Use of laser Doppler flowmetry for estimation of the depth of burns

The trend for treatment of deep second degree burns and third degree burns is toward early excision and skin grafting. The ability to predict burn depth accurately as early as possible is important for early excision and skin grafting. This study, prospectively evaluated the ability of laser Doppler flow measurements, obtained within 72 hours after burn injury, to predict the depth of burn wounds. A Periflux system 4001 laser Doppler flowmeter was used to measure the cutaneous microflow circulation of 100 selected points of burn wounds on 44 inpatients and of 1680 selected points on 120 volunteers from March of 1993 to February of 1994. The mean value of superficial second degree burns checked by laser Doppler was 194.6 perfusion units (PU). The value of deep second degree burns was 59.7 PU, and the value of third degree burns was 5.1 PU. The mean normal cutaneous blood flow of 120 volunteers (control group) was between 4 and 9 PU, except on the head, neck, hand, and foot. Blood flow of more than 100 PU correctly predicted (90.2 percent of cases) a superficial second degree burn. Blood flow between 100 and 10 PU correctly predicted (96.2 percent of cases) a deep second degree dermal burn. That of less than 10 PU correctly predicted (100 percent of cases) a third degree burn. There was also a significant correlation between initial flow measurements and the depth of burn wounds. We conclude that laser Doppler flow measurements performed early after burn injury are useful in predicting the depth of burn wounds. Laser Doppler flowmetry has the advantage of being easy to use and noninvasive and of providing immediate results for early determination of burn depth. Laser Doppler flowmetry is useful in selecting patients for early excision and grafting of burn wounds.     

The minimal sequence needed to define a functional DNA terminator in Bacillus subtilis

BACKGROUND: We wished to determine whether transcutaneous oximetry or laser Doppler flowmetry (LDF) could identify patients at risk for wound failure after conservative, limb-sparing surgery for extremity sarcomas. METHODS: Studies were performed on postoperative days (PODs) 1, 4/5, 7, and 9. Measurements of transcutaneous oxygen pressure (tcPO2) were taken at breathing room air (BL) and 100% oxygen (rate tcPO2). LDF measurements were taken at multiple sites along the wound, and a perfusion index was calculated. RESULTS: Twenty-four patients were studied. Four (17%) had nonhealing wounds. There was no difference in tcPO2 (BL) values between healed and nonhealing wounds. Measurement of rate tcPO2 on POD 1 was significantly lower in the nonhealing wounds than in those with normal healing (28.5 +/- 12.1 mm Hg vs 14.3 +/- 16.2 mm Hg, mean +/- SD, p = 0.03). Rate tcPO2 values increased significantly in healing wounds from POD 1 to PODs 7 and 9 (p = 0.006, p = 0.009). This increase was absent in nonhealing wounds. A clear separation was noted in rate tcPO2 values between groups, with a minimum rate tcPO2 value recorded in a healed wound of 9 mm Hg/min, compared with the maximum value in a nonhealing wound of 7 mm Hg/min. The LDF perfusion index failed to predict wound healing at any of the measured time points. CONCLUSIONS: This study showed that measurement of tcPO2 during oxygen inhalation can accurately predict wound healing in patients after excision of an extremity sarcoma.     

Laser Doppler imaging and capillary microscopy in ischemic ulcers

The local distribution of laser Doppler flux (mainly thermoregulatory perfusion) and capillary density (nutritive circulation) within 25 ischemic leg ulcers and their adjacent skin were investigated. For this purpose the technique of laser Doppler imaging and capillary microscopy were applied. In each ulcer a non granulation tissue area (NGTA), a granulation tissue area (GTA) and in adjacent skin a skin area (SA) were defined. In these areas the average laser Doppler area flux (arbitrary units, AU) and the number of capillaries/mm2 were determined for each patient. The mean+/-S.D. of laser Doppler area fluxes were: NGTA 1.30+/-1.93, GTA 2.13+/-1.53 and SA 1.21+/-0.77 AU, respectively. The differences between GTA and NGTA or SA was statistically significant (p < 0.001, each) The mean+/-S.D. of capillary densities were as follows: NGTA: 0.56+/-2.06, GTA 6.76+/-8.39 and SA 16.80+/-7.38 capillaries/mm2, respectively. The following differences were statistically significant: NGTA versus GTA (p < 0.01) and SA versus NGTA or GTA (p < 0.001, each). In conclusion following characteristics of the three areas can be described: In NGTA low laser Doppler area flux is combined with very low capillary density (ulcer area without healing). In GTA the highest laser Doppler area flux of all three areas and an intermediate capillary density (wound healing) is found. In SA an intermediate laser Doppler area flux is associated with the highest capillary density of all three areas with the healing process nearly completed and no granulation tissue.     

