Summary of findings and recommendations
In the following section, the evidence, conclusions, and any recommendations for each
research question/domain, are summarized. These are based on what was presented for
review by the ERG to ascertain the level of agreement in the phase 3 consensus process.
Minor changes to original statements have been made to correct syntax and grammatical
errors and improve clarity for the reader. [Table 1] summarizes the key points for each question.
Table 1
Overall Recommendations for EFSUMB PoCUS Part 1 Clinical Practice Guidelines.
|
PoCUS Application
|
Research Question
|
Overall Recommendation
|
Level of Evidence[*], GRADE Recommendation & Level of Consensus Agreement
|
|
Question 1: PoCUS use in diagnosing pericardial effusion and cardiac tamponade
|
In emergency patients is PoCUS superior to physical examination in terms of: 1) Recognition
of pericardial effusion; 2) Patient management in the case of pericardial effusion;
3) Patient outcome in the case of pericardial effusion?
|
EFSUMB suggests supplementing the physical examination with PoCUS in patients with
hypotension and/or cardio-respiratory symptoms for early recognition of pericardial
effusion/tamponade
|
LoE 3
weak recommendation strong consensus
|
|
Question 2: PoCUS use in diagnosing aortic root dissection
|
In emergency patients is point of care ultrasound (POCUS) superior to physical examination
in terms of: 1) Recognition of type A aortic dissection; 2) Patient management in
the case of type A aortic dissection; 3) Patient outcome in the case of type A aortic
dissection?
|
EFSUMB suggests that there is insufficient evidence to recommend supplementing the
physical examination with PoCUS for early recognition of type A aortic dissection
|
LoE 4
weak recommendation broad agreement
|
|
Question 3: PoCUS use in cardiac arrest
|
In adult patients with cardiac arrest, does the use of PoCUS echocardiography during
resuscitation predict survival in patients with cardiac activity and death in those
with no cardiac activity?
|
EFSUMB suggests that the use of PoCUS to assess for the presence of cardiac activity
may be useful as an adjunct tool to predict survival in cardiac arrest patients
EFSUMB suggests that the absence of cardiac activity on PoCUS is associated with a
very poor chance of survival and may assist in the decision to terminate resuscitation
in TCA (no survivors in patients with no cardiac activity). In MCA the absence of
cardiac activity is associated with a low but not no chance of ROSC/survival and should
not be used as the main basis to cease resuscitation
|
LoE 3
weak recommendation broad agreement
|
|
Question 4: POCUS use in evaluating left ventricular performance
|
Does bedside PoCUS focused echocardiography assessment of left ventricular (LV) performance
by clinician sonographer (CS) emergency physicians (EP) agree with echocardiographic
assessment (echo) by experienced sonographers (ES) (cardiologists/graduated sonographers/emergency
physicians who have completed ultrasound – echocardiography fellowship)?
|
EFSUMB suggests that novice emergency physician sonographers should be able to assess
left ventricular function using visual estimation (graded as normal, reduced, or severely
reduced) or EPSS. Despite the moderate to good agreement, the potential selection
bias in the studies and the fact that, in many cases, the novice sonographers received
additional training means that this level of agreement is not generalizable. There
is insufficient data to comment on the use of VTI
|
LoE 3
weak recommendation broad agreement
|
|
Question 5: PoCUS use in diagnosing hemodynamically significant pulmonary embolism
|
Is PoCUS useful in the diagnosis of hemodynamically unstable pulmonary embolism (PE)?
|
EFSUMB suggests that non-specialist PoCUS may be useful in the diagnosis of hemodynamically
unstable PE
|
LoE 3
weak recommendation broad agreement
|
|
Question 6: PoCUS use in diagnosing deep vein thrombosis
|
Is PoCUS useful in the diagnosis of deep vein thrombosis (DVT) in the ED?
|
EFSUMB recommends that PoCUS may be useful in the diagnosis of DVT in the ED. It may
be the case that emergency physicians with less experience can perform a limited PoCUS
exam for DVT with considerable but not perfect accuracy especially after a period
of focused instruction
|
LoE 3
strong recommendation
broad agreement
|
|
Question 7: PoCUS use in diagnosing pneumothorax
|
What is the diagnostic accuracy of PoCUS for the detection of pneumothorax?
|
EFSUMB recommends that PoCUS may be used to detect pneumothorax. It has good diagnostic
accuracy
|
LoE 3
strong recommendation broad agreement
|
|
Question 8: PoCUS use in diagnosing pleural effusion
|
What is the diagnostic accuracy of PoCUS for the detection of pleural effusion?
|
EFSUMB recommends that PoCUS may be used to diagnose pleural effusions. It has superior
diagnostic accuracy over CXR and clinical examination for the detection of pleural
effusions
|
LoE 3
strong recommendation broad agreement
|
|
Question 9: PoCUS use in diagnosing pneumonia
|
What is the diagnostic accuracy of PoCUS for the detection of pneumonia?
|
EFSUMB recommends that PoCUS may be used in the diagnosis of pneumonia
|
LoE 2
strong recommendation broad agreement
|
|
Question 10: PoCUS use in diagnosing interstitial syndrome
|
How accurate is PoCUS in diagnosing interstitial fluid syndrome in the ED in patients
with acute dyspnea?
|
EFSUMB recommends that PoCUS may be used in the diagnosis of interstitial fluid syndromes
in adult patients in the ED
|
LoE 2
strong recommendation broad agreement
|
* OCEBM (2011) [28].
