Assessment of safe use of high-frequency electric knives
2019-08-14
High-frequency electrosurgery is an electrosurgical instrument that replaces mechanical scalpels for tissue cutting. Its advantages are fast cutting speed, better hemostatic effect compared with instrument scalpel, and simple operation. The working principle is to use the increase in resistance when electric current passes through human tissue to cause high temperature, causing tissue cell degeneration, necrosis, dryness, shrinkage, carbonization, and eschar to achieve the purpose of hemostasis or cutting. However, due to the high frequency, small effective area, and high current density of electrosurgery, if used improperly, it can cause accidental injuries, bring pain to patients and even operators, and may even cause medical disputes. The experience of safe use of high-frequency electric knife is explained as follows.
1.0 Assessment of patient and environment
Communicate well with the patient, inform them of the precautions during the operation, understand whether the patient has dentures, artificial pacemakers, metal plates and other implants in the body, and explain to them the impact of metal on the use of high-frequency electrosurgery and its severity. Eliminate interference factors to high-frequency electrosurgery, anesthesia machines, and monitors during surgery. Preoperative psychological counseling for patients with pacemakers, perioperative safety assessment, understanding the specific conditions of the pacemaker carried by the patient, keeping warm during the operation, preparing rescue drugs and equipment, and fully considering the impact of anesthetics on the pacemaker during anesthesia influence, remind the surgeon to standardize the use of electrocution and electrocoagulation. Ensure that the operating room environment is safe, the temperature and humidity in the operating room are appropriate, and there should be no flammable or explosive gases, because the sparks generated by the high-frequency electrosurgery may ignite these gases. When operating on areas such as the front of the neck and maxillofacial area that are close to the oxygen channel, special attention should be paid to the high oxygen concentration in the patient's mouth, nose, and trachea, which may cause severe burns.
2.0 Power supply
Power supply stability is very important. If the input power supply voltage is unstable, the output power will vary greatly. When the electric knife has power output, the surgical operator must not touch the electric knife head, the patient's body, the examination bed and other conductive objects to prevent the operator from being burned by high-frequency and high-voltage discharge.
3.0 Equipment detection
Before powering on the equipment for testing, connect the power cord correctly and keep the ground wire, foot switch, neutral electrode, surgical electrode or bipolar electrode carefully inserted. Do not press any switch during the self-test of the instrument to avoid false alarms. Special attention should be paid to the power supply of the electric knife to a three-prong socket, which is a basic condition necessary to prevent electric shock. Different brands of electric knife have different power settings. Set the electric knife power correctly.
4.0 Safe use of negative plates
The effective conductive area of the negative plate: the children's plate is 65 square centimeters and the adult plate is 129 square centimeters. Once the contact area of the negative plate is reduced and the resistance increases to an unsafe level, the machine will automatically alarm and stop output. Children under 15 kg should choose infant negative plates. Suitable parts: easy-to-observe parts, flat muscle areas, rich blood vessel areas, clean and dry skin; for infants and young children, choose flat muscle areas such as thighs, back, and abdomen for the negative plate site. The negative plate should be placed as close to the surgical site as possible, which can reduce the working impedance of the electric knife, reduce the output power of the electric knife, and reduce the risk of burns. For patients with a pacemaker, the electrode plate should be kept as far away from the pacemaker as possible, and skin preparation should be performed on the gastrocnemius muscle of the right calf to ensure that the electrode plate is placed on clean, dry, hairless epidermis during the operation to reduce its interference with the pacemaker. [3]. Avoid sticking to bones, dry skin, joints and artificial implants, or close to ECG electrode wires. After moving the patient, first check whether the negative plate has fallen off or shifted. Avoid reuse of disposable negative plates to prevent possible cross-infection and burns.
