Erbe 10128-002, Instruction Manual

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3-1
3 RISKS AND SAFETY OF HIGH-FREQUENCY SURGERY
3.1 Unintentional thermal tissue damage
High-frequency surgery is associated in principle with various risks for the patient, the personnel
and surroundings. In order to avoid these risks in practice, the surgeon and his/her assistants
must recognize these risks and observe the appropriate rules for prevention of damage. In the
following, these risks and rules for prevention of damage are explained.
3.1.1 Unintentional thermal tissue damage due to HF leakage currents
During high-frequency surgery, the patient unavoidably conducts high-frequency electrical current
to ground potential. If the patient makes contact with electrically conductive objects during
high-frequency surgery, a high-frequency electrical current can result at the contact point between
the patient and this object, which can in turn cause thermal necroses. Not just objects made of
metal are electrically conductive objects, but also wet cloths.
WARNING!
The patient must be insulated against electrically conductive objects during high-frequency
surgery. The black elastic table covers on operating tables demonstrate a certain electrical
conductivity for diverting electrical charges. Therefore they are never suitable for ensuring the
required insulation of the patient against metal parts of the operating table. For this reason, an
electrically insulating intermediate layer, for example dry cover cloths, must be laid between the
patient and this black operating table cover during the application of high-frequency surgery.
Fig.: Insulated positioning of the patient on the operating table
If it is possible for this intermediate layer to become wet during the operation, for example due
to perspiration, irrigation liquid, urine etc., wetting of these intermediate layers must be prevented
by a watertight sheet of plastic. Urine should be carried away via catheter.
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Extremities lying against the trunk or skin-to-skin contact points should be insulated from
one another by laying dry cover cloths between them.
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Do not apply ECG electrodes closer than 15 cm next to the operating field.
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Needle electrodes or injection cannulae should not be used as ECG electrodes during
high-frequency surgery.
Electrically insulated
surface
Grounded operating table