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ARTICLE IN PRESSJournal of Cardiothoracic and Vascular Anesthesia 000 (2021) 1�16
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Review Article
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19th St, JT 804, Birmi
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Point-of-Care Ultrasound (POCUS) for the
Cardiothoracic Anesthesiologist
Hari Kalagara, MD*, Bradley Coker, MD*,Neal S. Gerstein, MD, FASEy, Promil Kukreja, MD, PhD*,
Lev Deriy, MDy, Albert Pierce, MD*,Matthew M. Townsley, MD, FASE*,1
*Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham,
Birmingham, ALyDepartment of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine,
Albuquerque, NM
Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a
multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing avail-
ability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21st-century stethoscope. With the current avail-
able and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-
making.
Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, mak-
ing POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of
the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating
room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.
� 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/)
Keywords: Point-of-Care Ultrasound; lung ultrasound; transthoracic echocardiography; airway ultrasound; gastric ultrasound; ultrasound education
POINT-OF-CARE ULTRASOUND (POCUS) is the use of
portable bedside ultrasound imaging for a variety of expedi-
tious clinical assessments or as guidance for a multitude of
acute care procedures. With the increasing availability of
affordable ultrasound systems over the past decade, POCUS
use has burgeoned over a similar time frame, with low-cost
portable systems now considered the 21st-century stetho-
scope.1,2 Ideally, POCUS use in clinical management should
be goal-directed, rapid, and reproducible. Varying aspects of
nearly all organ systems can be evaluated using POCUS (see
Table 1), and there are increasingly more clinical conditions
ence to Matthew M. Townsley, MD, FASE, 619 South
ngham, AL 35249-6810.
[email protected] (M.M. Townsley).
3/j.jvca.2021.01.018
e Authors. Published by Elsevier Inc. This is an open access a
in which the utilization of POCUS may have a role.3,4 In par-
ticular, this growth has been accelerated further with the
availability and accessibility of small handheld ultrasound
devices. In certain clinical contexts (eg, pneumothorax
[PTX], hemidiaphragmatic paresis), POCUS has superior
diagnostic sensitivity and specificity compared to other diag-
nostic modalities, while also mitigating the higher costs and
possible radiation side effects of non-ultrasound imaging.5
Various medical societies (eg, Society of Critical Care Medi-
cine, American Society of Echocardiography) have devel-
oped POCUS guidelines for its usage across a wide range of
clinical settings.6,7
Cardiothoracic anesthesiologists routinely have used porta-
ble ultrasound systems for nearly as long as the technology has
been available, particularly as a tool to guide vascular access
rticle under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Table 1
Common Point-of-Care Ultrasound (POCUS) Applications
POCUS Structures Utility
Airway CTM, trachea Cricothyroidotomy,
endotracheal intubation
Breathing (lung) Pleura, lung, diaphragm Pneumothorax, lung
parenchymal disease,
pleural effusion,
pulmonary edema
Circulation (cardiac) LV, RV, cardiac valves Myocardial ischemia,
CHF, valvular lesions
Pericardium Tamponade
Aorta & aortic arch Aneurysm and dissection
Gastric Antrum Gastric volume and
contents
Vascular Veins Central and peripheral
venous cannulation
Arteries Invasive monitoring,
IABP
IVC Volume status
VExUS scan Fluid overload
Deep veins DVT
Abbreviations: CHF, congestive heart failure; CTM, cricothyroid membrane;
DVT, deep vein thrombosis; IABP, intra-aortic balloon pump; IVC, inferior
vena cava; LV, left ventricle; POCUS, point-of-care ultrasound; RV, right
ventricle; VExUS scan, venous excess ultrasound scan.
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procedures and for echocardiographic applications. Since
transesophageal echocardiography (TEE) is used routinely by
most cardiothoracic anesthesiologists, POCUS applications
are a natural extension of existing practice.8,9 This narrative
review presents a broad discussion of the utility of POCUS for
the cardiothoracic anesthesiologist in varying perioperative
contexts, including the preoperative clinic, the operating room
(OR), and intensive care unit (ICU). Furthermore, POCUS-
related education, competence, and certification are addressed.
Airway Ultrasound (AUS)
POCUS of the airway is useful for identification of airway
structures, such as the cricothyroid membrane (CTM), tracheal
rings, cricoid cartilage, thyroid cartilage, and hyoid bone (see
Table 2).10 In difficult airway scenarios, identification of the
CTM by AUS has been shown to be useful for cricothyroidot-
omy procedures (see Fig 1). Kristensen et al. demonstrated
that the identification of the CTM by ultrasound had a higher
Table 2
Overview of Airway Ultrasound (AUS)
POCUS Structures Techniques
Airway CTM Cricothyroidotomy
Cricoid cartilage Cricoid pressure for RSI
Thyroid cartilage Airway blocks
Hyoid bone Airway assessment
Tracheal rings Percutaneous tracheostomy
Esophagus Endotracheal/esophageal intubation
Abbreviations: CTM, cricothyroid membrane; POCUS, point-of-care
ultrasound; RSI, rapid-sequence intubation.
success rate than traditional inspection and palpation meth-
ods.11,12 The utilization of ultrasound for preprocedural identi-
fication of tracheal rings, as well as pre- and paratracheal
anatomy and blood vessels (especially abnormal vasculature),
is helpful in assisting with the correct location and safe place-
ment of a percutaneous tracheostomy.13,14 AUS also is useful
for performing airways blocks to facilitate awake fiberoptic
intubations, improving airway and intubating conditions com-
pared to blind tecnhiques.15,16
AUS also has shown utility in confirming correct endotra-
cheal tube placement and in discerning between esophageal
and endotracheal intubation. With endotracheal intubation, a
single bullet sign (single air-mucosal interface with increased
posterior artifact shadowing) will be visualized, along with the
presence of bilateral lung sliding. Esophageal intubation has a
unique double-tract sign appearance and absence of bilateral
lung sliding. In a systematic review by Das et al., the authors
found that AUS had a pooled sensitivity of 0.98 (95% CI,
0.97-0.99) and pooled specificity of 0.98 (95% CI, 0.95-0.99)
in confirming endotracheal intubation.17 A meta-analysis by
Gottlieb et al., which included 17 studies and a total of 1,595
patients, showed transtracheal ultrasonography was 98.7%
sensitive (95% CI, 97.8-99.2) and 97.1% specific (95% CI,
92.4-99.0) in confirming endotracheal intubation, with a mean
time to confirmation of 13 seconds (95% CI, 12.0-14.0).18
AUS is a valuable and reliable adjunct for endotracheal intuba-
tion in cardiac arrest situations in which the end-tidal CO2 is
low.19,20 AUS has been described for the prediction and
assessment of difficult airways and evaluation of the epiglottis
and vocal cords.21,22 Skin-hyoid distance is known to predict
difficult mask ventilation and difficult laryngoscopy, while the
epiglottis-to-vocal cord space has been shown to correlate
with Cormack-Lehane intubation grade.23,24 Specifically, the
mean standard deviation of the minimum distance from the
hyoid bone to skin surface was 0.88 (0.3) cm in the easy mask
ventilation group versus 1.4 (0.19) cm in the difficult mask
ventilation group. The mean of this distance increased accord-
ing to the level of difficulty of mask ventilation and laryngos-
copy. The distance of the epiglottis to the vocal cord space
was found to be a better predictor of difficult laryngoscopy
compared to the hyomental distance ratio. A distance from the
epiglottis to vocal cords of more than 1.77 cm had 82%
Fig 1. Ultrasound (US)-guided airway examination to identify the cricothy-
roid membrane (CTM). The image on the left demonstrates probe positioning
for the performance of a US-guided airway examination, while the image on
the right illustrates key anatomy seen in the airway US examination.
