Tuesday, July 3, 2018

→ Human Pressure Cooker - Physical Science & Embalming

The abdominal evomo has made its way into our reading content. That stinks! For those of you who do not know what this is—the abdominal evomo refers to belly gas. First and foremost, if you haven’t read about what to do with an air pressure system, please refer back to our previous article.
For those that have read, let us get down to where it comes from and why it’s growing. The Clostridium Perfringens bacteria is present in approximately 80% of food poisoning deaths. Oddly enough, keeping food clean is a real challenge in our world, and when we age our body has a difficult time fighting things off. When we die from gas build-up or food poisoning, the death will mimic a heart attack. If there is a history of heart disease in the family (pretty much a guarantee, as “cardiopulmonary arrest” is the most commonly used immediate cause of death among physicians), there might be a doctor in the house willing to sign off that this death was heart related. However, do not be fooled. The presence of Clostridium generally goes hand-in-hand with fecal matter within our intestines. The bacteria is common enough that upon death, its presence will double every five minutes. Coincidentally, upon our death the body enters a state known as algor mortis, which refers to our temperature rising for a short time following death. Heat, as we know in chemical reactions, supplies energy and increases the number of reactions. In simple terms, if we heat fecal matter, we will produce more gas than if we left it alone. If you thought it wasn’t going to get worse, well, get ready. As the gas becomes trapped within the abdomen, forming a abdominal evomo, the air or gas compresses and pressurizes. Within our current understanding of chemistry, pressurized matter can reduce the energy needed for reaction. This can be best understood by the cold boiling process. To be put simply, if you pressurize fluid enough it can be brought to a boil without even becoming hot. As applied to our example, gas can be produced more and more rapidly every second.
As this process continues, the migration of this bacteria into the vascular system becomes more real. Once inside the vascular system, the bacteria will eat the sugar and fats, producing more and more gas and odor. Every step of the way, there will be a barrier of vapor lock left in its wake until it reaches the brain. If the bacteria arrives at the brain, we have a true case of embalmer’s nightmare. Due to the sugary and fatty tissue of the brain, the bacteria will produce large volumes of gas which will distort the facial tissue of the deceased, making it near impossible to restore. So with understanding this process and how it happens, it serves us well to remember to never allow the abdomen to rise higher than the chest. Read on for the rest.
-The Mortuary Scientist

→ Abnormal Pressure Systems - Physical Science & Embalming

Much like a UFO, specific cases yield many questions unanswered for embalmers. Furthermore, what we are able to detect with our eyes often still limits us from gathering all the details we need to do the best job. It was once said that an embalmer’s greatest disappointment or regret is never having the ability to get the same person twice. Hopefully as we grow together, we are able to keep good enough records and data to still advance and improve our capabilities.
While performing case analysis, it is essential that the embalmer is attentive to potential fluid or air obstruction which will prevent fluid traveling throughout the vascular system. Air obstructions might be regarded as the highest priority for the embalmer’s attention. Permitting the complete escape of air is the optimal result, however, we often can fall short of this expectation. Persistent channeling to release air may be necessary as the embalming process progresses. Often, a trocar is used to permit the escape of gas; however, this can often lead to just an intermittent release of gas. Following up the initial escape of gas with forceps or scissors can make an easier path for gas to travel through, despite what other obstructions may be present.
If air remains within the path of travel, fluid by nature has a very difficult time overcoming this obstruction. As fluid travels upstream against gravity without any air present, its ability to travel well is significantly impacted. When air is present in the vessel between fluid, a circumstance known as vapor lock occurs. This is great cause for concern, as truly there is no way to overcome this distribution issue without force, otherwise known as pressure. To even better understand this, know that air has the ability to compress, making it more and more challenging for a fluid to try to overcome it. We have already explained the negatives of a high internal pressure of the arterial system, so now we have the present problem of how we overcome vapor lock without also sacrificing the appearance of the deceased. We will cover the methodology that has been proven to overcome the embalmer’s nightmare, but you will have to keep reading. For now just remember, if its air, it stinks, so do what you can and let it loose!
-The Mortuary Scientist