The following recommendations assume that the PoCUS operator is appropriately trained
and skilled for each particular application.
Question 1: PoCUS use for diagnosing pericardial effusion and cardiac tamponade
In emergency patients is PoCUS superior compared to physical examination in terms
of:
-
Recognition of pericardial effusion
-
Patient management in the case of pericardial effusion
-
Patient outcome in the case of pericardial effusion
Summary of quantity and quality of evidence
21 studies, comparing PoCUS to physical examination in emergency patients with any
incidence of pericardial effusion, were included in the final analysis. All studies
were original studies. No systematic reviews and/or meta-analyses specifically compared
PoCUS to physical examination. Of the included studies, three were randomized controlled
trials (RCT), 14 were prospective observational studies with before/after methodology,
one was a prospective observational study with two parallel tracks, and three were
retrospective cohort studies. The three RCT studies included patients with shock,
cardiac arrest, and respiratory symptoms, respectively. Generally, the number of patients
with pericardial effusion was very low in these studies (2/273 in the shock study,
7/100 in the cardiac arrest study, and 4/315 in the study including patients with
respiratory symptoms). The prospective observational studies included patients with
acute dyspnea (four), shock (three), suspected acute cardiac disease (three), emergency
conditions (two), chest pain/dyspnea (one), chest pain/dyspnea/palpitations (one),
and cardiac arrest (one). The proportion of patients with pericardial effusion ranged
from 0.7 % to 14 % in these studies with a generally higher proportion in studies
including shock patients than in the other patient groups. One study, that was undertaken
in Rwanda, included dyspneic patients with a very high incidence of extrapulmonary
tuberculosis, and in this study, 25 % of patients had a pericardial effusion. The
three retrospective cohort studies examined patients with tamponade/large pericardial
effusions (n = 73), patients with penetrating cardiac injuries (n = 49), and patients
undergoing pericardiocentesis (n = 342).
All 15 prospective observational studies consistently demonstrated either a change
in primary diagnosis, a reduction in the number of differential diagnoses, additional
diagnoses disclosed (including pericardial effusion), an improvement in diagnostic
certainty, or a reduced time to correct diagnoses with POCUS compared to physical
examination alone. The quality of these studies was generally acceptable, but assessors
establishing final diagnoses (i. e., the reference standard) were rarely blinded to
the results of the PoCUS examination, which may bias the results towards increased
effects of the scan. The findings are, however, also consistent across studies with
good assessor blinding and are supported by findings of the two RCTs examining diagnostic
accuracy (in the third RCT only patient-related outcome measures were evaluated).
Both RCTs demonstrated an increase in the proportion of patients who had correct presumptive
diagnoses and improved recognition of pericardial effusion with the use of PoCUS compared
to physical examination alone.
In three of the fifteen prospective observational studies, PoCUS led to a change in
treatment in 25–52 % of the patients included. Specific data on changes in management
in patients with pericardial effusion were not reported.
Based on the three retrospective cohort studies, PoCUS reduced the time to pericardiocentesis
and/or operation in patients with tamponade/large effusions resulting in an improvement
in survival. However, the retrospective study design based on chart reviews in both
studies carries an inherent risk of bias favoring PoCUS. None of the RCTs demonstrated
changes in patient outcome measured as 30-day mortality, intensive care unit (ICU)
length of stay, or hospital length of stay with the use of PoCUS compared to physical
examination alone.
The research team concluded that there is sufficient good evidence demonstrating improved
recognition of pericardial effusion with the use of PoCUS compared to clinical examination
alone. Whether or not changes in management based on these findings have an impact
on patient outcome is unknown.
What is the clinical relevance and applicability?
Pericardial effusion can be caused by a range of diseases including infectious and
rheumatological diseases, malignancies, and trauma.
Small amounts of pericardial effusion are rarely clinically significant, but larger
effusions build up over time or rapidly developed smaller effusions can lead to cardiac
tamponade, compromising circulation, leading to cardiac arrest and ultimately to death.
Early identification of significant effusions – and especially signs of tamponade
– can potentially improve patient triage, management, and treatment. Clinical signs
of significant effusions and tamponade are non-specific, and PoCUS may increase the
proportion of patients in whom these conditions are identified and correctly managed
earlier.
What are the benefits or harms?
The potential benefits of early identification of significant effusions and/or tamponade
are improved triage (patients in need can be taken to relevant institutions with the
highest possible competences to manage the condition earlier) as well as earlier and
more correct management. These benefits may improve patient outcomes.
Ultrasound in itself carries no risks but use of PoCUS in inexperienced hands may
lead to false negatives (i. e., ruling out of effusion in a patient with significant
effusion) leading to a worse patient outcome. It may also lead to a high number of
false positives causing an increase in upstream resource consumption.
Overall recommendation
EFSUMB suggests supplementing the physical examination with PoCUS in patients with
hypotension and/or cardio-respiratory symptoms for early recognition of pericardial
effusion/tamponade (LoE 3, weak recommendation, strong consensus).
