Description of a graduate program in clinical nursing informatics.

This article describes the history and development of the Clinical Nursing Informatics Program at the University of Utah College of Nursing. Program philosophy and curriculum are discussed in the context of the conceptual framework. Courses and student projects are described. The authors reflect on the ensuing stage of program development.

Cutaneous blood flow and percutaneous absorption: a quantitative analysis using a laser Doppler velocimeter and a blood flow meter.

Cutaneous blood flow has been directly quantitated in vivo for the first time without animal death utilizing the rat skin sandwich flap. This was accomplished by conducting experiments that made a direct correlation between two instruments: a laser Doppler velocimeter and an electromagnetic blood flow meter. Data demonstrate that the correlation between these two instruments is high and reproducible (r = 0.96) with a small (1.3%) coefficient of variation. Blood flow to skin in the unmanipulated state varies from 0.7 to 1.2 mls/min in an anesthetized rat. Application of the blood flow correlation to the determination of percutaneous absorption of caffeine across human skin and benzoic acid across rat skin demonstrates that assuming cutaneous blood flow is a particular value day to day in any skin type results in an apparent wide range of total compound absorbed across that skin on independent occasions. Utilizing actual blood flow measurements to calculate the amount of chemical absorbed reduces the range of variability in the total amount of chemical absorbed and provides a more accurate knowledge of events occurring during a particular time of the absorption process. Quantitation of cutaneous blood flow will be useful in physiologic and pharmacologic studies where actual cutaneous blood flow is likely to be important to the processes studied, e.g., delivery of drug to skin, metabolism within the skin, and disposition of drug to blood and skin following topical drug application.

An experimental skin sandwich flap on an independent vascular supply for the study of percutaneous absorption.

Further insights into the composite interactive processes of topically applied agents and percutaneous absorption and metabolism by functional skin in vivo have been hampered by the lack of a model system wherein the blood flow to and from the skin is independent but experimentally accessible. Utilizing microsurgical techniques, split-thickness skin grafting with syngeneic skin grafts, and the congenitally athymic (nude) rat, a skin sandwich flap system has been generated that has an independent but accessible vasculature and thus fills this void. We describe the methodology that has been developed to create the flap and present experiments that: demonstrate a lack of significant collateral circulation; quantify the microcirculation of the skin sandwich flap, host side, and graft side at various times during and after the flap has been generated, and note that blood flow to the flap is basically unchanged from host skin; demonstrate the utility of the system in measuring the amount of [14C]benzoic acid that appears in the flap when deposited on the surface in volatile and nonvolatile vehicles as a function of time; and demonstrate the fact that the flap can be reused, and that the total amount of [14C]benzoic acid absorbed across skin does not change in a substantial way as the flap ages.

Determination of normal variation in skin blood flow velocity in healthy adults.

This study noninvasively measured cutaneous microcirculatory blood flow velocity at six clinically significant sites on the feet, legs, and abdomen. Subjects were 51 healthy adult volunteers, 44 females and 7 males, with a mean age of 32 years. A laser Doppler velocimeter (LDV) was used to measure skin blood flow velocity. Skin temperatures and LDV measures were concurrently obtained from the dorsal surface of the feet, medial aspects of the lower legs, and at two contralateral midabdominal sites. Ambient and oral temperatures were repeatedly measured and remained stable among subjects. Using paired t tests, there were no statistical significances for contralateral comparisons of mean flow velocity and skin temperature differences. Regional differences among feet, legs, and abdomen were significantly different. The findings suggest that blood flow velocity of contralateral sites is similar. Unilateral circulatory disturbances such as surgical and nonsurgical traumas, primary cutaneous lesions, and venous or arterial occlusions are often encountered clinically. Nursing care measures to improve blood flow can be evaluated on the basis of contralateral flow rates.

The development of a rat/human skin flap served by a defined and accessible vasculature on a congenitally athymic (nude) rat.

