Point-of-care ultrasonography for evaluation of acute dyspnea in the emergency department

Abstract

Background:
Acute dyspnea is a common symptom in the emergency department (ED). Standard approach to dyspnea often relies on radiologic and laboratoristic results, causing excessive delay before adequate therapy is started; an integrated point-of-care ultrasonography (PoCUS) approach can shorten the time needed to formulate a diagnosis maintaining an acceptable safety profile.

Methods:
Consecutive adult patients presenting with dyspnea and admitted after ED evaluation were prospectively enrolled. The gold standard was the final diagnosis assessed by two expert reviewers. Two physicians independently evaluated the patient: sonographer performed ultrasonography (US) evaluation of lung, heart and inferior vena cava, while treating physician requested traditional tests as needed. Time needed to formulate US and ED diagnosis was recorded and compared. Accuracy and concordance of US and ED diagnosis were calculated.

Results:
2683 patients were enrolled. Average time needed to formulate US diagnosis was significantly lower than that required for ED diagnosis (24±10 min vs 186±72 min, p 0.025). US and ED diagnosis showed a good overall concordance (k=0.71). There were no statistically significant differences in the accuracy of PoCUS and standard ED workup for the diagnosis of acute coronary syndrome, pneumonia, pleural effusion, pericardial effusion, pneumothorax and dyspnea from other causes; PoCUS was significantly more sensitive for the diagnosis of heart failure, while standard ED workup performed better in the diagnosis of chronic obstructive pulmonary disease/asthma and pulmonary embolism.

Conclusions:
PoCUS represents a feasible and reliable diagnostic approach to the dyspnoic patient, allowing a reduction of the diagnostic time. This protocol could help to stratify patients who should undergo a more detailed evaluation.

Full text

Point-of-Care Ultrasonography for
Evaluation of Acute Dyspnea in the ED
Maurizio Zanobetti, MD; Margherita Scorpiniti, MD; Chiara Gigli, MD; Peiman Nazerian, MD; Simone Vanni, MD;
Francesca Innocenti, MD; Valerio T. Stefanone, MD; Caterina Savinelli, MD; Alessandro Coppa, MD; Sofia Bigiarini, MD;
Francesca Caldi, MD; Irene Tassinari, MD; Alberto Conti, MD; Stefano Grifoni, MD; and Riccardo Pini, MD
BACKGROUND: Acute dyspnea is a common symptom in the ED. The standard approach to
dyspnea often relies on radiologic and laboratory results, causing excessive delay before
adequate therapy is started. Use of an integrated point-of-care ultrasonography (PoCUS)
approach can shorten the time needed to formulate a diagnosis, while maintaining an
acceptable safety profile.
METHODS: Consecutive adult patients presenting with dyspnea and admitted after ED eval-
uation were prospectively enrolled. The gold standard was the final diagnosis assessed by two
expert reviewers. Two physicians independently evaluated the patient; a sonographer per-
formed an ultrasound evaluation of the lung, heart, and inferior vena cava, while the treating
physician requested traditional tests as needed. Time needed to formulate the ultrasound and
the ED diagnoses was recorded and compared. Accuracy and concordance of the ultrasound
and the ED diagnoses were calculated.
RESULTS: A total of 2,683 patients were enrolled. The average time needed to formulate the
ultrasound diagnosis was significantly lower than that required for ED diagnosis (24 
10 min vs 186 72 min; P¼.025). The ultrasound and the ED diagnoses showed good
overall concordance (
k
¼0.71). There were no statistically significant differences in the
accuracy of PoCUS and the standard ED evaluation for the diagnosis of acute coronary
syndrome, pneumonia, pleural effusion, pericardial effusion, pneumothorax, and dyspnea
from other causes. PoCUS was significantly more sensitive for the diagnosis of heart failure,
whereas a standard ED evaluation performed better in the diagnosis of COPD/asthma and
pulmonary embolism.
CONCLUSIONS: PoCUS represents a feasible and reliable diagnostic approach to the patient
with dyspnea, allowing a reduction in time to diagnosis. This protocol could help to stratify
patients who should undergo a more detailed evaluation. CHEST 2017; 151(6):1295-1301
KEY WORDS: dyspnea; emergency medicine; ultrasound
ABBREVIATIONS: ALI = acute lung injury; CCT = chest CT; CXR =
chest radiograph; ECHO = echocardiography; IVC = inferior vena
cava; LUS = lung ultrasonography; PoCUS = point-of-care
ultrasonography
AFFILIATIONS: From the Emergency Department, Careggi University
Hospital, Florence, Italy.
FUNDING/SUPPORT: The authors have reported to CHEST that no
funding was received for this study.
CORRESPONDENCE TO: Maurizio Zanobetti, MD, Largo Brambilla 3,
50134 Firenze, Italy; e-mail: zanomau@libero.it
Copyright Ó2017 American College of Chest Physicians. Published by
Elsevier Inc. All rights reserved.
DOI: http://dx.doi.org/10.1016/j.chest.2017.02.003
[Original Research Pulmonary Procedures ]
journal.publications.chestnet.org 1295

