Electrosurgery Flashcards
What is electrosurgery?
application of high frequency electric current to biological tissue as a means to cut, coagulate, dessicate or fulgurate tissues
Why doesn’t electrosurgery electrocute people? What is their frequency?
200 kHz - 3.3 MHz
(muscle and nerve stimulation ceases at 100kHz, household appliances etc are 60Hz)
Electrocautery vs electrosurgery
electrocautery (direct current)
- often inaccurately described as electrosurgery
- current doesnt enter pt’s body, only the heated wire tip comes in contact w tissue
electrosurgery (alternating current)
- uses high freq alternating current (AC)
- AC circuit must be completed
Components of electrosurgical (AC) circuit
circuit = flow of current from electrosurgery unit to active electrode to the patient, to the pad and back to the ESU
current - flow of electrons through the electrical circuit
voltage - electrical force pushing current around the circuit, through varying degrees of tissue resistance
resistance - literally tissue being treated, which has varying characteristics
2 main types of electrical waveforms and what they do?
- Sinusoidal (continuous) - for cutting
- Modulated (with resting points) - for coagulation
3 things you must never touch with electrosurgery tip
vital tooth
bone
metal
2 principles about electricity
- always seeks ground
- always seeks path of least resistance
What is surgical smoke?
emissions made by equipment such as lasers and ESUs causing thermal destruction of soft and hard tissue
contain low volume of toxic gases such as benzene, hydrogen cyanide, formaldehyde, bioaerosols and dead and live material (like blood fragments and viruses)
usually insivisble to naked eye
Risks associated with surgical smoke
- unquantified infection risk
- occular and upper resp tract irritation
- visual problems for surgeon
- evidence of mutagenic potential but no evidence of human carcinogenicity
- risks vary according to circumstance - procedure, equipment, technique, patient
How to manage/remove surgical smoke?
- usually achieved by effective local exhaust ventilation (LEV) systems in hospital operating suits
- in dentistry, we use HVE to control plume
- dedicated smoke evacuators use a high efficiency particular air filter (HEPA)
Requirements for operating an ESU?
- equipment complies w Australian standards
- set up equipment in accordance w manufacturer instructions
- attend prelim training courses to attain adequate expertise is requirements
- be aware of potential fire and explosion hazards (e.g. alcohol skin preps, medical oxygen, N2O)
- check equipment for signs of damage (needs regular checked/serviced by licensed electrician)
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There is potential for alternate site burns when using ESU as electricity always seeks ground. What are some things that must be done to minimise this risk?
- observe skin touching conductive objects like IV poles, metal bed rails etc
- watch for anything touching metal
- check for arms over bedrails, handrails etc
- seperate all wires, including heart monitor wires from active cords and dispersive electrode cords
- CHECK MED HX FOR IMPLANTED METAL AND ELECTRICAL DEVICES (including metal piercings), verbally ask patient as well
What do we do if a patient has jewellery
remove all pierced and non-pierced jewellery
removal helps to avoid burns, avoid accidental injury, lower staff liability
navel and genital jewelry can be in circuit
tongue studs can damage scopes and impede intubation in an emergency
T/F Scarred skin (burns, tattoos, etc) and excessive hair in the area of the dispersive electrode may increase risk of injury
True
Where should the ground electrode NOT be placed? (5)
boney prominences
scar tissue (including tattoos)
skin/scars over implanted metal prosthesis
hairy surfaces - clip if necessary
lotions or oils on skin