Physical Agents In Rehab: Ultraviolet Therapy PDF

PHYSICAL AGENTS IN REHAB. ULTRAVIOLET THERAPY ULTRAVIOLOET IRRADIATION The student should be able to: 1. Describe the position of UVR in the electromagnetic spectrum 2.Describe the sources of UV rays as used in therapy. 3. Explain the physiological effects of UV rays. 4. Ju...

PHYSICAL AGENTS IN REHAB. ULTRAVIOLET THERAPY ULTRAVIOLOET IRRADIATION The student should be able to: 1. Describe the position of UVR in the electromagnetic spectrum 2.Describe the sources of UV rays as used in therapy. 3. Explain the physiological effects of UV rays. 4. Justify the use of UV in the management of wounds, pain, skin conditions  5. Describe the procedure for safely applying UV rays in treating wounds and other skin conditions. 6. Demonstrate safe and effective application of the modality 7. Explain the contraindications to and the precautions for applying the modality. UTRAVIOLET IRRADIATION UV rays are electromagnetic waves with wavelengths: 3200- 4000A – UVA 2900 – 3200A – UVB 2000- 2900 A - UVC Not used therapeutically as a thermal agent UV in EM spectrum Production of Rays Sources Sun - natural source Mercury vapour lamps Air- cooled or water- cooled Rays are absorbed in the first 1-2 mm of skin Photochemical effects produced on absorption Mercury vapour lamp Mercury vapour lamp Rays generated in quartz tube containing mercury and argon. Passage of electric current causes heating of argon Heat vaporizes mercury resulting in production/emission of UV rays Wavelength between 1890 and 3900 A. Most are 2530 Angstrom in length  Kromayer lamp (hand held) Rays are generated by the passage of current through argon and mercury. Cooling of lamp provided by distilled water pumped through the lamp Wavelength of rays between 1849-3900 A Used for treatment of sores and ulcers For both lamps it takes 5 minutes for the rays to be established contd Physiological effects Local effects 1. Reddening of the skin Not visible for an hour Reaches peak in 24 hrs Due to inflammatory reaction stimulated by rays Dilation of capillaries and arteries and fluid exudation Produced by rays with wavelength 2540-2970 A continued 2. Pigmentation This follows erythema Magnitude related to intensity of exposure Due to increased deposits of melanin formed in basal layers of skin Produced by rays with wavelength 2540- 2900 A Contd. 3 Desquamation Casting off of dead cells Acceleration of normal process Extent is related to the degree of erythema continued 4. Destruction of bacteria Short u.v rays (2500-2700A) destroy bacteria, viruses and other organisms on the skin. Occurs through suppression of DNA and RNA synthesis of the cells RES also stimulated to produce antibodies 5. Formation of vit.D Accelerated by u.v. Vit. D assists in the absorption of Ca from intestines continued 6. Thickening of epidermis Thickening of epidermis (hyperplasia) Increased activity of keratinocytes Sensitivity of skin decreases with repeated exposure. Degrees of erythema 1. Sub-erythema Length of u.v exposure (secs) insufficient to produce perceptible reddening 2. E1(First degree) The length (secs) of u.v. exposure required to produce light reddening of the skin with no irritation or soreness. Appears within 6-8 hours, fades within 24 hours contd 3. E2 (Second Degree) The length of u.v exposure required to produce more marked reddening of the skin with slight irritation. Appears in 4-6 hours and fades in 2-3 days E3(Third degree) The length of u.v. exposure that produces marked reddening which is hot and oedematous, appears in 24 hours and lasts for a week. contd E4 (Fourth degree) – The length of u.v. exposure required to produce intense erythema with blisters. Appears in 2-4 hours, lasts for a week or more (second degree burn). Therapeutic Effects of U.V 1. Promotes healing Erythema and increased blood flow Increased nutrients to tissues promotes healing An E2 or E3 erythema is used Used in treatment of bed sores, wounds and certain skin infections Contd. 