Question 2: PoCUS use for diagnosing aortic root dissection
In emergency patients is point-of-care ultrasound (POCUS) superior compared to physical
examination in terms of:
-
Recognition of type A aortic dissection
-
Patient management in the case of type A aortic dissection
-
Patient outcome in the case of type A aortic dissection
Summary of quantity and quality of evidence
Four studies in which POCUS was compared to physical examination in emergency patients
with any incidence of type A dissection were included in the final analysis. All studies
were original studies. No systematic reviews and/or meta-analyses specifically compared
POCUS to physical examination. Of the included studies, three were prospective observational
studies with before/after methodology and one was a retrospective cohort study based
on chart reviews and autopsies. The prospective observational studies included patients
with suspected cardiac disease (two), chest pain/dyspnea/palpitations (one). The number
of patients with aortic dissection was extremely low in these studies, rendering the
studies at a quality level of case-series for this research question. The retrospective
cohort study included patients with confirmed dissection (n = 32) and represents the
best available evidence on this research question.
All three prospective observational studies demonstrated changes in initially suspected
diagnosis with POCUS compared to clinical examination alone, including identification
of aortic dissection in two studies. One study demonstrated changes in patient management
with POCUS, but not specifically for patients with type A dissection.
In the retrospective cohort study, it was reported that the median time to diagnosis
was lower (80 vs. 226 minutes, p = 0.023), the misdiagnosis rate was lower (0 % vs.
43.8 %), and there was a non-significant trend towards lower adjusted mortality (15.4 %
vs. 37.5 %, p = 0.24) with POCUS compared to clinical examination.
In conclusion, there is very weak evidence suggesting a possible effect on improved
recognition of type A aortic dissection with POCUS compared to clinical examination
alone. There is insufficient evidence to arrive at conclusions regarding changes in
patient management and patient outcome with POCUS compared to clinical examination.
What is the clinical relevance and applicability?
Type A aortic dissection can cause a range of severe conditions including stroke,
other ischemic events, and cardiac tamponade, compromising circulation, leading to
cardiac arrest and ultimately to death.
It has previously been established that not even expert echocardiography can be used
to rule out type A dissection. Thus, the potential of POCUS lies in early identification
of type A dissection. This early identification can potentially improve patient triage,
management, and treatment. Clinical signs of type A dissection can be ambiguous, and
POCUS may increase the proportion of patients who have this condition so they can
be identified and correctly managed earlier.
What are the benefits or harms?
The potential benefits of early identification of type A aortic dissection are improved
triage (patients in need can be taken to relevant institutions with the highest possible
competences to manage the condition early) and early correct management – and thus
improved patient outcome.
Ultrasound in itself carries no risks but use of POCUS in inexperienced hands may
lead to false negatives (i. e., the ruling out of type A dissection in a patient with
dissection) that may cause clinicians to accept false safety leading to a worsen patient
outcome. It may also lead to a high number of false positives causing an increase
in upstream resource consumption.
Overall recommendation
EFSUMB suggests that there is insufficient evidence to recommend supplementing the
physical examination with PoCUS for early recognition of type A aortic dissection
(LoE 4, weak recommendation, broad agreement).
Question 3: PoCUS use in cardiac arrest
In adult patients with cardiac arrest, does the use of PoCUS echocardiography during
resuscitation predict survival in patients with cardiac activity and death in those
with no cardiac activity?
Summary of quantity and quality of evidence
Nineteen studies were included in this review. All of these studies were published
between 2001 and 2019. The study design for all but one study was an observational
cohort; 13 of which were prospective, and five were retrospective studies. There was
one RCT. Six studies were multicenter, with the largest recruiting from 20 centers.
Different study populations were noted, all with different inclusion criteria. All
19 studies included out-of-hospital cardiac arrest patients. Eight studies also included
patients in cardiac arrest in the emergency department (ED). Three studies were undertaken
in a prehospital setting, and the remainder involved PoCUS performed in the ED. Three
studies included only patients in traumatic cardiac arrest (TCA), and 9 studies included
only medical cardiac arrest (MCA) patients. The remaining studies included all cardiac
arrest patients regardless of the cause. While most studies included both shockable
and non-shockable rhythms, seven studies included patients in whom the initial presenting
rhythm was non-shockable. Two studies included only patients with pulseless electrical
activity. All participants in the studies were adults over 16 years of age.
Different ultrasound scanning protocols were also noted, with varying ultrasound probes,
variable views used to evaluate cardiac activity, and a different number of PoCUS
assessments. Only one study (Kim et al.) evaluated the correlation between serial
PoCUS assessments and the return of spontaneous circulation (ROSC) and found that,
in all patients with serial PoCUS cardiac standstill ≥ 10 minutes, no patient had
an ROSC.
A variety of definitions were used for cardiac activity within the studies, which
reflect the lack of standardized criteria in the literature. The accuracy of PoCUS
is known to be operator-dependent, and each study required a differing level of training
and clinical experience. Additionally, the inter-observer reliability for PoCUS was
not reported in most studies. However, Gaspari et al. revealed agreement of 0.63 using
Cohen’s kappa.
Each study reported one or more of the following outcomes: ROSC (10 studies), survival
to hospital admission (SHA) (10 studies), and survival to hospital discharge (SHD)
(seven studies). Three studies reported the neurological outcome of the surviving
patients at hospital discharge.
There was considerable heterogeneity in the methodological quality. Fourteen studies
were rated as high risk of bias for patient selection, mainly because of convenience
sampling and exclusion criteria (e. g., due to anatomical or technical difficulties).
