Targeted neonatal echocardiography service in neonatal intensive care in Manitoba, Canada

Echocardiography in the neonatal unit: current status and future prospects

INTRODUCTION

Traditionally echocardiography was used by pediatric cardiologists to diagnose congenital heart defects in neonates. Formalized neonatal hemodynamic fellowships have been established where neonatologists acquire advanced echocardiographic skills to gain anatomical, physiological, and hemodynamic information in real time and utilize this information in making a timely and accurate physiology-based clinical decision.

AREA COVERED

Differences between a comprehensive formal structural echocardiography, neonatologist performed targeted echocardiography and limited assessment on point-of-care-ultrasonography for specific indications have been covered. This article is focused at providing a comprehensive review of the status of echocardiography in the neonatal units, recent advancements and its future prospects in the neonatal intensive care units.

EXPERT OPINION

Comprehensive guidelines providing the scope of practice, a framework for training, and robust clinical governance process for the neonatologist performed targeted echocardiography have been established. In the last decade, echocardiography has emerged as essential vital bedside diagnostic tool in providing high-quality care to the sick infants in the neonatal units, and it has proved to improve the outcomes in neonates. It is now being considered as a modern hemodynamic monitoring tool. Advances in technology, machine learning, and application of artificial intelligence in applications of echocardiography seem promising adjunct tools for rapid assessment in emergency situations.

Targeted Neonatal Echocardiography: Basics of Knobology 101

Targeted neonatal echocardiography (TNE) is essential when approaching hemodynamic instability in neonates. Competency in this field requires standardized training, including robust hands-on experience. Proficiency in understanding the key elements of ultrasound knobology is indispensable for optimal acquisition of imaging. This is a narrative review summarizing the key elements of knobology in TNE. Literature review was mainly done through PubMed. There was no funding allocated for the production of this manuscript. KEY POINTS: · Robust and structured training is essential. · Understanding knobology is required to achieve competency in TNE. · Optimizing knobology is critical for an accurate hemodynamic interpretation report.

The impact of a care bundle with an emphasis on hemodynamic assessment on the short-term outcomes in neonates with congenital diaphragmatic hernia

OBJECTIVE

To evaluate the short-term outcomes of implementing a care bundle emphasizing frequent hemodynamic assessments by echocardiography in neonates with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a retrospective cohort study of infants with CDH admitted to a quaternary perinatal unit from January 2013 to March 2021. The primary composite outcome was defined as mortality or use of extracorporeal membrane oxygenation or need for respiratory support at discharge.

RESULTS

We identified 37 and 20 CDH infants in Epoch I and II, respectively. More patch repairs (50% vs. 21.9%, p = 0.035) and echocardiograms (6[4-8] vs. 1[0-5], p = 0.003) were performed in Epoch II. While there were no differences in the primary outcome, there was a reduction in mortality in Epoch II (0% vs. 27%, p = 0.01).

CONCLUSION

With the implementation of a CDH care bundle with an emphasis on hemodynamic assessment, we demonstrated a significant reduction in mortality.

Automated Identification of Patent Ductus Arteriosus Using a Computer Vision Model

OBJECTIVES

Patent ductus arteriosus (PDA) is a vascular defect common in preterm infants and often requires treatment to avoid associated long-term morbidities. Echocardiography is the primary tool used to diagnose and monitor PDA. We trained a deep learning model to identify PDA presence in relevant echocardiographic images.

METHODS

Echocardiography video clips (n = 2527) in preterm infants were reviewed by a pediatric cardiologist and those relevant to PDA diagnosis were selected and labeled (PDA present/absent/indeterminate). We trained a convolutional neural network to classify each echocardiography frame of a clip as belonging to clips with or without PDA. A novel attention mechanism that aggregated predictions for all frames in each clip to obtain a clip-level prediction by weighting relevant frames.

RESULTS

In early model iterations, we discovered training with color Doppler echocardiography clips produced the best performing classifier. For model training and validation, 1145 such clips from 66 patients (661 PDA+ clips, 484 PDA- clips) were used. Our best classifier for clip level performance obtained sensitivity of 0.80 (0.83-0.90), specificity of 0.77 (0.62-0.92) and AUC of 0.86 (0.83-0.90). Study level performance obtained sensitivity of 0.83 (0.72-0.94), specificity of 0.89 (0.79-1.0) and AUC of 0.93 (0.89-0.98).

CONCLUSIONS

Our novel deep learning model demonstrated strong performance in classifying echocardiography clips with and without PDA. Further model development and external validation are warranted. Ultimately, integration of such a classifier into auto detection software could streamline PDA imaging workflow. This work is the first step toward semi-automated, bedside detection of PDA in preterm infants.