2. Destruction of bacteria Increased blood flow, increased WBC, reinforces mechanism for fighting bacteria Bacteria also destroyed by direct effect of rays and effect on RES. Staphylococcus aureus, enterococcus faecalis Used in treatment of boils, infected wounds, acne Use E3 or E4 where there is no skin continued 3. Stimulation of growth of epidermis Superficial cells are damaged Repair hormone released Cells in basal layer proliferate and replace damaged ones Skin thickens and healing accelerated Used in the treatment of pressure sores, ulcers and acne continued 4. Desquamation Peeling results in the removal of thickened layer of epidermis Utilized in treatment of acne. Blocked pores open allowing escape of contents of hair follicle. Skin appearance improves 5. Counter-irritation- An E3 dose will cause irritation of sensory nerves. Used for pain relief Indications Acne Desquamation Erythema Growth of epidermis Destruction of bacteria Dose – E3 to small areas, E1 or E2 to face and neck Incipient pressure sore Prevent skin break down, destroy bacteria Dose- E1 progressed daily and E2 where skin is thicker continued Non- infected open wounds Growth of granulation tissue Promote healing Prevent infection Dose- Unprogressed E1 to granulation tissue; E1 progressed daily to surrounding skin; E2 to heel and ankles contd Infected wounds Promote healing Stimulate growth of epithelium and granulation tissue Kill bacteria Dose – E2 progressed daily to surrounding skin Unprogressed E1 to granulation tissue Yellow E3, Green E4, unprogressed, daily continued Psoriasis Decreases DNA synthesis Dose- Coal tar and E1 dose of UV- Leeds Regime Coal tar slows down skin cell regeneration PUVA- UVA and photosensitizing drug 8 methoxy psoralen Pain Counter-irritation Dose- E4 to small area  Vitiligo Stimulates proliferation and migration of melanocytes UVB Uraemic pruritis (itching from excessive urea in blood) Calculation of Dosage The basis for the calculation of dosage is the E1 determined from a skin test. All other doses are calculated from the E1. Consideration given to: Time of exposure Distance from source Contd. E2 = 21/2 times E1 E3 = 5 times E1 E4 = 10 times E1 Example – If E1 is 25 seconds at 100mm, E3 at 100mm is _________ Progression of Dosage UV when applied to the normal skin results in the thickening of superficial layers. Each dose must be progressed to maintain effective level of radiation continued E1 progressed by adding 25% of preceding dose E2 …by adding 50% of preceding dose E3… by adding 75% of preceding dose E4… by adding 100 % of preceding dose Example- If E1 is 30 seconds at 450 mm find the second progression of E1 (P2E1) First progression= (.25x30) + 30= 37.5 secs Second progression= (.25 x37.5) + 37.5= ___ secs Alteration of intensity with distance The law of inverse square applies. To calculate doses at different distances: nt = ot x nd2 / od2 nt= new time; od is old distance; nd is new distance Example 1- Using the Kromayer lamp, if the E1 is 1 second in contact find the E1 at 100mm Nt=1 x 100mm2/ 25mm2 contd - Example 2- Using the air cooled lamp, if the E1 at 900mm is 60 seconds find E1 at 450mm - Example 3- If the dose given yesterday was the second progression of E1 at 900mm; What dose was given and what time is necessary for treatment today if the dose is progressed and the distance is 450 mm? Selection of Dosage The dosage is determined by the effect required for the condition that is being treated. Guidelines for selection of dosage An E1 may be given to the total body area An E2 may be given to up to 20 % of total body area An E3 may be given to up to 250 cm2 of normal skin An E4 may be given to 25 cm2 of normal skin but usually given to non-skin areas (wounds). Frequency Successive doses of u.v must never be given to normal skin while erythema from preceding one is still visible. An E1 may be given daily An E2…. every second day An E3….every third or fourth day (twice weekly) An E4…once weekly or once every fortnight except when treating wounds Contd. Peeling- Normal protection lost, so reduce dosage to original level eg.P3E3 to E3 Determination of E1 The Skin Test Initial doses are determined by using a combination of factors; The E1 of the lamp The patient’s normal reaction to sunlight Use of sensitizing drugs Contd. Three test doses are used; If patient burns easily, E1 of lamp used as highest dose If response to sunlight is average, E1 of lamp used as middle dose If patient rarely burns, lamp’s E1 used as lowest dose continued Remaining doses are selected to give intervals of 1/3 E1 of lamp Example- if E1 of lamp is 60 seconds and patient rarely burns in sunlight, test doses would be 60, 80, 100 secs. Contd. Equipment needed Lamp sheets for screening grey or black paper with shapes Scissors Tape tape measure cotton wool goggles and stop watch continued Procedure Patient must be comfortable and part exposed Explain what is being done and why Warn patient not to move or look into lamp or remove goggles Tell patient to indicate any discomfort