Acute dyspnea is a frequent presenting symptom in the
ED. Emergency physicians need to rapidly and
accurately formulate a diagnosis to guide an early and
appropriate therapeutic intervention, especially in
critically ill patients in whom rapid stabilization is
crucial to reduce morbidity and mortality.
Dyspnea is the leading symptom of many diseases, and
rapid discrimination of the underlying pathologic
condition is often difficult for the emergency physician.
A careful anamnesis and a thorough physical
examination can direct diagnostic suspicion, but these
methods need to be integrated with laboratory and
radiologic testing, whose results are often also
delayed.
1-3
Patients with dyspnea are often evaluated by using chest
radiograph (CXR) or chest CT (CCT) scans; these
techniques, however, have some disadvantages,
including radiation exposure and contraindication in
pregnant patients.
4
Moreover, it can be difficult to
perform CXR in critically ill patients, and results may be
misinterpreted.
5,6
Conversely, CCT scanning, which is
considered the gold standard for the differential
diagnosis of dyspnea,
7
has high costs, is not feasible in
patients in unstable condition, and is not available 24 h a
day in all ED settings.
8
Point-of-care ultrasonography (PoCUS) has become a
widely used diagnostic tool in the ED. Because it can be
rapidly performed at the bedside by the emergency
physician, it should be considered an extension of the
physical examination, adding anatomic and functional
information to the clinical data.
9-11
This approach allows
identification of the most likely diagnosis and prompt
initiation of urgent therapies.
Many studies have confirmed the high accuracy of lung
ultrasonography (LUS) in the differential diagnosis of
acute respiratory failure. LUS seems to be at least as
accurate as CXR, with a higher sensitivity for pulmonary
edema, pneumothorax, pneumonia, and free pleural
effusion.
12-15
Emergency echocardiography (ECHO) performed by
emergency physicians can also add some important
information regarding patients with acute dyspnea
(ie, dilation of heart chambers, visual estimation of left
ventricular ejection fraction,
16-18
presence of pericardial
fluid). Integrating LUS and ECHO helps to differentiate
cardiogenic from noncardiogenic dyspnea.
19-21
Finally,
the inferior vena cava (IVC) diameter and its variations
during respiratory activity allow an indirect estimation
of right atrial pressure and an assessment of volume
status, providing useful information to guide fluid
therapy.
22,23
Based on this information, integration of lung, heart,
and IVC ultrasound with PoCUS could lead to a rapid
diagnosis and therefore to targeted, early treatment of
patients with acute dyspnea in the ED. The aim of the
present study was to evaluate the feasibility and
diagnostic accuracy of PoCUS for the management of
patients with acute dyspnea in the ED.
Patients and Methods
Design, Setting, Protocol, and Population
This prospective, blinded, observational study was performed in the
ED of a university-affiliated teaching hospital. The study, which is
consistent with the principles of the Declaration of Helsinki on
clinical research involving human subjects, was approved by the
institutional review board committee of the ED of Careggi University
Hospital (project approval no. 05/2012). Written informed consent
was obtained from each patient included in the study.
Consecutive adult patients (aged >18 years) presenting with acute
dyspnea of every degree were considered for the study; patients with
dyspnea of traumatic origin or discharged after ED evaluation were
excluded. The study was performed by 10 emergency physician
sonographers who had previously attended a professional 80-h
course of theoretical lessons and a training program comprising 150
LUS and 150 ECHO in the ED (as required by the American College
of Emergency Physicians’guidelines
24
) and with at least 2 years’
experience.
Primary assessment of enrolled patients consisted of a routine
evaluation with detection of vital signs, a medical history, physical
examination, and 12-lead ECG; the treating physician then requested
CXR, CCT scans, ECHO performed by a cardiologist, and blood
sampling or arterial blood gas analysis as needed. The treating
physician gave notification to one of the emergency physician
sonographers, who performed the PoCUS before the results of these
additional tests were received. After the completion of the ultrasound
evaluation, the sonographer investigator, only aware of the results of
the primary assessment, completed a standardized form, specifying
which diagnosis among heart failure, acute coronary syndrome,
pneumonia, pleural effusion, pericardial effusion, COPD/asthma,
pulmonary embolism, pneumothorax, ARDS/acute lung injury (ALI),
or other (cancer, interstitial lung disease, psychogenic dyspnea,
metabolic disorder, neurologic disorder, or musculoskeletal chest
pain) was the most likely (ultrasound diagnosis). For each patient,
up to two concomitant diagnoses could be present. Finally, the
treating physician, blinded to the PoCUS findings, after evaluating
results of the previously requested additional tests, completed a
standardized form specifying which one or two of the
aforementioned diagnoses were most likely (ED diagnosis).
For each patient, the time of entry into the visit room, the time needed
to perform the ultrasound scan and relative diagnosis, and the time of
formulation of ED diagnosis were recorded. Ultimately, the ultrasound
and ED diagnoses were compared with the final diagnosis, which was
considered the gold standard. The final diagnosis was formulated
1296 Original Research [151#6 CHEST JUNE 2017 ]