Table 3
Overview of Gastric Ultrasound (GUS)
POCUS Structures Assessment Aspiration Risk
Gastric Gastric antrum Gastric volume Low risk (<1.5 mL/
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H. Kalagara et al. / Journal of Cardiothoracic and Vascular Anesthesia 00 (2021) 1�16 3
sensitivity and 80% specificity in predicting difficult laryngos-
copy, whereas a hyomental distance ratio less than 1.085 had a
sensitivity of 75% and specificity of 85.3% in this prediction.
Additionally, AUS can be used for the application of cricoid
pressure during rapid-sequence induction.25
Gastric contents
(liquids or solids)
kg)
High risk (>1.5
mL/kg)
High risk (solid)
Abbreviations: POCUS, point-of-care ultrasound.
Gastric Ultrasound (GUS)
Perioperative aspiration prevention is an important consid-
eration during any surgical or interventional procedure, as
aspiration of gastric contents may lead to aspiration pneumo-
nia, which is associated with high morbidity and mortality.26
Evaluation of fasting status or assuring adequate gastric emp-
tying has occurred can be challenging in numerous circum-
stances, such as patients with altered mental status and those
with certain chronic medical conditions (eg, gastroparesis, dia-
betes, or chronic renal failure and liver failure). Aspiration risk
is particularly extant in the context of procedures performed
with moderate or deep sedation without an ETT (ie, out-of-
operating room transesophageal echocardiograph [TEE]
examinations). GUS allows for the identification and measure-
ment of gastric antral cross-sectional area, with accurate
assessment of gastric volume and contents in both the supine
and right lateral decubitus positions.27,28 Figure 2 illustrates
probe placement and imaging of the gastric antrum.
A randomized control trial by Kruisselbrink et al., using
simulated clinical scenarios in nonpregnant adults with a pre-
test probability of 50% full stomach, showed that bedside
GUS had a sensitivity of 1.0 (95% CI, 0.925-1.0), a specificity
of 0.975 (95% CI, 0-0.072), a positive predictive value of
0.976 (95% CI, 0.878-1.0), and a negative predictive value of
1.0 (95% CI, 0.92-1.0) in ruling out a full stomach in patients
in whom the presence of gastric contents was ambiguous.29
Using nomogram-based data derived from measured antral
cross-sectional area and patient age, gastric volume can be pre-
dicted (see Table 3) by GUS.30 In summary, GUS can be per-
formed easily at the bedside to provide qualitative and
quantitative assessment of gastric contents, aiding in the for-
mulation of a safe anesthetic airway management plan to mini-
mize aspiration risk.31 However, there are currently no major
society recommendations to replace nothing -by-mouth guide-
lines with gastric ultrasound.
Fig 2. Ultrasound (US)-guided gastric scan to assess gastric volume and con-
tent. The image on the left demonstrates probe positioning for the performance
of an US-guided gastric examination, while the image on the right illustrates
key anatomy seen in the gastric US examination.
Lung Ultrasound (LUS)
Lung ultrasound (LUS) (see Table 4) involves the study of
air-fluid interfaces in the lungs, as well as the interpretation of
ultrasound artifacts.32 Different transducers, such as phased-
array, convex, microconvex, or linear probes, are being used
for LUS to optimize the artifacts based on the lung pathology
to be determined and the patient’s body habitus.33 Longitudi-
nal scanning is performed in six or eight zones for focused
lung examinations, with transverse scanning recommended in
areas of specific interest for further evaluation of pathology.34
POCUS of the lung is indicated to evaluate dyspnea, hypoxia,
hypotension, thoracic trauma, pleurisy, and chest pain.35 Inter-
national evidence-based consensus recommendations for
point-of-care lung ultrasound from Volpicelli et al. have
proven helpful in guiding the implementation, development,
and standardization of LUS across a variety of clinical set-
tings.36 Figure 3 outlines a decision-making algorithm to guide
the assessment of lung pathology with LUS.
Normal LUS Mechanics
Normal lung aeration is characterized by lung sliding,
described as movement of the parietal and visceral pleura slid-
ing against each other at the pleural line (equivalent to a sea-
shore sign on the M-mode Doppler evaluations), as demon-
strated by Video 1. Normal lung parenchyma will have an A
profile pattern, seen as regular, repetitive horizontal reverbera-
tion artifacts arising from air below the pleural line (Fig 4).
When air is replaced with fluid, the image will show B lines,
which are comet-tail artifacts (vertical hyperechoic lines
Table 4
Overview of Lung Ultrasound (LUS)
POCUS Structure Assessment Disease
Lungs (LUS) Pleura Lung sliding Pneumothorax
Lung zones A and B lines Pneumonia, ARDS,
pulmonary edema
PLAPS point Lung bases Pleural effusion,
pneumonia
Diaphragm Diaphragm function Weaning/ventilation,
diaphragmatic
paresis/paralysis
Abbreviations: ARDS, acute respiratory distress syndrome; PLAPS, posterior
lateral alveolar pleural syndrome; POCUS, point-of-care ultrasound.
Fig 3. Decision algorithm for guiding the assessment of lung pathology using
LUS. LUS, lung ultrasound; DVT, deep vein thrombosis; PLAPS, posterior
lateral alveolar pleural syndrome.
Fig 4. Normal lung ultrasound (LUS) images and A lines. Panel A demon-
strates probe positioning for evaluation of ribs and pleura, while panel B dem-
onstrates ultrasound visualization of these structures. Panels C and D
demonstrate probe positioning and visualization of A lines, respectively.
Fig 5. Lung point. The presence of lung point, defined as the appearance and
disappearance of lung sliding with respiration at a particular point, is charac-
teristic and pathognomonic for pneumothorax.
Fig 6. Algorithm aiding the diagnosis and exclusion of pneumothorax using
lung ultrasound (LUS). PTX, pneumothorax.
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arising from the pleural line and fanning down all the way to
the bottom of the screen) demonstrated by Video 2.
Abnormal LUS Mechanics
When the ratio of fluid-to-air content increases, the number
of B lines increases in lung zones accordingly, resulting in a B
profile pattern. The presence of B lines rules out PTX.37 Inter-
stitial lung disease and pulmonary edema may be indicated by
the number and distribution of B lines (lung rockets) in each
zone (three or fewer in each lung zone is seen in a healthy
lung). Absence of lung sliding in a particular lung zone should
raise suspicion for PTX. The presence of lung point, defined as
the appearance and disappearance of lung sliding with respira-
tion at a particular point (equivalent to the M-mode strato-
sphere or barcode sign), is characteristic and pathognomonic
for PTX, with a reported overall sensitivity of 66% and a spec-
ificity of 100% for the diagnosis of PTX.37,38 Lung point is
demonstrated in Video 3 and Figure 5, while an algorithm
guiding the diagnosis and exclusion of PTX using LUS is illus-
trated in Figure 6.