Wound healing after laser surgery

Compared with scalpel wounds, CO2 laser wounds show delays in inflammation, collagen production, reepithelialization, and tensile strength in the early stages of healing. Some of these delays are similar to those seen with electrocautery and burn wounds. Later stages compensate for these early deficiencies, because scalpel and laser wounds become more similar in epithelialization and wound strength over time. Healed CO2 laser wounds tend to have less scar contraction than scalpel wounds. Débridement of initial laser wound char, tissue cooling techniques during lasering, and pulsed modes of laser delivery all seem to result in more rapid, favorable healing. Similar wound healing trends have been seen with the CO2 laser in bone, with other lasers, and with laser vascular and neural anastomosis. Biostimulation with low-level laser energy is a complex subject of ongoing investigations.     

Cryopreserved cadaveric allografts for treatment of unexcised partial thickness flame burns: clinical experience with 12 patients

Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservative treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision. Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at -180 degrees C for 30-48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required. It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days. Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.     

Dimensions of schizophrenia in the elderly. Correlations with cognitive and motor symptoms

Wound contraction is thought to be independent of site, and circular full-thickness skin wounds are though not to contract completely. To verify these statements four circular full-thickness skin wounds were created on each side of eight pigs and randomised to treatment with either split-thickness skin grafts, or healing by secondary intention under a hydrocolloid dressing. Time to healing, contraction, and final scar shape were evaluated. The median healing time was 12 days (range 6-18) in the grafted wounds and 30 days (range 15-45) in the secondarily healing wounds. There were significant differences in healing time between the different sites on the pigs. In the secondarily healing group, medial-caudal wounds healed in 21 (15-21) days compared with lateral wounds which healed in 36 (21-45) days (p < 0.005), while no differences were found in the grafted group. There was a clear relationship between site and contractility and shape of the scars in both treatment groups. Scars located on the lateral-caudal aspect of the pig were predominantly round and contracted only slightly. Scars located on the lateral aspect of the pig tended to be oval. Contraction was greatest in the medial scars and least in the lateral scars. Median contraction was 33% (range -2-63) in skin grafted wounds and 64% (range 42-82) in secondarily healed wounds. This randomised experiment showed that extent of wound contraction is dependent of site, and that circular wounds do heal with contraction.     

The medicolegal implications of bilateral cranial fractures in infants

OBJECTIVE: Transmission oximetry sites for intraoperative monitoring are frequently difficult to find in burn patients, as standard transmission oximetry sites are often burned or contained within the operative field. The objective of this study was to determine if reflectance oximetry is of potential value in monitoring this group of patients. METHODS: A total of 16 operative procedures in a group of acutely burned adult and pediatric patients with an average age of 9.7 years (range, 10 months to 37 years), average burn size of 42% of the body surface (range, 15% to 94%), and average weight of 34.2 kg (range, 9 to 100 kg) were done with simultaneous transmission and reflectance oximetry monitoring. RESULTS: During these 16 procedures in a diverse group of acutely burned adult and pediatric patients, there was no significant difference in saturations derived from transmission and reflectance oximetry probes. In smaller children, adequate signal for reflectance probe monitoring was often detected in hyperemic sites, such as healed partial thickness burn. CONCLUSIONS: This is the first published report documenting both the clinical use of the reflectance oximetry in burn patients and the clinical use of the Nellcor Oxisensor II RS-10 reflectance oximetry probe (Nellcor Corporation, Hayward, CA). This technique can facilitate the intraoperative monitoring of acutely burned adult and pediatric patients in whom standard transmission oximetry sites are difficult to find.     