by two emergency medicine experts, who reviewed the clinical chart
and were aware of the results of every laboratory, ultrasound, and
radiologic examination performed on the patient both during the ED
stay and the hospital stay. For each patient, up to two concomitant
diagnoses could be present.
PoCUS Evaluation
PoCUS was performed with a multiprobe machine (MyLab 30 Gold;
Esaote SpA) with a 4- to 8-MHz linear probe and a 2.5- to 3.5-MHz
curved array probe. Each ultrasound examination was performed by
following a systematic and standardized sequence (LUS, ECHO, IVC
evaluation) and according to predefined ultrasound protocols.
The lungs were examined by using longitudinal and oblique scans on
anterolateral and posterior thoracic areas. Anterolateral examination
was performed with the patient in the supine or near-to-supine
position; whenever possible, dorsal areas were scanned in the sitting
position or by turning the patient in the lateral decubitus on both
sides in case of forced supine position.
Lung examination was targeted to the detection of specific ultrasound
patterns identified according to international recommendations on
point-of-care lung ultrasound
25
: pulmonary edema as bilateral diffuse
interstitial syndrome; pneumonia as the presence of lung
consolidation and air bronchogram(s) with or without focal
interstitial syndrome; pleural effusion as the presence of an anechoic
space between the parietal and visceral pleura; pulmonary embolism
was considered in the presence of two or more triangular or
rounded pleural-based lesions indicating a pulmonary infarction,
26
or, as COPD/asthma, in the absence of any aforementioned pattern
in a patient with suggestive medical history; pneumothorax was
defined as the absence of lung sliding, B-lines, and lung pulse with
the presence of lung point; and ARDS as the presence of subpleural
anterior consolidations with the absence or reduction of lung
sliding, spared areas of normal parenchyma, pleural line
abnormalities such as irregularly thickened or fragmented pleural
line and nonhomogeneous distribution of B-lines.
Afterwards ECHO was then performed in an apical four-chamber view
to allow for qualitative evaluation of left ventricular ejection fraction
(which was considered reduced if <50%) and the presence of right
ventricular dilation (right/left ventricular end-diastolic diameter ratio
>1 at the level of atrioventricular valve annulus). A subcostal long-
axis view was performed to assess the presence of pericardial
effusion and to evaluate left ventricular ejection fraction.
Finally, IVC maximum and minimum diameters and the IVC
collapsibility index were measured in the subcostal view in M-mode
at 2 cm from the right atrial junction.
27,28
The IVC collapsibility
index was considered reduced if <50%, normal, or increased
if $50%.
29
Findings of the ultrasound examination were collected in a
standardized form.
Statistical Analysis
Data points are expressed as mean SD. The unpaired Student ttest
was used to compare normally distributed data. The Fisher exact test
was used for the comparison of noncontinuous variables expressed
as proportions. Pvalues <.05 indicate statistical significance; all P
values are two-sided. The diagnostic performance of PoCUS and of a
traditional ED evaluation was assessed by calculating sensitivity,
specificity, positive predictive value, negative predictive value, and
likelihood ratios. The
k
statistic was used to compare the
concordance between different diagnostic methods.
30
The McNemar
test was used to compare the sensitivities and specificities of PoCUS
and traditional ED evaluation for each diagnosis.
31
Calculations were
performed by using SPSS version 20.0 (IBM SPSS Statistics, IBM
Corporation).
Results
From January 2013 to December 2013, a total of 3,487
patients with dyspnea as their presenting symptom were
evaluated at the ED. Among them, 804 patients were
excluded from the study (734 were discharged from the
ED, 57 had dyspnea of traumatic origin, 7 did not
consent, and 6 died in the ED); 2,683 patients were thus
included. Enrolled patients had a mean age of 71.2 
18.6 years (range, 18-107 years), and 1,316 were women.
The main characteristics of enrolled patients are shown
in Table 1.
During the ED evaluation or the hospital stay, 2,629
patients underwent CXR (98%), 295 underwent CCT
scanning (11%), and 402 underwent ECHO performed
by a cardiologist (15%). PoCUS was performed in every
patient enrolled in the study with an average time of
72 min (3 1 min for LUS and 4 1 min for
ECHO). The average time needed to formulate the
ultrasound diagnosis was 24 10 min, whereas the
formulation of the ED diagnosis required a significantly
longer time (186 72 min; P¼.025).
Causes of dyspnea according to the ultrasound
diagnosis, the ED diagnosis, and the final diagnosis are
reported in Table 2. The total number of ultrasound
diagnoses, ED diagnoses, and final diagnoses was 2,791,
2,798, and 2,890, respectively; patients with a double
TABLE 1 ]General Characteristics of the Study
Population
Characteristic Value
Age, mean SD, y 71.2 18.6
Women, No. (%) 1,316 (49)
SBP, mm Hg 134.2
DBP, mm Hg 75.2
Heart rate, beats/min 88.2
Respiratory rate, breaths/min 22.6
Body temperature, C 36.8
SaO
2
,% 93
Patients with sinus rhythm, No. 2,120
DBP ¼diastolic blood pressure; SaO
2
¼oxygen saturation; SBP ¼systolic
blood pressure.
journal.publications.chestnet.org 1297