The PoCUS protocols that were used varied between studies, which is reflected in the
scoring of the index test. Ten studies failed to define a priori the presence or absence
of cardiac activity, which was the main reason for rating the index test as high risk
of bias. Due to inappropriate exclusion from the analysis (e. g., loss of follow-up)
in two studies, they were rated as high risk of bias in the flow and timing.
What is the clinical relevance and applicability?
PoCUS is widely used in the evaluation of patients in the ED to guide the diagnosis
and resuscitation of patients with acute breathlessness, shock, and cardiac arrest.
During resuscitation in cardiac arrest, PoCUS and blood gas are key in identifying
reversible causes of cardiac arrest. PoCUS is easily integrated into advanced life
support (ALS) and its use has been integrated into the universal ALS algorithm. The
use of PoCUS for TCA has also been advocated.
What are the benefits or harms?
PoCUS may have a role in identifying patients for whom resuscitation is futile with
predicted death, or successful with predicted good neurological outcome. It is also
useful in the recognition of the reversible causes of cardiac arrest which are found
to have a large impact on the patient’s management and outcome.
Two small prospective observational studies showed that PoCUS use is associated with
a longer duration of pulse checks. However, another study suggested that the implementation
of a structured ultrasound algorithm reduced the duration of pulse checks, which highlights
the importance of following a strict PoCUS protocol during cardiac arrest to minimize
interruptions of cardiopulmonary resuscitation (CPR).
Overall recommendation
EFSUMB suggests that the use of PoCUS to assess the presence of cardiac activity may
be useful as an adjunct tool to predict survival in cardiac arrest patients (LoE 3,
weak recommendation, broad agreement).
EFSUMB suggests that the absence of cardiac activity on PoCUS is associated with a
very poor chance of survival and may assist in the decision to terminate resuscitation
in TCA (no survivors in patients with no cardiac activity). In MCA the absence of
cardiac activity is associated with a low but not no chance of ROSC/survival and should
not be used as the main basis to cease resuscitation (LoE 3, weak recommendation,
broad agreement).
Question 4: POCUS use for evaluating left ventricular performance
Does bedside PoCUS focused echocardiography assessment of left ventricular (LV) performance
by clinician sonographer (CS) emergency physicians (EPs) agree with echocardiographic
assessment (echo) by experienced sonographers (ESs) (cardiologists/graduated sonographers/emergency
physicians who have completed ultrasound – echocardiography fellowship)?
Summary of quantity and quality of evidence
Ten papers were included in the final review, with a total of 1202 PoCUS examinations
involving 1104 patients being performed. Nine studies included 143 CSs (one study
did not specify the number of CSs).
Nine studies were prospective observational cohort studies and one was a retrospective
chart review – all were single-center studies. All studies included only patients
presenting to the hospital via the ED and all used cart-based ultrasound machines
with a phased array transducer. One study included PoCUS performed in the ED, ICU,
and wards. In all other studies, PoCUS was performed in the ED. Only one study recruited
all EPs in the recruiting ED and three recruited only EPs who met prespecified training
criteria. There was considerable heterogeneity regarding the ultrasound and echo experience
of the CSs. Eight studies offered study-specific training in echo to CS participants.
The ESs used the same ultrasound machines as the CSs in three studies, used different
machines in four studies, and reviewed the video clips made by the CS to report their
findings in four studies. The inclusion criteria for patients also varied: two studies
included only patients with hypotension, two recruited patients with dyspnea, five
studies recruited patients who required an inpatient echo for any reason, and one
included any patient with suspected cardiac disease. The ESs were also EPs in two
studies and cardiologists/sonographers in nine studies (one study combined EPs and
cardiologists as ESs). In five studies the CS performed PoCUS prior to the ES, while
in two studies the ES scanned first. In four studies the ES reviewed video images
taken by the CS. In three studies, videos taken by sonographers were reviewed by a
cardiologist ES, and, in three studies, ES cardiologists performed their own echo.
In nine studies the second sonographer was blind to the findings of the first, while
in one study, the ESs were not blind to E-point septal separation (EPSS) measures
by the CS. In four studies there was a time difference of greater than one hour between
CS and ES scans.
Quality was assessed using the QUADAS-2 tool. All studies scored high-risk in at least
one domain and seven scored high-risk in two or more. Thus, the quality of the included
studies was low with poor generalizability and all studies were assessed as having
a high risk of bias. All studies excluded a proportion of echo studies performed,
most commonly because of poor image quality. There is insufficient data to specify
the exact numbers of excluded patients.
Visual estimation of LV performance
In seven studies, visual estimation using ranked categories was the most used method
by CSs to assess left ventricular performance. The performance was typically ranked
as normal, reduced, or severely reduced (six studies, additional categories in one
paper). In six studies, performance was defined by estimated ejection fraction. In
two studies, both the CS and the ES estimated visual performance, in two studies the
CS estimated ventricular performance and the ES measured it using Simpson’s biplanar
technique, in two studies the ES estimated the ejection fraction using the Teichholz
method.
There was heterogeneity in the methods used to assess agreement between the CS and
the ES for visual estimation of ventricular performance: six studies reported a simple
or weighted Cohen’s Kappa (0.46–0.79) and one reported Pearson’s correlation (for
the two recruited EPs 0.77 & 0.78). Four studies reported row/overall agreement (69–93 %),
two used a Bland-Altman plot, and three calculated the specificity and sensitivity
for identifying a set level of ventricular performance.
