Arterial Embalming: Injection and Drainage — Supervised Laboratory I

Arterial Embalming: Injection and Drainage — Supervised Laboratory I

Purpose of This Laboratory Session

This laboratory session moves arterial embalming from classroom theory into supervised hands-on practice. You will perform the complete arterial procedure on an assigned case, guided at every stage by your instructor. The goal is safe, competent technique: correct vessel selection, proper instrument handling, controlled injection, and effective concurrent drainage — all carried out within strict personal protective equipment (PPE) and sanitation requirements.

PPE and Sanitation — Non-Negotiable First Steps

Before any contact with the case or equipment, don your full PPE: fluid-resistant gown or apron, gloves (nitrile or heavier chemical-resistant gloves are preferred), face shield or splash goggles combined with a surgical mask, and protective footwear. PPE is not optional. Arterial chemicals are formaldehyde-containing solutions classified as potential occupational carcinogens and respiratory hazards. Bloodborne pathogen exposure is a real risk on every case. OSHA's Bloodborne Pathogens Standard and your state regulations require full PPE throughout preparation room work.

Confirm the preparation room ventilation system is operating. Keep the room tidy: instruments not in immediate use remain on the side tray, waste is disposed of in labeled biohazard containers, and chemical spills are addressed immediately with approved disinfectant.

Vessel Selection and Location

The most common primary injection site in routine arterial embalming is the right common carotid artery with concurrent drainage from the right internal jugular vein, though the femoral or brachial vessels may be used depending on case conditions. For this laboratory, your instructor will assign the injection point.

Palpate the anatomical landmarks carefully before incision. For the carotid approach, locate the medial border of the sternocleidomastoid muscle at mid-neck. Your knowledge of surface anatomy directly determines whether your incision is placed correctly. An incision made too far medially risks the trachea; too deep without control risks injury to adjacent nerves and veins.

Incision and Vessel Raising

Using a scalpel with controlled, deliberate strokes, make a small, clean incision over the identified landmark. Undermine the skin edges with blunt dissection, then use arterial hemostats to gently separate tissue planes until the vessel is visible and isolated. Slide ligatures (tie strings) beneath the vessel — proximal and distal — before any arteriotomy. These ligatures control blood flow and secure the cannula.

Arteriotomy (the small opening cut into the artery wall) is made with arterial scissors or a scalpel, at an angle sufficient to admit the cannula tip. Control is everything: a jagged or over-large arteriotomy makes secure cannula seating difficult and may compromise distribution.

Cannula Insertion and Machine Connection

Insert the cannula into the vessel in the direction of intended flow (toward the head for carotid injection toward the face; away from the head for distribution to the trunk when raising distally). Secure it with the distal ligature tied snugly around the cannula groove. Connect the injection tubing from the embalming machine to the cannula hub, ensuring no air pockets remain in the tubing before flow begins.

For drainage, place a drainage instrument — typically a trocar button temporarily or, more commonly, a drain tube or the jugular opened with a drainage instrument — in the internal jugular vein and allow drainage to flow into the aspirator or sink drain under controlled conditions.

Solution Preparation and Injection Parameters

Your instructor or the case assignment sheet will specify the index (dilution strength) of the arterial solution. Index refers to the percentage of formaldehyde in the working solution, calculated from the arterial chemical's stated formaldehyde content and the dilution used. You will mix the solution in the machine tank according to those instructions.

Set the injection machine to the prescribed pressure and rate of flow. Typical starting pressures fall in a moderate range; your course text and instructor will direct the specific settings for your machine and case. Never exceed pressure settings without clinical reason — excessive pressure causes distension, solution leakage into tissue, and vessel damage.

Injection and Concurrent Drainage

Open the machine valve gradually. Observe the body for signs of distribution: firming of tissues, clearing of discoloration, and restoration of a natural skin tone in the areas being perfused. Monitor the drainage for blood and then serum; as drainage clears, distribution is progressing. Massage limbs and manipulate joints to encourage solution movement into poorly perfused areas.

If injection pressure rises without corresponding distribution, stop and troubleshoot: check for kinked tubing, closed clamps, or thrombus in the vessel before increasing pressure. Document any problem and its resolution on your case report form.

Post-Procedure Documentation

Accurate records are both a professional standard and, in many states, a legal requirement. Your case report form must include: the arterial chemical used and its stated index, the volume of solution mixed and injected, the injection pressure and rate settings, estimated drainage volume, your clinical observations on distribution, and any complications encountered. Thorough records protect you, your employer, and the family you serve.

Competency Evaluation

Your instructor will observe every stage using a step-by-step checklist. Critical errors — PPE violation, uncontrolled arteriotomy, failure to secure the cannula — result in an automatic remediation requirement regardless of overall score. A score of 80% or higher on the complete checklist is required to pass this laboratory session.