diagnosis comprised 108 (3.9%), 115 (4.1%), and 207
(7.2%). The most frequent double diagnosis was between
heart failure and pneumonia (32 cases for ultrasound
diagnosis, corresponding to 29.6% of double the
ultrasound diagnosis; 49 cases for ED diagnosis,
corresponding to 42.6% of double the ED diagnosis; and
75 cases for final diagnosis, corresponding to 36.2% of
double final diagnosis).
Concordance between the ultrasound and ED diagnoses
for each disease was first calculated, and the results
are reported in Table 3. Concordance was optimal
(0.8 <
k
<1) for the diagnosis of heart failure,
pericardial effusion, COPD/asthma, and pneumothorax;
good (0.6 <
k
<0.8) for acute coronary syndrome,
pneumonia, isolated pleural effusion, and other causes;
moderate (0.4 <
k
<0.6) for pulmonary embolism; and
poor for ARDS/ALI (0 <
k
<0.4). Overall concordance
was good (
k
¼0.71). Subsequently, ultrasound and ED
diagnostic performances for each specific diagnosis were
calculated comparing the ultrasound and ED diagnoses
with the final diagnosis; results are shown in Tables 4
and 5, respectively. For heart failure, the ultrasound
diagnosis was significantly more sensitive than the ED
diagnosis (88% vs 77%; P<.001), despite a minor
specificity (96% vs 98%; P<.001). A statistically
significant difference in sensitivity was also found in the
diagnosis of COPD/asthma and pulmonary embolism,
in which the ultrasound diagnosis was inferior to the ED
diagnosis (87% vs 92% [P<.001] for COPD/asthma;
40% vs 91% [P<.001] for pulmonary embolism). In
addition, specificity of the ultrasound diagnosis for
ARDS/ALI was significantly inferior to that of the
ED diagnosis, even if almost optimal (99.5% vs 99.9%;
P¼.002). There was no statistically significant
difference between sensitivities and specificities of the
ultrasound and ED diagnoses in terms of acute coronary
syndrome, pneumonia, pleural effusion, pericardial
effusion, pneumothorax, and other causes of dyspnea.
The ultrasound diagnosis was highly sensitive and
specific for the diagnosis of pneumothorax, pneumonia,
and pericardial effusion; moreover, it was also very
specific for the diagnosis of acute coronary syndrome,
pleural effusion, pulmonary embolism, and dyspnea
from other causes.
Discussion
This prospective study evaluated the feasibility and
usefulness of a PoCUS approach compared with a
standard ED evaluation. From these results, we can
affirm that PoCUS is a reliable and accurate tool that
could be used in the initial approach to patients in the
ED with dyspnea.
Our first goal was to show that the ultrasound diagnosis
was concordant with the ED diagnosis in enrolled
patients; the high obtained value of concordance
(
k
¼0.71), which is associated with a significant reduction
in diagnostic time in favor of PoCUS, confirms that
PoCUS provides a reliable early diagnosis in patients
with dyspnea and, subsequently, allows use of an early
targeted therapy.
TABLE 2 ]Causes of Dyspnea According to Ultrasound
Diagnosis, ED Diagnosis, and Final
Diagnosis
Variable
Ultrasound
Diagnosis
ED
Diagnosis
Final
Diagnosis
Heart failure 600 503 585
Acute coronary
syndrome
32 30 42
Pneumonia 1,096 1,091 1,086
Pleural effusion 97 111 98
Pericardial
effusion
45 48 44
COPD/asthma 735 782 759
Pulmonary
embolism
41 95 95
Pneumothorax 39 45 44
ARDS/ALI 20 7 16
Other causes 86 86 121
Total 2,791 2,798 2,890
ALI ¼acute lung injury.
TABLE 3 ]Concordance Between Ultrasound Diagnosis
and ED Diagnosis
Diagnosis
k
Heart failure 0.810
Acute coronary syndrome 0.706
Pneumonia 0.788
Pleural effusion 0.730
Pericardial effusion 0.858
COPD/asthma 0.845
Pulmonary embolism 0.549
Pneumothorax 0.903
ARDS/ALI 0.294
Other 0.628
Total 0.711
See Table 2 legend for expansion of abbreviation.
1298 Original Research [151#6 CHEST JUNE 2017 ]