→ Displacement - Physical Science & Embalming

Flowing fluid may travel fast or slow, it can be in large vessels or small vessels, or it can be in some vessels but not others. Due to the complexity of the vascular system, its beauty, for one, it is easier to disregard all this knowledge and continue as operated. If this information makes your head hurt as much as mine, try and remember the old phrase, “No pain no gain!”
As common hand pumps, syringes, machine pumps, and even gravity feeds are provided to the embalmer, please accept that they do not aid the embalmer very well to calculate displacement. The embalmer is left to calculate this all on his or her own, and it is done usually from memory and frame of reference. Displacement is the measure of volume over time. It is not a complicated concept for us to understand; like miles per hour, so, ounces per minute. All of the above mentioned instruments used to inject or displace fluid have a force that can be calculated. Some of the above have the ability to restrict or regulate flow as well. It should be noted that when we regulate or restrict flow, we conversely influence or affect pressure. Yet when we measure displacement, it remains constant until we adjust one of the previous two variables: pressure or flow, if available. This is why perhaps our most significant frame of reference as we embalm is not the dials, numbers, and switches, but the displacement. We can calculate this visually with our imagination, yet however well this might work for us, we can do better using a flowmeter. As we connect a flowmeter to an embalming machine, we can better understand how adjusting these variables can affect the displacement of fluid from the machine. From our machine, pump settings as “high pressure with very restricted flow” can yield a displacement value the same as “low pressure with moderate rate of flow.” So what is the difference, you might ask? Sorry to disappoint you, that is not covered yet.
To answer the question, there isn’t much of a difference in either of these examples. Both methods rely on pressurizing the arterial system slowly. The pressurized arterial system next begins to dilate the smaller vessels, and so on and so forth. It is important to move slowly at the beginning stages of embalming, for reasons best known to the vascular system itself. Factors such as time of death and refrigeration, to name a few, will lead to pooled blood throughout the arterial system. Pushing the pooled blood deeper into smaller vessels will cause distribution issues for the embalmer. The goal of the embalmer initially would be to distribute the fluid well, and next to pressurize all of the vascular pathways that have been opened. See our former chapter about why fast moving fluid will aid the embalmer in distributing fluid.
The embalmer’s ability to learn more about Physical sciences as it relates to embalming can prove as useful a tool as an aneurysm hook. Holding the vascular system in high regard and understanding how fluid will or will not move within it will aid the embalmer during challenging cases where there are multiple pressure systems being encountered, from air, to fluid within the abdomen, and everything else.
-The Mortuary Scientist

→ Pre-injection - Physical Science & Embalming

Wait a minute, this is supposed to be about Physical embalming—pre-injections are chemicals! We together have made some serious strides thus far, so thank you for reading. You did read this right, and it is important to support data and claims as we progress, so excuse me if this seems as though we have digressed. We haven’t, yet.
Undoubtedly, pre-injections have certainly proven themselves valid to those who have taken the time to see the effect they have prior to arterial embalming. Consider what they are. We could just ask the chemical company, couldn’t we? They break up and help push clots, is what I am told. Yet, I’ve never seen it dissolve a clot or some pooled blood. Would you agree that maybe we should stick to what we can touch and see right in front of us? Most pre-injection fluids are slippery as ever, they are generally thicker than water or arterial chemical, and they have color. Let us together consider what something slippery might do inside the vascular system. We have already established that restricted drainage will slow fluid movement within the vascular system, causing pressure to increase. How would high internal pressure benefit the embalmer? High internal pressure of the large vessels will lead to dilation of additional smaller vessel pathways. Not enough pressure within the large vessels will not permit the passage of fluid to the smaller pathways.
So what is the negative to high internal pressure within the body? If the pressure in the large and small vessels gets too high, the result could be devastating for families. Swollen tissue or severely dehydrated tissue could be the result. So how does this challenge of the embalmer relate to pre-injections, or pre-injection fluid for that matter? Read on.
Please visualize fluid traveling through a large diameter pipe to a smaller diameter pipe. From the small end of the pipe, fluid is able to escape through a very tiny hole. Consider what happens as we flow fluid from the large diameter pipe at a constant rate of gallons per second through the pipe and out of the small diameter end. Fluid entering the large diameter and leaving would be the exact same volume. So visually, we would see a large stream entering traveling apparently slowly, as compared to a tiny stream exiting traveling apparently much faster. This is not the same system we have while we are performing arterial embalming. The variable we would need to change and consider is the pipe. We have two very different vessel types: veins and arteries. For our purposes, in this example visualize the pipe being an artery. This artery is only capable of holding so much pressure before it has a negative consequence to the appearance of features. How would a slippery viscous fluid help the situation? Well, in short, it reduces the drag or friction within the vessel or pipe. Friction or drag would slow fluid down, while lubrication would help to keep speed. More simply, pre-injection fluid permits a higher pressure system within the vessels as compared to without. Furthermore, we talked about the Venturi effect and how it is enacted upon cross sections in the vessels. Well, increasing the density or viscosity of fluid will, by the Venturi formula, increase the suction or vacuum being enacted on pooled blood or clots.
The comment often heard is, “Wait a minute, I embalm with high pressure all the time! It isn’t dangerous, and the body looks great.” Interested to know what can be said about this? Well, we are pretty close to tackling this topic from an engineering perspective, so please read on.
-The Mortuary Scientist