The posterior lateral alveolar pleural syndrome (PLAPS)
point is the lowest point in the lung that should be investigated
with a curvilinear probe to rule out pleural effusion and con-
solidation.39 The detection of PLAPS point indicates
consolidation or effusion at the lung bases, while absence of
PLAPS point suggests other pathology at the lung bases. Nor-
mally, the spine above the diaphragm is not visible. However,
if pleural effusion is present, the spine is visible through the
fluid and is referred to as "spine sign". With a normally aerated
lung, the lung moves downward into the abdomen with inspi-
ration (curtain sign). In the presence of pleural effusion, this
curtain sign is absent. Dynamic air bronchograms signify con-
solidation, while static air bronchograms indicate atelectasis.
A meta-analysis comparing the accuracy of LUS and chest X-
ray (CXR) indicated that LUS had a higher pooled sensitivity
(0.95; 95% CI, 0.93-0.97) and specificity (0.90; 95% CI, 0.86-
0.94) with better diagnostic accuracy compared to CXR in aid-
ing the diagnosis of community-acquired pneumonia (using
chest-computed tomography as the gold standard).40
LUS Versus Other Imaging Modalities
LUS offers unique advantages over computed tomography,
as it is portable, reproducible, low cost, low risk, and highly
accurate, and possesses no radiation effects. As previously
Fig 7. Panel A depicts a supine patient position with the ultrasound (US)
probe placed along the midaxillary line. Panel B shows a US image of the dia-
phragm during inspiration (measuring diaphragm thickness of 0.25 cm).
Table 5
Diagnosis of Lung Disease Based on Lung Ultrasound (LUS)
Diagnosis Present on LUS Absent on LUS FOCUS
PTX Lung point
Barcode or stratosphere sign (M mode LUS)
Lung sliding, B lines, Lung pulse
PNA B lines, air bronchograms, PLAPS Lung sliding
CHF Bilateral B lines, lung sliding Reduced FS, EF, and EPSS
ARDS B lines, lung sliding Normal EF and EPSS
Pulmonary fibrosis B lines Lung sliding
COPD/asthma Lung sliding, A lines B lines, PLAPS
Pleural effusion Anechoic lung base, air bronchograms, spine sign Curtain sign Reduced EF in CHF
Pulmonary embolism Lung sliding, A lines Reduced TAPSE, reduced RV function,
Diaphragmatic paresis Reduced diaphragm excursion and thickness
Abbreviations: ARDS, acute respiratory distress syndrome; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; EF, ejection fraction;
EPSS, endpoint (mitral) septal separation; FOCUS, Focused Cardiac Ultrasound; FS, fractional shortening; LUS, lung ultrasound; PLAPS, posterior lateral
alveolar pleural syndrome; PNA, pneumonia; PTX, pneumothorax; RV, right ventricle; TAPSE, tricuspid annular plane systolic excursion.
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described, LUS can be used to diagnose PTX, with better sen-
sitivity and specificity compared to CXR.41 A meta-analysis
by Ding et al. indicated that LUS had a higher pooled sensitiv-
ity (0.88) compared to CXR (0.52), and similar specificity, in
the diagnosis of PTX.42 Notably, the accuracy of diagnosing
PTX with LUS is associated with the skill of the operator
(odds ratio, 0.21; CI, 0.05-0.96; p = 0.0455). Chan et al., in a
recent Cochrane Database systematic review examining LUS
versus CXR for the diagnosis of PTX in trauma patients,
reported a sensitivity of 0.91 (95% CI, 0.85-0.94) and specific-
ity of 0.99 (95% CI, 0.97-1.00) for LUS, compared to a sensi-
tivity of 0.47 (95% CI, 0.31-0.63) for CXR.43 This review
suggested the superior diagnostic accuracy of LUS versus
CXR for PTX diagnosis.
LUS also is efficacious in the diagnosis of pulmonary
edema.44 Maw et al. established that LUS is more sensitive
(0.88 [95% CI, 0.75-0.95]) than CXR (0.73 [95% CI, 0.70-
0.76]) in the detection of pulmonary edema in patients with
decompensated heart failure. The relative sensitivity ratio of
LUS compared to CXR was 1.2 (95% CI, 1.08-1.34; p <
0.001), proposing LUS as a useful adjunct modality in the
evaluation of patients with heart failure.44 A meta-analysis by
Al Deeb et al. demonstrated the sensitivity of LUS B lines to
diagnose pulmonary edema as 94.1% (95% CI, 81.3-98.3),
with a specificity of 92.4% (95% CI, 84.2-96.4%).45 Similarly,
Platz et al. demonstrated the utility of B lines with LUS for
prognostic purposes of heart failure therapy.46
LUS is efficacious in the diagnosis of lung parenchymal dis-
eases,40 while enabling a better understanding of heart-lung
interactions to assist in ventilatory management.47-50 LUS also
can be used for confirmation of double-lumen tube placement
during lung isolation maneuvers.51,52 Lichtenstein et al. incor-
porated LUS into their bedside lung ultrasound in emergency
(BLUE) protocol for the diagnosis of acute respiratory fail-
ure,39,53 and FALLS (fluid administration limited by LUS)
protocol for the management of acute circulatory failure.53,54
Table 5 highlights the diagnostic utility of LUS signs, along
with focused cardiac ultrasound, to help differentiate various
lung diseases.
Diaphragm Ultrasound (DUS)
The diaphragm is the core muscle of respiration, innervated
by the phrenic nerve and normally descending caudally and
increasing in thickness with inspiration. In cases of respiratory
distress, LUS, along with DUS assessment, are useful to rule
out potential etiologies such as PTX and diaphragmatic paraly-
sis (ie, post-brachial plexus blockade). Diaphragmatic excur-
sion during deep breathing (normally 6-7 cm) typically is
assessed by Doppler M-mode, but may be challenging at times
on the left side due to air in the stomach. A novel intercostal
approach that assesses the zone of apposition of the diaphragm
can be used to overcome this issue (see Fig 7). The intercostal
zone of apposition approach is used to measure diaphragm
thickness during inspiration and expiration. The thickening
fraction then is calculated, which can be used to quantify the
degree of paresis.55 This thickening fraction is useful for venti-
latory management and in guiding the process of weaning ven-
tilatory support in critically ill patients (normal thickening
fraction is 30%-96%). DUS possesses utility in the prediction
of extubation success by monitoring respiratory load, with
Table 7
Advanced Modalities With Focused Cardiac Ultrasound (FOCUS)
2D View Abnormal Values Disease
LA
Aorta
RV
PLAX
PLAX
PLAX, PSAX,
A4C, SC4C
Increased
Increased
Increased
Dilated LA
Aortic aneurysm
RVH, RVF, PE
M mode
FS and EF
EPSS
TAPSE
MAPSE
PLAX and PSAX
PLAX
A4C
A4C
Decreased
Decreased
Decreased
Decreased
CHF
CHF
RVF
LVF
Diastology
E/A
e’
E/e’ (LVEDP)
A4C
A4C
A4C
Increased
Decreased
Increased
Elevated LAP
Diastolic
dysfunction
Diastolic
dysfunction
CFD/CWD/PWD
RVSP
LVOT VTI
(SV, CO)
RVOT VTI
A4C
PLAX, A5C
PSAX
Increased
Decreased
Decreased
PHTN
LVF
RVF
Abbreviations: A4C, apical four-chamber; A5C, apical five-chamber; CFD,
color-flow Doppler; CHF, congestive heart failure; CO, cardiac output; CWD,
continuous-wave Doppler; EF, ejection fraction; EPSS, endpoint septal
separation; FS, fractional shortening; IVC, inferior vena cava; LA, left atrium;
LAP, left atrial pressure; LV, left ventricle; LVEDP, left ventricular end-
diastolic pressure; LVF, left ventricular failure; LVOT VTI, left ventricular
outflow tract velocity-time integral; MAPSE, mitral annular plane systolic
excursion; PE, pulmonary embolism; PHTN, pulmonary hypertension; PLAX,
parasternal long-axis; PSAX, parasternal short axis; PWD, pulsed-wave
Doppler; RV, right ventricle; RVF, right ventricular failure; RVH, right
ventricular hypertrophy; RVOT VTI, right ventricular outflow tract velocity-
time integral; RVSP, right ventricular systolic pressure; SC4C, subcostal four-
chamber; SV, stroke volume; TAPSE, tricuspid annular plane systolic
excursion.
