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Why No O's: Part 1 of 3

Why No O's: Part 1 of 3

If you have been in EMS for any length of time, you know that there are things that we once held in high esteem as medical practices that, if done today, would constitute medical malpractice.  For example, in my early career, we had a blue light in the back of the ambulance.  The way it was explained to be was that the light emitted from a blue light was calming and reduced anxiety.  (Try telling that to anyone who has the blue lights flipped on them while driving on any highway in any state!).  This blue light in the patient compartment was known as a shock light.  Turning it on for patients in shock was supposed to calm them and help deal with their shock.  There were two very serious problems with this hypothesis.  First, if your patient is cyanotic and you have a blue light on in the back of the ambulance, how do you know that you patient might need treatment!  Secondly, do you really want to suppress the sympathetic nervous system action in any patient that is in compensated or decompensated shock?  If you think about it, isn’t that all that’s keeping them alive until you get them to definitive care?

How about rotating tourniquets?  Rotating tourniquets were introduced more than 50 years ago as a measure to decrease left ventricular preload in patients with acute left heart failure.  As late as the latter part of the 1970’s we were using the rotating tourniquet on patient’s arms and legs in an effort to reduce congestive heart failure.  The theory was that by allowing the venous blood to start pooling in the arms and legs the damaged heart would ultimately survive with a better ejection fraction. They were incredibly time intensive to use since you had to loosen one TK and tighten on a patient every 15 minutes. 

Then we went high tech!  We purchased an automatic rotating tourniquet machine so that we could “Set it and forget it!”  Someone had the hindsight to do some research on them and found that they made no benefit to patients in the least!  As soon as Lasix came on the scene the rotating torture machine was rapidly abandoned. 

What about bag valve masks?  How many remember having only one BVM on their ambulance and it was REUSABLE between patients.  I remember cleaning BVMs after bloody traumatic cardiac arrests to get them ready for use on the next patient.  I would be less than honest with you if I told you that my effort to get them THOROUGHLY clean decreased with every minute the clock ticked past the hour of midnight!  What kind of problems would you get into today if you reused your BVM for EVERY patient that needed one?

My question for those of here today is, “what will be your rotating tourniquets?  What will be your shock light?  What will be your sodium bicarbonate?  What treatment and care are you delivering today that in the future will make you reminisce about how archaic and, yes even barbaric your actions were! What are you doing right now that in 5, 10 or 15 years might be considered malpractice, but it is the accepted level of care today?  Might it be the administration of oxygen?

It is important that you understand that this is going to require ongoing research and that research is going to be difficult to conduct.  The studies that I will present to you today come from limited patient sample populations. However, the results of these studies do raise some very interesting questions that must be answered, just as it did when we looked at the above named dinosaur EMS treatments.  Go home and do you own research.  Don’t take for gospel what I am about to share with you as to its accuracy and relevance.  I encourage you to go back and discuss my presentation with your fellow EMTs and Paramedics and especially with your medical director.  Seek his or her input into what the latest research shows. However I stress to you, and this is of the utmost importance…DO NOT deviate from your accepted local and or state protocols.

Oxygen is unique in that it is a drug that surrounds us.   We are endlessly exposed to a low doses that are delivered form the atmosphere around the earth.  From a clinically relevant perspective, oxygen is designed to turn back hypoxia.  What makes this drug different is that we regularly deliver it to our patients with no concerns for its dosage.  If a little is good for hypoxemia…then a lot must be better.  This could possibly be because it is so easy to administer.  Unfortunately, as we see with other medical treatments, better can be the mortal enemy of good! 

The benefit of oxygen is often conflicted with its basic yet forgotten biological harm. Severinghaus and Astrup [1] provide us with a novel and eloquent description of oxygen when they state: ‘‘Oxygen is addicting; in its grip are all the mitochondrial-rich eukaryotes who learned to depend on it during the past 1.4 billion years. This, the first atmospheric pollutant, is the waste product of stromalites (formation of algal plankton), which excreted it at least 2.3 billion years ago. Since then sediments have been rusted or oxidized. Oxygen is toxic. It rusts a person in a century or less. With oxygen came the danger and blessing of fire. If introduced today, this gas might have difficulty get- ting approved by the Food and Drug Administration.’’

EMS responders commenced administering oxygen not because it had been demonstrated to benefit patients.  The primary reason was, because they could.   Over the last two decades EMS has gotten into the routine of administering high-flow oxygen to just about everybody that they came into contact with. Previously all trauma patients were flooded with oxygen even though there were no clinical indications that they needed it.  This was an excellent example of EMS education teaching treatment that was not beneficial to the patient, but rather, what could be “left out” of the 1994 curriculum.  Current science shows that there is no need to continue this unless there is hypoxemia or hypovolemia present within your patient.   

Not having enough oxygen is detrimental, we can all agree on that.   John Scott Haldane recognized this when he wrote in 1917, “Hypoxia not only stops the motor, it wrecks the engine.” Patients begin to experience an altered mental status when oxygen sats are less than   64%. Humans will experience unconsciousness when the saturations go below 56 percent

Lately the research identifies that hyperoxia is often just as dangerous as hypoxia. The drug that we have relied upon for so many years as safe in abundance, may not be as safe as first indicated.  Therein lies the rub.  This is not new information within the medical community.    In 2004, Tulane MDs Zsolt Stockinger and Norman McSwain (who recently died) observed over 5000 patients who had no need for positive pressure ventilation to discover if the addition of oxygen improved or worsened their outcomes.   The two researches determined that there was clear value of additional oxygen, but only in particular situations and occurrences.  Any hypoxic patient that has a decreased difussionary action over the alveolar capillary membrane would most definitely benefit from increasing the amount of oxygen available to them

What they noticed though, in the setting of major systems trauma was the hypoxia was probably caused by the reduction on the abilty of the red blood cell to adequately move oxygen throughout the body or, potentially, by an obstruction of the airway.  The realized that aggressive airway management in conjunction with improving the circulation of the body would lower the need for any supplemental oxygen.  The outcomes from their study showed those who received oxygen did no different than those who did not receive the oxygen. They suggested that there is no survival advantage in using additional oxygen in the prehospital setting for traumatic patients who did require positive pressure ventilation or aggressive airway protection.   They did not go so far as to advocate not using oxygen on a routine basis, however, the observation was made that this might be helpful in natural disasters where supplies of supplemental oxygen delivery might be limited. 

In part two of this blog posting, we will examine the pathophysiology behind the oxidation process as well as nitrogen wash out from the alveoli. 

 

 

References

Stockinger ZT, McSwain NE. Prehospital Supplemental Oxygen in Trauma Patients: Its Efficacy and

                  Implications for Military Medical Care. Mil Med. 2004;169:609-612.

 

Author Bill Young is the program director of the EKU Emergency Medical program. CAAHEP-accredited since 1978, EKU offers top quality degree programs in emergency medical care.

Published on February 10, 2016

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