The time needed to formulate an ultrasound diagnosis
was significantly less than that required for an ED
diagnosis. Although we are aware that this difference
could be partially due to co-existing clinical duties that
distracted the treating physician from evaluation of the
patient with dyspnea, the difference in the average time
strongly favors the ultrasound evaluation.
Analyzing diagnostic performance, we found that
PoCUS was statistically superior to the standard ED
evaluation for a heart failure diagnosis, which
represented the final diagnosis in 20% of the study
patients; because the negative predictive value of the
ultrasound diagnosis for heart failure was very high
(97%), we concluded that the absence of the ultrasound
patterns associated with heart failure (ie, diffuse
interstitial syndrome, reduced ejection fraction) allowed
us to rule out with high reliability this condition as the
main cause of dyspnea.
The most common cause of dyspnea in this study
sample was pneumonia (38% of diagnoses); the
sensitivity and specificity of the ultrasound diagnosis
were similar to what have been reported in the
literature (sensitivity 88.5% vs 82.8% and specificity
91.6% vs 95.5%)
15
and comparable to those of the ED
diagnosis (neither Pvalue significant), but the diagnosis
was reached earlier with PoCUS.
Moreover, no significant difference in terms of
sensitivity and specificity was found for the diagnosis of
acute coronary syndrome, pleural effusion, pericardial
effusion, pneumothorax, or dyspnea due to other causes,
representing 12% of the final diagnoses.
However, the sensitivity of the standard ED evaluation
was statistically superior to that of PoCUS for the
diagnosis of COPD/asthma and pulmonary embolism.
In our opinion, this finding is due to a prevalent clinical
diagnosis of COPD/asthma, mostly derived from the
patient’s medical history and from improvement after
specific therapy, often without radiologic or ultrasound-
specificfindings. Concerning pulmonary embolism, the
lower sensitivity of the ultrasound diagnosis compared
with that of the ED diagnosis (40% vs 91%) is likely due
to the essential information provided by the CT
pulmonary angiography, which is frequently included in
the standard ED evaluation of patients with suspected
dyspnea. However, in the present study, of 41
ultrasound diagnoses of pulmonary embolism confirmed
at final diagnosis, 40 (97%) were associated with right
ventricular dilation and 27 (66%) with the detection of
pulmonary infarction. In 54 cases, pulmonary embolism
TABLE 4 ]Diagnostic Accuracy of Ultrasound Diagnoses
Variable Sensitivity, % (95% CI) Specificity, % (95% CI) PPV, % (95% CI) NPV, % (95% CI) þLR (95% CI) –LR (95% CI)
Heart failure 88 (85.1-90.6) 96 (95-96.8) 85.8 (82.8-88.5) 96.6 (95.8-97.4) 21.73 (17.61-26.82) 0.12 (0.10-0.16)
Acute coronary syndrome 47.6 (32-63.6) 99.6 (99.2-99.8) 62.5 (43.7-78.9) 99.2 (98.8-99.5) 104.8 (54.85-200.26) 0.53 (0.39-0.70)
Pneumonia 88.5 (86.4-90.3) 91.6 (90.1-92.9) 87.7 (85.6-89.6) 92.1 (90.7-93.4) 10.47 (8.90-12.32) 0.13 (0.11-0.15)
Pleural effusion 77.6 (68-85.4) 99.2 (98.8-99.5) 78.4 (68.8-86.1) 99.2 (98.7-99.5) 95.46 (61.54-148.09) 0.23 (0.16-0.33)
Pericardial effusion 86.4 (72.7-94.8) 99.7 (99.5-99.9) 84.4 (70.5-93.5) 99.8 (99.5-99.9) 325.59 (153.94-688.65) 0.14 (0.06-0.29)
COPD/asthma 86.8 (84.2-89.2) 96.1 (95.1-96.9) 89.7 (87.2-91.8) 94.9 (93.8-95.8) 21.98 (17.60-27.45) 0.14 (0.11-0.16)
Pulmonary embolism 40 (30.1-50.6) 99.9 (99.7-100) 92.7 (80.1-98.5) 97.8 (97.2-98.4) 345.07 (108.45-1097.94) 0.60 (0.51-0.71)
Pneumothorax 87.8 (75.2-94.5) 100 (99.8-100) 98.8 (89.1-99.9) 99.8 (99.5-99.9) 4634.67 (289.35-74236.28) 0.12 (0.06-0.27)
ARDS/ALI 43.8 (19.8-70.1) 99.5 (99.2-99.7) 35 (15.4-59.2) 99.7 (99.4-99.9) 89.75 (41.29-195.09) 0.57 (0.37-0.87)
Other causes 45.5 (36.4-54.8) 98.8 (98.3-99.2) 64 (52.9-74) 97.5 (96.8-98) 37.57 (25.16-56.08) 0.55 (0.47-0.65)
–LR ¼negative likelihood ratio; NPV ¼negative predictive value; PPV ¼positive predictive value; þLR ¼positive likelihood ratio.
journal.publications.chestnet.org 1299

