Embalming Science and Practice
Purpose and sequence
Embalming sanitizes, preserves, and restores. The embalmer first verifies authorization, reviews the death record, inspects the body, positions it, sets features, and applies universal precautions. Arterial injection usually uses the common carotid, femoral, or axillary artery; drainage is taken from a corresponding vein. After injection, the cavity is aspirated and treated with cavity fluid.
Fluids and dilution
Arterial fluid is rated by index-the percentage of formaldehyde in the concentrate. A 20-index fluid diluted one 16-ounce bottle into enough water to make one gallon yields about 2.5% formaldehyde: (20 × 16) ÷ 128 = 2.5. Water conditioners, anticoagulants, dyes, and humectants adjust the solution. Cavity fluid is much stronger and is not injected arterially.
Special cases
Autopsied bodies often require separate injection of the limbs and trunk and limited drainage. Decomposed, edematous, or emaciated bodies require modified strength and drainage. Infectious cases demand PPE and careful sharps handling. Complete an embalming report documenting vessels, fluids, and unusual findings.
Worked example
A 20-index bottle is added to 3 quarts of water, making one gallon total. The strength is (20 × 16) ÷ 128 = 2.5%. If the embalmer instead uses two bottles in one gallon, the strength doubles to 5%, which may be excessive for a jaundiced body and can worsen discoloration.
Traps
Confusing index with diluted strength, draining an autopsy case as if intact, skipping cavity treatment, and failing to document authorization or the embalming report are frequent errors.