5.0 Safe use of high-frequency electrosurgery in open surgery
Make an electrosurgical protective box and place the electrosurgical pen in the box with the tip pointed downward when ready for use to prevent the doctor from accidentally touching and activating the button during the operation, causing burns to the doctor and patient's normal tissues and causing in-hospital injuries. At the beginning of surgery, the antiseptic solution may act as a fuel, creating a safety hazard. The ignition of the skin disinfectant caused by the use of high-frequency electrosurgery is related to the type of disinfectant, the output power of the electrosurgery, and the evaporation time of the disinfectant. The drying judgment after using alcohol-based disinfectants should be based on the actual drying time. The high-frequency electric knife will form an arc when used, and it will burn or explode when it encounters flammable materials. Therefore, avoid using it in an environment with volatile and explosive gases. When using the electrosurgery, the tissue being cut should maintain a certain tension and remove the eschar on the head of the electrosurgery in a timely manner; at the same time, the contact time between the electrosurgery and the tissue should be shortened and repeated cutting of the tissue should be avoided. When electrocoagulation is used to stop bleeding, the bleeding point should be seen clearly, and the "chicken pecking rice" technique should be used. "Carpet bombing" back and forth cauterization should be avoided to reduce tissue trauma. The electric knife contacts the skin and directly cuts the outer plate of the foreskin, which may cause necrosis of the skin edge. Therefore, electrosurgery and electrocoagulation should be used correctly and operated carefully and accurately. During use, the smoke and particles generated should be sucked out in time. Once the instrument is out of control or a power supply accident occurs, the power supply should be cut off immediately to prevent the instrument from being damaged again and causing unnecessary losses.
6.0 Safe use of high-frequency electrosurgery in laparoscopic surgery
Adjust the power of electrocution and electrocoagulation before surgery. When using electrosurgery during surgery, attention should be paid to keeping the distance from the cavity organs greater than 5 cm. During electrosurgery, try to be as close to the solid organ side as possible and away from the titanium clip by more than 5 cm, to prevent heat conduction waves from causing damage to the intestines. When not in operation, you should get used to taking the instrument out of the body to avoid accidentally stepping on the switch and causing accidental burns to the patient, and avoid using the electrosurgery in liquids with electrolytes such as blood or physiological saline. Medical staff who operate should wear non-metal frame glasses to prevent high-frequency radiation from generating eddy current heating in the metal frame and scalding the medical staff's faces.
7.0 Safe use of high-frequency electrosurgery during surgery for patients with pacemakers
Set the pacemaker to VVI mode, use bipolar electrosurgical scalpel or ultrasonic scalpel as much as possible, and use low-energy, point-like hemostasis. If the trial electrosurgery has a great impact on the electrocardiogram waveform and is slow to restore the normal waveform, it should be avoided. If there is a lot of bleeding during the operation, use it intermittently. Limit the power of the electrosurgery to about 60W. It is best to use the electrosurgery continuously for less than 50 seconds. Continuous ECG monitoring and hemodynamic monitoring during the operation.
8.0 Postoperative maintenance of high-frequency electrosurgery
After the operation, the electrosurgical cutting and electrocoagulation functions on the control panel should be reset to zero. First cut off the power, then remove the power cord. After sorting out the components, return the electrosurgery to its original position and keep the equipment clean and dry. Develop the operating procedures and precautions for the instrument, seal them in the form of a card and fix them on the instrument. The operating room organizes small lectures in the department, and specialist nurses update and introduce the knowledge of relevant equipment and surgical instruments in stages, and establishes a complete assessment and employment system to ensure that the equipment and surgical instruments are used safely and correctly.
9.0 Potential safety hazards and management of high-frequency electrosurgery
Since high-frequency electrosurgery uses high frequency and high voltage for cutting and electrocoagulation, its most common safety problem is burns. The so-called electric burn means that a large current intensity passes through a part of the body, thereby generating a large amount of heat, which cannot be dissipated in time and damage the body. Burns can generally be divided into plate burns and non-plate burns. Partial or complete loss of electrode pads is the most common cause of burns. According to clinical statistics, electric current burns on the patient's tissue contact surface account for more than 80% of patient burns. Electrical current burns are not terrible. As long as you carefully check whether the high-frequency generator is intact before surgery, install the patient's electrode plate, confirm whether the patient's posture is correct, and adjust the high-frequency conditions required for surgery, accidents of current burns can be completely avoided.
Surgeons and operating room nurses should understand the principles and principles of use of high-frequency electrosurgery. A comprehensive assessment of the patient is carried out before the operation. During the operation, the surgical nurse promptly reminds the doctor of the patient's risk factors and urges the surgeon to use the electrosurgery correctly and safely to prevent accidents, increase the patient's pain and cause medical disputes.
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