was not diagnosed according to PoCUS; none of these
patients had right ventricular dilation, but 3 cases (5%)
had findings suggestive of pulmonary infarction. From
these results, it seems that right ventricular dilation is
essential for the suspicion of pulmonary embolism; the
presence of characteristic triangular or rounded pleural-
based consolidation is seemingly hardly interpreted as a
pulmonary infarction in the absence of right ventricular
dilation.
This study did have some limitations. PoCUS
examination was performed by emergency physicians
with at least 2 years’experience in ultrasound;
application of the same methodology by physicians with
less experience may lower accuracy and safety.
Another limitation is that patients who were not admitted
after ED evaluation were not included in the study.
The sensitivity of PoCUS for pulmonary embolism could
have been increased by performing a compression
ultrasound searching for DVT. This compression
ultrasound was not included because when we conceived
the study, this examination was considered too time-
consuming to be included in an integrated ultrasound
evaluation of patients with dyspnea compared with the
expected prevalence of pulmonary embolism in this setting.
The prevalence of ARDS diagnosis in this study
population was so limited (16 patients) that we could
not reach definitive conclusions about the clinical utility
of PoCUS in these patients.
Conclusions
The present study showed a good concordance between
the diagnoses reached after PoCUS evaluation and after
standard ED evaluation in the differential diagnosis of
patients with dyspnea. There was a significant reduction
in diagnostic time in favor of PoCUS; this finding is
extremely important in the emergency setting because a
rapid diagnosis and therapy are often critical for the
patient’s prognosis.
PoCUS may represent the first feasible and accurate
diagnostic approach to the patient with dyspnea in the
ED, helping stratifying patients who should undergo a
second-level diagnostic test (ie, cases with nonconclusive
ultrasound evaluation or needing more detailed studies).
If these data are confirmed by further studies, this
integrated ultrasound method could be the basis of a
new semeiotics and replace the current first diagnostic
approach to patients presenting with dyspnea, allowing a
drastic reduction in costs and diagnostic times.
TABLE 5 ]Diagnostic Accuracy of ED Diagnosis
