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Understanding the Relationship between
Surgical Gloves and Electrosurgery
Electrosurgery is the application of electrical (Radio Frequency [RF]) current to
biological tissue. An electrosurgical generator supplies the source of electric
current, which transfers energy (electrons) to tissue. The term “Bovie,” a manufacturer’s
trademark named after one of the early pioneers, Dr. William T. Bovie, is often
used synonymously with the term “Electrosurgery.” The terms “electrosurgery” and
“electrocautery” are also often used synonymously; however, this is incorrect, and
it is important that the two are not confused.
In electrosurgery, the electrical current is applied directly to the tissue and
the patient is part of the circuit. Electrocautery is the indirect application of
electrical current by heating a conductive element, which burns tissue. Another
distinguishable difference is that electrosurgical units are considered AC (alternating
current) energy sources and electrocautery units are DC (direct current) sources.
An electrosurgery source is quickly identifiable in the OR by the patient return
electrode/ dispersive pad applied to the patient.
HOW COMMON IS ELECTROSURGERY?
The use of electrosurgery during an operative procedure is almost as common as wearing
gloves. There are various energy sources and methods employed with the use of electrosurgery.
RF current is typically used by the surgeon to cut tissue or to obtain hemostasis
(stop bleeding). Electrosurgery is a safe and efficient instrument for both invasive
and minimally invasive surgical (MIS) procedures.
HOW AN ELECTROSURGICAL UNIT OPERATES
The circuitry of an electrosurgery unit is composed of the generator and active
electrode (handheld instrument), the patient, and the patient return electrode/
dispersive pad, which is sometimes referred to as the passive or ground electrode
(patient pad or plate). Electrons, or the electrical charge, travel from the generator
through the active electrode, through the patient, and return to the generator via
the patient return electrode/dispersive pad, completing the electrical circuit.
At the point where the current passes through the active electrode, the electrical
energy is converted into thermal energy, resulting in high-energy heat. The heat
causes disintegration of tissue cells, which may be seen as desiccation (destruction)
or hemostasis of the tissue. Of course, the effect upon the tissue depends on a
multiplicity of factors, such as the amperage of the electrical current, the size
of the active electrode tip, and the time the electrical generator is activated.
A final, but very important, point to stress here is to consider an absolute law
of electricity, which is: electrical current always follows the path of least resistance.
During electrosurgery, if the environment so dictates, the hand of the operating
surgeon or assistant may offer the optimal path.
WHAT PROBLEMS EXIST WITH ELECTROSURGERY?
Advances in electrosurgical technology have made it a safe and necessary practice
in almost all types of surgical intervention. However, there are idiosyncrasies
linked to the modality which warrant astute awareness by all members of the healthcare
team involved when electrosurgery is employed. Among the potential concerns for
the operative team are interference with video and anesthesia monitoring equipment,
patient return electrode/ dispersive pad site burns, and alternate site burns to
the patient that may occur if the electrosurgical current is sufficiently concentrated
to a site other than the patient return electrode/ dispersive pad. Also, sparks
from an electrosurgery unit could provide an ignition source for an intraoperative
fire.
Another problem related to the use of electrosurgery is electrical shock or burn
to the operating surgeon or assistant through the surgical glove.1 When
this occurs, the clinician often attributes the hazard to a preexisting hole in
the glove (i.e., a break in insulation). The clinician simply changes gloves and
continues on. While this may be the case, and changing gloves is likely the solution,
there are other variables to be considered. It is possible that the hazard did not
occur from a preexisting hole in the glove barrier but, in effect, a hole could
result from the electrical hazard. The glove barrier may not have had a hole in
it at all before the episode occurred. It has been suggested by researchers that
the potential for a member of the operative team to receive a shock or burn through
the surgical glove—natural rubber or synthetic—may occur three different ways aside
from a preexisting hole:
- DC Conduction
- RF Capacitive Coupling
- High-voltage Dielectric Breakdown2
DC Conduction
This suggests that the impedance of the glove barrier to the electrical current
is low enough to let the current pass through. The impedance or resistance properties
of a surgical glove may be reduced as a result of extended wear and exposure to
blood and fluids, or from perspiration inside the glove. A “ballooning” phenomenon
can typically be seen at the tips of the glove, which suggests that the glove has
lost some of its barrier protective property. Another term often used to explain
the barrier breakdown effect is “hydration,” simply defined as the absorption of
water into the latex film. A glove that has become hydrated measures a lower electrical
resistance than a non-hydrated glove.3 A surgical glove that hydrates
slowly may offer added protection against the problems associated with electrosurgical
shock. Routine re-gloving and double-gloving can prevent these problems as well.
RF Capacitive Coupling
During electrosurgery the operating surgeon’s perspiring conductive skin and the
metal hemostat applied, for example, to a blood vessel, are considered capacitors
(two conductors) separated by an insulator, the glove barrier. When alternating
current is applied to the hemostat from the active electrode, it induces electrical
charge on the other conductor. The thinner the glove film, the more efficiently
current can be induced to surge from one conductor (the hemostat) to the other conductor
(the surgeon’s hand). This does not imply that electrical shock is imminent in every
procedure; certainly, conditions (as described in this manual) dictate. But what
is suggested in the literature is that all gloves, intact or otherwise, are capable
of transferring large amounts of RF current.1 Here again, selectively
choosing an optimal barrier (e.g., an ultra-thick glove) may prove to be a more
effective insulator for the operating surgeon when employing electrosurgery.
High-voltage Dielectric Breakdown
This phenomenon results when the glove barrier cannot withstand the effects of the
high-energy force from an electrosurgery generator. If the voltage is sufficiently
high, it can produce a hole in the glove and a resultant burn. Again, there are
contributing variables, such as the amount of time the current is applied or the
surgical technique used. Example: It is a very common practice for the surgeon or
first assistant to clamp a bleeding vessel and “zap” the bleeder with the active
electrode while holding onto the hemostatic instrument. The voltage or force from
the generator is exerted onto the entire clamp. The real potential for an electrical
hazard is to the person holding the clamp. If the clamp is being held by just the
tip of one finger, this allows only a small area for the current to concentrate,
increasing the current density to the finger holding the clamp. If all conditions
are right, the result is an electrifying “zap.” Basically, it is the same principle
as touching a doorknob with your finger and getting “zapped” after walking across
a carpeted room and generating static electricity. A safe method is to keep a firm
hold on the hemostat while obtaining hemostasis with the electrosurgery instrument.4
This ensures a larger area, decreasing the chance for the concentration of current
at the site.
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