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optimal cutoffs greater than 30% to 36% for thickening frac-
tion, serving as a beneficial tool in detecting diaphragmatic
dysfunction.56
Focused Cardiac Ultrasound (FOCUS)
In hemodynamically unstable patients, a focused transtho-
racic echocardiographic (TTE) examination (FOCUS) is useful
to evaluate global and regional left and right ventricular func-
tion, assess for valvular dysfunction, and identify the presence
of any hemodynamically significant pericardial effusions.57
Specific cardiac pathology easily recognized with a FOCUS
examination includes aortic stenosis (see Video 4), dilated car-
diomyopathy (see Video 5), pericardial tamponade (see Video
6), hypertrophic obstructive cardiomyopathy with dynamic
left ventricular outflow tract obstruction (see Video 7), endo-
carditis (see Video 8), and pulmonary embolism (see Video 9).
Practice advisory guidelines for the appropriate use of bedside
cardiac ultrasonography in the evaluation of critically ill
patients, as well as grading recommendations regarding
FOCUS usage for various cardiac pathologies, chest trauma,
and diseases of the great vessels, are readily available.58,59
FOCUS most commonly is performed with a low-frequency
cardiac phased-array probe, with patients typically placed in
supine or left lateral position to best optimize imaging and
acoustic windows.60,61 Basic FOCUS views can be used for
assessment of cardiac pathology (see Table 6), as well as quan-
titative assessments of cardiac function (see Table 7). Via et al.
have published international evidence-based recommenda-
tions, delineating the nature, technique, benefits, clinical inte-
gration, education, and certification in FOCUS to offer a
framework for applying FOCUS applications across different
clinical settings around the world.62
Table 6
Overview of Focused Cardiac Ultrasound (FOCUS)
FOCUS View Assessment Clinical Indication Pathology
PLAX LV, RV, LA, aorta
AV and MV
Function, valves,
effusion
MI, CHF, AS,
HOCM
PSAX LV, RV
Pericardium
Function, effusion Ischemia,
hypovolemia,
Tamponade
A4C RA, RV, LA, LV
TV, MV, AV
Function, valves,
effusion
PE, MI,
cardiomyopathy, Tamponade, HOCM
CHF, RVF, PHTNSC4CRA, RV, LA, LVFunction, valves, effusionPE,
hypovolemia, TamponadeSC IVCIVCVolume statusHypovolemia
Fluid overloadSS viewAortic arch and branchesAortic lesions
IABPAortic dissection
Coarctation of aorta
Abbreviations: A4C, apical four-chamber; AS, aortic stenosis; AV, aortic
valve; CHF, congestive heart failure; HOCM, hypertrophic obstructive
cardiomyopathy; IABP, intra-aortic balloon pump; IVC, inferior vena cava;
LA, let atrium; LV, left ventricle; MI, myocardial infarction; MV, mitral
valve; PE, pulmonary embolism; PHTN, pulmonary hypertension; PLAX,
parasternal long-axis; PSAX, parasternal short axis; RA, right atrium; RV,
right ventricle; RVF, right ventricular failure; SC4C, subcostal 4-chamber; SS,
suprasternal; TV, tricuspid valve.
Hemodynamic perturbations and unexplained hypotension
are extremely common issues encountered in the perioperative
setting, with FOCUS being a useful tool for determining the
etiology of unexplained hemodynamic instability, as well as
for guiding clinical management and interventions. FOCUS is
particularly helpful in detecting right ventricular dysfunction
and regional wall motion abnormalities following ischemia in
patients presenting with acute coronary syndromes.63,64
When FOCUS is used to answer a specific clinical question
(eg, investigation of newly discovered systolic murmur or to
determine the underlying etiology of unexplained hemody-
namic instability or decreased functional capacity), its use has
a significant impact on perioperative care (eg, altered anes-
thetic technique, prompted decision to perform invasive moni-
toring, or led to a change postoperative care disposition) in up
to 82% of patients.65 In the aforementioned study, major find-
ings from anesthesiologist-performed FOCUS examinations
(ie, significant valvular lesions) were confirmed subsequently
by cardiology evaluation in 92% of patients. Massive pulmo-
nary embolism and cardiac tamponade are potentially devast-
ing perioperative complications in which FOCUS provides
rapid diagnostic confirmation to guide immediate lifesaving
Table 8
Vascular Ultrasound Applications
Modality Structures Procedures/Assessments
Vascular access IJ, subclavian, and
femoral veins
Radial, brachial, and
femoral arteries
Peripheral veins
Central lines
Arterial lines
PIVs
Volume assessment IVC
Common carotid artery
Common femoral vein
CVP, RAP
CFT, carotid VTI
Pulsatility (RV
function)
VExUS IVC (transverse view)
Hepatic vein
Portal vein
Renal vein
VExUS score for fluid
overload
Venous scan Lower extremity veins DVT
Abbreviations: CFT, corrected flow time; CVP, central venous pressure; DVT,
deep vein thrombosis; IJ, internal jugular; IVC, inferior vena cava; PIVs,
peripheral intravenous lines; RAP, right atrial pressure; RV, right ventricle;
VExUS scan, venous excess ultrasound scan; VTI, velocity-time integral.
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treatments. Valvular stenosis, valvular regurgitation, left and
right ventricular dysfunction, cardiac masses, and cardiomyop-
athies (ie, hypertrophic cardiomyopathy, dilated cardiomyopa-
thy) can be assessed quickly and, where relevant, quantified
with a FOCUS examination.66
FOCUS also is emerging as a valuable tool in the diagnosis
and management of cardiac arrest. The Focused Echocardio-
graphic Examination in Life protocol describes FOCUS usage
during performance of advanced cardiac life support (ACLS)
protocols.67,68 Importantly, FOCUS can be incorporated into
the performance of ACLS without interrupting performance of
standard chest compressions, with subcostal views best facili-
tating this indication. Adequate images may be obtained dur-
ing brief (ie, ten-second) periods when compressions are
interrupted to assess for underlying cardiac rhythm and pulse.
The presence of underlying cardiac activity by FOCUS assess-
ment during ACLS has been associated with improved survival
following return of spontaneous circulation.69 The use of
FOCUS in this setting also enables clinicians to diagnose
potentially treatable and reversible causes (eg, pulmonary
embolism, tamponade, or severe left ventricular dysfunction)
and to guide further therapeutic interventions.
