Useful Info

 
Surgical Gloves & Electro Surgery
Surgeons have been using electrosurgery, which uses high-frequency alternating current to cut and coagulate tissue, since the beginning of this century. However, minimally invasive procedures, especially laparoscopic and other endoscopic techniques, have made electrosurgery much riskier than when it was used in traditional open procedures.


There are two basic principles of electricity: 1) electrical current flows to ground and 2) it follows the path of least resistance. Monopolar electrosurgery creates a complete electrical circuit from the active electrode, to the target tissue, to the dispersive return electrode, and back to the generator. Because surgeons now work through keyhole incisions and manipulate electrodes and instruments through long, narrow channels, it is more difficult than ever to prevent the electricity from traveling outside this path and burning or vapourizing non-targeted tissue.

An experience of electrical shock and or ‘burn’ may occur during electrosurgery. The surgeon or assisting personnel will usually attribute shock/burn to a hole in their glove. While this may be true, it usually is not the cause as our gloves are made and inspected very thoroughly for such breach of barrier and tested electronically before delivery. The chances of a hole at the very place of contact are of very low probability. It is possible that the hazard did not occur from a pre-existing hole in the glove but a hole is burned through the glove as a result of the breach of insulation.

The following is to give all healthcare personnel a better understanding of this phenomenon so that extra care can be taken to avoid such incidences. Most common cause of electrosurgery shocks and burns to users of such equipment are:


  1. Insulation Failure
  2. Continued regular use or cleaning and sterilization can cause the layer of insulation covering the shaft of the active electrode to break down. Tiny, visually undetectable tears are actually more dangerous than large cracks, since the current escaping from these miniscule breaks is more concentrated, and therefore capable of causing sparks (averaging 700 C). These sparks can cause severe burns and even ignite fires, especially in oxygen-rich environments. Unfortunately, many users unknowingly contribute to the problem. Routine use of the high voltage coagulation current may actually compromise insulation integrity. The higher the voltage, the greater the risk that the current will break through weak insulation.

    Solution
    First, encourage surgeons to always use the lowest voltage they can. All electrosurgery systems will allow you to use a coagulation or cutting waveform of current. Coagulation current is released in rapid high-voltage bursts to desiccate tissue and cause hemostasis; cutting current comes out in a lowervoltage, uninterrupted flow to dissect tissue.

    In most cases, try to use the cutting current for both cutting and coagulation. The coagulation mode is really only necessary when you need to fulgurate, or stop diffuse bleeding on highly vascularised tissue. Using the lowest voltage may reduce the wear on the insulation and minimize the chance that the current can escape through hairline cracks.

    Keep in mind, however, that using the cutting current minimises, but does not eliminate, the risk of insulation failure. To really be sure that the insulation is not compromised, I recommend implementing an electrosurgical unit that employs active electrode monitoring technology (AEM). This technology virtually eliminates these types of electrical burns.

    Lower Electrical Impedance in Gloves
    Alternatively, the impedance of the glove barrier to the electrical current could be low enough to let the current pass through. The impedance or resistance properties of a surgical glove may be reduced as result of extended wear and exposure to blood and fluids or from perspiration inside the glove. There will be slow microscopic absorption of water into the latex film. The water molecular migration does not breach the glove barrier but such a glove that has become hydrated measures a lower electrical resistance than a non-hydrated glove.

    Solution
    Routine re-gloving and double-gloving can prevent these problems

     

  3. Capacitive Coupling
  4. The phenomenon of capacitance is the ability of two conductors to transmit electrical flow even if they are separated by an intact layer of insulation. Capacitive coupling can occur even in the best-case scenario that is, when the insulation around the active electrode is intact and the tip of the electrode isn’t touching anything metal. If the active, insulated electrode is wrapped around a towel clamp, or placed inside a metal trocar sleeve, or comes in close contact with any conductive substance for an extended period of time, the current in the active electrode may induce a current in the second conductor.

    As long as the induced current can dissipate easily through a large surface of tissue, it will not present a problem. The danger occurs if the second conductor contains some insulating material, as in the case of a metal cannula held in place by a plastic anchor. The plastic anchor will prevent the energy from dissipating and increase the likelihood of a thermal burn. Burns from apacitance current may occur when the surface area is less than 3 cm2 or the current density is approximately 7 w /cm2.

    This will also occur when the user of the equipment reduces the contact surface of his grip to perhaps just the minimal finger tips. This will direct a high dissipation of electrical capacitance through that reduced area of glove barrier. Such a high capacitance may breakdown the nonconductive capacity of the glove.

    Solution
    As with direct coupling, the best way to prevent this phenomenon is to use the active electrode monitoring system that prevents current from capacitive coupling from building to dangerous levels. Also, you should avoid all plastic-metal hybrid instruments, including cannulae, trocars, and clamps, when doing electrosurgery. Apply a firm hold on the hemostat instrument to impact a larger contact area to avoid high capacitance over a small area of the glove.

    Adventa Health’s surgical gloves are made for the purpose of biological protective barrier as well as chemical protection. While the glove is an excellent electrical insulator and care is taken to ensure this, there are limitations and it is prudent to take certain measures to avoid incidences of such shocks and burns.

    A recommendation is to use double gloving, or increase changing of gloves during electrosurgery procedures.



Acknowledgement
  1. Dr. Vilos, Professor of Obstetrics and Gynecology and the Director of Endoscopic Surgery at the University of Western Ontario
  2. Tucker RD, Physics of Electrosurgery 1986