→ High Speed Low Drag - Physical Science & Embalming

As an embalmer, you may be a fan of good drainage. Good drainage has long been linked with great distribution. If you have been reading, you now better understand why.
Great drainage requires high flow. Flow in and out at high speed will yield many positive effects. Distribution, blood or staining removal, and “whip,” to name a few. We might agree “whip” is not something we often hear discussed among embalmers. To be put simply, “whip” is the desaturation of tissue. It is an effect that happens when flowing fluid travels fast enough to pull from surrounding tissue. Take the time to concentrate on how this works. Visualize a car traveling under 5 MPH in a straight line. Air in front of the car will be pushed around the car and air will replace the space behind that car as the car moves forward. Now picture this same car traveling above 190 MPH, also in a straight line. The car will cut through the air, leaving a trail in the vehicle’s wake empty. Air will rush to fill this space rapidly from the surrounding area. This is much like what happens as fluid travels fast through the vascular system. The vessels will draw fluid from the surrounding tissue. This is a physical means that can be used to reduce edematous tissue. The embalmer must consider and account for drainage being near equal to the displacement of fluid via injection. To utilize this method to its full potential, the embalmer must also consider the injection point and drainage point.
As an example, consider the injection site at the right common carotid artery with injection south towards the heart, with drainage via the jugular vein. Generalized edema is observed within the legs. This method is going to promote fluid remaining within the body, and be only partially effective to desaturate the legs. Compare the above method to an injection site at the right common carotid artery with a cannula deep within the abdominal aorta and drainage via the femoral arteries. With delivery of the fluid closer to the target location, fluid has less of an ability to travel via other vessels, therefore increasing the volume of fluid being delivered to the area. Subsequently, the drainage from this area can now be greater. By being closer to the target location, the embalmer can affect or influence the drainage with more control, using drainage instruments designed to pull fluid. These instruments which pull fluid will only increase the speed of drainage and therefore increase the desaturation of tissue.
It is wise of the embalmer to consider their approach to be certain that they have spent the proper amount of time desaturating tissues, as well as saturating tissues, to achieve proper preservation. From injection to drainage, where, why and how. Furthermore, the particular case circumstances of as example edema location is necessary to maximize the results of the embalming process.
-The Mortuary Scientist