Table 9
Simplified Venous Excess Ultrasound (VExUS) Scoring System
Organ system VExUS = 0
(No Congestion)
VExUS = 1
IVC IVC < 2 cm IVC > 2 cm
Hepatic vein
Doppler
Normal pattern Normal
(S > D)
Portal vein
Doppler
Normal pattern Normal
(<30% pulsatility index)
Renal vein
Doppler
Normal pattern Normal
(continuous monophasic flow)
NOTE. Adapted from: Beaubien-Souligny et al.74
Abbreviations: D, diastolic wave; IVC, inferior vena cava; S, systolic wave; VExUS
Vascular Ultrasound (VUS)
VUS (see Table 8) with a linear probe commonly is used for
the placement of central venous, arterial, and peripheral intra-
venous catheters. Furthermore, FOCUS examination aids in
assessing volume status, as central venous pressure or right
atrial pressure estimations (performed using the subcostal infe-
rior vena cava [IVC] view), can be obtained by measuring
IVC diameter, respiratory variation, and collapsibility index.70
A meta-analysis evaluating the utility of using measurements
of IVC diameter and respiratory variation to predict fluid
responsiveness found the modality more sensitive and specific
in mechanically ventilated patients compared to spontaneously
breathing patients.71 Other modalities, such as carotid Dopp-
ler, can be used for hemodynamic assessments.72,73 Using
POCUS to assess change in carotid flow time is an acceptable
method for noninvasive assessment of fluid responsiveness in
shock states, and also can act as a surrogate for cardiac output.
If the IVC transverse diameter is more than 2 cm, the use of
combined hepatic vein, portal vein, and renal vein pulsed-
wave Doppler assessments, as a part of venous excess ultra-
sound (VExUS) scan, can be done to evaluate for volume over-
load and systemic venous congestion. Beaubien-Souligny et al.
described a VExUS scoring system (see Table 9) to quantify
systemic congestion and its impact on renal dysfunction in
post-cardiac surgery patients.74-76 The severity of the VExUS
score is used as a guide for fluids, inotropes, vasodilators, and
diuretic management. Measurement of the right ventricular
outflow tract velocity-time integral with FOCUS, when com-
bined with the VExUS scan, enables a global evaluation of
right ventricular function and, when dysfunction is present, its
effects on systemic organ congestion.
Additionally, evaluation for the presence of lower-extremity
deep vein thrombosis (DVT) is a core part of the POCUS
examination, especially in critically ill patients. A comprehen-
sive scan should begin with visualization of the common fem-
oral vein. Subsequently, all five major points of vascular
bifurcation within the lower-extremity veins are identified,
with a two-point compression test performed at each point to
rule out DVT.77,78 A systematic review assessing the accuracy
of emergency physician-performed ultrasound found a sensi-
tivity of 96.1% and specificity of 96.8% for the diagnosis of
DVT.79 Also, positive findings from the VUS DVT scan, when
VExUS = 2 VExUS = 3
(Severe Congestion)
IVC > 2 cm IVC > 2 cm
Mild abnormality
(S < D)
Severe abnormality
(S wave reversal)
Mild abnormality
(30%-49% pulsatility index)
Severe abnormality
(>50% pulsatility index)
Mild abnormality
(discontinuous biphasic flow)
Severe abnormality
(discontinuous monophasic flow)
, Venous Excess Ultrasound Score.
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8 H. Kalagara et al. / Journal of Cardiothoracic and Vascular Anesthesia 00 (2021) 1�16
accompanied with FOCUS assessment of RV function (along
with focused LUS), can be helpful in ruling out pulmonary
embolism.80-82
Regional Anesthesia
Interfascial plane blocks play an emerging role in periopera-
tive pain management.83 Due to the risks associated with epi-
dural and paravertebral techniques, interfascial plane blocks
(see Table 10) are a safer alternative for patients after cardiac
surgery and can be incorporated readily into a multimodal pain
management plan for a number of cardiac, thoracic, and vascu-
lar procedures, due to their relative ease of performance and
low level of complications.84,85 The implementation of these
blocks into multimodal cardiac enhanced recovery pathways
helps to minimize opioid consumption, reduce nausea and
vomiting, reduce postoperative ventilatory time, improve
patient satisfaction, and provide cost reductions.86,87 Involve-
ment of the cardiothoracic anesthesiologist with these regional
techniques has the additional benefit of providing further expe-
rience in performing LUS, as these interfascial plane blocks
are performed on the chest. In particular, it is important to be
facile in recognizing the presence of pneumothorax, which is a
complication associated with paravertebral blocks. Many cen-
ters use paravertebral blocks for pain control after thoracot-
omy, with these novel interfascial plane blocks playing an
important role in enhanced recovery pathways for cardiac and
thoracic surgeries. Nagaraja et al., in a comparison of thoracic
epidural analgesia versus bilateral erector spinae plane (ESP)
blocks for cardiac surgical procedures, revealed comparable
pain scores until 12 hours postoperatively, along with similar
Table 10
Ultrasound-Guided Regional Anesthesia Applications for the Cardiothoracic
Anesthesiologist
Regional Site of Injection of
Local Anesthetic
Surgical Procedures
PECS I and II blocks Between PMaM and
PMiM and between
PMiM and SAM
ICD, pacemaker
insertion
Right anterior
thoracotomy
SAPB Between the rib and
SAM or between
SAM and LDM
Thoracotomy, VATS,
Rib fracture
Minimally invasive
cardiac surgery
ESPB Between the TP and
ESM
Thoracotomy, VATS
Rib fracture
Sternotomy
PIFB/TTPB Between PMaM and
EIM/between IIM
and TTM
Sternotomy,
sternal fracture
Abbreviations: EIM, external intercostal muscle; ESM, erector spinae muscle;
ESPB, erector spinae plane block; ICD, implantable cardioverter-defibrillator;
IIM, internal intercostal muscle; LDM, latissimus dorsi muscle; PECS block,
pectoral nerve block; PIFB, pecto-intercostal fascial block; PMaM, pec major
muscle; PMiM, pec minor muscle; SAM, serratus anterior muscle; SAPB,
serratus anterior plane block; TP, transverse process; TTM, transversus
thoracic muscle; TTPB, transversus thoracis plane block; VATS, video-
assisted thoracoscopic surgery
ventilator days and ICU duration of stay, suggesting ESP block
as a viable alternative to thoracic epidural analgesia.88 In a sec-
ond patient-matched controlled study, continuous ESP block
was associated with decreased opioid consumption and earlier
mobilization after open cardiac surgery.89 In a randomized
controlled trial comparing serratus anterior plane block with
thoracic epidural analgesia for thoracotomy, Khalil et al. found
comparable pain scores and opioid consumption in both
groups, without a significant drop in mean arterial blood pres-
sure compared to baseline values in the serratus block group,
suggesting serratus plane block is a safe and effective alterna-
tive for postoperative analgesia in thoracotomy.90
Focused Assessment With Sonography in Trauma (FAST)
FAST is a commonly used diagnostic modality in trauma
patients to evaluate for intrabdominal fluid, as well as to guide
surgical interventions.91,92 In the postoperative setting, FAST
can be used rapidly to assess for intra-abdominal fluid collec-
tions in the workup for hypotension.93 The FAST examination
(see Table 11) can be performed easily at the bedside and
repeated according to the clinical context to guide continued
clinical management. In a Cochrane review on the evaluation
of POCUS for diagnosing thoracoabdominal injuries in blunt
trauma, positive findings, such as free fluid in thoracic or
abdominal cavities, major solid organ injuries, or lesions of
major vessels, were found to help regarding guiding manage-
ment decision, with a sensitivity of 0.68 and specificity of 0.95
for abdominal trauma.94 The Rapid Ultrasound for Shock and
Hypotension protocol is useful in patients with undifferenti-
ated shock, incorporating POCUS of the heart, IVC, Morison’s
pouch, aorta, and pneumothorax to identify rapidly reversible
causes of hypotension.95
POCUS in the Critical Care Setting
POCUS use in the critical care setting has burgeoned over
the past decades, with the core competencies of POCUS now
widely viewed as mandatory skill sets required by the modern
critical care medicine clinician.96 In the following, various
applications of POCUS in the ICU are addressed, including
ICU-specific echocardiography, LUS, abdominal ultrasound,
and vascular ultrasound.
