Point-of-care, bedside or clinical ultrasonography is defined as ultrasonography performed by the doctor in charge directly where the patient is for clinical assessment. It is used for addressing specific problems or questions immediately and in real time.1 Compared to ultrasonography performed by radiologists, which can provide more comprehensive and accurate information, point-of-care ultrasound usually focuses on yes/no questions to facilitate diagnosis and especially on procedural guidance.1 Furthermore, since it is easily repeatable, it can be used to assess changes in different clinical situations or conditions.

The size of paediatric patients facilitates the access of ultrasound waves to different organs while obtaining high-quality images. This fact, along with the elimination of the risks associated with the use of ionising radiation techniques, is clearly stimulating an increase in the use of ultrasonography.2,3 Decreasing costs, decreasing size and improvements in the specifications of ultrasonography systems in recent years have also been essential in the expansion of its use outside radiology units.

It has multiple applications in the field of paediatrics, which are clearly expanding.4–6 This is demonstrated by the increasing availability of ultrasound units in the paediatric emergency departments of some countries, as well as its increasingly frequent inclusion in clinical practice guidelines and training curriculums of different specialties.7–9

Paediatric critical care and emergency care are probably the fields in which the use of bedside ultrasonography by the paediatrician in charge is becoming most widespread. This is probably due to several factors, such as the immediacy of its use, the possibility of performing serial assessments, and above all the increasing number of clinical applications. More specifically, in the field of intensive care, there is evidence that ultrasonography can be used by critical care physicians to guide the performance of other techniques, such as establishing vascular access10,11 or the drainage of effusions in different locations.12 Furthermore, clinical ultrasonography can be used to answer specific questions regarding multiple organs and systems, and has demonstrated a high sensitivity and specificity in the diagnosis of various lung diseases.13 It allows the assessment of different aspects to determine the haemodynamic status of a patient, such as myocardiac contractility or blood volume,14,15 detect the presence of intra-abdominal lesions16 or assess changes in blood flow in different vital organs, such as the brain17 or kidneys.18

To date, although some studies have found clear evidence of its increasing use in adult intensive care units and paediatric emergency departments,7 only one study conducted in the United States has described its availability and the characteristics of its use in paediatric intensive care units (PICUs).19

The main objective of our study was to characterise the availability and use of point-of-care ultrasonography in Spanish PICUs. More specifically, we sought to identify the most widely used clinical applications. Our secondary objective was to determine the level of training on the use of ultrasonography in the care of critical paediatric patients of Spanish clinicians.

We conducted a multicentric cross-sectional descriptive study. We developed an online survey using the Google Forms online platform that consisted of 45 questions organised into three sections. We gathered contact information for 51 PICUs in Spain. The survey was distributed by the Sociedad Española de Cuidados Intensivos Pediátricos (Spanish Society of Paediatric Critical Care) by electronic mail to the service chief or contact person of the different paediatric intensive care units. In a second phase, we attempted to contact the units that had not completed the questionnaire by electronic mail.

The first section of the survey consisted of questions that explored the characteristics of the PICU and its activity and those of the hospital to which it belonged.

The second section explored the availability of ultrasound machines, their location, exclusive or shared use, frequency of use and use for different applications. In the last section, the questionnaire asked about the training on ultrasonography of the PICU staff including physicians and nurses, the need for training and guidelines, and the usefulness of specific training in ultrasonography.

We analysed the responses by means of the SPSS software for Mac OS X version 20.0.0 (IBM Corp, Armonk, New York, USA). We described categorical variables by the percentage of answers in each category, and continuous variables as median and interquartile range. We compared groups by means of nonparametric tests (Kruskal–Wallis, Fisher's exact and Mann–Whitney U), and defined statistical significance as a p-value of less than 0.05 in these tests.

Point-of-care ultrasound is a tool used increasingly in the care of critical patients and has a clear impact on the diagnostic and therapeutic approach.2,20 Our study describes the extent to which clinical ultrasonography is used in Spanish PICUs. The results of our survey are a good reflection of the current status quo, as the response rate was high, greater than the one reported by Lambert et al. in the United States,19 and it included PICUs of very different sizes and with different types of patients.

