ELECTROSURGERY BASICS
(1.0 Contact Hours)
Produced through an educational partnership between:
& 
Written by Donna Y. Swanson, MBA, RN
The price of this course is $12.00. You will only be asked to pay for the course if you decide to grade the Post Examination to earn a certificate with Contact Hours (CEUs).
 |
LEARNING OBJECTVES:
Upon successful completion of this educational activity, the participant will be able to:
- State the components of a complete electrical circuit.
- Describe three tissue effects that can be achieved with electrosurgery.
- Discuss the differences between monopolar and bipolar electrosurgery.
- List five safety considerations during electrosurgical procedures.
INTRODUCTION
Since its introduction in 1924 by neurosurgeon Dr. Harvey Cushing and Dr. William Bovie, a Harvard physicist, electrosurgery has gained widespread acceptance. Now used in approximately 80% of all surgical procedures, electrosurgery has reduced both operating and patient recovery times.
Electrosurgery refers to surgical procedures that pass high frequency, alternating electrical current through body tissues to produce cutting and/or coagulation. Electrocautery refers to a process that uses direct current to heat electrodes that are used to produce coagulation. Electrocautery is often confused with electrosurgery. To understand this distinction, clinicians need to know how electricity behaves and its impact on the body.
PROPERTIES OF ELECTRICITY
Blood flowing through the veins illustrates some of the basic properties of electricity. The flow of blood, cardiac output, is similar to the flow of electrons, called a current and is measured in amperes (amps). In narrowed, clogged blood vessels, the heart continues to pump blood at the same rate, the pressure on the veins increases, and the pressure builds, resulting in high blood pressure. In electricity when a steady flow of electrons, called a current, encounters resistance, e.g. human tissue, the force of the flow, voltage, increases. Increased resistance also produces heat. When an electrosurgical unit (ESU) is used, this heat can cut and coagulate tissue.
An intact path, called a completed circuit, must be present in order for electricity to flow. In electrosurgery, this circuit is composed of the ESU, the active electrode, the patient and the patient return electrode. Electricity will maintain an established circuit unless it encounters an alternate pathway that offers less resistance. Electrical current will follow “the path of least resistance” possibly causing significant injury to the patient or medical staff.
When current flows in a single direction, it is a direct current (DC), as in a battery. When the flow repeatedly changes direction, it is an alternating current (AC), as in our homes. The more often the direction reverses, the more cycles per second and the higher the frequency of the AC current. This frequency is measured in hertz (Hz). Most household appliances in the United States run on 60 Hz, which means the current changes direction 120 times for 60 complete cycles.
When a low frequency electric current passes through human tissue at 60 Hz, it can lead to cardiac arrest. However, as electricity’s frequency increases its effect on tissue also changes. At 100,000 Hz, the current no longer stimulates muscles or nerves. Between 500,000 Hz and 3,300,000 Hz, the radiofrequency range where electrosurgical generators operate, the current can be used to cut and coagulate tissue.
|