Echocardiography, both TTE and TEE, long have been used
in the ICU. The causes of ICU-related hemodynamic instabil-
ity are diverse and include, but are not limited to, ventricular
dysfunction, myocardial ischemia, arrhythmias, sepsis, acute
blood loss, cardiac tamponade, and respiratory failure.97 Mul-
tiple examples exist within the literature demonstrating the
value of POCUS for diagnosing etiologies of hemodynamic
instability.95,98 The utility of TTE and TEE for the manage-
ment of hemodynamically unstable cardiac and patients after
noncardiac surgery has been shown to result in the determina-
tion of definitive diagnosis and subsequent change in clinical
management in 58.8% of patients in this context.99
Patients in the ICU benefiting from the use of POCUS also
include those requiring mechanical circulatory support
Table 11
Focused Assessment With Sonography in Trauma (FAST)
FAST View Structures Positive Signs
RUQ Liver, right kidney, hepatorenal pouch, diaphragm, right lung Morison’s pouch +, inferior pole of liver +
LUQ Spleen, left kidney, splenorenal recess, diaphragm, left lung Splenorenal pouch +, subphrenic space +
Pelvic sagittal and transverse Bladder, rectum, uterus (in women) Rectovesical pouch + (men)
Pouch of Douglas + (women)
Extended FAST
(e-FAST)
Lungs (LUS)
Cardiac (SC4C)
Pneumothorax
Hemothorax
Tamponade
Abbreviations: blood present; LUQ, left upper quadrant; LUS, lung ultrasound; RUQ, right upper quadrant; SC4C, subcostal four-chamber view.
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devices. Lu et al. demonstrated that trained intensivists can
perform adequate bedside TTE, TEE, and FAST examinations
on patients with mechanical circulatory support to guide medi-
cal and surgical management.100 In their study, 189 rescue
POCUS examinations were performed in a mixed cardiac med-
ical/surgical ICU, of which 4% led to extracorporeal mem-
brane oxygenation or ventricular assist device cannula
reposition, 2% lead to extracorporeal membrane oxygenation
or ventricular assist device setting change, and 1% led to right
ventricular assist device insertion.
In addition, POCUS has utility in the evaluation of fluid
responsiveness and to help guide appropriate fluid resuscita-
tion. When combined with LUS, echocardiography (specifi-
cally IVC imaging) can aid in fluid resuscitation management
in the critically ill, as demonstrated by Lee et al.101 By com-
bining current literature on lung and IVC ultrasound with
expert opinion on the ability of transthoracic ultrasound to pre-
dict fluid responsiveness, investigators were able to develop a
qualitative fluid resuscitation guide that categorized critically
ill patients into one of three broad groups: fluid resuscitate,
fluid test, and fluid restrict. Validation of this resuscitation
guide to help clinicians prescribe fluid therapy still is pending.
LUS is helpful in the evaluation of respiratory failure and
can diagnose acutely and guide treatment for a wide range of
lung pathologies, including pulmonary edema, pleural effu-
sion, pneumonia, and PTX.39 The FALLS protocol uses ele-
ments of the BLUE protocol, in combination with basic
echocardiography, to rule out other causes of shock (obstruc-
tive, cardiogenic, and hypovolemic) while highlighting an end-
point of resuscitation for distributive shock (the transition on
lung ultrasound from an A-profile to a B-profile).
In addition, LUS can aid in identifying the need for postop-
erative ventilatory support, as established by Dransart-Raye
et al.49 In this study, the presence of two areas of consolidated
lung was associated with a lower PaO2 per FIO2 ratio, the need
for postoperative ventilatory support, longer intensive care
stays, and episodes of ventilator-associated pneumonia requir-
ing antibiotics. In summary, LUS has the ability to diagnosis
acutely and accurately the causes of respiratory failure, aid in
volume resuscitation, identify patients likely to need postoper-
ative ventilatory support, and assist in weaning mechanical
ventilation.
Abdominal POCUS long has been used in emergency medi-
cine; has a reported sensitivity, specificity, and accuracy of
bedside sonography in identifying intraperitoneal hemorrhage
of 81.8%, 93.9%, and 90.9%, respectively; and is able be per-
formed in less than a minute in most ICU patients.102 The ini-
tial abdominal ultrasound protocol (FAST examination) has
been updated to the extended FAST examination (e-FAST),
which incorporates LUS for the assessment of PTX and was
found to have sensitivities and specificities superior to those of
CXR.103 FAST and e-FAST examinations are unique in their
ability to allow the intensivist to evaluate fresh postoperative
cardiac surgery patients experiencing hypotension for abdomi-
nal or thoracic hemorrhage. Abdominal ultrasound also has
been used to measure abdominal aortic aneurysm diameter and
to diagnose aneurysm rupture.104 In addition, bedside abdomi-
nal ultrasound can be used to evaluate, quantify, and guide par-
acentesis for abdominal ascites.6 POCUS also has been used to
diagnose obstructive nephropathy,6 hydronephrosis,105 neph-
rolithiasis,106 and bladder distention,107 as well as assisting in
difficult Foley catheter placement.108 All of these attributes
make abdominal ultrasound ideally suited for routine use in
the ICU.
The use of vascular ultrasound in the ICU ranges from vas-
cular access (central venous access, arterial access, and periph-
eral venous access) to the diagnosis of DVT. Central venous
access has been an accepted application of POCUS for a long
period of time, as demonstrated by multiple studies in the liter-
ature, dating back to the early 1990s.109-112 The benefits of
vascular ultrasound for central venous access include identifi-
cation of appropriate vessels for cannulation, identification of
aberrant vascular anatomy, verification of vessel patency, and
real-time confirmation of correct device placement,113 as well
as higher first attempt success rates and lower mechanical
complication rates.114 These benefits are associated most
strongly with internal jugular vein access, while being associ-
ated less strongly with subclavian and femoral vein access.114
POCUS also has been demonstrated to be superior to tradi-
tional blind cannulation techniques for both peripheral IVs and
arterial lines regarding success rate, time to cannulation, and
number of skin punctures.115-118 Another useful application of
vascular ultrasound in the ICU is the detection of DVT. One
study demonstrated that proximal lower-extremity DVT diag-
nosed by POCUS had an 86% sensitivity and 96% specificity
compared to formal ultrasound studies.119 POCUS allows for
the early detection and timely intervention in thromboembolic
disease processes seen in the ICU.
