Terminologies
- Monopolar = 1 tip at the end of surgical electrode
- Bipolar = 2 tip at the end of surgical electrode
- Monoterminal = Use of treatment electrode without ground plate (indifferent electrode)
- Biterminal = Both treatment and indifferent electrodes (ground plate) are used
Electrosurgery modalities
Modality | Electrode configuration | Waveform | Indications | Remarks |
---|---|---|---|---|
DC | ||||
Electrocautery | Patients with ICDs and pacemakers | No current passes through patient (direct heat transference to tissue) | ||
AC | Unaltered sine wave | |||
a. High voltage, Low ampere | Can be tolerated in patients with pacemakers at low dosage | |||
Electrodessication | Monoterminal | Markedly damped | Superficial tissue destruction | Probe directly contacts tissue |
Electrofulguration | Monoterminal | Markedly damped | Probe held far (spark effect) | |
b. High ampere, Low voltage | Cannot be tolerated in patients with pacemakers | |||
Electrocoagulation | Biterminal | Sine wave – 6% on and 94% off | Deep tissue destruction | Higher contact surface area Lower impedance Lower current density |
Electrosection (pure cut) | Biterminal | Sinewave – 100% on | Cutting | Vaporization Lower contact surface area Higher impedance Higher current density |
Blend (coagulation + cut) | Biterminal | Sine wave – different proportions of on/off | Hemostasis + Cutting |
Mnemonic: ABC
- Ampere high
- Biterminal
- Coagulation, Cut, Coagulation + Cut (blend)
Mnemonic: VMDeF
- Voltage high
- Monoterminal
- Dessication
- Fulguration
Complications
Mnemonic: ABCDE
1. Active electrode trauma: inappropriate contact or inadvertent activation
2. Blaze (fire): near alcohol source or oxygen
3. Current diversion: ACID
- Alternate ground site burns
- Capacitive coupling: Transfer of current between 2 conductors (electrode tip and metal cannula) separated by insulator through the electrostatic field (reduced by plastic cannula instead of metal cannula); risk increased with –
- High voltage (coagulation mode)
- Open activation (electrodes not in contact with tissue)
- Increased impedance (wrapping of cable around metal clamps like towel clip or activation over previously coagulated tissue)
- Insulation failure: Mainly with high voltage coagulation; smaller the break in insulation, higher the density of current dispersed
- Direct coupling: Transfer of current from one conductive source to another
4. Cardiac pacemaker: Interference from electromagnetic current; reduced by using –
- Bipolar electrode
- Short bursts of monopolar electrode
- Application of dispersive electrode as far as possible from pacemaker
- Immediate deactivation and activation of ICD preoperatively and postoperatively respectively
5. Dispersive electrode burns
- Loss of contact of electrode with patient
- Inappropriate application of electrode on bony prominences or adjacent to ECG leads
6. Explosions: in the vicinity of inflammable gas under pressure
Further reading: Complications, Implications, and Prevention of Electrosurgical Injuries: Corner Stone of Diathermy Use for Junior Surgical Trainees – PMC (nih.gov)
![dr. sulabh kumar shrestha](https://epomedicine.com/wp-content/uploads/2020/07/profile.jpg)
He is the section editor of Orthopedics in Epomedicine. He searches for and share simpler ways to make complicated medical topics simple. He also loves writing poetry, listening and playing music.