2
particularly in case the patient is moved or liquids are poured.0. The position of neutral electrode as to the operating area produces a run to the H.F.
current. Remind that eventual metal items (prostheses, catheters, and so on) on that area may cause too strong current condensations, so following a
warming, till the burn of the nearest tissue.
11. The connection cables of the unit’s electrodes have not to touch the patient or other conductors.
12. Always use the lowest possible power in relation to the operative necessities.
An eventual poor efficiency of the apparatus, compared with the usual run, may be done by: incorrect position or poor contact of neutral electrode,
defect of the electrodes connections, bad conditions of active electrode; so verify these things before raising too much power.
13. To operate on small size areas or cavities, use bipolar technique to avoid too wide and not wanted coagulations.
14. When the unit is put ON don’t set at direct contact the active electrode with the neutral one (short circuit) and reduce at min. the time when active
electrode doesn’t touch the tissues - it might cause detrimental warming or reduce the life of the unit. On this connection, please follow as much as
possible the suggested work times.
15. To use ‘disposable electrodes’ address you to the Technical Dep.
16. In case of supply mains lack, set all controls to ZERO and put OFF the unit.
THE POSITION OF PATIENT AND NEUTRAL ELECTRODE
By using an high-frequency surgical apparatus by monopolar technique it’s very important the all current reaching the patient returns correctly to the unit by
means of neutral electrode.
To forget to apply neutral electrode or wrong application, causes two big troubles:
1. High-frequency current discharges from the patient through an insufficient part of the same neutral electrode or by means of casual contacts of
conductive items (operating table, wet clothes, supports, and so on ) so, because these are contact surfaces relatively small, the density of current
crossing them may be such as to cause some burns.
2. Power delivery of the unit may lower considerably.
For above reasons it’s very important that neutral electrode is used by keeping in mind all indications detailed on points 7, 8, 9, and 10 of the par.
‘GENERAL PRECAUTIONS’.
On this connection must be also reminded that the phenomena usually named ‘shocks’ may be of concern of electrosurgical units’ use and normally they are
very slight stimulation phenomena or small radio-frequency discharges depending on the same contact between the operator and patient.
In most cases said phenomena don’t happen or, at least, are such as to not be noticed , but in case they happen it’s advisable that the operator avoids direct
contacts with patient (for ex. use surgical gloves as insulating) and, if possible, has not earth contacts (use clogs, insulating chair, and so on).
THE PRINCIPLES OF CUT AND COAGULATION
As already stated on the introduction , the electrosurgery takes best advantage from thermal effect in the tissues of high frequency current to coagulate or cut
them.
Coagulation happens when the current ‘reaches’ the tissues with a ‘density’ limited enough such as to allow infra an extra cellular liquids to evaporate slowly ,
so there is the coagulation of the components of the tissues which can be coagulated that during this process tend to contract , closing and blocking the blood-
vessels.
Cutting of the tissues, on the contrary, happens when the current has a ‘density’ more higher , so warms the tissues at a such quickness and temperature so that
the liquids inside them don’t succeed in evaporating slowly and produce a so high pressure to explode cellular membranes and consequently destroy them, so
destroying the same tissues too.
Finally, blend cut happens when the phenomenon is a middle course between above said.
The components concurring to produce said processes are essentially two:
- the kind of current delivered by the unit - the kind of electrode used.
Delivered current depends on technical characteristics of the apparatus, so the operator cannot interfere on them by no means except in power adjusting,
whereas the choice of the electrode depends on his will, so it’s advisable to have exact information about.
More suitable electrodes for pure or blend cut are, of course, the ones having smaller section (needle type, knife, loop with thin wire, electrodes for uterine
conization, polypectomy et cetera) because they concentrate the current on a very exact point , so help considerably to raise its ‘density’ on the application
point.
On the contrary, the electrodes more suitable for coagulation are the ones having larger section (round end, and so on) since help to lower the ‘density’ of the
current on the application point.
PRACTICAL PROPOSALS
By keeping in mind general indications stated on the previous par., it’s possible to give a series of practical proposals to get the optimum units’ running by
reducing all problems that their use concern.
First of all, there are three general indications to keep in mind at any circumstance, that is to say:
1. Do not activate the unit before active electrode is in touch with the tissues, otherwise some electric arcs are produced which carbonise them
superficially, then preventing from good cicatrisation.
2. Keep active electrode clean as much as possible otherwise may be produced some sparks or superficial carbonisation’s of the tissues . Dirty patina on
an electrode tends to insulate it in a way such as to determine even a lowering of the power delivery because of poor contact between said electrode and the
tissues. Always use the lowest possible power .In fact, to use too high power allows to have quicker surgical action, but causes superficial discharges, sparks
and flashes and certainly produces superficial carbonisation’s.
Pure cut (for biopsy, laparoscopy, tissues extirpations, cut or skin incision, uterine conization, in gynaecology etc., in general for any case
needing cut without coagulating effect).
1. Use small size electrodes, such as for ex.:
E7 ‘thin needle electrode’ (from 3 ÷ 4 W)
SAD, SAD/1, SAD/2, SAD/3 ‘extra-fine needle electrodes’ not insulated, with diam. from 0.10 to 0.40 mm (from 3 ÷4 W)
E42, E43, E44, E45 ‘long type electrodes’ with different ends (from 10 W)
All LLETZ type electrodes for gynaecology from E50 to E58 (from 10 W)
2. Select ‘CUT’ current and, in case, get quick as much as possible sliding of the electrode on the tissue.
Blend cut (for laparoscopy, polypectomies, papillomies, fistulas, haemorrhoids, in general for any case needing cut combined with an
effective coagulating effect).
1. Use the electrodes already mentioned for pure cut or, if possible, the one provided with bigger section, such as for ex.:
E1 ‘knife electrode’, E5 ‘thick needle electrode’ (from 4 ÷ 5 W)
2. Select ‘BLEND’ current and, in case, slow as much as possible sliding of the electrode on the tissue.
In case coagulating effect is not sufficient, use coagulation currents too, the better is ‘FORCED’ type.
Micro Coagulation (for ex.: in dermatology, epilation, telangiectasis, spider naevi, pointformed red-ruby angiomas, etc.).
1. Use extra-fine needles: AID ‘insulated needle’ (the best for epilation), all SAD ‘long type, not insulated needles’ above mentioned for cut too.
2. Select ‘SOFT COAG’ current (from 0.5 W)
