1. Electrosurgical/Surgical Diathermy Units
Copyright 2007

2. Electrosurgical/Surgical Diathermy Units
Electrosurgical Basics
Electrosurgical Burns
Laparoscopic Accidents
Injuries to Medical Staff
Fires
Copyright 2007

3. Some Basic Electrosurgery Facts
Health Canada Talks, Session 10
Some Basic Electrosurgery Facts
23-25 February 2005
Used in about 80% of all surgical procedures
Very effective surgical tool
Cutting
Coagulation
Fulguration
Not well understood by clinicians
Commonly seen in FDA and ECRI problem reporting databases
Cutting
Typically, small-surface active electrode tip (e.g., needle, wire loop, edge of flat blade)
Initially applied (in contact) with target tissue
Sufficient amount of steam from vaporized tissue separates electrode from tissue
Sparks through vapor layer between active electrode and tissue carry cutting current
Relatively low voltage compared to coagulation
Contact coagulation (dessication)
Direct contact between active electrode and target tissue
Results in vaporization of cellular water, denaturation of protein, and drying of tissue
Achieved with broad surface active electrode tip and low-voltage mode
Produces white coagulum
Frequently misapplied for cutting and dessication
Arcing (Fulguration)
Arcs (sparks) char bleeding tissue surface
Intensely concentrated current at small points on tissue surface
Active electrode tip held slightly above bleeding tissue surface
Produces black coagulum
High-voltage mode
Greatest potential for interference with other medical devices
Copyright 2007
ALdeR

4. Basic Principles of Electrosurgery
Health Canada Talks, Session 10
23-25 February 2005
Basic Principles of Electrosurgery
Frequency
Typically operate at frequencies between 300 KHz and 1 MHz
300 kHz to 1Mhz avoids complication of electrical nerve stimulation
Under certain conditions (e.g., arcing between two dry metal surfaces) low frequency components (<10 KHz) can be introduced with the delivered electrical current
Current conducted through a complete circuit including
the generator, insulated cables, electrodes, and the patient
Copyright 2007
ALdeR

5. Monopolar Electrosurgery
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6. Bipolar Electrosurgery
Health Canada Talks, Session 10
23-25 February 2005
Bipolar Electrosurgery
Electrosurgical
Unit
Current
Flow
Current conducted between two electrodes on the same instrument (e.g., forceps)
Dispersive return electrode is not needed
Current is confined to target tissue at the surgical site between the two electrodes
Allows for lower output power than monopolar electrosurgery
Generally safer than monopolar electrosurgery – but procedures are often performed on more “delicate” tissue
Tissue between
tips of forceps
Copyright 2007
ALdeR

7. Electrosurgery Safety Features
Continuity Monitor
Verifies that a return electrode is connected to electrosurgical unit
Cannot detect if return electrode is disconnected from or in poor contact with the patient
Copyright 2007

8. Electrosurgery Safety Features
Return Electrode Contact Quality Monitor (RECQM)
Offers better level of protection than continuity monitor
Assures that good contact exists between the dispersive electrode and patient
ECRI strongly recommends using electrosurgical units with RECQM
Copyright 2007

9. Dual Plate Return Electrodes
Health Canada Talks, Session 10
23-25 February 2005
Dual Plate Return Electrodes
Interrogation current flows
between each plate of the electrode and the patient. If one side is partially detached from the patient, an alarm will sound.
Single-foil return electrodes must not be used with RECQM safety feature
Dual-foil return electrodes must be used with RECQM
Return electrode site should be properly prepped prior to placing on patient
Area should be shaven to remove excess hair and cleaned to provide optimal electrode-patient contact
Electrode should be properly oriented on patient with respect to surgical site
Copyright 2007
ALdeR

10. Electrosurgical Accidents
Skin Burns
Fires, Explosions
Prepping Solutions, Surgical Drapes, Bowel Gas
Oxygen-Enriched Atmosphere
Active Electrode Arc or Spark
Too Much/Too Little Power Delivered
Organ Perforations
Copyright 2007

11. A Misconnection Problem
Health Canada Talks, Session 10
23-25 February 2005
A Misconnection Problem
See Hazard report: monopolar activation
more power than expected
bowel perforation
Copyright 2007
ALdeR

12. Electrosurgical Accidents
Health Canada Talks, Session 10
23-25 February 2005
Electrosurgical Accidents
Argon Beam Coagulators
Gas Embolism
Interference (EMI)
ESU as “Source” of EMI
User Injuries
Hand sensation
Alternate pathways
Hand sensation: mostly during urologic procedures (TURP)
capacitive coupling of instrument handle
Wet environment
startle injuries
Only 2 cases in US history of “muscular degeneration due to ESU. There is not enough current to cause extensive injury. History of use does not support MDs’ contention.
Copyright 2007
ALdeR

13. Electrosurgical Injuries
Return Electrode Issues
Poor electrode placement
Lack of skin prep
Complete or partial removal of return electrodes
Skin reactions to adhesives
“Edge effects”
High electrosurgical currents and long activation times
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14. Electrosurgical Injuries
Active Electrode Issues
Insulation surrounding conductive shaft
Breakdown
Repeated Sterilization
Cuts, Nicks, Abrasions
Capacitive Coupling
Electrical current induced by means of capacitance to other instruments or tissues
Inadvertent activation!
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15. Electrosurgical Injuries
Active Electrode
Organ Perforations
Alternate Site Burns (Use a Holster!)
Laparoscopic Active Electrodes
Laparoscopic Cannula Burns
Failure to Use Activation Tone
Copyright 2007

16. Active Electrode Accidents
Inadvertent activation of the ESU due to unintentional switch activation
User places active electrode on the patient or the surgical drape between intended activations
Safety holster not used
Audible activation tone volume is set too low
Insulation failure along shaft during procedures, such as tonsillectomy causing burn to tissue inside mouth or to lip
User makes direct contact with nontarget tissue
Copyright 2007

17. Electrosurgical Injuries
Return Electrode
Poor Site Preparation
Poor Application technique
Non-uniform Conductivity
Repositioning
Patient
Electrode
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18. Return Electrode Accidents
Burns
Use of electrolytic (conductive) distention/irrigation media during TURP
Conductive solution may render electrosurgery less effective
Disperses current away from intended surgical site
Lower surgical effect may lead user to increase power output of ESU
Conductive solution lowers impedance at active electrode, elevating current
Increased power and lower impedance increases current through dispersive return electrode
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19. Laparoscopic Electrosurgery
Monopolar vs. Bipolar
Current leakage though cannula
Insulation breakage
Fire
Copyright 2007

20. Laparoscopic Injuries
Inadvertent tip to tissue contact
Insulation failures
Capacitive coupling
Trocar insertion sites
Device interference
Resulting in bowel perforations, excess bleeding, damage to nontarget tissue, etc.
Copyright 2007

21. ESU-caused Fires Heat, sparks, flaming gases
Rarely a device failure – “a known complication”
Copyright 2007