Safe use of monopolar electrosurgery

Monopolar electrosurgery is a commonly used electrosurgical tool in medical surgery. It has the characteristics of generating high-frequency current and is widely used for surgical operations such as tissue cutting, hemostasis and coagulation. However, the safe use of monopolar electrosurgery is crucial, related to the effectiveness of surgery and patient safety. This article will delve into the safe use of monopolar electrosurgery and provide more safety guarantees and operating guidelines for medical staff and patients.


1. Composition of monopolar electrosurgery
Unipolar electrosurgery generally consists of a host machine, an electrosurgical pen, a foot control switch and a negative plate (wire).

2. Working principle of monopolar electrosurgery
It uses 300-500HZ high-frequency current to release heat energy and discharge to cut the tissue and stop bleeding. The current forms high temperature, thermal energy and discharge at the tip of the electrosurgical knife, causing the contacted tissue to quickly dehydrate, decompose, evaporate, and coagulate blood, thereby achieving tissue decomposition and coagulation to achieve the purpose of cutting and hemostasis.

3. Application scope of monopolar electrosurgery
Monopolar electrosurgers are widely used in surgery, dermatology, and dentistry, and can be used to cut different tissues according to their functions.
(1) Pure cutting function: mainly used for clear, precise and damage-free cutting of any tissue.
(2) Mixed cutting function: used for cutting any tissue and has good coagulation function.
(3) There are generally three types of coagulation functions:
a. Low-pressure contact coagulation (desicate/low): generally used for laparoscopic surgery and fine tissue coagulation.
b. Non-contact coagulation (fulgurate/med): effective for most tissues and suitable for most surgeries.
c. Spray coagulation (spray/high): used for large-area tissue oozing and forming a very shallow tissue coagulation layer.

4. Operation steps
1. Connect the power cord and negative plate circuit.
2. Turn on the power, perform self-test, and select the appropriate output power according to the instructions and procedures.
3. The negative plate is pasted on the appropriate part of the patient's muscles.
4. Connect the electrosurgical pen line and use the hand control or foot control switch.
5. After use, turn off the power of the host first, and then unplug the power plug.

5. Precautions
1. High-frequency electrosurgical devices should be operated by trained medical personnel. Even before using a new electrosurgical device, the instruction manual should be read carefully to prevent safety issues caused by misoperation.
2. Selection of negative plates: Hard negative plates are less safe than soft negative plates. Double-circuit negative plates are safer than single-circuit negative plates. Pay attention to them when using them.
3. When the output power reaches 100~700W, it is extremely easy to cause burns or damage other electronic equipment.
4. Negative plate area: required to be greater than 100c㎡. It is generally required that the effective conductive area of ​​the negative plate for children is 65c㎡. The effective conductive area for adults is 129c㎡. Once the effective contact area is reduced and the resistance increases to an unsafe level, the machine will automatically alarm and stop output. If the plate temperature exceeds the skin temperature by 6°C, burns may occur.
5. Selection of placement location of negative plate:
①Unsuitable parts: bony protrusions, scars, skin folds, fat tissue or thick fat, epidermis, weight-bearing parts, parts where fluid may accumulate, metal implants or near pacemakers.
② Suitable parts: easy-to-observe parts, flat muscle areas, shaved skin, clean and dry skin. The negative plate should be more than 15cm away from the ECG electrode; try to be as close as possible to the surgical incision site to reduce the current loop, but because first Consider ideal sticking sites such as: calves, inner and outer thighs, buttocks, waist, back, abdomen, upper limbs; try to avoid current loops passing through grafts, pacemakers, ECG electrodes, hearts, etc.; the long side of the negative plate Perpendicular to the direction of high-frequency current.
③Infant negative plates: Choose flat muscle areas such as thighs, back, and abdomen. Children under 15 kg should choose infant negative plates.

6. Precautions for using disposable flexible negative plates:
① It should be kept flat and cutting and folding are prohibited.
② Single use, no reuse: After use, the conductive adhesive on the surface of the negative plate adheres to dander and hair, and its physical and chemical properties change, resulting in poor conductivity, reduced safety performance, and an increased possibility of burns to the patient. Negative plates used at the same time may contain bacteria, HIV, HBV, etc. or dander from patients with skin diseases. Cross-infection may occur if the same negative plate is used repeatedly between different patients.
③When removing the negative plate, remove it slowly from the edge along the direction of the skin lines to avoid mechanical damage caused by excessive speed and excessive force.

7. Note during use: Remove the eschar on the electric knife head in time to maintain good conduction function. It is forbidden to scratch the surface of the electric knife head with sharp objects. Use a special electric knife wiper or moist saline gauze to wipe it off; if it is not used temporarily When using the electrosurgery, it should be placed in an insulated container and should not be placed in areas that hinder the doctor's operation or on the patient's exposed body surface to avoid causing burns to medical staff and patients.

8. Patients with pacemakers are prohibited from using high-frequency monopolar electrosurgery.

9. Avoid direct contact between the patient's limbs and metal during use. An insulation layer of at least 4 cm thick should be maintained between the patient and the metal bed. If necessary, cloth or hand pallets can be used to fix the limbs.

10. The electrosurgical pen is a one-time use item and must be destroyed after use.

As a commonly used electrosurgical cutting tool in medical operations, monopolar electrosurgery plays an important role in surgical operations. However, the safe use of monopolar electrosurgery is key to ensuring surgical results and patient safety. Medical staff need to fully understand the working principles and safe use methods of monopolar electrosurgical devices, improve their operating skills and safety awareness, and provide more safety guarantees and operating guidance for medical operations.