surgical diathermy

(redirected from diathermocoagulation)

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.

sur·gi·cal di·a·ther·my

electrocoagulation with a high frequency electrocautery, resulting in local tissue destruction; usually used to seal blood vessels and arrest bleeding.

surgical diathermy

sur·gi·cal di·a·ther·my

(sŭr'ji-kăl dī'ă-thĕr-mē)
Electrocoagulation with a high-frequency electrocautery, resulting in local tissue destruction; usually used to seal blood vessels and arrest bleeding.

diathermy

the use of high-frequency electrical currents as a form of physical therapy and in surgical procedures.
Diathermy is used in physical therapy to deliver moderate heat directly to pathological 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. See also electrosurgery.

surgical diathermy
electrosurgery.