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Limitations of POCUS
It is critical to understand the limitations of each POCUS
application in clinical practice. Identification of an appropriate
POCUS indication based on clinical presentation and knowl-
edge of the pre-test probability are the first steps for successful
POCUS usage. Understanding the sensitivity and specificity of
each POCUS application, in comparison to other standard
techniques, plays a key role in the successful application of
POCUS for diagnostic purposes. Both individual patient fac-
tors and operator experience should be taken into consider-
ation. The complete clinical context of the patient should be
taken into account rather than simply treating the images
obtained. It is advisable to seek expert help and archive images
in situations of especially challenging POCUS diagnoses to
ensure safe patient care and avoid errors in clinical manage-
ment. Adequate training, as well as adherence to established
competencies and credentialing, are essential.
POCUS Education and Certification
Ultrasound use has become ever more ubiquitous across a
variety of medical disciplines, and ultrasound education is
now part of the core curriculum of multiple medical
schools.120 A four-component rationale for incorporating ultra-
sound education into medical education has been proposed by
education leaders in the California medical school system, pos-
iting that ultrasound education (1) enhances traditional medi-
cal education, (2) improves the diagnostic and procedural skill
set of trainees, (3) promotes more efficient patient care, and
(4) serves as a basis for more advanced and specialty-specific
ultrasound training during residency training and beyond.121
In the context of anesthesiology, POCUS education includes
echocardiography (transesophageal and transthoracic), proce-
dural ultrasound for vascular access and regional anesthesia,
as well as a growing variety of diagnostic uses (abdomen-
chest-airway evaluation, gastric volume determination, and
intracranial pressure estimation).122 While cardiac echocardi-
ography and ultrasound for regional anesthesia have been
well-established core elements of anesthesiology residency
education, as yet, no single structured POCUS curriculum or
professional society guidelines have become uniform across
all anesthesiology training programs.123 With the introduction
of novel surgical techniques two decades ago, a similar situa-
tion was faced by the American College of Surgeons (ACS),
with a need to demonstrate proficiency in these laparoscopic
and endoscopic surgeries. The ACS engendered the Funda-
mentals of Laparoscopic Surgery (FLS) and Fundamentals of
Endoscopic Surgery (FES) programs, which enable the evalua-
tion of surgical trainees’ knowledge base, technical skills, clin-
ical judgment, and overall competency in these respective
surgical areas.124,125 In 2019, the National Board of Echocardi-
ography, in conjunction with 9nine medical societies, adminis-
tered the first Examination of Special Competence in Critical
Care Echocardiography, with successful completion leading to
testamur status.126 The Examination of Special Competence in
Critical Care Echocardiography content transcends cardiac-
specific topics and includes content germane to a variety of
POCUS topics: ultrasound physics, ultrasound technical skills,
ultrasound image optimization, lung and pleura imaging, as
well as focused vascular and abdominal imaging. Though sig-
nificant momentum for POCUS education is occurring at the
medical school and graduate medical education level, a need
now exists to incorporate all of the aforementioned POCUS
applications and content into both anesthesiology residency
education and for those clinicians beyond training. For clini-
cians beyond training seeking ultrasound and POCUS training,
a variety of regional and national medical societies (eg, Ameri-
can Society of Anesthesiologists, Society of Critical Care
Medicine, American Society of Regional Anesthesia, Society
of Cardiovascular Anesthesiologists), as well as independent
commercial organizations (eg, POCUS Certification Acad-
emy), offer POCUS-related educational activities; additional
options after training typically include self-directed learning
and simulation-based training.123 In a 2017 survey of a variety
of 343 critical care medicine clinicians of varying back-
grounds, as compared to other specialties, those clinicians
with primary residency training in emergency medicine were
more likely to have received POCUS training during their resi-
dency training (73.5%, p < 0.001) compared to the other sur-
veyed specialties (8.7%). Of the nonemergency medicine
specialties, including anesthesiology, POCUS training was
derived from an external educational course (26.5%) or
through self-guided learning (17.2%).127 To date, there is no
literature specifically examining POCUS education in the
training context versus thereafter via conferences and work-
shops. Hence, at present, quality assurance as to the education
experience for a given clinician only may be assessed by com-
petency evaluations, which include mandating a minimum
number of reviewed POCUS scans and imaging analogous to
existing echocardiography certification pathways.128 As grow-
ing numbers of perioperative clinicians, who already have
completed training seek POCUS education, as well as the
broad variety of POCUS training options outside of the formal
medical education systems, the need for codifying what consti-
tutes adequate POCUS education and competency should be
prioritized.
As POCUS continues to evolve in its diagnostic and proce-
dural applications, there is yet to be a single unified or codified
POCUS training curriculum in the United States analogous to
the ACS FLS and FES programs. In a 2016 call to action, Mah-
mood et al. outlined three components needed for the develop-
ment of a core POCUS educational program: (1) during
anesthesiology residency, POCUS training should be
“continuous and structured” and (2) residency programs
should develop individual ultrasound education tools and
means for evaluation that align with existing Accreditation
Council for Graduate Medical Education milestone expecta-
tions.122 Analogous to the aforementioned FLS and FES pro-
grams, anesthesiology residency programs also should work to
develop a structured and unified approach to anesthesiology
POCUS training, and (3) additional advanced POCUS con-
cepts and skills training at the fellowship level or beyond also
should be part of constructing a unified POCUS educational
Table 12
Pathways for Attaining POCUS Competency
POCUS Competency Pathways
Supervised Training Pathway Established Expertise Pathway
POCUS Modality Minimum No. of supervised
studies personally performed
and interpreted
Minimum No. of additional
supervised studies
interpreted but not
personally performed
Obtain written/signed endorsement from 3 attending physicians
attesting to the following:
1. Explain why letter author is qualified to write the letter.y
2. Describe the letter author’s relationship to the candidate
applying for POCUS privileging.
3. Include a specific attestation statement listed below as pertains
to the POCUS domain(s) being discussed (see below).
Each supporting letter should be from an attending physician who
has directly observed candidates’ competence for the given
POCUS application.
Expertise Pathway: Attestation Statements for POCUS Modalities
Focused airway u/s 30 20 “I personally attest that Dr. <Insert Name> is qualified to perform
focused airway u/s. Specifically, in my time working with him/her,
I observed that he/she could properly use u/s to evaluate for,
among other things, the following: laryngo-tracheal anatomy and
endobronchial vs esophageal vs endotracheal intubation.”
FAST exam 30 20 “I personally attest that Dr. <Insert Name> is qualified to perform a
FAST exam. Specifically, in my time working with him/her, I have
observed that he/she could properly use u/s to evaluate for life-
threatening conditions in trauma patients, including but not limited
to: intraperitoneal fluid/hemorrhage and pericardial effusion/
hemopericardium.”
Focused cardiac u/s 50 100 “I personally attest that Dr. <Insert Name> is qualified to perform
focused cardiac u/s. Specifically, in my time working with him/
her, I have observed that he/she could properly use cardiac u/s to
evaluate for, among other things, the following: pericardial
effusion/cardiac tamponade, gross left ventricular dysfunction,
gross right ventricular dysfunction, and gross hypovolemia.”
