So, Systemic Inflammatory Response
Syndrome is a relatively new diagnosis, although
it's been around for a long time. And it's often,
but not always, associated with sepsis. It's part
of a syndrome that may lead to septic
shock and death, but not always.
It's associated with a general
breakdown of the body's immune system with the development
of generalized tissue inflammation. And we really don't
understand this process. It's not always
related to infection, but a nonspecific
response to ischemia, loss
of oxygen, trauma, inflammatory
processes or infection. It's part
of a continuum and is often seen
as the presenting condition of this problem.
So the diagnostic criteria
for the SIRS Continuum are SIRS,
Sepsis and Septic Shock,
follow this pattern. For SIRS
criteria you need two criteria,
either a temperature greater than 38ºC,
a heart rate greater than 90,
a respiratory rate greater than 20, or PaCO2
of less than 32, in other words the patient's
really working at breathing, and a white
blood count that's greater than 12,000.
So you need two of those to make the diagnosis
of SIRS. To take the next step and make
the diagnosis of Sepsis, you need to have
SIRS plus a source of infection.
So you either have to have a suspected source or
be able to prove that you've got a source of infection.
The next step is Severe Sepsis.
And this is when organ dysfunction
begins to intervene, low blood pressure
and decrease profusion of organs. And this is
characterized by Lactic Acidosis, which is measured
in the blood, systolic blood pressure of less than
90, or a great drop in systolic pressure.
So those things in combination
define Severe Sepsis Criteria. Septic shock
is the next step in this very bad condition.
This is severe Sepsis with Hypotension despite
adequate fluid resuscitation. So, in a situation
where you're sure you've fluid
resuscitated adequately and you still have
hypotension, you've got Severe Shock Criteria.
And then the final stage of this,
prior to death in many cases
unfortunately, is Multiple Organ Dysfunction
Syndrome. So everything above plus the evidence
of more than two organs failing.
So cardiac, respiratory, renal, any two
organs, often liver failure at this point.
Treatment is very aggressive and starts
with early antibiotics therapy.
Every delay in administering
antibiotics increases mortality by 8%.
That's an amazing statistic.
A one hour delay in starting antibiotics increases
the likelihood the patient's going to die
by 8%. Effective Hemodynamic
Support is essential, but difficult.
The current drug of choice is Norepinephrine,
or Noradrenaline is the other name for it,
and it's given intravenously obviously, but
in very high doses in some of these patients.
The third step is Effective Volume
Management. This is also important
to use the best fluid replacement substance
and this is very controversial. So,
artificial colloid, albumin, normal saline, balanced
salt, high concentration saline, 3% or
5% saline, which are the right agents
to use, or hypotonic solutions.
It's all extremely controversial and it has been
for 40 or 50 years. I've read documentation
from after the Second World War, showing that
the right fluid at the right time has been a challenge
for medical people for a very long period
of time. The best fluid is not known,
but maintenance of normal or slightly high central
venous pressure appears to be the best path,
irrespective of the fluid used.