Reviewer's report
Title:Focused cardiac ultrasound: a training course for pediatric intensivists and
emergency physicians
Version:1Date:24 December 2013
Reviewer:Michael Woo
Reviewer's report:
This study is a program evaluation to determine the number of practical
echocardiographic exams required to reach the same level as a trained pediatric
echocardiographer. The authors have attempted to tackle a challenging yet
pertinent topic for training in point of care ultrasonography. There are detailed
descriptions of the curriculum including topics, instructor-learner ratios, and time
spent over a period of time. The strengths of the study are the use of real patients
and the description of the pathology of the patients and evaluations over a
longitudinal period.
The conclusion suggests that 16 supervised practical examinations for LV function
and 24 supervised practical examination for CI are required. It cannot be
determined from this study whether this should be applicable to all physicians or
only the physicians indicated in this study. As a result the authors overstate the
need for implementation of this course or others at the level of residency and
medical school programs.
Thank you, Mr. Michael Woo, for the excellent suggestions. They were of
fundamental importance to improving the manuscript. We answered each item
individually with the hope of clarifying any questions or uncertainties. The manuscript
was submitted for a review of English grammar by an expert in the area, and the
certificate is attached.
Major Compulsory Revisions
1. There are insufficient details about the physicians participating in the study
that makes it difficult for readers to compare their physician characteristics
with those of the study. Basic demographics such as age, sex, and work
experience are missing.
That piece of information is indeed crucial. We added physician demographic
information in the last paragraph of the Selection of participants - Methods section.
2. A description of the ICU is provided but not of the ER. Why did the
authors choose ICU and ER? Why not ICU only? Which physicians were
excluded in the end (ICU vs. ER)?
The course aimed to train pediatric physicians (ER or ICU) on how to
perform echo examinations in critically ill children, which are assisted in the ER
and ICU. The choice of performing the training in the ICU was based on the
observation that the most severely ill children usually are found in the ICU; thus,
this unit had the highest probability of finding abnormal echocardiographs (as
impaired cardiac function and volume status variation). All 16 physicians,
including the ER physicians, performed the full program (training and
evaluation) in the ICU. This information can now be found in the Methods
section under the subheading ‘Course model and curricular content’.
We decided to allow the participation of intensivists and ER physicians
because they both treat critically ill children in our hospital and thus would
benefit from this training. We think that the heterogeneity of pediatric specialists
was positive in an attempt to highlight the interest of many pediatric specialties
in echo learning.
Among the 20 ICU/ER physicians who volunteered to participate, 16
were randomly selected to attend the training to fulfill the study schedule and the
calculated sample size of 16 participants. The 4 excluded physicians included 3
pediatric intensivists and 1 ER physician. This information can now be found on
Selection of participants - method’s section.
3. There was no evaluation of the theoretical component indicated in the
manuscript. Was there a reason for this?
The theoretical component is undoubtedly essential. As the theoretical content
was based on the main topics of one consensus of experts (Mayo PH, - Chest
2009;135:1050-60) [we added this information at Course model and curricular content],
our goal was not to separately evaluate the theoretical content of the training. However,
we believe that the bedside assessment was enough to evaluate the entire learning
content (theoretical and practical) because echocardiography is an imaging exam and
any associated theoretical knowledge has no clinical applicability without the practical
skills.
4. The authors provide the evaluation form (Table 3) for the practical
component. There is no mention of the validity or reliability of the
evaluation tool. They compare the means of the physician operators with
the pediatric echocardiogaphers. It would be interesting if the inter-rater
reliability were performed between pediatric echocardiographers that
would support the use of this evaluation form. In addition, the range of
results should be reported (including the means which are reported) to
determine if there were any outliers in the physician operator results.
Table 3 shows the echocardiographic parameters analyzed in the practical
evaluation. This format was used only to clarify which variables were recorded
and to help with their tabulation.
The two echocardiographers have the same echo training and large amount
of experience. They are accustomed to diagnosing complex heart disease, are both
members of the American Society of Echocardiography and are Advanced
Pediatric
Echocardiographer
according
to
the
American
Society
of
Echocardiography guidelines. For those reasons, we believe that both performed
similar analyses, especially given that our study involved basic echocardiographic
analyses, which are not at all challenging for an expert to perform. Therefore, we
did
not
determine
the
interobserver
reliability
between
the
two
echocardiographers.
There was no outlier in the study. For continuous variables (EF and CI), we
described the median analysis (in addition to the mean), and the analysis of both
together improved the interpretation of the results. The median values can now be
found in the results section.
Minor Essential Revisions
1. The patients used for practical instruction and evaluation should be
described as a convenience sample. As a result it should be indicated the
echocardiographic exams performed could be subject to selection bias
particularly at the evaluation phases.
