This document provides an overview of basics of electrosurgery. It discusses the differences between cauterization and electrosurgery, as well as monopolar and bipolar electrosurgery. Key aspects of electricity such as current, voltage, resistance and power are explained. The document also covers tissue effects of different electrosurgery modes like cut, coagulation, and fulguration. Safety issues including pad burns and fire risks are reviewed. The document provides a concise yet comprehensive primer on fundamentals of electrosurgery.
2. (A) BASICS of Electrosurgery
What is the difference between Cauterization & Electrosurgery?
Properties of Electricity : Current , Circuit , Voltage , Resistance , Power?
What is difference between Direct & Alternating current?
What is difference between electric current of home appliances & that
used in electrosurgery? – why patient Don’t undergo electrical shock?
Whats difference between Monoplar –Bipolar Electrosurgery?
Overview
3. (B) Clinical effects of Electrosurgery
What is difference between CUT mode &
COAGULATION mode?
Effect of electrosurgery on tissues ,
Factors affecting it ?
Pure cut – desiccation – Fulguration
Effect : What's the difference?
8. Current
• Current : flow occurs when electrons flow from one
atom to the orbit of an adjacent atom during a period of
time.
• measured in amperes.
9. Circuit
Pathway for the uninterrupted flow of electrons
A completed circuit must be present in order for electrons to
flow.
A completed circuit is an intact pathway through which
electrons can travel
10.
11. Voltage
• “force” or “push” that provides electrons with the ability to travel from
atom to atom
• Force pushing current through the resistance
• measured in volts
• Safety is more with Low Voltage .
12.
13.
14. Resistance - Impedance
• Obstacle to the flow of current
• Resistance = measured in ohms (impedance = resistance)
23. Frequency
• Standard electrical current alternates at a frequency of 60 cycles per second (Hz).
• Electrosurgical systems could function at this frequency
24. NO
Why
• because current would be transmitted through body tissue
at 60 cycles, excessive neuromuscular stimulation and
perhaps electrocution ( Electrical shock)would result.
25. 1881 was an important milestone in the
development of electrosurgery. It was then that
Morton described a safe alternating current with a
frequency of 100 KHz
Because nerve and muscle stimulation cease at 100,000 cycles/
second (100 kHz), electrosurgery can be performed safely at
frequencies above 100 kHz.
26.
27.
28.
29. An electrosurgical generator
At this frequency electrosurgical energy can pass through the patient
with minimal neuromuscular stimulation and no risk of electrocution
60 cycle per second
current
over 200,000 cycles
per second
current
and increases the
frequency
40. Variables that modify tissue effects
Waveform ( Cut – coagulate – Blend)
Power Setting
Size of Electrode (Current Density)
Time
Manipulation of Electrode (Electrode-tissue interface)
Type of Tissue : (Peritoneum VS uterus)
Eschar(high resistance to current : so clean electrode enhance performance)
45. Time – Power
Size of the electrode: The smaller the
electrode, the higher the current
concentration. Consequently, the same
tissue effect can be achieved with a smaller
electrode, even though the power setting is
reduced.
Time : At any given setting, the
longer the generator is
activated, the more heat is
produced. And the greater the
heat, the farther it will travel to
adjacent tissue (thermal spread)
Power: increase power setting
= more thermal damage
47. What is difference
between CUT &
Coag Waveform:
• Cut Waveform :
Continuous
Low voltage
• Coagulation Waveform :
Intermittent (6% of duty cycle)
High voltage
48.
49.
50. Electrode Tissue interface
Near – Contact (1-2 mm Away) Direct Contact
Spark formation – more thermal effect less thermal effect than near contact
Cut mode Coagulation mode Cut mode Coagulation mode
Cutting -
incision
Fulguration Desiccation Desiccation
52. Sparking to tissue maximum current concentration high power
density
intense intracellular heat
Boiling of intracellular water Explosion &
Vaporization of cell
• The vaporization of the cell dissipates heat, a cooling effect that reduces thermal damage to adjacent tissue. This cooling
effect, however, allows for little heat transfer to deeper tissue, resulting in minimal or no coagulation effects when
electrosurgery is used at the CUT mode.
+ Small
electrode tip
Steam vapor occupies six times the
volume of liquid water
53.
54. So, To Incise Tissue
Use CUT current
Use
Use small or thin electrode
Use
Activate ESG just before making contact with the target tissue
Activate
Speed of passage of electrode :
Speed
55. Speed of passage of electrode (TIME
factor)
• Although most choose a scalpel to incise the skin, a needle electrode can mimic the
incision if the surgeon applies the principle of speed of passage and waveform.
• if the speed of passage is swift and the waveform is set at pure CUT, no visible
desiccation of tissue occurs, but like a knife, the skin bleeds with minimal coagulation
effect.
• A slow deliberate sweep of the electrode causes some desiccation effect, and the skin
may blister and heal poorly.
56.
57. Can I Cut with coagulation Mode
• Electrode
• Power setting
• Risk of high voltage ??
• So WHY ??
59. Direct contact ( Cut-Coagulate) Cell dehydration protein
denaturation
Coagulum formation
Coaptive coagulation
• The most common desiccation maneuver used in surgery is the coaptation of blood vessels
• Coaptive coagulation involves clamping a bleeding vessel with a conductive clamp and applying a current to
coagulate and promote a collagen weld of the vessel.
61. Why coagulation waveform don’t
cause vaporization ( Cutting –
incising tissue)
• due to the intermittent heating effect
• cellular temperature does not increase rapidly
or sufficiently to vaporize.
• It is during the “off” intervals that the tissue is
cooled and denatured (coagulated), which
increases resistance.
62. Can I Desiccate by Cut Mode
• Low voltage ( less lateral thermal spread)
• Continuous Intermittent activation
• MIS
63.
64. Fulguration
• fulguration occurs when (noncontact) superficial sparking occurs.
• Due to the high peak voltage at high current density, the sparks are sprayed in
a random fashion in repeated intermittent cycles, resulting in tissue necrosis
and charring.
• Given equal current density, noncontact fulguration is more efficient at
creating surface necrosis and charring.
• However, contact desiccation yields a greater depth of tissue dehydration.
65.
66. • Surface charring is desirable to stop surface oozing, such as muscle bleeding of a
venous nature.
• For arterial vessels larger than 1 to 2 mm, fulguration is usually not effective, and
desiccation, staples, or ligatures are usually required.
• during fulguration techniques, the higher output settings can be used with more
efficiency, reducing the chance of touching the electrode to the tissue, which might
cause an undesirable desiccation effect.
67.
68. Hazards of electrosurgery
1. Unintended burns (patient):
Active
electrode
Dispersive
electrode
1- Lateral thermal
spread ( voltage – time
– power setting)
2- Inadvertent
activation
Unfortunately
Its your responsibility
69. Dispersive electrode
(a) Site
• Choose: Well-vascularized muscle mass
• Avoid:
Vascular insufficiency
Irregular body contours
Bony prominences
• Consider: Incision site
