Electrosurgery

Question 1

Electrosurgery does not cause nerve and muscle stimulation because

Answer 1

The frequency is too high to produce this effect

Question 2

Monopoles electrosurgery

Answer 2

High frequency current
Active electrode
Tissue effect
Passes through patient
Return electrode

Question 3

Advantages of monopolar

Answer 3

Readily available
Inexpensive
Range of configurations and variables
Wide range of tissue effects
Most popular

Question 4

Tissue effects of monopole

Answer 4

Derived from passage of electrical current through the patient

Stray current injuries can occur

Question 5

Variables under surgeon’s control

Answer 5

Power
Waveform (coag or cut)
Electrode configuration
Contact or non-contact
Time

Question 6

Vaporisation

Answer 6

Non-contact
100 degree C
Rapid heat, cell explosion and heat dissipation

Question 7

Desiccation/coag

Answer 7

Contact
Lower heat 60-100, loss of cell integrity and cytoplasm, proteins denatured
Coag - hydrogen bonds reform

Question 8

Fulguration/surface carbonization

Answer 8

Non-contact
Haemostasis
eg LLETZ

Question 9

Coaptation

Answer 9

Contact and compression of vessel wall with cont or interrupted current, denaturation and renaturation of proteins, similar to bipolar

Question 10

Types of electro surgical injury

Answer 10

Iatrogenic
Lateral thermal spread
Stray current injury (out of field of view)
    -insulation failure
   -capacitive coupling
   -direct coupling

Question 11

Capacitive coupling current

Answer 11

Two conductors separated by an insulator
Current flow through conductor one

Results in
Current flow induced in conductor 2
Current will try to find earth

Low risk of injury at laparoscopy as current is dissipated via anterior abdo wall

Question 12

Which allows sealing of larger caliber vessels

Answer 12

Bipolar

Question 13

Advantages of bipolar

Answer 13

Readily available
Inexpensive
No current flow through patient
Good vessel sealing
Desiccation, coag

Question 14

Disadvantages of bipolar

Answer 14

Limited dissection capability
Risk of lateral thermal spread
Need additional technology for transection

Question 15

Ultrasonic energy devices

Answer 15

Result in less lateral thermal spread
Convert electrical energy into vibrations
Temp under 100C
Cutting - large oscillation distance, mechanical shearing forces
Vessel sealing - small oscillation distance

Question 16

Advantages ultrasound devices

Answer 16

No current flow through patient
Good vessel sealing
Desiccation, coagulation
Has transection mechanism
Decreased instrument traffic
Less sticking
Less thermal spread

Question 17

Disadvantages ultrasound devices

Answer 17

Relatively expensive
Reasonable dissection capability
Lowest smoke plume
No tissue feedback
Risk of lateral thermal spread high due to post activation temperatures

Question 18

Monopolar tissue effects

Answer 18

Vaporisation: not contact, tissue tension
Fulgeration: no contact
Dessication: contact, no tissue tension

Question 19

Bipolar tissue effects

Answer 19

Dessicataion: no tissue tension

Question 20

Advanced bipolar tissue effect

Answer 20

No tissue tension, sharp cutting

Question 21

Ultrasonic tissue effect

Answer 21

Dessication: no tissue tension, mechanical cutting

Question 22

Direct contact injury

Answer 22

Hot instrument touched to bowel or incorrect/unintended activation of instrument

Question 23

Capacitive coupling

Answer 23

Electric current is passed from one conductor through insulation and into adjacent conductive materials without direct contact

Question 24

Direct coupling

Answer 24

Accidental activation when electrode is in contact with another metal instrument

Question 25

Insulation failure

Answer 25

Break or defect in the insulation that coats the instrument