Variable Sensitivity, % (95% CI) Specificity, % (95% CI) PPV, % (95% CI) NPV, % (95% CI) þLR (95% CI) –LR (95% CI)
Heart failure 77.3 (73.7-80.6) 97.6 (96.8-98.2) 89.9 (86.9-92.4) 93.9 (92.8-94.9) 31.8 (24.2-41.8) 0.23 (0.20-0.27)
Acute coronary syndrome 52.4 (36.4-68) 99.7 (99.4-99.9) 73.3 (54.1-87.7) 99.3 (98.84-99.5) 172.92 (81.72-365.93) 0.48 (0.35-0.66)
Pneumonia 89.8 (87.8-91.5) 92.7 (91.4-94) 89.4 (87.4-91.1) 93 (91.7-94.2) 12.36 (10.36-14.74) 0.11 (0.09-0.13)
Pleural effusion 86.7 (78.4-92.7) 99 (98.5-99.3) 76.6 (67.6-84.1) 99.5 (99.1-99.7) 86.23 (58.37-127.39) 0.13 (0.08-0.22)
Pericardial effusion 93.2 (81.3-98.6) 99.7 (99.5-99.9) 85.4 (72.2-93.9) 99.9 (99.7-99.9) 351.30 (166.92-739.34) 0.07 (0.02-0.20)
COPD/asthma 92.2 (90.1-94) 95.7 (94.7-96.6) 89.5 (87.2-91.6) 96.9 (96-97.6) 21.64 (17.49-26.77) 0.08 (0.06-0.10)
Pulmonary embolism 90.5 (82.8-95.6) 99.7 (99.3-99.8) 90.5 (82.8-95.6) 99.7 (99.3-99.8) 260.31 (135.16-501.36) 0.10 (0.05-0.18)
Pneumothorax 95.5 (84.5-99.4) 99.9 (99.7-100) 93.3 (81.7-98.6) 99.9 (99.7-100) 839.68 (270.49-2606.65) 0.05 (0.01-0.18)
ARDS 37.5 (15.2-64.6) 99.9 (99.8-100) 85.7 (42.1-99.6) 99.6 (99.3-99.8) 1000.12 (127.57-7840.72) 0.63 (0.43-0.91)
Other diagnoses 54.6 (45.2-63.6) 99.2 (98.8-99.5) 76.7 (66.4-85.2) 97.9 (97.3-98.4) 69.87 (43.85-111.34) 0.46 (0.38-0.56)
See Table 4 legend for expansion of abbreviations.
1300 Original Research [151#6 CHEST JUNE 2017 ]

Acknowledgments
Author contributions: M. Z. is the guarantor
of the manuscript. M. Z. contributed to study
conception and design and data acquisition,
analysis, and interpretation; drafted the
manuscript; edited the manuscript for
important intellectual and scientific content;
served as the principal author; and edited the
revision. M. S. and C. G. contributed to study
conception and design, conducted statistical
analysis, drafted the manuscript, and edited
the revision. P. N. contributed to study design
and data acquisition, drafted and edited the
manuscript for important intellectual and
scientific content, and edited the revision.
S. V., F. I., V. T. S., and C. S. contributed to
data acquisition, conducted statistical
analysis, and edited the revision. A. C., S. B.,
F. C., I. T., A. C., and S. G. contributed to
data acquisition. R. P. contributed to study
conception and design, as well as to data
analysis and interpretation. All authors
approved the final draft.
Financial/nonfinancial disclosure: None
declared.
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