Re: [OFFLIST] Re: Question regarding fluid resuscitation

[Guest guest]

I know it's belated, but I just thought of it.... How does this change for

pedis? Or does it?

Regards,

Alyssa Woods, NREMT-B

CPR Instructor

Sent from the itty bitty keyboard on my iPhone

> Good information, .

>

> GG

>

> Re: Question regarding fluid resuscitation

>

> Gene,

>

> I was not taught in Paramedic school but that was a little bit ago. I was

taught the concept in CCEMT-P, TCCC and PHTLS/ITLS.

> You can put all the NON-oxygen carrying volume you want but there comes a

point that you have a lot of fluid and only one little cell trying to oxygenate

the body and brain. I am also with you on vasopressors, they have there place

but not when it comes to an empty tank.

> There is at least one study out there saying low hematocrit through

hemodilution increases ICP and causes a worsened neurological outcome.

> So you can give your patient fluids to help meet your CCP and MAP levels and

help decrease the ICP. However, Because you've had a loss of volume through a

bleed somewhere, you give the fluids which causes hemodilution which causes low

hematocrit which causes increased ICP so you are potentially causing the very

thing which you are trying to avoid or help treat in the first place. The

answer? Blood and/or blood products. You can do many things to help with the

increased ICP issues: good oxygenation to assist your lone cell trying to

oxygenate, raise the head of the bed slightly which can sometimes decrease the

ICP, hypothermia is sometimes helpful, watch your glucose levels, mannitol,

steroids (although research is showing that steroids should not be used in

TBI),blood and/or blood products, AND adequate sedation and pain treatment.

> I've looked to see if there was an article or study on the internet saying at

what hematocrit level does oxygenation cease and can't find one. I found

research saying in general hematocrit levels <23% increase mortality but still

nothing specific to at what point does oxygenation cease.

> Now that I have put in my two cents worth I'll go back to my bat cave....

>

>

>

>

> >

> > > For the last few years, fluid resuscitation of trauma patients has been

aimed at maintaining a systolic BP of 80-90 mm Hg. The concept is that of

" permissive hypotension " based upon hydrostatic concerns about the effects of

heightened hydrostatic pressures in the fact of internal bleeding. It has been

postulated that increased hydrostatic pressures will dislodge clots that have

been formed as a natural response to injury, and that increased fluid volumes

will dilute clotting factors and lead to increased bleeding. These concepts are

valid.

> > >

> > > However, I propose that this concept fails to take into consideration one

vital aspect of trauma care, that of adequate perfusion of the brain. Cerebral

perfusion pressure (CPP) is the measure of brain perfusion, and it must be

maintained at a level of 80 mm Hg or better. Studies show that when a patient's

CPP is maintained at that level, there is a 35% improvement in outcomes, whereas

lower CPPs result in poorer outcomes.

> > >

> > > There are two components of blood pressure: the systolic and diastolic

readings. Systolic pressure represents hydrostatic pressure, and diastolic

pressure represents the degree of vasoconstriction. This is an

oversimplification, but it is

> > >

> > > basically accurate. Simply maintaining a systolic pressure of 80-90 mm Hg

does not insure adequate CPP.

> > >

> > > In order to figure CPP, one must first determine mean arterial pressure

(MAP) and estimate the intracranial pressure (ICP). Intracranial pressure cannot

be monitored in the field, but can be estimated based upon clinical

observations.

> > >

> > > The formula for CPP is this: CPP = MAP - ICP.

> > >

> > > MAP can easily be computed by this formula: (1/3 pulse pressure) +

diastolic pressure. Thus, a patient with a BP of 140/80 will have a pulse

pressure of 60. One-third of 60 is 20, and added to the diastolic pressure of

80, results in a MAP of 100.

> > >

> > > Normal patients without head injuries, at rest, have an ICP of from around

5 to 15 mm Hg. This can vary depending upon posture. For example, if a patient

who is supine suddenly stands up, his ICP will fall, and if he is dehydrated or

taking antihypertensives that antagonize alpha-1 vasoconstriction, he can become

dizzy or even faint. Conversely, when one coughs or sneezes, ICP spikes, but

only for a few seconds.

> > >

> > > With a MAP of 100, and an estimated ICP of 15, the CPP would be 85, which

is fine. But if the BP is, for example, 90/50, then the MAP is only 63. [1/3

pulse pressure (40) = 13. Diastolic pressure of 50 + 13 = 63, the MAP.

> > >

> > > Using the formula CPP = MAP - ICP, if one assumes a normal ICP of 10 mm

Hg, then MAP (63) - estimated ICP (10) = 53, far below the target CPP of 80. In

fact, a CPP of 53 is close to the limit for survival.

> > >

> > > And this is in a patient without a head injury. Given a patient with

rising intracranial pressure, it becomes obvious that a higher MAP is needed to

adequately perfuse the brain.

> > >

> > > These concepts are taught in the traumatic brain injury courses, but not

emphasized, I fear, in paramedic training.

> > >

> > > So my question is this: How many of you who are EMS educators use this in

your teaching? How many of you who are Paramedics have had this training and

understand these concepts?

> > >

> > > Are we doing enough to educate our medics to the basics of brain perfusion

with the current guidelines about fluid resuscitation?

> > >

> > > Gene Gandy, JD, LP, NREMTP

> > > PERCOMONLINE.COM

> > > Tucson, AZ

> > >

> > > .

> > >

> > >