The use of a convenience sample revealed that some echocardiographic
abnormalities, such as right ventricular dysfunction and moderate/severe
pericardial effusion, were present only in a small percentage of patients and that
there was no case of cardiac tamponade. These findings limited our assessment
regarding the learning curve of these echocardiographic alterations. Therefore,
we believe that the use of a convenience sample caused some limitations
(additional text was included in the limitations section) but did not really led to a
selection bias.
2. Was there a time limit in the performance of the evaluation and how long
did it take for physician operators to do the each echocardiographic study.
Did the length of time change with each evaluation?
The time to perform the echocardiography was limited to 10
minutes/exam. In all cases, the examination was performed completely within
this time. We did not perform any additional analysis regarding the duration of
the echo exam comparatively during the 3 stages of evaluation. We believe that
10 minutes is an acceptable length (from a clinical point of view) and that the
goal of the training was the quality of the exam and not the speed at which it was
performed. We added this information to the Assessment in the Methods section.
3. Did the physician operators perform any echocardiographic examinations
in addition to the practical and evaluation sessions? Could this have had an
impact on the results?
Yes, because this could have had an impact on the results, the physicians
in training did not perform any echocardiographic examinations in addition to
the practical and evaluation sessions to avoid this mistake. We added this
information to the Methods section under the subheading “Course model and
curricular content”.
4. 96 exams are reported to have been performed, but how many different
patients were studied. Could this be an indicator of selection bias and the
results interpreted accordingly?
A total of 96 different patients were assessed during the three phases of
the evaluation. Each evaluation was performed in a different patient. Patients
were assessed repeatedly only during the practical training. As previously
mentioned, we think that there were limitations caused by the design of the study
and additional text was included in the limitations section.
The clinical and echocardiographic characteristics of these 96 patients are
shown in the 1st paragraph of the results section, as follows: “Among the
patients, 44% were male, and 56% were female, with a median age of 63
months. A total of 66 (69%) patients underwent mechanical ventilation, and 44
(45%) received vasoactive agents. The most frequent clinical diagnosis was
septic shock (39%), followed by acute respiratory failure (33%) and neurological
disease (16%). There was one case of pulmonary hypertension. We observed TR
in 35 (37%) subjects, with 27 (28%) classified as mild, 5 (5%) as moderate
(Figure 5) and 3 (3%) as severe. MR was found in 21 (22%) subjects, with all
classified as mild. PE occurred in 15 (16%) subjects, LV dysfunction in 10
(10%) (Figure 5), and RV dysfunction in only two (2%). There were no cases of
cardiac tamponade.”
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Reviewer's report
Title: Focused cardiac ultrasound: a training course for pediatric intensivists and
emergency physicians
Version:1Date: 4 January 2014
Reviewer: John Atherton
Reviewer's report:
The authors evaluate a combined theoretical and practical training course for
focussed echocardiography in 16 paediatric intensivists/ emergency physicians.
They observed reasonable concordance rates compared with experienced
echocardiographers for assessing left ventricular function qualitatively and IVC
distensibility. Quantitative assessment of left ventricular function and cardiac
index were comparable. There were small numbers of patients with right
ventricular dysfunction, severe valvular regurgitation and no cases with cardiac
tamponade.
This is a topical area for a number of subspecialty groups. The study is
appropriately designed to evaluate their training protocol, although they were
underpowered to assess the utility of their program to train clinicians to identify
significant valvular regurgitation, cardiac tamponade and right ventricular
dysfunction. The findings are clearly reported and I agree with their conclusions.
The limitations are appropriately acknowledged. Whilst the manuscript is
generally well written, there are a number of grammatical errors largely related to
English translation, which require correction.
Major compulsory revisions:
There are a number of grammatical errors largely related to English translation,
which require correction. For example, parasternal is misspelt in a number of
areas through the manuscript and tables (parasternal)
Thank you, Mr. John Atherton, for the warning. The manuscript was submitted
for a review of English grammar by an expert in the area, and the certificate is attached.
I hope these inaccuracies have been resolved and that the manuscript has been
sufficiently improved to meet the publication requirements.
Minor essential revisions:
1. The 2nd sentence of the background in the abstract needs to be rephrased.
Thank you for this advice. We rewrote the sentence and hope that it has become
clearer.
2. Page 4-5: In the methods section, I could not understand the paragraph that
describes the power of the study.
We also rewrote this sentence and hope that it has become clearer.
3. Page 5: Should be eight (not eighth) physicians/ group.
The misspelling was corrected.
4. Page 10: Should be “Longjohn also demonstrated a good……..in
subjectively differentiating ….”
The misspelling was corrected.
5. Page 10: Should be “…was performed in a pioneering way…”
The misspelling was corrected.
6. Table 3: Parasternal is misspelt. I think the authors mean “Stroke volume”,
not “Systolic volume”.
The misspelling was corrected.
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, and I have assessed the statistics in my report