One salient finding was that the availability of ultrasound machines was not associated with the size or level of care of the PICUs, which may be due to many different factors (the attitude of professionals, the resources of each hospital, etc.). However, a more frequent use of this technique was associated with the number of admissions per year and the type of patients usually served in the PICU, as well as with the existence of a transplant programme or the availability of ECMO. Units that had more beds used point-of-care ultrasound more frequently, but this difference was not statistically significant. A study published by Lambert et al., however, did find a clear association between the use of this technique and the number of beds in the unit, the number of admissions and the existence of paediatric intensive care training programmes.19

We ought to note that when it came to the specific applications of point-of-care ultrasound, we found that this technique has ceased to be solely used to guide other procedures and has become just another tool that contributes to the assessment of multiple organs and systems. The ability to quickly and directly address specific questions concerning the patient's haemodynamic, respiratory or neurologic status, among others, helps clinical decision-making in the daily practise of paediatric intensivists. In our study, we found a high proportion of PICUs that used point-of-care ultrasound for purposes other than cannulation (more than 70% for many uses). This percentage exceeded the 50% reported in the study Lambert et al.19

The use of ultrasonography can reduce the risk of complications in certain procedures, such as vascular cannulation or the assessment of effusion (mainly pleural and pericardial). We found it surprising that while the percentage of units that reported using ultrasonography to guide these procedures in our study was high, its use is not yet widespread, despite the mounting scientific evidence and international recommendations that support it.21,22 More specifically, when it came to the use of ultrasound for guiding vascular cannulation, a high percentage of the PICUs (between 30% and 50%, depending on the type of vascular access) reported ultrasound was only used sometimes. Likewise, the frequent use of ultrasound to guide vascular cannulation only reached approximately 60% when it came to placement of jugular vein catheters. Thus, the use of ultrasound for guiding these procedures needs to be promoted.

As one would expect, we found that ultrasonography was used more frequently in PICUs with staff trained in its use. Given the high availability of ultrasound machines, we think that the development of a structured training programme in ultrasonography is essential.

Several studies have analysed the status quo of specialised training in point-of-care ultrasound in intensive and emergency care units in the United States.7–9,23,24 In the United States, training on point-of-care ultrasound is part of the educational curriculum of paediatric intensive care and paediatric emergency care subspecialties. In Spain, these subspecialties are not officially recognised in paediatrics, although most subspecialties have established educational curricula. We believe that basic competencies in the use of point-of-care ultrasound should be included in the learning objectives of paediatricians that will be working in paediatric intensive care settings, as is the case of other techniques such as incubation care or vascular cannulation. This has already been done in other countries, such as Canada, through consensus meetings.25

Our study shows that there is large proportion of physicians in the surveyed PICUs that had training on point-of-care ultrasonography (in up to one third of the PICUs, up to 50% of the medical staff had training in ultrasonography). This proportion was higher than the one found by the study by Lambert et al.19 from 2011, in which the percentage of institutions with formal training did not reach 30%. Most respondents in our study considered that the availability of online educational resources on clinical ultrasonography in paediatric patients is useful, and that paediatricians that care for critical paediatric patients should be trained on this technique. We believe that specific training in point-of-care ultrasound is essential to standardise its use and reduce errors in its interpretation.

The main limitation of our study, which applies to all voluntary surveys, is that it does not reflect reality directly, but rather the views of those surveyed. Despite the high response rate (64.7% of the identified units), we cannot rule out the possibility that the PICUs that responded to the survey were those that use ultrasonography more frequently.

On the other hand, when it came to training on point-of-care ultrasound, there were no established criteria to assess the quality and homogeneity of the training received, so it may have varied widely between units.

Point-of-care ultrasound is a frequently used technique in Spanish PICUs. Ultrasound units are available at a high percentage of the PICUs independently of their level of care. Point-of-care ultrasound was used not only to guide vascular cannulation or drainage placement, but also for the assessment of different organs and systems to complement physical examination and monitoring. Specific training is irregular and should be an essential strategy to promote its use.

The authors have no conflicts of interest to declare.