Diathermy in Surgery

High Frequency alternate polarity radio-wave electrical current to cut or coagulate tissue during surgery.

• Can be either monopolar or bipolar; both actions require the electrical circuit to be completed
• In monopolar action, the electrical current oscillates between the surgeon’s electrode, through the patient’s body, until it meets the ‘grounding plate’ (positioned underneath the patient’s leg) to complete the circuit.
• In bipolar diathermy, the two electrodes are found on the instrument itself. The current is then passed between the electrodes.

• The main two settings of diathermy are cutting and coagulation.

• Cutting uses a continuous waveform with a low voltage. 

• In cutting mode, the electrode reaches a high enough power to vaporise the water content. 
• it is able to perform a clean cut but is less efficient at coagulating. 
• The cutting mode focuses heat at the surgical site, using sparks being the more focussed way to distribute heat.

• Coagulation uses a pulsed waveform with a high voltage. 
• The tip should be held slightly away from the tissue,  the sparks are spread over a wider area causing charring rather than cutting.

 

 

 

                     Monopolar diathermy cautery         

Bipolar diathermy cautery