO). Access and return ECMO cannulae were positioned using an ICE-guided technique. Following the assessment of cannulae position, the ICE probe was then introduced inside the cannulae, noting location of the tip. After 24 h, the sheep were euthanized and cannulae position was determined at post mortem. The two-tailed McNemar test was used to compare iCATHe with ICE cannulae positioning.

Results

ICE and iCATHe imaging was possible in all 20 sheep commenced on ECMO. There was no significant difference between the two methods in assessing access cannula position (proportion correct for each 90%, incorrect 10%). However, there was a significant difference between ICE and iCATHe success rates for the return cannula (p = 0.001). Proportion correct for iCATHe and ICE was 80% and 15% respectively. iCATHe was 65% more successful (95% CI 27% to 75%) at predicting the placement of the return cannula. There were no complications related to the ICE or iCATHe imaging.

Conclusion

iCATHe is a safe and feasible imaging technique to guide real-time VV ECMO cannulae placement and improves accuracy of return cannula positioning compared to ICE.

Electronic supplementary material

The online version of this article (doi:10.1186/2197-425X-2-2) contains supplementary material, which is available to authorized users.

Chest tube placement in children during extracorporeal membrane oxygenation (ECMO)

BACKGROUND

Pleural collections of air and fluid are frequent in infants and children treated with extracorporeal membrane oxygenation (ECMO). In this anticoagulated population, chest tube placement is potentially hazardous, and catastrophic hemorrhage has been reported. We sought to define the risks associated with chest tube placement in a large population of children managed with ECMO.

METHODS

The records of 189 consecutive children managed with ECMO at two children's hospitals were reviewed. Demographics, indications for ECMO, and ECMO courses were reviewed. In particular, the occurrence of pleural collections and the frequency and technique of chest tube placement were evaluated. The incidence of complications and mortality were determined.

RESULTS

The median age of the subjects was 2days. The overall mortality was 26.5%. A pneumothorax was found in 19 (10.1%), a pleural effusion in 26 (13.8%), and a hemothorax in 2 (1.0%). A chest tube was placed in 27 (19 by a needle-guide wire technique and 8 by cut-down). Major bleeding complications occurred in 6 subjects (22%).

CONCLUSIONS

There was a significant incidence of major bleeding complications and death in subjects in whom chest tubes were placed. The placement of a chest tube during ECMO should be done only if it is likely to improve pump flow or promote weaning of support.

Transthoracic echocardiography visualization of bicaval dual lumen catheters for veno-venous extracorporeal membrane oxygenation

Bicaval dual lumen catheters improve the efficiency of veno-venous extracorporeal membrane oxygenation by minimizing recirculation with an innovative design, which requires precise placement of three catheter ports in the superior vena cava, right atrium, and inferior vena cava, respectively. However, the exact position of these catheter ports is usually not known during placement because they cannot be visualized with conventional radiography. We performed a retrospective review of our experience over the past year using transthoracic echocardiography to evaluate the position of the catheter ports. From a subcostal, sagittal imaging approach, we were able to identify all three catheter ports in 11 of 11 studies. At least one of the catheter ports was incorrectly positioned in 5 of 11 studies. Further prospective evaluation is necessary to determine if catheter repositioning based on transthoracic echocardiography findings can further improve the clinical efficiency of veno-venous extracorporeal membrane oxygenation.

Echocardiography, not chest radiography, for evaluation of cannula placement during pediatric extracorporeal membrane oxygenation

OBJECTIVE

Optimal cannula position is essential during extracorporeal membrane oxygenation (ECMO). We hypothesize that echocardiography is superior to chest radiography in diagnosing abnormal cannula position during ECMO.

DESIGN

Retrospective.

SETTING

Pediatric hospital.

PATIENTS

100 pediatric patients requiring ECMO.

MEASUREMENTS AND MAIN RESULTS

We reviewed the medical records of all ECMO patients (n = 100), including reports of all echocardiograms (n = 326), during the years 2002-2004. Of the 91 patients who had echocardiograms while on ECMO, 33 had at least 1 echocardiogram for cannula-position evaluation. Of the remaining 58 patients with echocardiograms for reasons other than cannula-position evaluation, 4 (7%) were found to have abnormal cannula position. These included arterial cannula (AC) within 2-4 mm of the aortic valve (n = 2), AC across the aortic valve into the left ventricle (n = 1), and venous cannula (VC) abutting the atrial septum (n = 1). Of the 33 patients with echocardiograms for evaluation of cannula position, 8 (24%) required intervention. Of those 8 patients, 4 required cannula repositioning due to VC in the coronary sinus (n = 1), VC abutting atrial septum (n = 1), AC in left subclavian artery (n = 1), and AC within 3 mm of aortic valve (n = 1). The remaining 4 with normal cannula position required upsizing of the VC (n = 2), increased circuit flow (n = 1), or intravascular volume administration (n = 1). Overall, 12 of 91 patients (13%) required intervention based on echocardiographic findings. Chest radiography did not detect abnormalities of ECMO cannula position in any of the 8 patients with this problem, nor were any additional patients with abnormal cannula position identified by chest radiography.

CONCLUSIONS

Echocardiography appears to be superior to chest radiography for assessing ECMO cannula position in our institution. A prospective study, including cost analysis, comparing chest radiography and echocardiography, is needed to definitely determine the preferred diagnostic test or sequence of tests to establish ECMO cannula position.