2.5 Hemostasis

Mechanical Hemostasis

Hemostasis is the arrest of bleeding, essential for visibility and patient safety. The three broad methods are mechanical, thermal, and chemical, and the CST must anticipate which the surgeon will use at each step.

Mechanical hemostasis physically obstructs the vessel:

• Clamps (hemostats) are placed on a bleeding vessel to compress it; the surgeon then ligates or cauterizes.
• Ligatures ("ties") are strands of suture tied around a vessel. A free tie is a single strand handed on a pass; a tie on a passer is loaded on a clamp to reach deep vessels.
• A suture ligature ("stick tie" or transfixion suture) is suture on a needle passed through the vessel and tied around it so it cannot slip off — used on larger or pulsatile vessels.
• Ligating clips (Hemoclips, Weck/Hem-o-lok) are metal or polymer clips crimped across a vessel.
• Pressure, packing with sponges, tourniquets, and pneumatic (Esmarch/pneumatic tourniquet) devices provide temporary control; the bovie/ESU and bone wax are covered below.

Thermal Hemostasis

Thermal hemostasis uses heat to coagulate tissue and seal vessels:

With monopolar electrosurgery, current flows from the active electrode through the patient to the dispersive (return/grounding) pad, which must be placed over clean, dry, well-vascularized muscle close to the site to prevent burns. Bipolar confines current between two tines, making it safer near delicate structures and in patients with pacemakers.

The surgeon selects a mode matched to the goal: cut (a continuous waveform that vaporizes tissue with little coagulation), coagulation (an interrupted waveform that produces heat to seal vessels), or blend (a mix of both). Fulguration sprays sparks to char a broad oozing surface, while desiccation holds the electrode in direct contact to dry tissue.

The CST keeps the active electrode in an insulated holster when idle, watches for insulation failure on laparoscopic instruments (a break can burn out-of-view tissue), and remembers that smoke (surgical plume) carries hazardous byproducts and is removed with a smoke evacuator. Because heat and sparks are involved, electrosurgery is also the leading ignition source for surgical fires, tying hemostasis directly to the fire-safety topic.

Chemical and Topical Hemostatic Agents

Chemical/topical hemostatic agents promote clotting at the bleeding surface and are kept ready on the field:

• Bone wax — a sterile beeswax compound smeared onto cut bone edges (sternum, cranium) to tamponade marrow bleeding mechanically.
• Absorbable gelatin (Gelfoam) — a porous sponge that provides a scaffold for clot formation; often soaked in thrombin.
• Oxidized cellulose (Surgicel, Oxycel) — a knitted fabric that swells and forms a clot; also mildly bactericidal.
• Microfibrillar collagen (Avitene) — promotes platelet aggregation on oozing surfaces.
• Thrombin — a topical enzyme (often sprayed or applied with Gelfoam) that converts fibrinogen to fibrin; never injected intravascularly.
• Fibrin sealant (Tisseel) — combines fibrinogen and thrombin to form a fibrin clot/glue.
• Epinephrine — added to local anesthetic to cause vasoconstriction, reducing bleeding (avoid in digits/end-arteries).

The CST keeps all field medications and agents labeled (name, strength, amount, expiration) to prevent errors and anticipates the agent matched to the tissue — bone wax for bone, Gelfoam/thrombin for oozing soft tissue.

Physiologic Hemostasis and the CST's Role

Understanding the body's own hemostatic process helps the CST anticipate when surgical control is needed. Natural hemostasis proceeds in stages: vascular spasm (vasoconstriction) narrows the injured vessel, platelet plug formation seals small breaks, and the coagulation cascade converts fibrinogen to a stable fibrin clot. Patients on anticoagulants (warfarin, heparin, DOACs) or antiplatelet agents (aspirin, clopidogrel), or with liver disease, hemophilia, or thrombocytopenia, bleed more, so the team prepares extra hemostatic supplies.

The CST contributes directly to bleeding control by keeping the field ready:

• Keep clamps loaded and ties cut to length so a bleeder is controlled in seconds.
• Keep the ESU pencil clean (use a tip cleaner/scratch pad) so eschar does not impede coagulation, and keep it holstered when idle.
• Keep sponges counted and available for pressure and packing.
• Keep suction patent so the surgeon can see the bleeding source.
• Have topical agents and a syringe of warm saline ready for oozing surfaces.

Matching the right method to the bleeding source — and having it instantly ready — is one of the clearest measures of an effective surgical technologist.