→ Fast & Slow - Physical Science & Embalming

To address how distribution is directly affected by drainage, one must thoroughly understand “fluid in motion” vs. “fluid not in motion.” Fluid which is moving or flowing, as we better understand, is considered to be low in pressure. Conversely, if fluid is not moving or flowing, the fluid is considered to have high pressure. As an example, fluid within a vessel flowing in and out equally is without pressure, and so will not saturate the surrounding tissue. If drainage was restricted, pressure would accumulate within the vessel and saturate the surrounding tissue. To have a greater understanding of this, considering reading more on “Bernoulli Principle.”
In our previous chapter, our example described how low pressure could have a greater ability to distribute fluid. Without pressure, how could this be? It is important to realize that flow and pressure are not mutually exclusive. For example, you can have fluid moving very fast at high pressure, and moving slowly with low pressure. For our purposes, please continue to allow slow to be high pressure, and fast to be low pressure. The result of greater distribution with low pressure or fast flowing fluid traces back to vascular design. There are many cross-sections of vessels throughout the vascular system, on both the arterial side and the venous side. After death, pooled or still blood will coagulate, forming thick masses which can obstruct or impact the flow of fluid. Other circumstances, such as true clots or obstructions, may also exist and pose greater challenges to the embalmer. When we flow fluid across these section of vessels, we enact a “Venturi effect” upon the obstructions. The Venturi effect is a vacuum, or suction effect, that works much like a hydro-aspirator. The obstructions are pulled into the larger vessels where they then can easily travel out. This process is known as vascular clot removal.
While fast moving fluid or low pressure does not always have the ability to saturate tissue, it most certainly has the greatest ability to remove obstructions. Conversely, though slow moving fluid or high pressure will certainly saturate tissue, it does not have the easiest time pushing a clot out of the body. The arterial system narrows towards extremities, and so the idea behind pushing an obstruction through a narrower and narrower vessel is just not plausible. Furthermore, the pressure needed to achieve this poses a risk of swelling the features everywhere in circulation from injection site to obstruction.
-The Mortuary Scientist

→ Distribution - Physical Science & Embalming

There are a seemingly endless amount of combinations of mixtures and solutions an embalmer might create per case. For our purposes of discussing fluid dynamics, please consider water being mixed with your favorite arterial solution. This fluid is now capable of entering the human body and preserving it for a finite amount of time.
What is most significant about our solution is that it must make contact with the area we intend to preserve. For it to affect and preserve tissue, it must be able to reach, saturate, and act upon the tissue. Perhaps the first greatest adversity for the embalmer is reaching the area. Secondly, has enough fluid arrived to saturate the tissue without distortion? And lastly, has enough time elapsed before the fluid leaving for it to reach its full preservation potential?
So how does it get there? Embalmers commonly advise on their methodology: “high pressure and low rate of flow,” “low pressure and low rate of flow”—it seems there might be enough combinations to make someone’s head explode. Let’s for now agree to revisit those concepts at a later time, but remember it is very significant.
For our purposes now, we will be using the “Mortuary Magic Hand”. We can restrict flow enough that it slowly enters the hand. Once we see fluid draining, if we stop drainage then we are now pressurizing the tissue in the hand. As per our flow restriction, as time goes on the tissues of the hand will become more and more saturated in the areas we have distributed fluid. This fluid will not necessarily reach all of the areas of the hand we might have intended. If we were to start and stop drainage, we might see it distribute more thoroughly. If you already know why this is, great job. If you don’t, please consider or try and visualize why.
Consider another method commonly employed by embalmers: concurrent drainage. This time, we will inject the hand and not restrict drainage in any way. In fact, while fluid begins to escape freely, we will decrease the restriction of injection flow. This will increase the displacement of fluid into the hand, where it will enter at a rate faster than it can escape. This method will also saturate the tissue, but you might notice that distribution of fluid will happen on its own.
In our next chapter, we will begin to address why this is.
-The Mortuary Scientist

→ Intro - Physical Science Embalming

The chemistry of science as it relates to embalming has been long analyzed and interpreted by many. This article is to bring to light the science that has been less acknowledged by the embalming community. We refer to the science of Physics to explain the physical science of flowing fluids, specifically fluid dynamics.
Physical science in conjunction with the Chemical science is responsible for the embalming procedure, and knowledge of one without the other can ultimately lead to a failed operation and an unsatisfied client family. The Physical science of embalming accounts for how fluid is distributed within the vascular system, whereas the Chemical science accounts for the effect the fluid will have on the tissue. A good knowledge of both will lead the embalmer to a greater understanding of where and how to make adjustments to achieve positive results.
As a short example, please consider a known working solution for an edema case. The water has been retained within the legs of the deceased. The operator will use a waterless solution of a high index chemical, and consider salts as well. The operator will use a single point injection via carotid artery and drainage from the jugular vein. This Chemical approach to the problem can prove successful in reducing the tissue in the legs; however, it could cause massive dehydration to the upper extremities. So allow us to ask: is there a Physical approach to this problem which could yield greater results with less effort or room for error?
You might agree, after reading on, that there are many superior Physical approaches to this problem.
-The Mortuary Scientist