Overall, there was moderate to high agreement between the CS and the ES for the visual
estimation of left ventricular performance. There was good agreement in identifying
left ventricular performance as normal and with severe dysfunction. Agreement was
moderate in identifying moderate dysfunction.
E-point septal separation (EPSS) assessment of LV performance
EPSS was assessed in three studies. No studies compared EPSS assessment by both the
CS and the ES. Two studies compared EPSS by the CS with visual estimation by the ES
(one used Kappa (0.85) and the other one calculated the Spearman’s correlation (0.84)).
One study compared the EPSS by the CS to the ejection fraction assessed according
to Teichholz by the ES and assessed agreement using Pearson correlation (0.73)
Velocity time integral (VTI) assessment of LV performance
One study assessed VTI. The agreement was moderate with a Kappa of 0.56.
In summary, the CS had moderate to high agreement with the ES in assessing left ventricular
performance using visual estimation categorizing left ventricular function as normal,
moderately impaired, or severely impaired, and using EPSS. There is considerable heterogeneity
among studies. The findings have limited generalizability.
What is the clinical relevance and applicability?
Acute cardio-respiratory dysfunction is the most common emergency presentation in
most emergency departments in Europe, North America, and Australasia. Assessment of
left ventricular function is a key diagnostic test in the assessment of acute dyspnea,
shock, and cardiac arrest. It assists in defining etiology and guiding therapy. Due
to the time-critical nature of these presentations, PoCUS is best performed on or
close to the patient’s arrival in the ED.
What are the benefits or harms?
The main benefit is early diagnosis of problems with LV performance, which may result
in early treatment and improved outcomes.
A poorly performed or interpreted CS PoCUS leads to an incorrect diagnosis and/or
wrong treatment. We found no evidence of wrong interpretation by the CS that would
lead to wrong management decisions. The levels of agreement were highest for normal
and severe dysfunction. There were lower levels of agreement in differentiating mild
from moderate left ventricular function. However, this is unlikely to result in significant
errors in care.
Overall recommendation
EFSUMB suggests that novice emergency physician sonographers are able to assess left
ventricular function using visual estimation (graded as normal, reduced, or severely
reduced) or EPSS. Despite the moderate to good agreement, the potential selection
bias in the studies and the fact that, in many cases, the novice sonographers received
additional training means that this level of agreement is not generalizable. There
is insufficient data to comment on the use of VTI (LoE 3, weak recommendation, broad
agreement).
Question 5: PoCUS use for diagnosing hemodynamically significant pulmonary embolism
Is PoCUS useful in the diagnosis of hemodynamically unstable pulmonary embolism (PE)?
Summary of quantity and quality of evidence
Five studies were identified in a systematic review of the literature – all included
studies adopted prospective observational methods. Three studies were multicenter
and two were single-center. Across the five studies, a total of 124 patients had hemodynamic
instability and a proven PE. Only one study was concerned with the population of interest;
the other four studies provided a post hoc analysis of hemodynamically unstable patients
representing a small subgroup. Two of the included studies solely evaluated the heart,
one study utilized a protocol that included evaluation of the lungs, heart, and abdomen
(including IVC), one study evaluated the heart and deep veins, and one study evaluated
the lung, heart, and deep veins. All of the studies were designated “high risk” in
one domain of the QUADAS2 tool and had at least one or more “unclear risks”.
The current evidence specifically looking at non-specialist PoCUS in the context of
hemodynamically unstable patients with PE is both scarce and of poor quality. Despite
the quantity and quality of the evidence being insufficient to make a strong recommendation,
the results of these limited studies do suggest that PoCUS could have a role in the
diagnosis of hemodynamically unstable PE. This is in keeping with the experience in
specialist echocardiography as well as anecdotal and clinical experience. Further
high-quality research with sufficient patient populations is required to provide better
evidence regarding this question.
What is the clinical relevance and applicability?
Patients presenting with hemodynamic instability may demonstrate a range of underlying
pathologies, with PE as one possibility. It can be a difficult diagnosis to make and
can present in an atypical manner. In patients with a suspected PE who are hemodynamically
unstable, a delay to commencing definitive treatment can have a negative impact on
mortality and morbidity. However, reperfusion therapy is associated with possible
adverse effects and therefore the decision to perform this type of therapy can also
be difficult. It is accepted that specialist/expert echocardiography in PE can demonstrate
evidence of right heart strain and failure. This is especially true for PEs causing
hemodynamic instability. Given the widespread use of PoCUS in acute care settings
and the use of echocardiography for identifying the cardiac sequelae of PE, it is
logical there could be a role for non-specialist PoCUS in identifying signs consistent
with hemodynamically unstable PE. The identification of echocardiographic findings
and, therefore, the likely presence of PE as the cause of hemodynamic instability
could facilitate earlier treatment and give treating physicians greater confidence
regarding diagnosis and management. Conversely, the absence of echocardiographic findings
could prompt physicians to consider alternative diagnoses. This systematic review
investigates whether non-specialist PoCUS looking for evidence of right heart strain
or failure, findings consistent with hemodynamically unstable PE, are concordant with
gold standard diagnostics for PE.
What are the benefits or harms?