Check for contraindications Ascertain E1 of lamp, patient’s reaction to sunlight and use of sensitizing drugs continued Prepare skin in the same way as the area to be treated Screen areas that will not be exposed Cut three shapes in paper and place on a suitable area Expose shapes to u.v for required time Ensure lamp is kept at required distance After each shape has been exposed, remove lamp and turn off Instruct patient to look for reaction in 6-8 hours continued Record information and arrange for patient to return in 24 hours E1 is determined as the area which appeared erythematous in 6-8 hours and just disappears in 24 hours Once the patient’s E1 is determined then treatment dose (exposure time) can be set depending on the condition to be treated. Treatment procedure with air- cooled lamp Air cooled lamp is used for irradiation of large areas Turn lamp on 5 minutes before treatment Check for contraindications Explain to patient what will be done and why Give sensitizers and wash area as necessary Drape area that is not to be treated Protect the eyes of operator and patient with goggles continued Use immovable land marks to delineate area to be treated If large areas are to be treated, divide into sections Drape the patient Lamp arrangement Align lamp parallel to part but not directly over it Lamp is placed 30 inches from the part Remove drape and time the exposure Cover area immediately after exposure and remove lamp Note: exposure time is based on E1 determined from skin test  Record: exposure time lamp used distance of lamp from patient specific area treated based on land marks Treatment with spot quartz or cold quartz Spot quartz lamp used for local irradiation such as for ulcers and wounds E1 of lamp is 12-15 secs at 2.5 cm or 1 inch Used to test for patient’s E1 E2 is 36- 45 secs at 2.5 cm E3 is 72-90 secs at 2.5 cm E4 is 135- 180 secs at 2.5 cm Assess wound Clean wound using sterile technique Screen surrounding area if necessary  Wound assessment Size Depth Wound bed- slough, eschar, granulation tissue Wound edges- thickness, colour Wound drainage-type, colour, consistency and amount Wound odor Wound size Granulation tissue Wound depth Eschar Wound edges Wound exudate Wound cleaning https://www.youtube.com/watch?v=Tr2MiuAv3fY&featur e=youtu.be https://www.youtube.com/watch?v=WGDTi5yYfOY continued Screen granulation tissue if necessary Allow lamp to warm up for 3-5 mins Position lamp perpendicular to skin Use tongue depressors or ruler to obtain required distance. Expose wound for required time Turn off lamp at end of treatment Screening Screening contd. 1. Surround the wound with strips of cotton soaked in saline and cover cotton with paper towel. 2. Surround the wound with petroleum jelly and place gauze over petroleum jelly. The evidence Patients with chronic infected leg ulcers > 3 months were treated for 180 seconds per wound site (E4) with 254 nm UV rays. Wound cultures were done before and after. A statistically significant reduction in amount of MRSA was noted after 1 treatment. (Thao et al, 2005) UV plus US given alternately for 5 days per week to 22 ulcers in persons with SCI, had a greater effect on wound healing compared to nursing care alone and LASER (Nussbaum et al 1994) Contraindications Hypersensitivity to sunlight – Photo sensitive patients may not tolerate even a minimum dosage Dermatological conditions such as dermatitis and acute eczema Febrile disorders- a further rise in temperature may occur Certain diseases- tumours, TB, acute diabetes, severe cardiac conditions, SLE, syphillis, renal disease Deep radiation therapy- May make person hypersensitive to sunlight Sensitizers – Strawberries, lobster, eggs, coal tar, gold, sulphonamides, shellfish, phenothiazine (largactyl), insulin, tetracycline, barbiturates, hypnotic drugs (eg. Veronal) and oral contraceptives Dangers 1.Conjunctivitis 2.Iritis and cataracts 3.Overdosage – blisters and burns Occurs if ; care is not taken to prevent dosage overlap Previously untreated areas are exposed to progressed dosage Area is not screened Dosage not calculated or progressed properly Patient used sensitizers continued If overdosage occurs i.r can be given for 20 minutes and hydrocortizone applied subsequently 4.Premature aging- if used for long periods 5.Skin cancer Care of apparatus Clean surface of lamp to get rid of oils or dust. These can impair transmission. Check intensity at least once per year using E1. Intensity may be reduced after 100 hours so recalibration may be necessary.