Probably the most important part of the embalming process is the arterial injection of embalming fluids. Using the body's own vascular system (arteries, veins, and capillaries), embalming fluid flows to all parts of the body, penetrating into and preserving muscle, skin, and organs.
Arterial embalming begins by selecting an artery to inject the fluid into and a vein to drain away blood. The most popular site (however multiple injection and drainage sites may be used) is on the right side of the body near the collarbone. Here are located, right next to each other, the right common carotid artery and the right internal jugular vein. A small incision is made just deep enough to cut the skin and an aneurysm hook is used to separate the tissue above the vein and artery. The embalmer raises the artery above the skin surface and passes two pieces of suture string beneath it to create a ligature to tie off the vessel once the arterial tube is inserted. The same is done with the vein.
Each vessel will receive a tube to facilitate injection and drainage. The artery is incised (very carefully as to not cut it in half) and an arterial canula (tube) is inserted into the artery towards the heart. The ligature is now tightened so that a seal is made between the tube and the artery. The same is done with the jugular drain tube. A hose is attached to the drain tube, and the hose from the embalming machine is connected to the arterial tube. Drainage can also be achieved by keeping the vein open using angle forceps. Many embalmers prefer this as it allows clots and blockages to be more easily flushed from the vascular system.
The embalmer has a wide variety of embalming fluids available to him or her. Pre-injection chemicals break up clots and condition vessels. Co-injection chemicals restore dehydrated tissues, fight edema (too much fluid in the tissues), and correct hard water. Cauterants dry, seal and preserve open wounds. The most important chemical, the arterial fluid, is made up of preservatives, germicides, anticoagulants, dyes, and perfume.
The main ingredient of arterial fluids is formaldehyde, but a few chemical companies are manufacturing chemicals with less toxic (but less effective) glutaraldehyde. The formaldehyde content in arterial fluids is measured by index. Index means the total percentage of formaldehyde gas in the fluid. Fluids with an index of 5 to 15 are considered to be low firming fluids - 16 to 24 produces medium firming - 25 and above highly firms the tissue.
Formaldehyde is extremely toxic and a known carcinogen. OSHA (Occupational Safety and Health Administration) regulates its use in funeral homes. It requires exhaust fans in prep rooms, signs warning of the presence of formaldehyde, as well as numerous other rules and regulations. However, for some odd reason some people enjoy smoking marijuana that's laced with embalming fluid. They call it "fry," and as you can imagine, it quite literally "fries" the brain of the user.
There is a new trend in embalming, which is the use of the chemical Glutaraldehyde. Some embalmers prefer it over formaldehyde because it doesn't produce fumes as irritating as formaldehyde does, plus some say that it does a superior job of preservation. One reason it hasn't caught on is that it doesn't produce as much firmness as formaldehyde, and firmness is one sign that embalmers use to gauge the amount of penetration and preservation of the arterial & cavity chemicals.
The embalmer must inject about 1 gallon of fluid for every 50 pounds of body weight. A typical gallon of fluid might be made up of 1 bottle of arterial fluid, 1 bottle of co-injection fluid, 1 bottle of water corrective, and enough water to complete the gallon. This recipe changes depending on the condition of the body.
Once the chemicals are in the reservoir of the embalming machine it is time to begin injection. The embalming machine has two knobs which regulate pressure (the force of the fluid) and rate of flow (speed of the fluid). These knobs are adjusted differently during embalming for each case to create the optimum rate of injection for the body. Some machines have a pulse feature that pumps the fluid much like a heart would pump, with alternating pressure. This is very effective in avoiding swelling of tissues. The machine is switched on and the fluid begins to move through the hose, through the arterial tube and into the body.
Once the embalming fluid begins to flow into the arterial system, pressure begins to build up in the entire vascular system. This helps the fluid reach all parts of the body and penetrate into the tissues. Evidence of this can be seen in bulging veins throughout the body. The jugular drain tube is opened periodically (it is normally closed) to allow blood to escape and prevent too much pressure in the vascular system which could cause swelling. The blood drains directly into the sewer system, which sounds gross, but in reality MUCH worse things go into our sewers.
There are several signs the embalmer uses to gauge whether embalming fluid has permeated through the entire body. Dyes used in arterial fluids help the embalmer know where fluid has reached and where it has not (these dyes also help to produce a more pleasing cosmetic appearance). Return of the arterial fluid from the jugular drain tube tells the embalmer that fluid has gone throughout the entire vascular system. Also, firming of the tissues lets an embalmer know that preservative chemical has reached tissues.
Once arterial injection has been completed, the arterial and jugular tubes are removed, the vessels are tied closed, and the incision used to access the vessels is sutured closed and sealed with a special chemical. The remains are almost ready...