What is the key difference between monopolar and bipolar electrosurgery?

Monopolar requires a dispersive (grounding) pad; bipolar does not. In monopolar electrosurgery, current flows from the active electrode (Bovie pencil) through the patient's body to a dispersive electrode (grounding pad). In bipolar electrosurgery, current flows only between the two tips of the bipolar forceps, so no grounding pad is needed. Bipolar is safer near delicate structures.

A surgeon asks for a topical hemostatic agent to control capillary oozing on the liver surface. The surgical technologist should provide:

Gelfoam soaked in thrombin. Gelfoam (absorbable gelatin sponge) soaked in thrombin is an excellent choice for controlling capillary oozing on the liver surface. The Gelfoam provides a scaffold that absorbs blood and promotes clotting, while thrombin directly converts fibrinogen to fibrin. Bone wax is for bone bleeding, and a tourniquet is for extremities only.

The dispersive electrode (grounding pad) for monopolar electrosurgery should be placed:

On a well-vascularized, fleshy area such as the thigh. The dispersive electrode must be placed on a well-vascularized, fleshy area (usually the thigh or upper arm) to ensure even dispersal of electrical current. Placing it over bony prominences, scar tissue, metal implants, or hairy skin increases the risk of thermal burns due to poor current distribution.

Which hemostatic agent is specifically used to control bleeding from cut bone?

Bone wax. Bone wax (beeswax) is used specifically to control bleeding from cut bone surfaces, such as the sternum during cardiac surgery or the skull during craniotomy. It acts as a mechanical tamponade, plugging the bleeding channels in the bone. It does not promote clotting — it physically blocks the bleeding.

Key Takeaways

Hemostasis means stopping bleeding — it is a critical intraoperative responsibility
Mechanical hemostasis includes direct pressure, clamping, ligature, hemostatic clips, and bone wax
Thermal hemostasis includes electrosurgery (monopolar and bipolar), laser, and argon beam coagulation
Chemical hemostasis includes topical agents like Gelfoam, Surgicel, thrombin, and Avitene
Monopolar electrosurgery requires a dispersive (grounding) pad on the patient and uses a Bovie pencil
Bipolar electrosurgery passes current between two forcep tips — no grounding pad needed; safer near nerves
The surgical technologist keeps the Bovie tip clean by wiping with a moist sponge (not dry)
Tourniquet use requires noting inflation time — maximum 1-2 hours depending on location

Hemostasis

Controlling bleeding is one of the most critical aspects of surgery. The surgical technologist must understand all methods of hemostasis and be prepared to provide the appropriate instrument or agent immediately.

Methods of Hemostasis

1. Mechanical Hemostasis

Method	Description	Use
Direct pressure	Applying a sponge or finger to bleeding point	First-line response to bleeding
Clamping	Hemostats (mosquito, Kelly) applied to vessels	Temporary occlusion before ligation
Ligature (tie)	Suture tied around a clamped vessel	Permanent mechanical occlusion
Suture ligature (stick tie)	Suture passed through tissue, then tied around vessel	Larger vessels that may slip off a free tie
Hemostatic clips	Metal or polymer clips applied to vessels	Quick, precise vessel occlusion (e.g., Ligaclips)
Bone wax	Beeswax applied to cut bone edges	Controls bleeding from bone (sternum, skull)
Tourniquet	Constricting band around extremity	Bloodless surgical field (note inflation time)

2. Thermal Hemostasis (Electrosurgery)

Monopolar Electrosurgery

Most common type — uses a Bovie pencil (active electrode)
Current travels from the Bovie tip through the patient to a dispersive electrode (grounding pad)
Cutting mode: Continuous waveform, high frequency — vaporizes tissue
Coagulation mode: Intermittent waveform — desiccates tissue and seals vessels
Blend mode: Combination of cut and coag

Bipolar Electrosurgery

Current passes only between the two tips of a bipolar forceps
No grounding pad required
Safer near delicate structures: nerves, small vessels, in confined spaces
Used commonly in neurosurgery, microsurgery, and ENT

Electrosurgery Safety

The dispersive pad must have full contact with a well-vascularized, fleshy area (usually the thigh)
Avoid placing the pad over bony prominences, scar tissue, metal implants, or body hair
Keep the Bovie tip clean — wipe with a moist (not dry) sponge
Keep flammable items away from the active electrode
Do NOT activate electrocautery in the presence of pooled prep solutions or oxygen enrichment

3. Chemical/Topical Hemostasis

Agent	Composition	Mechanism	Use
Gelfoam	Gelatin sponge	Absorbs 45x its weight in blood; provides scaffold	Capillary bleeding, liver/spleen oozing
Surgicel	Oxidized regenerated cellulose	Swells, forms gel, aids clotting	Oozing from raw surfaces
Thrombin	Topical enzyme (bovine or recombinant)	Converts fibrinogen to fibrin directly	Applied to Gelfoam or sprayed on tissue
Avitene	Microfibrillar collagen	Attracts platelets, triggers aggregation	Diffuse capillary bleeding
FloSeal	Gelatin matrix + thrombin	Combined mechanical + enzymatic	Moderate to severe oozing
Bone wax	Beeswax	Mechanical tamponade	Bleeding from cut bone

CST Certified Surgical Technologist Exam

1Introduction: CST Exam Overview

2Chapter 1: Perioperative Care — Preoperative Preparation

3Chapter 2: Perioperative Care — Intraoperative Procedures

4Chapter 3: Postoperative Procedures & Ancillary Duties

5Chapter 4: Basic Science

6Chapter 5: Exam Strategy & Practice