Growth of targeted neonatal echocardiography in Chinese neonatal intensive care units: gaps in practice and training

To evaluate clinical practice, neonatologists' attitudes, and the extent of training and accreditation regarding targeted neonatal echocardiography (TnEcho) among Chinese neonatologists. A web-based questionnaire was emailed to 331 neonatologists across China who completed training in subspecialty neonatology. The survey covered various aspects of TnEcho, including the characteristics of clinical practice, attitudes towards its usefulness, and perceived barriers to implementation and training methods. Survey response rate was 68.0% (225/331). Seventy-nine (35.1%) respondents stated that TnEcho was utilized in their NICUs. Most respondents reported the use of echocardiography to evaluate hemodynamic significance of the patent ductus arteriosus (PDA, 94.9%). The eyeballing technique was most used to evaluate left (82.3%) and right (77.2%) ventricular function. Most respondents (87.3-96.2%) positively valued the role of TnEcho in providing timely and longitudinal hemodynamic information to guide cardiovascular care. Access to TnEcho was more likely in centers with on-site pediatric cardiology service (p = .003), larger bed capacity (p = .004), or level IV status (p = .003). Lack of experienced practitioners with echocardiography expertise (88.9%) and accredited training programs (85.8%) was perceived to be the major barrier to implementation. Of concern, most practitioners with TnEcho skills received training in an informal manner through workshops (60.8%) or self-directed learning (54.4%). Conclusions: The use of TnEcho for longitudinal evaluation of infants with hemodynamic instability is growing within Chinese NICUs. There is an urgent need to develop standardized training programs and accreditation for TnEcho which are adapted to the Chinese context.

Evaluation of the Hypotensive Preterm Infant: Evidence-Based Practice at the Bedside?

Choosing the appropriate management approach for the preterm infant with low blood pressure during the transition period generally involved intervening when the blood pressure drifted below a certain threshold. It is now clear that this approach is too simplistic and does not address the underlying physiology. In this chapter, we explore the many monitoring tools available for evaluation of the hypotensive preterm and assess the evidence base supporting or refuting their use. The key challenge relates to incorporating these outputs with the clinical status of the patient and choosing the appropriate management strategy.

Echocardiography performed by the neonatologist: the impact on the clinical management

BACKGROUND

The aim of this study was to assess whether neonatologist-performed echocardiography (NPE) changed the previously planned hemodynamic approach in critically ill newborn infants.

METHODS

This prospective cross-sectional study included the first NPE of 199 neonates. Before the exam, the clinical team was asked about the planned hemodynamic approach and the answer was classified as an intention to change or not to change the therapy. After being informed about the NPE results, the clinical management was grouped as performed as previously planned (maintained) or modified.

RESULTS

NPE modified the planned pre-exam approach in 80 cases (40.2%; 95% CI: 33.3-47.4%), and variables associated with an increased chance of this modification were exams to assess pulmonary hemodynamics (prevalent ratio (PR): 1.75; 95% CI: 1.02-3.00) and to assess systemic flow (PR: 1.68; 95% CI: 1.06-2.68) in relation to those requested for patent ductus arteriosus, pre-exam intention of changing the prescribed management (PR: 2.16; 95% CI: 1.50-3.11), use of catecholamines (PR: 1.68; 95% CI: 1.24-2.28) and birthweight (per kg) (PR: 0.81; 95% CI: 0.68-0.98).

CONCLUSION

The NPE was an important tool to direct hemodynamic management in a different approach from the previous intention of the clinical team, mainly for critically ill neonates.

IMPACT

This study shows that neonatologist-performed echocardiography guides the therapeutic planning in the NICU, mainly in the more unstable newborns, with lower birthweight and receiving catecholamines. Exams requested with the intention of modifying the current approach were more likely to change the management in a different way than planned pre-exam.

Hospital variation in neonatal echocardiography among very preterm infants at US children's hospitals

OBJECTIVE

Estimate hospital variation in echocardiography (echo) among very preterm infants.

STUDY DESIGN

Retrospective cohort study of very preterm (<32 weeks) infants discharged between 2012 and 2019 from US children's hospitals. Echo exposure was identified using daily billing, and hospital variation was estimated after adjustment for illness severity. Variation in very early echo use (<3 days of life) was compared to exposure to treatment of a patent ductus arteriosus (PDA), and other practice patterns.

RESULTS

27,498 subjects across 39 children's hospitals were included. Very early echo use had the greatest hospital variation (3-34%). Increasing very early echo use was not associated with PDA treatment (p = 0.93), but was associated with nitric oxide (p < 0.01) and vasoactive medications (p < 0.01).

CONCLUSIONS

Hospital variation in echo use among preterm infants was greatest in the first few days of life and was associated with increasing nitric oxide and vasoactive medication use. The impact of this variation on clinical outcomes is uncertain and warrants further investigation.

Hemodynamic consequences of respiratory interventions in preterm infants

Advances in perinatal management have led to improvements in survival rates for premature infants. It is known that the transitional period soon after birth, and the subsequent weeks, remain periods of rapid circulatory changes. Preterm infants, especially those born at the limits of viability, are susceptible to hemodynamic effects of routine respiratory care practices. In particular, the immature myocardium and cardiovascular system is developmentally vulnerable. Standard of care (but essential) respiratory interventions, administered as part of neonatal care, may negatively impact heart function and/or pulmonary or systemic hemodynamics. The available evidence regarding the hemodynamic impact of these respiratory practices is not well elucidated. Enhanced diagnostic precision and therapeutic judiciousness are warranted. In this narrative, we outline (1) the vulnerability of preterm infants to hemodynamic disturbances (2) the hemodynamic effects of common respiratory practices; including positive pressure ventilation and surfactant therapy, and (3) identify tools to assess cardiopulmonary interactions and guide management.