Focused gastric u/s 30 20 “I personally attest that Dr. <Insert Name> is qualified to perform
focused gastric u/s. Specifically, in my time working with him/her,
I observed that he/she could properly use u/s to evaluate for,
among other things, the following: full stomach (defined as solid
gastric content or clear fluid in excess of baseline secretions
[Grade 2 antrum]).”
Focused pleural and lung u/s 30 20 “I personally attest that Dr. <Insert Name> is qualified to perform
focused lung u/s. Specifically, in my time working with him/her, I
have observed that he/she could properly use lung u/s to evaluate
for, among other things, the following: pneumothorax, pleural
effusions, interstitial syndromes, and consolidation.”
Focused u/s for DVT 30 20 “I personally attest that Dr. <Insert Name> is qualified to perform
focused u/s for evaluation of DVT. Specifically, in my time
working with him/her, I have observed that he/she could properly
use u/s to evaluate for, among other things, the following: a DVT
in the proximal lower extremity veins and in the internal jugular
vein.
NOTE. Based on the 2019 Committee Work Product on Diagnostic Point-of-Care Ultrasound of the American Society of Anesthesiologists. (A copy of the full text
can be obtained from ASA, 1061 American Ln, Schaumburg, IL 60173-4973 or online at www.asahq.org.).132
Abbreviations: DVT, deep vein thrombosis; FAST, focused assessment with sonography in trauma; POCUS, point-of-care ultrasound; u/s, ultrasound.
yExamples: (1) possession of a relevant national certificate or certification in u/s, (2) history of teaching at relevant u/s workshops, (3) history of performing and
interpreting diagnostic u/s examinations at their home institution, with an estimated annual volume of relevant u/s examinations that they personally perform
and interpret and number of years they have practiced this modality of diagnostic u/s.
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H. Kalagara et al. / Journal of Cardiothoracic and Vascular Anesthesia 00 (2021) 1�16 11
curriculum.122 In addition to these three elements, other
authors also highlighted that a complete POCUS educational
curriculum should include maintenance of POCUS skills after
training and professional development.129 The International
Federation of Emergency Medicine published a consensus
document in 2015 that provided stepwise guidance for POCUS
training in their domain; however, this POCUS training
framework is relatively generic and applicable to anesthesiol-
ogy.130 Applied to POCUS education, this framework began
with defining what applications (core and advanced techni-
ques) are to be taught and how each of these applications will
be taught. Regarding POCUS education methodology, a four-
step process should be used: application introduction, experi-
ential use and development (ie, documented via case log),
Table 13
POCUS Curriculum Levels of Competency
Competency Level Level Description Included Competencies
Level 1 � Core � Expected standard of knowledge and practice� Generic and basic competences to be obtained during residency
training
� Able to perform common u/s examinations and interventions
safely and accurately� Able to recognize normal and abnormal anatomy and pathology� Able to use u/s in real time to guide common invasive
procedures� Able to recognize when consultation for a second opinion is
indicated� Able to understand benefits of u/s imaging and its value and rela-
tionship to other imaging modalities used in perioperative
medicine
Level 2 � Extended � More advanced level of skill and practice; level 2 practice for
clinicians with specialized interest in u/s� Overlapping nature of practice is proposed such that a clinician
may be level 2 in one area (ie, vascular access) and level 1 in
another (ie, regional anesthesia).
� Significant experience of level 1 practice (ie, >12 months)� Able to perform the complete range of examinations� Able to recognize significant organ system-specific pathology� Able to use u/s to guide full range of procedures related to prac-
tice area� Able to act as mentor and instructor for level 1 clinicians� Able to accept referrals from level 1 clinicians
Level 3 �Advanced � Specialized and advanced training (ie, advanced echocardiogra-
phy training)� Level 3 practice is unlikely to be pertinent to most practicing
perioperative clinicians.
� Able to accept referrals from level 2 clinicians and perform spe-
cialized examinations� Level 3 clinicians are involved in all areas of u/s training and
participate in u/s research.
NOTE. Adapted from the Association of Anaesthetists of Great Britain and Ireland, the Royal College of Anaesthetists, and the Intensive Care Society’s
“Ultrasound in Anaesthesia and Intensive Care: A Guide to Training”.133
Abbreviations: CCM, critical care medicine; u/s, ultrasound.
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obtaining competence (expert review of case log along with
skills assessment), and maintenance of competency (continu-
ing POCUS education and case log maintenance). In assigning
levels of competency, neither the Accreditation Council for
Graduate Medical Education nor any specific American anes-
thesiology society has yet to set standards, milestones, or
required levels of training specific to POCUS.128 However, the
American Board of Anesthesiology, as part of the Objective
Structured Clinical Examination component to board certifica-
tion, includes testing candidates’ interpretation of basic TEE,
basic TTE, and chest ultrasound imaging, with specific
POCUS applications being added to the Objective Structured
Clinical Examination beginning in 2022.131 Building on the
aforementioned POCUS educational framework concepts, in
2019 the American Society of Anesthesiologists convened its
first Ad Hoc Committee on POCUS, which, in part, specifi-
cally addressed the minimum level of training in diagnostic
POCUS needed for competence. See Table 12 for the Ameri-
can Society of Anesthesiologists Ad Hoc Committee’s recom-
mendations on training requirements required to be considered
POCUS competent based on the 2019 Committee Work Prod-
uct on Diagnostic Point-of-Care Ultrasound of the American
Society of Anesthesiologists.132 The Association of Anaesthe-
tists of Great Britain and Ireland and the Intensive Care Soci-
ety POCUS training curriculum offer three competency levels
that could be applied similarly in the United States (see
Table 13).133
Given the expertise and familiarity of cardiothoracic anes-
thesiologists with echocardiography and perioperative ultra-
sound applications, it is natural to conclude that they should
play an important role in all aspects of POCUS education.
Conclusions
POCUS is a valuable bedside diagnostic tool for the expedi-
tious diagnosis of a variety of acute and life-threatening condi-
tions, clearly earning its burgeoning reputation as the 21st-
century stethoscope. For each organ system evaluated, the
application of POCUS has its own unique advantages. LUS
has better sensitivity and specificity over CXR for certain lung
conditions, such as PTX, pulmonary edema, lung consolida-
tion, and pleural effusion. 40,42,44 Cardiac ultrasound has a cen-
tral role in the evaluation of challenging hemodynamic
situations and undifferentiated shock states. Combinations of
POCUS modalities, such as LUS along with FOCUS, have
higher rates of accurate diagnosis in complex situations and
multiorgan system involvement.134,135 Diagnosis and treat-
ment using POCUS should be within the clinical context of the
patient, and the ultrasonographer must be aware fully of the
limitations.136,137 Analogous to the National Board of Echo-
cardiography training and certification standards for echocar-
diography, standardizing POCUS education and delineating
competency levels also are central to ensuring appropriate
quality assurance. This is even more critical as POCUS use
increases and more physicians seek to attain POCUS expertise
to incorporate this technology more widely into routine clini-
cal practice. With the current available and growing evidence
of clinical value of POCUS, its utility across the perioperative
arena adds enormous benefit to clinical decision-making.
Conflict of Interest
The authors declare no competing interests.
ARTICLE IN PRESS
H. Kalagara et al. / Journal of Cardiothoracic and Vascular Anesthesia 00 (2021) 1�16 13
Supplementary materials
Supplementary material associated with this article can be
found, in the online version, at doi:10.1053/j.jvca.2021.01.018.
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