→ 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