The benefit of PoCUS in the diagnosis of hemodynamically unstable PE would be to reduce
the time to diagnosis thereby allowing commencement of lifesaving treatment sooner.
The ability to identify signs consistent with PE causing hemodynamic instability using
non-specialist PoCUS would give physicians greater confidence to start a lifesaving
but not entirely benign treatment. In the absence of PoCUS signs of hemodynamically
unstable PE, this would prompt the attending physician to consider alternative diagnoses.
Non-specialist PoCUS does not present any direct harm to the patient. However, there
are circumstances where it could indirectly cause harm. If PoCUS delayed a patient
receiving a gold standard investigation, this could lead to patient harm. PoCUS is
a user-dependent modality with accuracy linked to the skill/experience of the individual
operator. Incorrect interpretation of PoCUS findings leading to inappropriate provision
or withholding of treatment could cause patient harm.
Overall recommendation
EFSUMB suggests that non-specialist PoCUS may be useful in the diagnosis of hemodynamically
unstable PE (LoE 3, weak recommendation, broad agreement).
Question 6: PoCUS use for diagnosing deep vein thrombosis
Is PoCUS useful in the diagnosis of deep vein thrombosis (DVT) in the ED?
Summary of quantity and quality of evidence
The review examines the accuracy of EP-performed PoCUS to identify DVT when compared
to gold standard radiology imaging.
23 studies were identified in a search of the literature from 2000 up to an including
2020. Most were prospective observational studies. One study was conducted as a randomized
controlled trial. No meta-analyses were included. Studies were included from seven
international centers. However, most originated in North America. 21 out of 23 studies
were carried out at a single center.
Across all of the studies, there was a total patient population of 3,530, including
757 patients with a confirmed DVT. Most patients were selected by convenience sampling
based on operator availability in the ED.
Operators had a wide level of training using PoCUS ranging from newly qualified EM
residents to experienced EPs certified to perform this application.
In general, when experienced physicians carried out the PoCUS examination, the reported
sensitivity and specificity were usually high with narrow confidence intervals. Less
experienced operators reported a lower sensitivity and/or wide confidence intervals.
Scanning protocols differed across many of the studies. The region of interest that
was examined was not standardized in this review. Different imaging techniques were
also used ranging from 2-point and 3-point compression techniques to color Doppler
and duplex studies. On account of this degree of heterogeneity, it is difficult to
carry out a comparative quantitative analysis of the 23 studies.
Using the QUADAS-2 tool, 10 studies showed a low risk of bias, eight studies had unclear
risk, and five studies had at least one domain with a high risk of bias.
What is the clinical relevance and applicability?
Patients presenting to the ED with signs and symptoms of DVT may be managed safely
without hospital admission. Physician-performed PoCUS presents the opportunity to
facilitate the rapid assessment, triage, and possible discharge of this cohort.
PoCUS for DVT in the ED is probably best applied as part of a rule-in strategy. The
absence of occlusive thrombosis, therefore, should not rule out this diagnosis. If
the clinical pretest probability is low and sonographic signs of DVT are not present,
then it may be reasonable to withhold anticoagulant therapy entirely or until gold
standard imaging is available.
In the hands of well-trained emergency physicians, PoCUS is generally quick and accurate,
especially when used as a rule-in test for DVT. This aspect may also limit generalizability
in EDs where such expertise is not available. However, the evidence supporting PoCUS
for DVT is weak for less-experienced operators. This may lead to delays in disposition
or failure to treat patients appropriately.
What are the benefits or harms?
ED patients are often treated empirically when DVT is suspected and there may be a
delay with respect to definitive radiological diagnosis. PoCUS may reduce the use
of therapeutic anticoagulation if used at the early stages of clinical evaluation
rather than waiting for gold standard imaging. PoCUS may also decrease the morbidity
and mortality from complications of DVT. Such end points are beyond the scope of this
review. In addition, the use of PoCUS for DVT may also help identify alternative pathology
such as cellulitis, abscess, superficial thrombophlebitis, popliteal cysts, and muscular
tear/hematoma.
The use of PoCUS for DVT presents no direct harm to patients. However, incorrect interpretation
and application of point-of-care findings may lead to inappropriate withholding or
provision of anticoagulants or other therapies.
Overall recommendation
EFSUMB recommends that PoCUS may be useful in the diagnosis of DVT in the ED . It may be the case that emergency physicians with less experience can perform a limited
PoCUS exam for DVT with considerable but not perfect accuracy, especially after a
period of focused instruction (LoE 3, strong recommendation, broad agreement).
Question 7: PoCUS use for diagnosing pneumothorax
What is the diagnostic accuracy of PoCUS for the detection of pneumothorax?
Summary of quantity and quality of evidence
40 studies, five meta-analyses, and one narrative systematic review were identified.
Many of these studies were prospective, single-center, single-blinded studies. The
40 studies included more than 7000 patients, the majority of whom were trauma patients;
six studies were in patients undergoing lung biopsies, and one study was in patients
post subclavian line insertion.
15 studies were considered good quality, 12 studies were of average quality, and 13
studies were of poor quality. The studies showed a high sensitivity and specificity
of lung ultrasound (sensitivity range: 47–100 %; specificity range: 78–100 %). However
there was significant heterogeneity between studies.
What is the clinical relevance and applicability?
