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52
Their number has no clinical relevance, while their presence does.
Be aware: A-lines are not moving; they are normal pattern in both PTX and
normal lung! You can fi nd similar artifacts even looking at it in the bowel.
B-lines are vertical, laser-like artifacts, departing from the pleural line and
descending to the lower edge of the screen, increasing in thickness as they go down
(Figs. 4.19 and 4.20 ). They move synchronously with the sliding lung. They can be
as few as one or multiple. Plenty of B-lines (till a so-called white lung) means a wet
lung (lung contusion, pulmonary edema, ARDS) (Figs. 4.21 ). Fine US lung semiol-
ogy is out of the scope of this book.
B-lines are better visualized with convex or phased array probe.
The last artifact of interest is called E-line (Fig.
4.22 ).
Generated by the air in the subcutaneous tissue , this particular artifact appears as
long or short vertical lines, masking the bat sign. It is very important to identify the
bat sign BEFORE starting to classify artifacts for diagnosis, because if you have
subcutaneous emphysema, you cannot see the pleural line and thus you cannot tell
a PTX.
Figs. 4.19, 4.20, and 4.21 B-lines and the so-called lung rocket. The laser-like vertical lines go
down to the edge of the screen
A.A. Casamassima and M. Zago
53
Figs. 4.19, 4.20, and 4.21 (continued)
4 Thoracic Views: Anatomy, Techniques, Scanning Tips and Tricks, Abnormal Images
54
4.3 Clinical Meaning: Diagnosis of Pneumothorax
Let’s get to the core: how can I diagnose a PTX with US?
When you suspect a PTX, you should apply the probe on the anterior chest wall
and check for the sliding lung.
If you can detect it, your patient has no PTX.
Move the probe toward the feet, till you see the liver (on the right side) or heart
(on the left). Small PTX are located parasternal, over the diaphragm (right), and
over the heart (left), not at the apex, as your patient is in supine position.
If you cannot tell the sliding lung and you can see the A-lines, you should check
for a lung point. If lung point can be seen, that’s your evidence of PTX. With lung
point detection, you also have a crude idea of the extension of the PTX. If in dif-
ferent positions over the chest you cannot detect the lung point (and sliding lung
neither), you should think of a massive PTX and act accordingly.
Fig. 4.22 E-lines. They look
almost like the B-lines, but
no bat sign can be detected.
There is subcutaneous
emphysema: Lung US not
possible
Key Points
• Sliding lung → no PTX
• Sliding? No comet tails? Yes → apneic patient or wrong intubation
• Sliding + lung point → PTX
• No Sliding + no lung point → complete PTX
A.A. Casamassima and M. Zago
55
Here is a small fl ow chart (Fig. 4.23 ):
In the very spirit of “think binary,” with this chart in mind, we can exclude or
diagnose a PTX (and have a rough idea of its extension as well) in less than 2 min.
Sliding lung?
(B-mode or M-mode)
YES
YES
YES
Mild
Moderate
Severe
Complete PTX
PTX
Lung point?
Vertical
artifacts?
NO
NO
NO
NO PTX
Fig. 4.23 Pneumothorax diagnosis fl ow chart
4 Thoracic Views: Anatomy, Techniques, Scanning Tips and Tricks, Abnormal Images
56
Suggested Reading
1. Blaivas M, Lyon M, Duggal S (2005) A prospective comparison of supine chest radiography
and bedside ultrasound for the diagnosis of traumatic pneumothorax. Acad Emerg Med
12:844–849
2. Lichtenstein DA, Menu Y (1995) A bedside ultrasound sign ruling out pneumothorax in the
critically ill. Lung sliding. Chest 108:1345–1348
3. Lichtenstein D, Meziere G, Biderman P, Gepner A (1999) The comet-tail artifact: an ultra-
sound sign ruling out pneumothorax. Intensive Care Med 25:383–388
4. Lichtenstein D, Meziere G, Biderman P, Gepner A (2000) The “lung point”: an ultrasound sign
specifi c to pneumothorax. Intensive Care Med 26:1434–1440
5. Soldati G, Testa A, Sher S, Pignataro G, La Sala M, Silveri NG (2008) Occult traumatic pneu-
mothorax: diagnostic accuracy of lung ultrasonography in the emergency department. Chest
133:204–211
6. Zhang M, Liu ZH, Yang JX, Gan JX, Xu SW, You XD, Jiang GY (2006) Rapid detection of
pneumothorax by ultrasonography in patients with multiple trauma. Crit Care 10:R112
Remember
• Check for hemothorax at the same moment you scan abdominal RUQ and
LUQ with the convex probe
• Don’t lose time: missed small hemothorax are not clinically relevant; you
are treating a trauma patient!
