00:00
So let's talk
about some fairly common diagnoses
in the Intensive Care Unit.
00:07
So Infection is a major reason
to admit patients to the ICU.
00:13
Failing organ systems is a second reason
for admitting patients. Heart failure, renal failure,
respiratory failure. And medical conditions
with high mortality such as vasculitis,
overdoses, toxic syndromes.
Patients in need for ventilation.
00:31
Respiratory failure, pulmonary edema, closed
head injuries, diabetic ketoacidosis, renal failure
again, and other system,
major system disease. SIRS,
which we'll talk about briefly in a moment, is Systemic
Inflammatory Response Syndrome, and requires intensive
care treatment. And any time a patient requires
complex equipment, such as a ventilator,
or a left ventricular assist or right ventricular
assist device, which we'll talk about in a minute,
continuous renal dialysis or as it's more properly
called, continuous renal replacement therapy,
CRRT, or extra corporeal
membrane oxygenation, ECMO.
01:13
So the modern ICU ventilator is a highly sophisticated piece
of equipment which can deliver different modes
of ventilation according to the patient's
needs. It tends to be a little higher
quality than the ones we use in the operating room, although that's
changing. The ones we're using in the operating room are increasingly
being used for critical care patients who were transferred
from the ICU to the OR. So we basically
need the same equipment in both places.
Volume control ventilation is the commonest
mode of ventilation control in which we set the volume
and the minute ventilation or the ventilatory rate
that we want the patient to receive. And we
usually adjust this according to the patient's
arterial oxygen saturation and carbon dioxide
levels. And we can do either blood gases,
or we can do end-tidal CO2, or just use
saturation continuously on these patients.
02:07
Pressure-Controlled ventilation is used
for patients with high airway pressures, who
are at risk of barotrauma or damage
to the lungs from high pressure,
from volume-controlled ventilation. And
in this situation, instead of setting the volume,
the maximum inspiratory pressure is set. And the ventilator
rate is set according to blood gases, or
saturations, or end-tidal CO2. Pressure
assistant ventilation is a situation in which
the ventilator assists the patient's own ventilatory
efforts by providing a boost in pressure with each
breath to assure adequate ventilation. So, the ventilator
can sense when a patient is trying to breathe
and quickly intervene to make sure that they
get a breath, and that they get an adequate breath.
02:55
We can easily add Positive End-Expiratory
Pressure which is, basically
applying pressure that is maintained in the lungs
even at end expiration. So, normally when
you expire fully, there's very little pressure
in your lungs. But when we're healthy,
there's still a lot of gas in our lungs that continue
to supply oxygenation to the body. In sick people
that can be a problem. So PEEP is added,
usually in fairly low levels, just to maintain lung
volume in sick people, so
oxygenation is supported.
03:31
If ventilation is prolonged and the patient cannot
be weaned, tracheostomy is often provided
and the patient may be ventilated through
the tracheostomy, or in a better situation, they start
to breathe spontaneously through their tracheostomy.
Other organ systems are also extremely important,
such as kidney. And renal failure in the ICU
is now treated primarily with
Continuous Renal Replacement Therapy
or CRRT. The reason this is used is, it's
a slow gradual technique rather than
the more rapid dynamically dramatic
changes that occur with hemodialysis. So
when you put a person on hemodialysis,
you tend to push their blood pressure down, their
volume's changed very rapidly. And normally
people can tolerate that, but they can't when they're
critically ill. So continuous renal replacement therapy has
replaced that. Acute Lung Injury
or ALI, used to be called
ARDS or Adult Respiratory Distress
Syndrome. And has been
revolutionized, the treatment of this disorder, by changes
in ventilatory mode that have only been
introduced in the last 5 years or so. And these
have included using much smaller tidal volumes than
we used to, and more rapid respiratory
rates that's creating good minute
ventilations, but low pressures in the lungs.
This has reduced ventilator
associated lung trauma dramatically
and has improved outcomes. ECMO
or Extra-Corporeal Membrane Oxygenation, is used
more frequently and more effectively than it once
was and we'll talk about this
in a minute. Cardiac failure. We
work by using Left-Ventricular
Cardiac Assist Devices at a much
earlier state than we used to. And these devices, and we'll
discuss this in more detail in a moment, can act as
a bridge to heart transplant, or more
appropriately as a treatment
from which the patient will recover from their heart
failure and the left-ventricular assist device can be
removed. So, infection that is often difficult
to treat is a very common problem
in the ICU. And ventilatory Associated
Pneumonia, VAP, is a common
problem. And intensive care units now use
what's known as a VAP Pack, which reduces
the incidence of VAP and improves
the treatment of VAP.