Hereditary motor and sensory neuropathy with spastic paraplegia and optic atrophy: report on a family

To determine the effect of RGP contact lens solution on corneal epithelial wound healing, the following solutions including Soaclens, Contopharma GPHCL-S, Boston condition, Bausch & Lomb condition and Duracare were applied on corneal epithelial wounds of enucleated pig eyes to evaluate possible cytotoxicity of RGP solutions. The wounds, created by excimer laser, were 1.5mm in diameter with 70 microns in depth. The eyeballs were maintained in an incubator using a perfusion system. After twenty-four hours, a score from 3 to 0 was given depending on the size of defect from absence of healing to completely healing. The average scores of the epithelial defect in each group are: Soaclens: 0.38 +/- 0.74; GPHCL-S: 0.63 +/- 0.52; Boston condition: 0.38 +/- 0.52; Bausch & Lomb condition: 0.25 +/- 0.46 and Duracare: 2.38 +/- 0.52. Most of the epithelial wounds healed with one exception, the eyeballs which received Duracare still had large defects. The difference of scores between Duracare and other groups are statistically significant. Duracare, which contains benzalkonium chloride, may be responsible for retarded wound healing.     

Usefulness of platelet-derived growth factor as a prognostic factor in pulmonary adenocarcinoma

The effects of 6-methyluracil given in single intraperitoneal doses of 50 and 2.7 mg/kg on the healing of burn wounds and some physicochemical parameters of lipid peroxidation regulation were studied in the liver and erythrocytes of noninbred albino rats with thermal burns. 6-Methyluracil was shown to alter the time course of a wound process and to accelerate the healing of burn wounds. The drug doses under study were found to exert a great effect on the level of lipid antioxidative activity and the composition of phospholipids of the liver and erythrocytes, which remained for a long time after burn. The findings suggest the hypothesis that the capacity of 6-methyluracil to be involved in the regulation of lipid peroxidation processes underlies its therapeutic effect.     

Malingering behavior in private medical practice

OBJECTIVE: This study investigated the influence of the fetal environment on the healing characteristics of adult skin. SUMMARY BACKGROUND DATA: The remarkable ability of the fetus to heal without scarring is poorly understood. The unique qualities of fetal wound healing may be caused by the fetal environment, the fetal tissues, or a combination of both. There are numerous differences between the prenatal and postnatal environments that may play a role in the unique fetal response to injury. METHODS: Full-thickness adult sheep skin was transplanted onto the backs of 60-day-gestation fetal lambs (term, 145 days of gestation). The adult skin grafts were thus perfused by fetal blood and bathed in amniotic fluid. Previous work has demonstrated that, before midgestation, fetal lambs do not reject allogenic skin grafts. Forty days later (100 days of gestation), incisional wounds were made on both the adult skin graft and the adjacent fetal skin. The wounds were harvested 14 days postwounding and analyzed by both light microscopy and immunohistochemical testing using antibodies to collagen types I, III, and VI. RESULTS: The wounds in the adult skin grafts healed with scar formation. This observation contrasts strongly with the scarless healing of the incisional fetal skin wounds. CONCLUSIONS: This study suggests that scarless fetal skin healing properties are intrinsic to fetal skin and are not primarily the result of the fetal environment.     

Ischemic and pressure-induced hyperemia: a comparison

OBJECTIVE: There is reason to question whether hyperemia after pressure occlusion is caused solely by local ischemia. This study quantitatively compared the response to the two forms of occlusion on the finger. DESIGN: Blood flow was measured by laser Doppler continuously before, during, and for 40 minutes after a 2-minute occlusion of flow at the finger dorsum and at the plantar surface of the finger tip (finger pulp), which has a much higher arteriolar density than the dorsum. Occlusion to the same low level was carried out either with a cuff at the base of the finger or by direct pressure of the laser Doppler probe head. Comparison experiments were performed with the probe head heated to 44 degrees C to elicit maximal local vasodilation. SETTING: Outpatient clinic. PARTICIPANTS: Eleven healthy volunteers. MAIN OUTCOME MEASURES: Magnitude and duration of skin blood flow after occlusion. RESULTS: Cuff occlusion at the base of the finger produced a typical, short-lived hyperemic response at both finger dorsum and finger pulp. The peak level at finger dorsum was 17.6 +/- 1.4mL/min/100g, approximately a twofold increase over the baseline flow level. The duration of the hyperemic response was 3.6 +/- 0.8 minutes. The baseline flow at the finger pulp was three times greater than at the finger dorsum, and peak flow after occlusion was also three times higher (44.3 +/- 2.6 mL/min/100g). The duration of hyperemia at finger pulp was 4.2 +/- 0.9 minutes. After pressure occlusion at the finger dorsum the hyperemic peak was higher (26.7 +/- 4.2 mL/min/100g; p < .05) and the duration of hyperemia was four times longer (16.9 +/- 2.3 minutes; p < .01) than after cuff occlusion. At the finger pulp, the pressure-induced hyperemic peak was also greater than the peak after cuff occlusion (56.3 +/- 1.7mL/min/100g; p < .05), with a longer duration than after cuff occlusion (11.1 +/- 1.1min; p < .01). Thermal stimulation significantly reduced the differences between cuff- and pressure-induced occlusion. There was a slow increase in flow over the 40-minute monitoring period. The maximal flow reached was approximately 100mL/min/100g at both finger dorsum and finger pulp. At both sites, however, the maximal flow level was attained more rapidly than the control condition without prior occlusion. CONCLUSIONS: These results confirmed that the pressure-induced hyperemic response is greater and of longer duration than that produced by flow ischemia alone. Thermal stimulation essentially abolishes the differences, suggesting that there is a common mechanism of vasodilatation. The mechanistic differences between pressure-induced and ischemic hyperemia remain to be determined.     

