Chapter 15 (Energy Sources in Surgery)

INTRODUCTION TO SURGICAL TECHNOLOGY

• Health Tech Academy's guide to become a certified Surgical Technologist.

CHAPTER 15: Fundamentals of Electrosurgery

• Understand the principles of conduction, frequency, and impedance.

• Learn about electrosurgery uses and components in surgical procedures.

• Differentiate between monopolar and bipolar circuits.

• Ensure safe use of patient return electrodes and prevent electrosurgery hazards.

• Distinguish capacitive and indirect coupling.

• Describe components of smoke plume and minimize exposure.

• Explore laser applications and safety measures in laser surgery.

01 ENERGY SOURCES IN SURGERY

Learning Objectives

• By the end of this chapter, the reader will be able to:

  1. Understand conduction, frequency, and impedance principles.

  2. Explain electrosurgery uses and components.

  3. Differentiate between monopolar and bipolar circuits.

  4. Discuss patient return (dispersive) electrode safety.

  5. Identify hazards and outline prevention methods for electrosurgery.

  6. Distinguish capacitive and indirect coupling.

  7. Describe smoke plume components and strategies to minimize exposure.

  8. Understand laser applications in surgical procedures.

  9. Identify different types of laser media.

  10. Discuss necessary safety measures during laser surgery.

15.1 Understanding Electricity

Key Concepts

• An electron is a negatively charged atomic particle orbiting an atom's nucleus.

• Free electrons: Outer electrons in some compounds that can flow between atoms, highly prevalent in metals.

• Conductive materials, which release free electrons, include metals like copper and silver.

• Insulators such as rubber or glass do not allow free electron flow.

• The electrical circuit is formed when a conductive path loops back on itself.

15.1.1 Free Electrons

• They are vital for conductive paths.

15.1.2 Conduction and Circuits

• Discuss how resistance to electricity is termed impedance.

• The electron flow seeks alternative routes when encountering resistance, generating heat.

• Example: Tungsten wire in a lightbulb emits light due to resistance heat.

15.1.3 Current and Impedance

• Importance of understanding current in surgical technology.

15.1.4 Voltage

• Voltage forces electrons through conductive materials, creating heat due to resistance.

15.1.5 Electrosurgery

• Uses electricity-generated heat for changing/destroying tissue.

• Common procedures: tissue cutting, minor blood vessel coagulation.

15.1.6 Effects of Electrosurgery on Tissues

• Tissue response depends on types (collagen, water content), exposure time, current density, and frequency.

15.2 Electrosurgery Components and Their Use

Key Components

• Power Generator: Provides controls and radiofrequency power. Must adhere to operational standards to avoid misuse.

• Generator Safety: Alarm systems should remain operational for safety alerts.

15.2.1 Power Generator

• Controls and settings for safe operation are vital.

15.2.2 Generator Safety

• Must adhere to safety protocols to prevent burns.

15.2.3 ESU Handpiece and Active Electrode

• Active electrode, usually a pencil device, connects to the generator.

• Different tips available depending on procedure (e.g., monopolar spatula electrode for cutting).

15.2.4 Active Electrode Safety

• Must ensure proper handling to avoid electrical malfunctions and burns.

15.2.5 Patient Return Electrode in Monopolar ESU

• Essential for directing current away and preventing burns.

15.2.6 Smoke Plume

Risks of Smoke Plume

• Composed of 95% water, 5% chemicals and cells, causing health risks.

• OSHA recommends using local evacuation systems (LEV) to minimize exposure.

15.2.7 Smoke Evacuation System

• Essential in any electrosurgery procedure to protect surgical staff.

15.2.8 Bipolar Electrosurgery

• Uses two contact points for current directly through tissue, minimizing patient risk.

15.2.9 Electrosurgical Bipolar Vessel Sealing

• Advanced systems prevent accidental heating and use specialized tools for efficient tissue welding.

15.2.10 Argon-Enhanced Electrosurgery

• Focuses current to improve safety and efficiency in electrosurgery.

15.2.11 Radiofrequency Ablation

• Uses radiofrequency for targeted tissue destruction in surgeries.

15.3 Electrosurgery in Minimally Invasive Surgery

Key Points

• MIS utilizes telescopic tools; bipolar circuits reduce risks associated with monopolar systems.

• Risk of capacitive coupling and direct coupling remains; preventive measures include active electrode monitoring.

15.3.1 Capacitive Coupling

• A burn hazard where current unintentionally passes through insulation.

15.3.2 Direct Coupling

• Occurs when an active electrode contacts another conductive device; can cause severe burns.

15.3.3 Ultrasonic Energy

• Converted electricity produces mechanical energy for cutting and coagulating tissues simultaneously.

15.3.4 Safety Precautions

• Necessary to prevent unintended burns from the instrument.

15.3.5 Ultrasonic Ablation

• Used for tissue destruction during surgeries like tumour removal.

15.3.6 Cryosurgery

• Destroys tissue using freezing gas or probes, often in an outpatient setting.

15.4 Laser Surgery

Overview

• Lasers utilize light amplification and radiation emission for surgical procedures.

• Strict safety protocols are essential due to the potential harm from improper use.

15.4.1 Laser Standards and Regulations

• Development of safety measures and training is critical in surgical settings.

15.4.2 How Lasers Work

• Operate through optical resonators and various types of lasing mediums.

• Controlled via a panel for laser functions.

15.4.3 Effects of Lasers

• Various parameters determine the targets’ reaction to laser light, including its wavelength and power.

15.4.4 Laser Media

• Different lasing mediums suitable for various surgeries (e.g., Argon, CO2, and YAG lasers).

15.4.5 Laser Safety

• Ensuring safety precautions to safeguard patients and staff during laser usage.

15.4.6 Laser Classification

• Classification based on the safety risks; Class 4 lasers pose the highest risk.

KEY CONCEPTS

• Electrosurgery plays a vital role in surgery, and surgical technologists must understand electrical properties to protect patients.

• Components include generators and electrodes; proper usage minimizes hazards such as burns and tissue damage.

• Risks include smoke plumes containing harmful materials; evacuation systems are essential.

• Ultrasonic and laser technologies offer alternative methods for tissue management, each with its own safety protocols.

REVIEW QUESTIONS

1. Differentiate between bipolar and monopolar circuits.

2. Why position the patient return electrode over a muscle mass?

3. Types of electrosurgery requiring a return electrode?

4. Effects of impedance on electrical flow.

5. Define cryoablation.

6. Risks of eschar on the active electrode.

7. Meaning of 'laser'.

8. Precautions for laser surgery in the throat.

9. Why are laser goggles not colour-coded?

10. Describe capacitive and direct coupling.

TERMINOLOGY

• Ablation: Complete tissue destruction.

• Active electrode: Part of electrosurgical instrument delivering current.

• Bipolar circuit: Electrosurgery circuit that returns current directly without passing through the patient.

• Cryoablation: Injecting gas to freeze and destroy tissue.

• Electrosurgery: Direct use of electricity to cut and coagulate tissue.

BIBLIOGRAPHY

List of essential resources used to compile the information.