Ultrasound has many advantages for critically ill patients in the ICU. It enables rapid, repeated, and inexpensive bedside evaluation. There are two main probe types: B-mode produces 2D images while M-mode shows motion over time, analogous to video. Ultrasound can assess volume status by measuring the diameter and collapse of the inferior vena cava. It can diagnose pneumothorax by lung sliding signs or stratosphere and seashore artifacts. Ultrasound is also used for vascular access, intubation, diaphragm assessment, and identifying pleural effusions and hemothorax. Critical care physicians should receive training to utilize ultrasound's benefits for critically ill patients.
2. Ultrasound in the field of critical care
• The use of ultrasound has expanded enormously
over the last two decades in critical care research
and practice. Despite the fact that the method is
operator dependent . It has many advantages, it
enables clinicians for rapid, by-the-bed, relatively
inexpensive, can be repeated, and save diagnostic
evaluation of unstable patients.
8. B-mode VS m-mode
• B-mode or 2D mode (brightness mode): a linear array
of transducers simultaneously scans a plane through
the body that can be viewed as a two-dimensional
image on screen.
• M-mode (motion mode): pulses are emitted in quick
succession – each time B-mode image is taken. Over
time, this is analogous to recording a video in
ultrasound. As the organ boundaries that produce
reflections move relative to the probe, this can be
used to determine the velocity of specific organ
structures.
9. Examples 0f use of US in ICU
• 1- Assessment of volume status
• 2- US of the lung
• 2- Diagnosis of pneonumothorax, hemothorax
and pleural effusion.
• 3- Vascular access
• 4- proper endotracheal intubation
• 5 – prediction of post-extubation stridor
• 6- Assessment of the diaphragm.
• 7 differential diagnosis of shock
10.
11.
12.
13. Assessment of volume status
• The 2008 ACEP Policy Statement on Emergency
Ultrasound Guidelines includes the evaluation of
intravascular volume status and estimation of
central venous pressure (CVP) based on
sonographic examination of the inferior vena cava
(IVC).
• ACEP Policy Statement on Emergency Ultrasound Guidelines. Ann.
Emerg. Med. 2009;53:550-70.
14.
15.
16. Can US give us a rapid answer to this
question
Does this patient need fluid??
35. Different values
Measuring the IVC/Ao irrespective to the
respiratory cycle has made the study simpler and
patient specific, and does not necessitate looking
at reference values for each age group. The mean
IVC/Ao in patients euvolemic is 1.2 ± 0.12 SD,
hypovolemic is 0.7 ± 0.09 SD, and volume
overloaded is 1.6 ± 0.05 SD, respectively.
36.
37. Pneumo and hemothrax
Ouellet J-F et al., The sonographic diagnosis of pneumothorax. J
Emerg Trauma Shock. 2011
Stone MB et al., The heart point sign: description of a new ultrasound
finding suggesting pneumothorax.
Acad Emerg Med. 2010
seahore- sign
stratosphere- sign
M- mode, sliding lung sign
comet- trail- artifacts
reverberations
B- mode
65. The problem of pediatrics
• There are no established age-wise norms for
diaphragmatic excursions. Diaphragmatic
excursion less than 4 mm, paradoxical
movement, and difference of more than 50%
between excursions of the hemidiaphragms at
M-mode US are diagnostic of unilateral
paralysis.
75. An advice of 2 steps
1- When I was a child
I talked like a child
I thought like a child
I reasoned like a child
When I became a man
I put childish ways behind me
2- Now I see but a poor reflection .
Then I shall see face to face
Now I know in part
Then I shall know fully.
76. Summary
• Ultrasound is a very useful tool in the field of
ICU and critical care medicine.
• Ultrasound machine should be available in
every ICU and emergency department.
• We should encourage ICU and critical care
physicians for the use of US by adequate
training.