diathermy


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Related to diathermy: surgical diathermy

diathermy

 [di´ah-ther″me]
the use of high-frequency electromagnetic currents as a form of physical therapy and in surgical procedures. The term diathermy is derived from the Greek words dia and therma, and literally means “heating through.” adj., adj diather´mal, diather´mic.

Diathermy is used in physical therapy to deliver moderate heat directly to pathologic lesions in the deeper tissues of the body. Surgically, the extreme heat that can be produced by diathermy may be used to destroy neoplasms, warts, and infected tissues, and to cauterize blood vessels to prevent excessive bleeding. The technique is particularly valuable in neurosurgery and surgery of the eye.

The three forms of diathermy employed by physical therapists are short wave, ultrasound, and microwave. The application of moderate heat by diathermy increases blood flow and speeds up metabolism and the rate of ion diffusion across cellular membranes. The fibrous tissues in tendons, joint capsules, and scars are more easily stretched when subjected to heat, thus facilitating the relief of stiffness of joints and promoting relaxation of the muscles and decrease of muscle spasms.

Short wave diathermy machines utilize two condenser plates that are placed on either side of the body part to be treated. Another mode of application is by induction coils that are pliable and can be molded to fit the part of the body under treatment. As the high-frequency waves travel through the body tissues between the condensers or the coils, they are converted into heat. The degree of heat and depth of penetration depend in part on the absorptive and resistance properties of the tissues that the waves encounter.

The frequency allowed for short wave diathermy operations is under the control of the Federal Communications Commission. The frequencies assigned for short wave diathermy operations are 13.66, 27.33, and 40.98 megahertz. Most commercial machines operate at a frequency of 27.33 megahertz and a wavelength of 11 meters.

Short wave diathermy usually is prescribed for treatment of deep muscles and joints that are covered with a heavy soft-tissue mass, for example, the hip. In some instances short wave diathermy may be applied to localize deep inflammatory processes, as in pelvic inflammatory disease.

Ultrasound diathermy employs high-frequency acoustic vibrations which, when propelled through the tissues, are converted into heat. This type of diathermy is 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.

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.

Microwave diathermy uses radar waves, which are of higher frequency and shorter wavelength than radio waves. Most, if not all, of the therapeutic effects of microwave therapy are related to the conversion of energy into heat and its distribution throughout the body tissues. This mode of diathermy is considered to be the easiest to use, but the microwaves have a relatively poor depth of penetration.

Microwaves cannot be used in high dosage on edematous tissue, over wet dressings, or near metallic implants in the body because of the danger of local burns. Microwaves and short waves cannot be used on or near persons with implanted electronic cardiac pacemakers.

As with all forms of heat applications, care must be taken to avoid burns during diathermy treatments, especially to patients with decreased sensitivity to heat and cold.
surgical diathermy electrocoagulation with an electrocautery of high frequency; often used for sealing blood vessels or stopping the bleeding of incised vessels.

di·a·ther·my

(dī'ă-ther-mē),
Local elevation of temperature within the tissues, produced by high frequency current, ultrasonic waves, or microwave radiation.
Synonym(s): transthermia
[G. dia, through, + thermē, heat]

diathermy

(dī′ə-thûr′mē)
n.
The therapeutic generation of local heat in body tissues by high-frequency electromagnetic currents.

di′a·ther′mic (-mĭk) adj.

diathermy

Sports medicine The use of high-frequency electromagnetic waves to ↑ temperature of deep tissues due to resistance to the passage of energy Types Microwave diathermy, shortwave diathermy. See Microwave diathermy, Shortwave diathermy Surgery Cauterization, see there.

di·a·ther·my

(dī'ă-thĕr-mē)
Therapeutic use of short or ultrashort waves of electromagnetic energy to heat muscular tissue.

diathermy

The use of high-frequency alternating current to heat or burn tissues. Diathermy can be used to produce a diffuse warming effect or an intense local cutting or coagulating effect for bloodless surgery.

Diathermy

Also called electrocautery, this is a procedure that heats and destroys abnormal cells. It is gradually being replaced by cryosurgery, lasers, or LEEP.
Mentioned in: Colposcopy

di·a·ther·my

(dī'ă-thĕr-mē)
Local elevation of temperature within tissues, produced by high-frequency current or other means.
References in periodicals archive ?
Comparison of post-operative nasal patency following microdebrider-assissted turbinoplasty was done with that of submucosal diathermy in patients of hypertrophic inferior turbinates which showed that 73.33% (n=44) in Group-A and 93.33% (n=56) in Group-B had good nasal obstruction relief while 26.67% (n=16) in Group-A and 6.67% (n=4) in Group-B had no good nasal obstruction relief, p value was calculated as 0.003 (table-IV).
It is standard practice that diathermy not be used past the anterior trachea or the thyroid gland.
These instruments have been routinely utilised in endoscopic abdominal and thoracic surgery due to their excellent combination of coagulation and cutting effects where conventional diathermy and ligature methods are difficult to apply.5 Hemostasis of vessels 6-7mm can be achieved with ultrasonic instruments by using the low amplitude coagulating mode while most effective cutting effect is achieved if amplitude of vibration is set to full power.5 Ligation of lingual artery using ultrasonic scissors has already been reported.6
The chemical constituents are the toxins which are present in the gases and are largely responsible for the offensive smell associated with diathermy. There are thought to be over 80 chemicals present in surgical smoke and many are believed to have a carcinogenic effect (Barrett & Garber 2004).
There was no significant difference between the operative times of both groups; it was 15.90 minutes for cold steel tonsillectomy and 12.50 minutes for bipolar diathermy group.
In monopolar diathermy, HFAC is generated in the electrosurgical device and is emitted via an active electrode controlled by the operator.
The most common modality used for tonsillectomy in New South Wales, Australia, is electrodissection tonsillectomy with monopolar diathermy. This technique is associated with a shorter operating time and less intraoperative bleeding compared with cold dissection techniques, but there is some evidence that it may cause more postoperative pain and bleeding.
In the first method, bipolar diathermy was used for both dissection and hemostasis.
The researchers found that the estimated recurrence rates were similar for excision, Mohs surgery, curettage and diathermy, and external-beam radiation (3.8, 3.8, 6.9, and 3.5 percent, respectively).
* Diathermy use after implantation: Diathermy produces heat to cut and coagulate tissues.
Objective: To determine the mean post-operative pain in scalpel versus diathermy opening of midline laparotomies.