Pneumothorax remains an important cause of acute respiratory embarrassment, and its
rapid detection can aid in accurate diagnosis and treatment (thoracocentesis). Clinical
examination is poor at detecting small pneumothoraces and can have difficulty detecting
tension pneumothorax. Chest X-ray (CXR) is highly specific but has poor sensitivity.
Computed tomography (CT) remains the gold standard, however, may be logistically difficult
in the hemodynamically unstable patient.
PoCUS has much to offer in this regard as a portable, non-ionizing diagnostic tool
that can not only detect pneumothorax but can also be used to assess for other causes
of breathlessness and shock. It can also be used to assess for pneumothorax after
bedside procedures such as vascular access, chest drain removal, and biopsy.
What are the benefits or harms?
Potential benefits include decreased time to diagnosis of suspected pneumothorax,
shortened time to potentially lifesaving intervention as well as reduced reliance
on CXR and CT for diagnosis, minimization of risks to patients of transportation,
and minimization of costs. Potential harms include a risk of misdiagnosis – pneumothorax
PoCUS is an expert technique. The technique is prone to confounders such as endobronchial
intubation, bullae, and high positive end-expiratory pressure (PEEP). A lung point
is not always seen. Clinical integration and experience are thus crucial to ensuring
the accuracy of the technique. PoCUS may distract the clinician (and team) from obvious
clinical cues and delay the implementation of interventions (such as CPR).
Overall recommendation
EFSUMB recommends that PoCUS may be used to detect pneumothorax. It has good diagnostic
accuracy (LoE 3, strong recommendation, broad agreement).
Question 8: PoCUS use for diagnosing pleural effusion
What is the diagnostic accuracy of PoCUS for the detection of pleural effusion?
Summary of quantity and quality of evidence
Nine studies and two meta-analyses were identified. Seven studies were prospective
observational single-center trials, with one being a subgroup analysis of a previous
trial, and one being a case-control study. The majority were single-blinded. The 9
studies contained a total of 1054 patients. The meta-analyses contained 1554 and 924 patients,
respectively. The populations were a mixed group including intensive care patients,
trauma patients, patients with acute heart failure, and patients with acute dyspnea
presenting to the emergency department. Four studies were considered “good”, three
“average”, and two “poor” quality. Both meta-analyses were considered average quality.
All studies showed PoCUS to have a good diagnostic accuracy, approaching that of CT
and better than that of CXR and clinical examination.
What is the clinical relevance and applicability?
Pleural effusions are common and can either be a direct cause of respiratory compromise
or can be secondary and associated with other illnesses, including heart failure,
malignancy, and empyema. Pleural fluid drainage as a diagnostic or therapeutic maneuver
is a standard competency in many hospital specialties.
What are the benefits or harms?
Potential benefits include reduction in time to diagnosis, increased diagnostic accuracy,
and improved safety of pleural procedures.
The main harm is the result of user error – either due to misdiagnosis or a procedural
error.
Overall Recommendation
EFSUMB recommends that PoCUS may be used to diagnose pleural effusions. It has superior
diagnostic accuracy over CXR and clinical examination for the detection of pleural
effusions (LoE 3, strong recommendation, broad agreement).
Question 9: PoCUS use for diagnosing pneumonia
What is the diagnostic accuracy of PoCUS for the detection of pneumonia?
Summary of quantity and quality of evidence
Nine studies were identified: two studies were systematic reviews and the remaining
seven were systematic reviews and meta-analyses. Eight of these studies consistently
found the sensitivity of PoCUS in detecting consolidations to be at least 80 % and
the specificity to be over 70 %. One study identified a broader range of sensitivity
and specificity results, 68–100 % and 57–100 %, respectively.
The AMSTAR-2 tool was used to assess the quality of the studies included. Although
most studies were assessed with low or critically low quality, this was mostly due
to domains 2 and 7 of the AMSTAR-2 tool, which required an explicit statement on timing of establishment
of review methodology, and provision of all excluded studies. Overall, the other critical
domains relating to consideration and assessment of bias and the handling of data from included
studies were mostly appropriately achieved. The research team felt that although domains 2 and 7 are AMSTAR-2 critical domains, they are focused on the structure of the publication
rather than the quality of the work done and had a consistently disproportionate impact
on the reviewed papers and the overall result.
What is the clinical relevance and applicability?
Patients with pneumonia may present with symptoms that can be attributed to a number
of conditions, but treatments for the broad range of differential diagnoses vary greatly
and in certain conditions may be time-critical. The most common diagnostic workup
for pneumonia combines the bedside clinical assessment and laboratory tests alongside
plain CXR imaging or the gold standard of CT imaging. It is not feasible to perform
a CT scan on all patients presenting with signs and symptoms of pneumonia due to constraints
on time and resources and the exposure to radiation but transferring patients for
CXR is also time-consuming and has a lower diagnostic yield, which may contribute
to uncertainty between conditions within the differential diagnoses. The competent
use of PoCUS in clinical care can assist in developing a definitive diagnosis at the
same time as initial clinician assessment, thus reducing the time to correct diagnosis
and treatment and minimizing the harm of unnecessary treatment given to cover the
broad spectrum of acute differential diagnoses. Effective use in a clinical context
can reduce the number of CT scans performed to confirm diagnosis, except in those
cases with deeper consolidative changes not reaching the pleural line, where CT remains
the gold standard investigation.
What are the benefits or harms?