Costs of dressings in the community

This study compares the costs of dressings used in the treatment of patients with a variety of wound aetiologies. The two dressings investigated were a hydrocolloid dressing and a hydrocellular dressing. Secondary objectives included a comparison of dressing durability, time to complete healing, ease of wound cleansing and dressing removal. The study was an open prospective single-centre randomised parallel group trial involving 100 patients, treated in the community, who were randomised to the two dressing groups. For all aetiologies except pressure sores, the costs of the hydrocolloid dressing were less than the costs of the hydrocellular dressings. Similar healing rates were observed in the leg ulcer and 'other wound' groups. There were, however, significant differences in the number of healed wounds observed in patients with pressure sores treated with the hydrocellular dressing.     

Use of the scalp as a donor site for large burn wound coverage: review of 150 patients

The characteristics of rapid wound healing and multiple harvest capacity make the scalp an important donor site when dealing with large and deep burn wounds. This paper reports the results of a retrospective analysis of 150 patients treated for large burn wounds. The findings indicated that bleeding during graft skin harvest could be limited to 50 ml by intradermal injection of epinephrine (1:2,000,000), high-concentration epinephrine-soaked gauze compression (1:20,000), and temporary porcine skin coverage. Use of a scalp graft also carried a low risk of complications, with only four (2.7%) major complications including three cases (2.0%) of visible alopecia and one case (0.7%) of hair transplantation. There were no hypertrophic scars, even in the patient who had the largest number (11) of repeat harvests.     

Does a good correlation exist between the figures for fasting capillary blood glucose and glycosylated hemoglobin?

In order to investigate the function of epidermal growth factor (EGF), the following experiments were performed. Thirty white rats were chosen and divided into 3 groups. In the back of each rat, two 2 cm x 2 cm wounds were made bilaterally, the skin and subcutaneous tissue was removed. EGF were used in one of the two wounds randomly, while those without EGF usage in control. After 1, 2 and 3 weeks, the rats were sacrificed. The area of the wounds was measured, and the healing time of each wound was recorded. The results showed that the healing time of EGF group was 14.6 days while that of control group was 18.5 days (P < 0.01). Furthermore, the DNA, protein and hydroxyproline contents of EGF group were higher than those of the control group (P < 0.01). It was suggested the EGF could accelerate wound healing and shorten the healing time.     

Serum sodium imbalance in the bedridden elderly. Part One: Realities and problem of management

This study assessed the topical effects of bitumen on burn wounds and their surrounding skin in guinea-pigs. It consisted of three different experiments. The bitumen used in this experiment was a soft tar produced by Daye Steel Plant. The first experiment showed that the skin of the bitumen group marked pathological changes under both light and electron microscopes. The second experiment suggested that healing of the burn wounds of bitumen group was delayed, and less hair follicle counts and a lower intradermal thickness were found as compared with the other groups. The third experiment indicated that the wound edges had been seriously destroyed by bitumen, leading to enlargement of the size of the ulcers, and hypertrophy of scar occurred after healing. It is concluded that bitumen, especially the soft coal tar, has more errosive, irritating and destructive effects, therefore in bitumen burns the bitumen must be immediately and entirely removed from burn wounds.     

