We investigated the utilization of NPE in Italian NICUs, being echocardiography increasingly used by neonatologists as an adjunct in the clinical assessment of the hemodynamic status in neonates.
Previously reported data showed international variation in the utilization of f-echo, ranging from an almost total coverage (e.g. France, Australia and New Zealand) to a minority of NICUs having f-echo capability (e.g. USA, Canada) [9, 11, 15,16,17]. To the best of our knowledge, no data were available from Italian NICUs.
The survey received a high response rate (77%), almost entirely from level III neonatal units and the remaining from level IV. Individual phone call positively raised response rate after e-mail reminder.
We found that the vast majority of Italian neonatal units practiced NPE (94%). Like in other European countries, there is no legal impediment to doctors to use ultrasound imaging, this probably was, among others, an essential factor that allowed widespread utilization of functional echocardiography in Italy [3, 15].
F-echo was mainly performed by neonatologists rather than cardiologists and the clinical indications were: PDA, PPHN, perinatal asphyxia, hypotension/shock, cardiac tamponade, assessment of line position. These data were similar to the ones from other European countries, Australia, and New Zealand [3, 15].
Almost all units had an exclusive ultrasound machine and the echocardiographic equipment fulfilled the requirements of the ESPR/ESN Consensus Statement (i.e. high frequency probe, B-mode, M-mode, pulse wave doppler, continuous wave doppler). Instead, ECG tracing during echocardiography, digital image archiving system and standardized reporting, that were considered by the ESPR/ESN recommendations essential components in every scan, were still not widespread. More effort should be done to implement these components of NPE in order to meet the European standards and to improve practice.
Both ESPR/ESN and UK recommendations proposed measures to prevent infections and to maintain cardiorespiratory and thermal stability while scanning. Our data showed adequate attention to these issues. Nevertheless, a simple measure such as the use of heated gel was not widely adopted and it should be implemented [7, 18]. Although some studies showed that echocardiography could be performed in critically ill neonates without significant cardiorespiratory or thermal instability, we did not investigate specifically this topic [8, 19]. Further prospective studies should be carried out to ensure that NPE is safely performed among NICUs.
In the past, lack of universally accepted guidelines of NPE practice together with the little evidence on how to integrate these data in the clinical decision-making led to differences in practice between centers [11]. The latter was confirmed by our data, showing that practice of NPE was markedly heterogeneous between Italian NICUs and even within the same center. In fact, in 30% of centers there was no institutional protocol to regulate the practice of echocardiography. Where present, protocols for PDA and PPHN management were more common, compared to other clinical scenarios.
Echocardiographic parameters used to evaluate the cardiac function in different clinical scenarios were performed according to the currently available guidelines [6, 7]. They included: evaluation of LV systolic and diastolic function, RV function, pulmonary pressure, assessment of atrial-level shunt, PDA, systemic blood flow and pericardial effusion.
Normal values where not clearly defined by guidelines and not investigated in our survey. Lack of universally renowned normal values for echo parameters contributes to increase the heterogeneous application of f-echo in daily clinical practice.
Minimal differences were found between measurements used by neonatologists and cardiologists. Neonatologists more frequently assessed cardiac output than cardiologists (SVCf and LVO) and chose eyeball evaluation of left ventricular systolic function, whereas cardiologists preferred quantitative measurements (SF and EF). A continuous collaboration between cardiologists and neonatologists would promote more consistency in functional assessments and better understanding of hemodynamic compromise. However, considering the number and the specificity of functional assessments required in a busy neonatal unit, in addition to the need to integrate echo and clinical data in clinical decision-making, functional echocardiography would probably remain the domain of neonatologists with adequate training [1,2,3, 20].
The utilization of NPE poses a unique challenge: structural normality cannot be assumed because around 0.5–1% of all newborn infants have CHDs [16]. TNE and ESPR/ESN guidelines recommended that the first evaluation should always be a comprehensive study, in order to safely identify babies with structural abnormalities [6, 7]. Our data showed that only in 63% of cases the first evaluation was a comprehensive study aimed at excluding a CHDs, in addition to functional assessment; from our survey it cannot be ascertained if normal heart structure were confirmed afterwards.
There is an urgent need to train Italian neonatologists to practice functional echocardiography following the ESPR/ESN recommendations, in order to ensure safety of practice. This can not be overemphasized, in particular because, according to our data, a considerable number of neonatologists performed echocardiography in critically ill neonates even with suspicion of CHDs, in order to identify congenital abnormalities [6, 7, 16]. ESPR/ESN guidelines recognize that many neonatologists across Europe undertake additional clinical roles in diagnosis and follow-up of CHD; it could be argued that lack of pediatric cardiology centers within the same institution would favor this, an event that occurs especially in centers with lowest volume of work. According to our survey, the majority of neonatal units had a pediatric cardiology service on site (63%) and the vast majority of centers had a pediatric cardiologist they could contact on a 24/7 basis (86%). Nevertheless, pediatric cardiologists could not constantly provide an echocardiography on site in a timely manner.
We feel that a close collaboration with pediatric cardiologists should be further implemented among Italian NICUs, according to the ESPR/ESN guidelines, in order to ensure safety and accuracy in identifying babies with critical CHDs [7]. Further studies should be carried out to investigate the percentage of misdiagnosed CHDs, if any, when the first ultrasound evaluation is performed by neonatologists. Due to the limits of our survey study (i.e. respondent biases), we could not address this topic.
However, available data showed that, in the presence of a close collaboration between neonatologist and pediatric cardiologists during training and beyond, there was concordance of echocardiographic findings between neonatologists and cardiologists, even in the presence of structural abnormalities [21].
The majority of neonatologists did their training in echocardiography attending in pediatric cardiology centers and in neonatal units renowned for their expertise in functional echocardiography. More than half of respondents had high level training, however median percentage of neonatologists with the skills to perform a structural echocardiography in the respondent centers was up to 55% at most. Courses offered both nationally and internationally had non-homogeneous programs, greatly lacking in practical training. The development of an accredited training pathway in NPE was perceived essential by the majority of respondents.
Our data highlight many issues related to acquirement of competency, health care organization and training, similarly to those observed in other countries [8, 16, 17]. In response to these needs the SGNC, in agreement with the SIN, is currently designing and implementing a formalized and accredited training program in NPE. A close collaboration is retained with the Italian society of pediatric cardiology (SICPED), that supported and endorsed this project. Aims are to offer adequate training to meet the standards required by the ESPR/ESN recommendations, to ensure safety and to uniform practice of NPE.
This was a survey study and data were self-reported, therefore they may be open to respondent biases.
