Contraindications and precautions: by 0QR83h

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									Low level Lasers Contraindications and precautions:


There are no absolute contraindications for (LT) laser
therapy. However, it is always better to be cautious when treating
patients in high-risk categories. Laser therapy should be given
with special caution in the following cases:

   Patients with pacemakers Pacemakers are electronic devices and
well protected inside a cover and insensitive to light. All therapy lasers
are approved medical devices and have an EMC approval (Electro
Magnetic Compatibility) therefore should not interact with pacemakers.

   Patients with a history of cardiac arhythmias or unexplained
chest pain Laser therapy applied to mid-thoracic area (Th4-7) para
spinally may induce transient coronary spasm and/or arrhythmias in rare
occasions.

   Patients who are pregnant Laser therapy should not be applied
directly over the fetus. The same applies to the so-called forbidden
acupuncture points (e.g. Hegu (LI4), Sanyinjiao (SP6), and points in
lumbosacral region) to avoid uterine contractions. However, nausea and
vomiting (hyperemesis gravidarum) may be treated through Neiguan
(PC6) point.

   Patients with labile epilepsy As pulsing light (especially with 5-10
Hz frequency) can induce epileptic attacks laser therapy using visible
low frequency pulsed emission should be avoided when treating these
patients. Note! Remember to use eye protective goggles!

   Endocrine glands According to Spanish studies thyroid gland seems
to be sensitive to light. Therefore laser therapy over the thyroid gland
should be avoided unless there is a need for activation of thyroid
function.

   Patients with tumors Laser therapy has not induced or accelerated
tumor growth in any of the reported in vivo studies. However, laser
therapy should not be directed over the tumor tissue as the precise
reactions of existing tumors to laser therapy is unknown.

   Patients with prostheses Although laser therapy does not increase
the temperature of deeper tissues (muscles, cartilage, bone) or that of
materials used in prostheses markedly, some very sensitive patients
may react to laser therapy over the prosthesis by temporary increase of
pain.

   Risk of eye injury As the cornea and lens focus radiation onto the
retina, the power density may increase to more than 100,000 times
higher than the primary energy density on the skin or cornea. The
cornea, aqueous humour, lens and vitreous humour are more
conductive of radiation with a wavelength of 450-900 nm. The risk of
retinal injury is reduced if laser therapy is given in a bright light when the
pupil size is at the minimum. IR lasers are more dangerous than those
emitting at visual wavelengths, as the invisible beam does not provoke
an eye-blink reflex.

   To date, no retinal injuries have been reported during or after
laser therapy. Due to the individual characteristics of each laser
beam (parallel, focalized or divergent) and in order to avoid any
future discussions of possible eye injuries it is recommended that
patients always wear goggles. On the contrary, laser therapy may
be applied through the lids and eyeball to alleviate inflammatory
reaction after high power laser irradiation to correct retinal
detachment or even retinal lesions from accidental direct laser
beam exposures.

   Patients with solar eczema or hypersensitivity to sunlight may
react to laser therapy when high photon densities are used. Avoid
photosensitizers when laser therapy is given over the newly abrased
skin, especially in the face.

Note! Discoloration due to pigment reaction is possible. Radiation
over dark skin or tattoos may cause thermal reactions.

   Hematological interactions There is no evidence that LT could
induce either thrombosis or prolonged bleeding time. Instead LT is
indicated for its anti-inflammatory and pain relieving effect in acute
injuries from fresh wounds and bruises to joint injuries and fractures.
Increase of microcirculation and lymphatic flow prevent stasis and
reduce existing oedema, and form basis for fast recovery.
Note! When adequate LT provides only a short lasting relief of pain and
dysfunction and this response is not getting better with repeated
treatments the underlying disturbances in homeostasis (e.g. systemic
disease, infection, tumours) or interactions with medication should be
taken into account.
    There is clinical evidence that cholesterol lowering drugs like fibrates
and statins (e.g. serivastatin) may induce muscle pain and fatigue in
about 1-2 percent of patients, in rare cases increase of S-CK and
rhabdomyolysis leading to myoglobinaemia, myoglobinuria, kidney
failure and death. More common is poor response to adequate pain
therapy with any form of peripheral stimulation including LT. Increased
muscle pain and fatigue 1-2 months from beginning of statin medication
is a clear sign of this side effect. The normal response to LT may take
some 2-4 weeks after cessation of medication. Statins provide valuable
protection against cardiovascular accidents and should be terminated
gradually and not stopped abruptly. Other drugs that may interact with
statins are macrolides (e.g. erythromysin), cyclosporins, konazoles,
nicotinic acid and fibrates.
Pekka J. Pöntinen, MD, PhD, FICAE, FASLMS
Assoc. Prof. Tampere University
Tampere, Finland

Today, LASERS play a very important role in industry,
medicine and research.
Lasers are applied in measuring distances, laser imaging,
cutting materials and identifying materials. In
communications, LASER enables faster data transmission.
Three characteristics make the LASER a unique form of
light: monochromaticity, coherence/polarization and
capability of parallelism. LASER stands for: Light
Amplification by Stimulated Emission of Radiation.

1. Monochromaticity
A term, which describes electromagnetic radiation (light) of only one
precise wavelength (or color).

Low level LASER devices applied in Laser therapy, however, are
non thermal light sources emitting always the same light color
without significantly changing the skin temperature.

2. Coherence/Polarization
Coherence means that all the light waves are of the same phase.
Coherence guarantees an orderly photon emission and an optimized
photon density. This is a LASER specific property. Laser light has some
sort and degree of polarization.

3. Parallelism
Laser light can be emitted into one direction in a parallel way. In the
present, most Therapy-Lasers are emitting a slightly divergent beam for
safety purposes.

By contrast to laser light, the white light as emitted by normal
bulbs or daylight (sun) is a mixture of all wavelengths. In other
words, sunlight contains all spectral colors of the visible part from
400 nm to 750 nm, including some ultraviolet and considerable
infrared portions. The latter quality in an average power light bulb
of 60 Watts causes perceptible heat. This is also called thermal
radiation. Moreover, the light of bulbs is emitted in a spontaneous
and non-coherent way.


Laser light in medicine
The active LASER media determines its possible application in
medicine according to its characteristic color (wavelength) and
operation mode (pulsed or continuous waves). The specific wavelength
determines its possible absorbers and leads to photo-bio-medical
effects.


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