In clinical practice, for both high and low resource settings, CT is rarely used to
diagnose acute pneumonias. Therefore, although it is the gold standard investigation,
the typical clinical comparator is the CXR and clinical assessment.
POCUS may improve the diagnostic accuracy of standard bedside clinical assessment
resulting in a high sensitivity for consolidative changes reaching the pleural line
which may reduce the time to correct diagnosis. The number of CT and CXR investigations
performed may be reduced by utilizing PoCUS in clinical practice.
While these studies did not report any direct or indirect harm as a result of using
bedside PoCUS, indirect harm may occur when its use delays gold standard investigation
and treatment. The operator-dependent nature of the investigation may lead to misinterpretation
which may lead to inappropriate intervention or withholding of treatment.
Overall Recommendation
EFSUMB recommends that PoCUS may be used in the diagnosis of pneumonia (LoE 2, strong
recommendation, broad agreement).
Question 10: PoCUS use for diagnosing interstitial syndrome
How accurate is PoCUS for diagnosing interstitial fluid syndrome in the ED in patients
with acute dyspnea?
Summary of quantity and quality of evidence
Eight prospective studies and three systematic reviews with meta-analyses were identified.
Of the prospective studies, two were RCTs and six were prospective cohort studies.
All of the studies included ED patients with acute dyspnea or recent worsening of
chronic dyspnea. Most of the studies used a similar focused lung PoCUS protocol and
diagnostic criteria for interstitial syndrome. The target condition in all studies
was either acute pulmonary edema or acute decompensated heart failure. Study investigators
were blinded to the reference standard in all studies. In some studies, the sonologist
was not blinded to the clinical information or was involved in the clinical workup
of the patient. We regarded this as a pragmatic approach as it is likely that the
clinician would be performing the PoCUS scan as an adjunct to the physical exam and
as part of their clinical evaluation. In many studies, PoCUS was performed by expert
operators, apart from three studies where non-experts performed the scan. However,
the accuracy of PoCUS was still relatively high in these studies which provided some
insight into the potential benefits, even in non-expert hands. The proportion of patients
with pulmonary edema or acute decompensated heart failure was similar among the studies.
One RCT excluded critically unwell patients with dyspnea who may have been likely
to benefit from PoCUS. Published data indicated that PoCUS was highly sensitive and
specific in diagnosing interstitial fluid syndrome (range: sensitivity 70–96 % and
specificity 75–95.5 %). The main limitation of the studies was non-consecutive patient
enrollment with most studies considered to have an unclear or high risk of bias in
the patient selection domain. There was risk of bias and applicability concerns with
half of the studies. Two studies had a high risk of bias due to inconsistently applied
reference standards.
Among the systematic reviews and meta-analyses, PoCUS accuracy was similar with sensitivity
ranging from 73 % to 94 % and specificity from 84 % to 92 %. One of the systematic
reviews included pre-hospital and ICU-based PoCUS, and another included ward-based
PoCUS. Furthermore, there was significant heterogeneity among studies. However, appropriate
quantitative synthesis models were used for the meta-analysis to account for this.
Overall, our confidence level was moderate to high for all of the systematic reviews.
Many studies in this review were prospective cohort studies with two RCTs. While there
was some heterogeneity between studies and some limitations in patient selection,
all showed a trend towards good diagnostic accuracy of PoCUS compared to the final
clinical diagnosis or standard care.
What is the clinical relevance and applicability?
Interstitial fluid syndromes are an important cause of acute dyspnea and respiratory
failure in patients presenting to the ED. It is important to recognize this pathology
early and distinguish it from other important causes of respiratory distress such
as an exacerbation of chronic obstructive pulmonary disease (COPD), as the treatment
is vastly different. However, this differentiation can be difficult due to the overlap
of signs and symptoms. Physical examination and common investigations such as CXR
and Brain Natriuretic Peptide (BNP) have limited sensitivity in the diagnosis of pulmonary
interstitial fluid. PoCUS is a rapid and effective bedside tool for evaluating the
acutely dyspneic patient and can improve the accuracy of clinical assessment.
What are the benefits or harms?
PoCUS may augment the sensitivity of clinical evaluation. Furthermore, it may reduce
the time to diagnosis and treatment and help to categorize acute dyspnea as cardiogenic
or non-cardiogenic in origin. Using PoCUS may reduce ionizing radiation resulting
from CT and CXR.
Theoretical risks from mechanical and thermal effects on tissues from ultrasound use
may exist but this is considered less relevant in PoCUS practice. Indirect harms could
be caused by misdiagnosis – as B-lines (dynamic vertical ring-down-type artifacts
seen on lung PoCUS) are not specific for interstitial fluid syndromes. Patients may
be initiated on incorrect treatment based on PoCUS findings alone. Therefore, it is
essential that PoCUS is integrated with the clinical assessment and applied in the
appropriate context with a focused question in mind. In the context of the current
Covid-19 pandemic, we now acknowledge that B-lines are a key finding in Covid-19 pneumonitis
as well. Therefore, practitioners must understand that in areas with a high prevalence
of Covid-19, the specificity of B-lines for pulmonary edema may be reduced even further.
Overall recommendation
EFSUMB recommends that PoCUS may be used in the diagnosis of interstitial fluid syndromes
in adult patients in the ED (LoE 2, strong recommendation, broad agreement).