Environmental health implications of heavy metal pollution from car tires

OBJECTIVE: To determine the effect of retinoic acid on wound healing of laser burns to explants of porcine retinal pigment epithelium (RPE). DESIGN: With the help of a mirrored attachment to a Coherent argon laser, laser burns (spot size 100 mu, power 500 mW, duration 0.2 seconds) were performed in 12 explants. The explants were then cultured in the presence (six explants) or absence (six explants) of 1 microM retinoic acid. Two explants in either group were recovered 4, 8 and 12 days after treatment for histologic study and scanning electron microscopy. OUTCOME MEASURE: Mean burn area remaining after culture. RESULTS: The area of wound remaining unhealed in the presence of retinoic acid was significantly larger than the area of wound remaining unhealed in the absence of retinoic acid at each time point. CONCLUSIONS: Retinoic acid inhibited wound healing of laser burns to porcine RPE. This effect may illustrate a role for retinoic acid in the pharmacotherapy of proliferative disorders.     

Secretoneurin and chemoattractant receptor interactions

Regional alterations in cerebral blood flow (CBF) are widely used as a surrogate for neuronal function based on an intact coupling between changes in regional CBF and metabolism, activation-flow coupling (AFC). To further investigate parameters affecting AFC, we have implemented a rat model with electrical forepaw stimulation under alpha-chloralose anesthesia using laser Doppler (LD) measurements of flow parameters through thinned skull over contralateral somatosensory cortex. Signal averaging of the LD response was used to improve reproducibility. A characteristic flow response to electrical forepaw stimulation was reliably recorded from the somatosensory cortex using signal averaging. Stimulation at 5 Hz maximized the LD response, and constant current stimulation up to 1 mA did not induce changes in systemic blood pressure. The shape of the flow response consisted of an initial peak followed by a steady state plateau phase which was observed for stimulation durations longer than 4 s. When individual LD parameters of velocity, red blood cell concentration (CRBC), and cerebral blood flow (CBF) were compared, changes in LDCBF were primarily attributable to changes in LDvelocity rather than LDCRBC. This finding was also observed during hypercapnia. Characterization of AFC in the model provides a background for future studies of the effects of pharmacological manipulation or pathophysiological states.     

Self-blame, compliance, and distress among burn patients.

This study addressed self-blame and adaptation by using data collected from 49 patients hospitalized for the treatment of acute burn wounds. Nurses and physical therapists rated patients' compliance with the therapeutic activities essential for proper healing, and they rated pain behavior. After controlling for burn severity and time since admission, regression analyses showed that behavioral self-blame for the burn accident was a significant predictor of poorer compliance with nurses, more pain behavior, and greater depression. People with a prior psychiatric history were also more depressed and more likely to blame themselves for the accident. These data are contrasted with research on the adaptive features of self-blame. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Toe transplantation for isolated index finger amputations distal to the proximal interphalangeal joint

Functional deficit following single distal index finger amputations has been considered insignificant, and reconstruction is usually not recommended. Herein, 19 cases of second toe transplantation for reconstruction of isolated index finger amputation distal to the proximal interphalangeal joint are presented with long-term functional results. There are 14 men and 5 women. The average age was 26 years. The toe transplantations were performed either as a primary procedure (5 patients) while the wounds were still open or as a secondary procedure (14 patients) after the wounds healed. In 11 patients, the dominant hand was involved. All toes survived completely, although re-exploration was required in three cases (16 percent). The functional evaluation included (1) sensory recovery, where the average static and moving two-point discrimination were 8 mm (range 4 to 15 mm) and 6 mm (range 2 to 15 mm); (2) motor function, where the average of index-thumb pulp-to-pulp pinch compared with the normal hand was 67.5 percent (range 36 to 96 percent); (3) average range of motion in index finger joints (extension/flexion), where metacarpophalangeal joint was 14/90, proximal interphalangeal joint was 0/94, and distal interphalangeal joint was 19/38; and (4) functional and cosmetic results, where percentage of involvement in daily activities and functional capacity of the reconstructed index were 69 percent and 70.5 in average, respectively, over a total score of 100. Average scores of aesthetic appearance and acceptability of donor-site deformity were 74 and 87.5 over a total score of 100, respectively. Toe transplantation for distal index finger amputations improved hand function when performed in selected patients with specific job requirements or high motivation.