• Detection of PTX is simpler than free fl uid in the abdomen
• Start with linear probe for PTX if you are not an expert
• Don’t move the probe checking for PTX (you are fi nding for lung
sliding!)
• Small PTX are caudal, not at the apex
A.A. Casamassima and M. Zago
57
M. Zago (ed.), Essential US for Trauma: E-FAST, Ultrasound for Acute Care Surgeons,
DOI 10.1007/978-88-470-5274-1_5, © Springer-Verlag Italia 2014
5.1 Introduction
You have learned to recognize fl uids: liquid effusions (in abdominal or pericardial
or pleural cavity) or free air in the thorax. In other words, you know how to quickly
detect hemothorax, pneumothorax, pericardial effusion, and free fl uid in the
abdomen.
You also know that the sequential steps for a decision-making process helped by
US could be summarized as follows:
Is my patient in a life-threatening condition?
Should I overcome EFAST?
If no,
EFAST
where is fluid/air?
PHYSIOLOGY + ANATOMY +
EFAST
⇓
my decision is
↓
life-saving maneuver or immediate DCS or further work-up
D. Mariani , MD (*)
General Surgery Department , AO Ospedale Civile di Legnano ,
Via Papa Giovanni Paolo II , Legnano , Milano 20025 , Italy
e-mail:
diemar@me.com
M. Zago , MD
General Surgery Department , Minimally Invasive Surgery Unit,
Policlinico San Pietro , Bergamo , Italy
e-mail:
maurozago.md@gmail.com
5
Including EFAST in Trauma Algorithms:
When? What Now?
Diego Mariani and Mauro Zago
58
5.2 The Common Role of US Exam in Trauma
The “golden hour” paradigm is not a strictly clock-related concept but means an
evidence increasing of morbidity and mortality if care is delayed beyond the fi rst
hour after injury.
So a quick examination like focused sonography found a kind of a natural place
in the primary evaluation of traumatized patient, both in hospital and in prehospital
settings.
The fi rst aim of EFAST is to assist in assessing the undifferentiated hypotensive
status secondary to a blunt trauma.
It could be also selectively applied in the evaluation of penetrating torso
trauma.
For its “focused” nature, EFAST sonography has some limits which must be
known.
Specifi city is high. So, if my EFAST is positive, I could be sure there is an effu-
sion (abdominal, pericardial, or thoracic), and these results must be related with the
clinical condition of the patient.
Sensitivity depends on my skills, the patient, and time from trauma. So, if my
EFAST is negative, it is very important to be very sure about my images and inter-
pret them cautiously in both blunt and penetrating traumas, because the presence of
an underlying lesion in abdominal trauma is not always related with free fl uid, espe-
cially in the early period.
Some lesions don’t produce free fl uid (retroperitoneal bleeding, intraparenchy-
mal lesions); others sometimes require time to develop effusion (bowel injuries, for
instance).
When we performed a focused sonography examination in trauma setting, we do
a particular sonography with a particular point of view.
• Neither detection of injured organs nor a precise diagnosis is required for
decision
• The key point on which to apply EFAST findings is patient
physiology
• All lesions not “producing” free fl uid will not be in the range of EFAST: if
you suspect them, go ahead with your further step
D. Mariani and M. Zago
59
Taking in mind the basic ATLS method of assessing a trauma patient, which is
valid for both major and minor traumas, it will be not so diffi cult to realize and agree
what is depicted in the box above.
