<s>
Prehospital	B-Algorithm
ultrasound	I-Algorithm
is	O
the	O
specialized	O
application	O
of	O
ultrasound	B-Application
by	O
paramedics	O
,	O
to	O
guide	O
immediate	O
care	O
and	O
treatment	O
procedures	O
.	O
</s>
<s>
Like	O
conventional	O
ultrasound	B-Application
,	O
it	O
is	O
a	O
device	O
that	O
produces	O
cyclic	O
sound	O
pressure	O
to	O
penetrate	O
a	O
medium	O
(	O
flesh	O
)	O
and	O
reveal	O
details	O
about	O
the	O
inner	O
structure	O
of	O
the	O
medium	O
.	O
</s>
<s>
Many	O
emergency	O
physicians	O
now	O
view	O
screening	O
ultrasound	B-Application
as	O
a	O
tool	O
,	O
and	O
not	O
a	O
procedure	O
or	O
study	O
.	O
</s>
<s>
While	O
conventional	O
ultrasound	B-Application
can	O
be	O
a	O
lengthy	O
process	O
,	O
and	O
is	O
usually	O
conducted	O
with	O
non-mobile	O
units	O
and	O
advanced	O
image	O
filtering	O
and	O
manipulation	O
built	O
into	O
the	O
unit	O
,	O
emergency	O
ultrasound	B-Application
is	O
as	O
simple	O
and	O
quick	O
to	O
operate	O
as	O
possible	O
,	O
and	O
narrowly	O
focused	O
on	O
a	O
small	O
set	O
of	O
criteria	O
.	O
</s>
<s>
Cardiac	O
ultrasound	B-Application
exam	O
in	O
hypotensive	O
or	O
cardiac	O
arrest	O
patients	O
to	O
place	O
them	O
in	O
one	O
of	O
five	O
states	O
:	O
Cardiac	O
standstill	O
,	O
severe	O
hypovolemia	O
,	O
-cardiogenic	O
shock	O
,	O
pericardial	O
tamponade	O
or	O
right	O
ventricular	O
obstruction	O
.	O
</s>
<s>
In	O
most	O
cases	O
,	O
prehospital	O
providers	O
will	O
employ	O
the	O
use	O
of	O
a	O
portable	O
ultrasound	B-Application
unit	O
.	O
</s>
<s>
In	O
every	O
instance	O
,	O
an	O
attempt	O
is	O
made	O
to	O
find	O
the	O
area	O
best	O
suited	O
to	O
an	O
ultrasound	B-Application
and	O
utilize	O
bare	O
skin	O
if	O
possible	O
.	O
</s>
<s>
There	O
are	O
two	O
main	O
areas	O
of	O
emergency	O
ultrasound	B-Application
.	O
</s>
<s>
Ultrasound	B-Application
visualization	O
of	O
the	O
optic	O
nerve	O
sheath	O
has	O
been	O
shown	O
to	O
be	O
useful	O
as	O
a	O
surrogate	O
for	O
more	O
invasive	O
intracranial	O
pressure	O
monitoring	O
,	O
allowing	O
for	O
more	O
advanced	O
monitoring	O
of	O
brain	O
injuries	O
in	O
the	O
field	O
.	O
</s>
<s>
This	O
means	O
that	O
in	O
terms	O
of	O
trauma	O
diagnosis	O
involving	O
brain	O
injury	O
,	O
sonography	O
will	O
be	O
difficult	O
and	O
requires	O
high-end	O
ultrasound	B-Application
machines	O
.	O
</s>
<s>
The	O
depth	O
penetration	O
of	O
ultrasound	B-Application
is	O
limited	O
,	O
making	O
it	O
difficult	O
to	O
image	O
structures	O
deep	O
in	O
the	O
body	O
,	O
especially	O
in	O
obese	O
patients	O
.	O
</s>
