This document discusses diathermy, which uses high frequency current to cut and coagulate body tissue. It describes the different types of diathermy including shortwave, ultrasound and microwave. Shortwave diathermy uses condenser plates to concentrate heat in subcutaneous tissues. Ultrasound uses acoustic vibrations converted to heat, while microwave diathermy uses similar radiation to radar waves. The document also covers monopolar and bipolar diathermy configurations and safety precautions for using diathermy.

1. By………. Dr Shivraj Sharma
1st year resident
Dept.of General Surgery
NMCTH,BIRGUNJ

2.  “ the cutting and coagulation of body tissue
with high frequency ( i.e. radiofrequency )
current ’’
 term “diathermy” is derived from the Greek
words “Therma”, meaning heat, and “Dia”,
meaning through.
 Diathermy literally means “Heating through”.

3.  1908 German physician Karl Franz Nagelschmidt coined the
term diathermy, and performed the first extensive
experiments on patients.
 founder of the field.
 first textbook on diathermy in 1913, which revolutionized
the field.

4.  Depending on the amount of heat generated, diathermy can be
used to merely warm or to destroy tissue.
 In the first instance, it is particularly beneficial in relieving
muscle soreness and sprain.
 In the second, as an adjunct to surgery, diathermy is used to
coagulate, prevent excessive bleeding, and seal off traumatized
tissues.
 It is particularly effective in eye surgery, neurosurgery &
dermatology, ent and general surgery.

5. 3 forms of diathermy - wide use in hospitals :
 Shortwave
 Ultrasound
 Microwave

6.  In shortwave diathermy, the part to be
treated is placed between two condenser
plates, and the highest temperature is
concentrated in the subcutaneous tissues.
 It is usually prescribed as treatment for deep
muscles and joints and is sometimes used to
localize deep inflammatory disease.

7.  employs high-frequency acoustic vibrations
which, when propelled through the tissues, are
converted into heat.
 especially useful in the delivery of heat to
selected musculatures and structures because
there is a difference in the sensitivity of various
fibers to the acoustic vibrations
 some are more absorptive and some are more
reflective. For example, in subcutaneous fat,
relatively little energy is converted into heat, but
in muscle tissues there is a much higher rate of
conversion to heat.

8.  The therapeutic ultrasound apparatus
generates a high-frequency alternating
current, which is then converted into acoustic
vibrations.
 The apparatus is moved slowly across the
surface of the part being treated.
 Ultrasound is a very effective agent for the
application of heat, but it should be used only
by a therapist who is fully aware of its
potential hazards and the contraindications
for its use.

9.  Microwave diathermy uses radiation of very
high frequency & short wavelength similar to
radar waves.
 All physiologic responses are due to its
heating effect.
 Microwave diathermy is used in the
management of superficial tumours with
conventional RT & CT.

10.  Surgical diathermy is usually better known as
"electrosurgery". (It is also referred to
occasionally as "electrocautery“)
 Electrosurgery and surgical diathermy involve
the use of high frequency A.C. electrical
current in surgery.

11. Diathermy can be used for 3 purposes :
 Coagulation – Sealing of blood vessels.
 Fulguration – the destructive coagulation of
tissues with charring.
 Cutting – used to divide tissues during
bloodless surgery.

12.  MONOPOLAR
 BIPOLAR

13.  Most common configuration, high frequency current is
delivered to an active electrode held by surgeon.
 Current density is high where electrode touches body
tissue,producing local heating effect.
 electrical current passes from one electrode near the tissue
to be treated to other fixed electrode (indifferent electrode)
elsewhere in the body.
 Usually this type of electrode is placed in contact with
buttocks or around the leg.
 NOTE: Misapplication of the patient plate is by far the most
common cause of inadvertent diathermy burns.

15.  Active electrode in
surgical site.
 Patient return electrode –
electrical plate – attached
elsewhere.
 Current flows through
patient.
 Localised heating at tip
of instrument.
 Minimal heating on plate
as more surface area.

17.  Bipolar, where both electrodes are mounted
on same pen-like device and electrical
current passes only through the tissue being
treated.
 Advantage of bipolar electrosurgery is that it
prevents the flow of current through other
tissues of the body and focuses only on the
tissue in contact.
 This is useful in microsurgery and in patients
with cardiac pacemaker.

