Guest guest Posted August 7, 2011 Report Share Posted August 7, 2011 Hey Gene, Dr. Genzel wanted me to tell you he started teaching that 10 years ago. Joby Berkley Sent from my iPhone > 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 > > > > > > > > . > > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted August 8, 2011 Report Share Posted August 8, 2011 I was taught that when dealing with hypovolemia and your patients systolic is falling past 80. Or there is absent radial pulse. Fluid resuscitation with hetastarch is best to get the bp back because less fluid is needed and you will have less of a chance of washing out the blood. However once the bp is back to 80 systolic DX the hetastarch and continue with NS and monitor closely. I was never taught this ICP formula though. Where can I get more info on this? - Quote Link to comment Share on other sites More sharing options...
Guest guest Posted August 8, 2011 Report Share Posted August 8, 2011 , Just Google Mean Arterial Pressure, Cerebral Perfusion Pressure, and Intracranial Pressure and you will get a slew of great stuff to read. The problem with a " target systolic " is that CPP depends upon MAP, which depends partly on diastolic pressure. Therefore, while systolic pressure may " appear " within normal range, the brain may not be getting enough blood for adequate perfusion. Level of consciousness is one indicator, but in head injured patients, LOC may not reflect the true situation with CPP. The problem is that we must estimate ICP, but we can make some assumptions based upon Glasgow Coma Scores, LOC, and so forth. CPP should be maintained at 80, ideally. I hope this helps. Gene Gandy Re: Re: [OFFLIST] Re: Question regarding fluid resuscitation I was taught that when dealing with hypovolemia and your patients systolic is falling past 80. Or there is absent radial pulse. Fluid resuscitation with hetastarch is best to get the bp back because less fluid is needed and you will have less of a chance of washing out the blood. However once the bp is back to 80 systolic DX the hetastarch and continue with NS and monitor closely. I was never taught this ICP formula though. Where can I get more info on this? - Quote Link to comment Share on other sites More sharing options...
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