Experience in microvascular surgery on rats and availability of athymic (nude) rats led us to believe that a long-term functional rat/human skin sandwich flap could be generated on a defined and experimentally accessible vasculature on nude rats. Such a system has been developed and validated. Microvasculature has been assessed. The volume of blood to the flap ranges from 1 to 2 ml/min, collateral circulation to the flap exists, but is negligible, and there is little change in the capillary blood flow as the flap ages. The flap can be utilized to study absorption of compounds from a half-cell diffusion chamber or from direct deposition on the skin, and can be utilized to study various parameters of percutaneous absorption, e.g., the effect of hydration on the stratum corneum. Transdermal flux can be determined. Altering the microcirculation directly affects the percutaneous absorption of compounds that are rapidly absorbed. The absorption of benzoic acid through an experimentally vasoconstricted area (iontophoresis of phenylephrine) significantly alters the time to peak absorption, with values being 14 times that of the control site. The system has been utilized to assess metabolic activity of skin in situ using [3H]adenine arabinoside and studying the appearance of its major metabolite, [3H]Ara-H, in flap blood, as well as the back diffusion of this compound into the donor chamber. Recently the human/rat skin sandwich flap component has been developed. With this system, it has been demonstrated that benzoic acid, when applied to the human skin component of the flap has an absorption profile which is quite different from that when benzoic acid is applied to rat skin, peak flux occurred 2 hr after application. This contrasts with 10 min to peak flux when the same experiment is carried out on the rat/rat skin sandwich flap. To our knowledge, the human/rat skin sandwich flap is the first example of a viable, functional human organ that is chronically maintained by a biologic support system which has the added distinction of being on an independent but accessible vasculature. The validation experiments strongly suggest that this system will be important in gaining insights into the more sophisticated in vivo components of skin, relative to toxicology and pharmacology.

Hypertrophic scarring in argon laser treatment of port-wine stains.

The argon laser (488 to 514 nm) is being used with increasing frequency in the treatment of port-wine stains (PWS). Good results are reported, but scarring is a major complication in all series. The purpose of this paper is to describe the incidence and extent of scarring in a more definitive fashion by quantitating this complication in terms of size, elevation, and color in a consecutive series of 146 patients followed for over 1 year. Scars were assigned a severity score of 1 through 5. A midstudy evaluation led to a significant change in treatment methodology. Therefore, the patient population was divided into two groups. Group I consisted of the first 73 patients and included 30 males and 43 females with an age range of 7 to 81 years (M = 35 years). Group II consisted of the next 73 consecutive patients and included 24 males and 49 females with an age range of 12 to 75 years (M = 43 years). Group II received a different treatment technique than group I. In group I the incidence of scarring was 38 percent for patients under 12 years and 21 percent for patients over 12 years. In group II the incidence was 13.7 percent with concomitant reduction in severity. Statistical analysis (M- HX2 ) compared group I children and adults, P = 0.36; children and group II adults, P = 0.08; group I adults and group II adults, P = 0.42. The most frequent and severe scarring occurred on the upper lip and central portion of the face. Individualization of energy fluency and attention to unique patient factors in healing are important in improving results.

Patient's evaluation of argon laser therapy of port wine stain, decorative tattoo, and essential telangiectasia.

One hundred fourteen patients were studied to assess their perception of the results of argon laser therapy for port wine stains (PWS), tattoos, or essential telangiectasia of legs. At least 1 yr following treatment patients were surveyed using a 30-item mail questionnaire. A 91% response rate was achieved. The findings indicate that patients with PWS and tattoo treated with argon laser are moderately satisfied with the results and 85% of them would have treatment again. Laser therapy of these lesions should be continued. Treatment results of essential telangiectasia of the legs are disappointing and only 49% of patients would have treatment again. Discontinuance of argon laser therapy using the described techniques is recommended.

How lasers work.

The thermal energy of the laser light beam allows simultaneous cutting, coagulation of vessels, and sterilization. The beam is produced by inducing a "population inversion" of excited atoms in a lasing medium. This stimulated emission of light is then amplified to create the lasing effect. Each type of laser causes a different tissue response consistent with its wavelength, energy fluence, and tissue absorption properties.

The microcirculation.

The geometric organization and control of the microbed varies with different organs and tissue elements. The moment-to-moment regulation of local blood flow occurs without dominant control by the extrinsic nervous system. This enhances the exchange of fluids, solutes and blood gases, and allows rapid redistribution of blood flow during states of stress and high metabolic demand.