Pulsed lasers produce efficient and precise tissue ablation with limited residual thermal damage. In this study, the efficiency of pulsed CO2 laser ablation of burned and normal swine skin was studied in vitro with a mass loss technique. The heats of ablation for normal and burned skin were 2,706 and 2,416 J/cm3 of tissue ablated, respectively. The mean threshold radiant exposures for ablating normal skin and eschar were 2.6 J/cm2 and 3.0 J/cm2, respectively. Radiant exposures greater than 19 J/cm2 produced a plasma, which decreased the efficiency of laser ablation. Thus the radiant exposures for efficient ablation range from 4 to 19 J/cm2, and within this radiant exposure range 20-40 microns of tissue are ablated per pulse. We also examined, on a gross and histopathologic basis, in vivo burn eschar excision with a pulsed CO2 laser. The laser allowed bloodless excisions of full thickness burns on the backs of male hairless rats. The zone of thermal damage was approximately 85 microns over the subjacent fascia. The pulsed CO2 laser can ablate burn eschar efficiently, precisely, and bloodlessly and may prove valuable for the excision of burned and necrotic tissue.
Expedient primary excision of deep dermal and full-thickness burn wounds with subsequent skin grafting is the standard of care in most burn institutions, but differentiating full-thickness from partial-thickness burns is often difficult. Because accurate early assessment of burn depth may improve care, a variety of technical methods have attempted to measure burn depth but these methods have had limited success. We describe a new technique to determine burn depth that uses infrared (840- to 850-nm) fluorescence emission from intravenously administered indocyanine green following excitation with infrared (780 nm) and UV light (369 nm). Full-thickness and partial-thickness burns in hairless rat skin were distinguished based on the infrared-induced and UV-induced fluorescence intensity ratios relative to normal, unburned skin immediately after the burn and on post-burn days 1 through 3 and 7. Dual-wavelength excitation of indocyanine green infrared fluorescence can delineate full-thickness from partial-thickness burns at an early date, allowing prognosis, surgical planning, and early primary excision and grafting.
We conclude that the focused pulsed CO2 laser is capable of precisely and bloodlessly ablating skin with conservation of residual subjacent adnexal elements, minimal early interference with epibolic epithelial outgrowth, and no pathologic effects on the wound healing process. Pulsed CO2 lasers may be a valuable instrument for the conservative ablation of skin and skin lesions.
800 mg/d) in divided doses. Clinical improvement was assessed at monthly intervals, and liver function tests were repeated.Significant improvement was noticed after 2 months of therapy. The improvement consisted of a decrease in infiltration and size of the nodules. On completion of 3 months' therapy, one patient showed moderately elevated levels of serum aspartate transaminase (72 U/L) and serum alanine transaminase (48 U/L). Clinically, he appeared normal, and the other laboratory tests revealed no abnormality. The dose of ketoconazole was continued, hoping that the liver function would not deteriorate further. When this patient neared 4 months' therapy, the serum aspartate transaminase level rose (100 U/L), the serum alanine transaminase level rose (120 U/L), and, clinically, gynecomastia was noted. Therapy was stopped, and we continued observation of this patient. The second case showed satisfactory improvement after 4 months, and, at 6 months, the papules had regressed well. Ketoconazole had to be given for a total of 9 months before the patient could be declared both clinically and histopathologically cured. The third patient showed similar improvement but, unfortunately, gynecomastia developed toward the end of 8 months of therapy. Laboratory tests showed an increase in the serum alanine transaminase level to 72U/L; serum aspartate transaminase levels were normal. Ketoconazole therapy was discontinued, and we contin¬ ued observing the patient. The condition of the fourth patient im¬ proved, but he dropped out after 4 months of treatment. Ketocona¬ zole toxicity has developed in two patients; gynecomastia has almost subsided in one patient and in another it is regressing. The abnormal enzyme levels are also decreasing. We intend to administer sodium antimony gluconate after their condition is completely restored to normal. The hypopigmented macules showed no significant change in any of the patients.Comment. -Ketoconazole (400 mg/d) has been successfully used to treat cutaneous leishmaniasis when given for a period of 3 months.3 It has also been given for a relatively shorter duration of 4 weeks,4 the difference in the length of treatment being attributed to the species of parasite prevalent in a region and the host response. In visceral leishmaniasis, keto¬ conazole (600 mg/d) was given for 4 weeks to bring about a cure.2 None ofthese patients experienced serious side effects sufficient to warrant stoppage of therapy. In a previous study (unpublished) we tried ketoconazole (400 mg/d) in two pa¬ tients with PKDL for almost 3 months without any signs of the disease subsiding. This made us increase the dose to 800 mg/d in the present study. Only one person was complete¬ ly cured after 9 months of therapy. Gynecomastia and raised aminotransferase levels developed in two patients, one of them having almost reached the end of therapy.In fungal infections where ketoconazole has been used for prolonged periods in doses ranging from 200 to 400 mg/d, it has generally been well tolerated, the incidence of gyneco¬ mas...
238 pp, with color illus, $95, Philadelphia, Pa, WB Saunders Co, 1992. This book, by major authorities in the field of contact dermatitis, provides a pictorial atlas of the most common contact dermatitides, often including pictures of the inducing agents or antigens alongside the associated cutaneous eruption. A pr\l=e' \cisaccompanies each picture, providing a concise patient history, pertinent description of the clinical course, and useful clinical comments about the offending agent. The photographs are of high quality and fairly consistent color. The two major textbooks on contact dermatitis, Contact Dermatitis,
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