19.  It cannot be used for “cutting’’ as this involves a continuous
arc (spark) between the active electrode and the tissue
involved. The arc can be struck only between limbs of the
forceps.
 It will not work when a hemostats has grasped a vessel and
then touched with active diathermy electrode
 Current passes directly from one diathermy forceps limb to
other and no current passes through the tissue held by
hemostastis

21.  For cutting , the generator produces a continous output ,
causing arc to be struck between the active electrode and
tissue and creating temp upto 1000c
 Cell water is instantly vaporized causing tissue disruption
with some coagulation of bleeding vessels.
 Coagulation diathermy current causes sealing of blood
vessels with minimal tissue disruption.
 Most diathermy generators have “ blend’’bfacility,functioning
only when in cutting mode,allowing a combination of cutting
and coagulation waveform ,increasing the degree of
haemostasis.

22.  Explosion
 Burns
 Lap.surgery

23.  Sparks from diathermy can ignite any volatile
or gases or fluid within the theatre.
 Alcohol based skin preparation can catch fire
if they are allowed to pool or around the
patient.

24.  Faulty application of the
indifferent electrode
with inadequate contact
area.
 Patient being earthed by
touching any metal
object.
 Faulty insulation of
diathermy leads.
 Inadvertent activity
such as accidental
activation of foot pedal.

25.  Diathermy of wrong structure becoz of lack of clarity of vision
or crowded space
 Faulty insulation of any lap instrument.
 Intraperitoneal contact of diathermy with another metal
instrument.
 Inadvertent activity while tip is out of vision of the camera.
 Retained heat in the tip – touching the bowel.

26.  BEWARE of using diathermy on or inside the intestine- its gas
contains hydrogen and methane ,both are inflammable and
explosive.
 Beware of using diathermy on appendages such as salphinx
or penis or isolated tissues such as testis ; high current
density can persist beyond the operative site.
 It can damage other structures, such as sutures and
endotracheal tubes and their balloons.

27.  Short circuit instances leading to
electrocution
 Interfere with pacemaker function
 Channeling effects if used on viscous with
narrow pedicle (e.g. penis or testis)

28.  The ESU should be protected from spills. Fluids should not be
placed on top of the ESU
 The return electrode mat should be the appropriate size for
the patient’s weight.
 In most circumstances, only active electrodes recommended
by the manufacturer should be used. If an adapter is used, it
should be one that is approved by the manufacturer and does
not compromise the generator's safety features.

29.  Before the start of the procedure, the peri operative team
must ensure that any part of the patient is not touching any
earthed objects such as the trim of the operating table or
intravenous (IV) drip stands.
 Minimal materials between the patient and the return
electrode mat must be ensured to prevent any injury to the
patient. This includes draw sheets, sliding sheets,
blankets,nappies and any other clothing. A high level of
patient dignity must be upheld at all times.

30.  it should be inspected and safety features tested (eg lights,
activation of the return electrode sound indicator) before each
use.
 All cables and electrodes must be checked prior to use to
ensure insulation is intact .
 Any problems must be reported to the Biomedical
Engineering department immediately .
 The volume of the activation sound indicator should be
maintained at an audible level .
 it should be mounted on a wheeled stand that is tip-
resistant and moves easily.
 it should not be used in the presence of flammable agents
eg, alcohol, tincture-based fluid

31.  it should be operated at the lowest effective power setting to
achieve the desired effect for coagulation and cutting .
 it should be of adequate length and flexibility to reach the
appropriate electrical outlet without stress. Any kinks, knots
or curls should be removed from the cord before it is plugged
into the appropriate electrical outlet.
 A The patient’s skin integrity should be evaluated and
documented in the peri-operative care plan before and after
its use The type of return electrode used should also be
documented in the care plan.
 The patient’s jewellery must be removed .
 If two are used simultaneously during an operative
procedure they must have the same technology, eg both are
grounded or isolated A

32.  A young woman went to her doctor complaining of pain. "You have
to help me," she cried. "I hurt all over!"
 "What do you mean, all over?" asked the doctor, "try to be a little
more specific."
 The woman touched her right knee with her index finger and yelled,
"Ow, that hurts." Then she touched her left cheek and again yelled,
"Ouch! That hurts too." Then she touched her right earlobe, "Ow,
even THAT hurts," she bellowed, bursting into tears.
 The doctor checked her thoroughly and announced his diagnosis:
"You have a broken finger.“
…………………..have a nice day…………………….