5.3 Common Algorithms
Simple algorithms including EFAST and its meaning for clinical decision in blunt
and penetrating trauma are shown below. Brief comments are given for each one in
order to explain some points of the fl ow chart.
Before taking a look at them, please consider that:
• There is a great debate in the last few years about the concept of hemodynamic
instability. For this reason, in order to do not be confusing, we prefer to talk
about “normal” or “not normal” hemodynamics and physiology. Always remem-
ber that the fi rst treatment of bleeding is to stop the bleeding and misdiagnosed
latent shock should be carefully anticipated (with EFAST too).
• For didactical purposes, fl ow charts are presented for different anatomic
areas (thoracic, abdominal). In order for you to merge them, you could imag-
ine to apply them to some complex trauma patients you mananged a few days
ago.
• These fl ow charts are not fully comprehensive trauma algorithms. They highlight
the place and the decisional role of US.
• Finally, local resources can signifi cantly change the clinical path. For that reason,
sometimes a list of option is shown.
• EFAST applies to thoracic and abdominal trauma
• The choice of the sequence of scans is mostly dependent on the patient’s
trauma status and mechanism
• EFAST should be performed
– During the primary survey in physiologically unstable patients
– At the end of primary survey in normal and stable patients
– During the secondary survey and whenever needed by changes in
patient clinical status
• EFAST refers to B and C steps of the primary survey
5 Including EFAST in Trauma Algorithms: When? What Now?
60
5.3.1 Blunt Abdominal Trauma
Here following a Flow chart on Blunt Abdominal Trauma (Fig. 5.1 ) to which some
additional considerations are to be made:
1. *Other sources of shock: hemorrhage elsewhere (thorax, pelvis, bones, retroperito-
neum), tension PTX, cardiac tamponade, neurogenic shock, cardiac pump failure.
Consider you could rule in/rule out some of them with US in a few seconds!
2. Peritonitis in trauma is a mandatory indication for surgery. Further workup and/or
laparoscopy could be used in selected cases
3. The list of possible indications for CT after a negative or slightly positive abdom-
inal EFAST views is based on literature proposals. Having your own protocol is
advisable
a
b
Fig. 5.1 Proposed algorithm
for blunt abdominal trauma
D. Mariani and M. Zago
61
5.3.2 Pelvic Trauma
This fl ow chart is for a patient with clinically or more often radiologically docu-
mented pelvic fracture at high risk of bleeding (in the vast majority of cases, Tile
B/C fractures).
US has a pivotal role for orienting the defi nitive treatment.
Comments to the Pelvic Trauma Flow Chart
1. Possible options for treatment are listed; choice depends on skills, resources,
training, etc., and is out of the goal of this chapter.
2. Physiology (hemodynamics, coagulation, core temperature, pH, etc.) and pelvis
X-ray features (type of fracture relates to the mechanism of injury) are the main
criteria for choosing the best treatment. FAST is the best tool for assessing priori-
ties and deciding for the need of full laparotomy, extraperitoneal packing, or
external fi xation +/− angioembolization.
3. Don’t forget the KISS (keep it simple and stupid): close the pelvic ring immedi-
ately before any further diagnostic and therapeutic maneuver, if needed.
4. In up to 18 % of patients with pelvic fracture, free abdominal fl uid is urine (blad-
der rupture): if in doubt and clinical and US fi ndings do not fi t with patient status,
use again US and perform a diagnostic peritoneal aspiration (DPA). In 20 s, with-
out risks, you solve your problem: immediate or maybe delayed surgery for
repairing a ruptured bladder.
5. In stabilized patient, you have time for CT and eventually angioembolization.
6. If patient hemodynamics is normal, algorithm is that of blunt abdominal trauma
(see Fig. 5.1 ).
Fig. 5.2 US driven protocol
for Pelvic Trauma
5 Including EFAST in Trauma Algorithms: When? What Now?