The patient, a 31-year-old male, sustained an electric burn injury (16 kV, AC/DC) while working with electric power lines. He was acutely admitted to a national burn center in Southeast Sweden, where burns equalling 29% of the total body surface area were noted. The burns were located at the front of the abdomen, upper arms bilaterally, and the left hip region, and the lesions were estimated to be mainly of the dermal type, what was believed initially to be caused mainly by an electric flash. There were no obvious entry or exit sites of the electric current. However, myoglobin in plasma was elevated as a sign of muscular degradation, suggesting that at least some current had passed through the tissues. According to the paramedic report there was an episode of a few minutes of unconsciousness immediately after the injury, but the patient was fully awake and alert on admission. There was no concomitant trauma.

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Objectives

Using transoesophageal echocardiography (TEE) we investigated the occurrence, and the association of possible abnormalities of motion of the regional wall of the heart (WMA) or diastolic dysfunction with raised troponin concentrations, or both during fluid resuscitation in patients with severe burns.

Patients and methods

Ten consecutive adults (aged 36–89 years, two women) with burns exceeding 20% total burned body surface area who needed mechanical ventilation were studied. Their mean Baux index was 92.7, and they were resuscitated according to the Parkland formula. Thirty series of TEE examinations and simultaneous laboratory tests for myocyte damage were done 12, 24, and 36 h after the burn.

Results

Half (n = 5) the patients had varying grades of leakage of the marker that correlated with changeable WMA at 12, 24 and 36 h after the burn (p ≤ 0.001, 0.044 and 0.02, respectively). No patient had WMA and normal concentrations of biomarkers or vice versa. The mitral deceleration time was short, but left ventricular filling velocity increased together with stroke volume.

Conclusion

Acute myocardial damage recorded by both echocardiography and leakage of troponin was common, and there was a close correlation between them. This is true also when global systolic function is not deteriorated. The mitral flow Doppler pattern suggested restrictive left ventricular diastolic function.

Background: The Parkland formula (2-4 mL/kg/burned area of total body surface area %) with urine output and mean arterial pressure (MAP) as endpoints; for the fluid resuscitation in burns is recommended all over the world. There has recently been a discussion on whether central circulatory endpoints should be used instead, and also whether volumes of fluid should be larger. Despite this, there are few central hemodynamic data available in the literature about the results when the formula is used correctly.

Methods: Ten burned patients, admitted to our unit early, and with a burned area of >20% of total body sur-face area were investigated at 12, 24, and 36 hours after injury. Using transesophageal echocardiography, pulmonary artery catheterization, and transpulmonary thermodilution to monitor them, we evaluated the cardiovascular coupling when urinary output and MAP were used as endpoints.

Results: Oxygen transport variables, heart rate, MAP, and left ventricular fractional area, did not change significantly during fluid resuscitation. Left ventricular end-systolic and end-diastolic area and global end-diastolic volume index increased from subnormal values at 12 hours to normal ranges at 24 hours after the burn. Extravascular lung intrathoracal blood volume ratio was increased 12 hours after the burn.

Conclusions: Preload variables, global systolic function, and oxygen transport recorded simultaneously by three separate methods showed no need to increase the total fluid volume within 36 hours of a major burn. Early (12 hours) signs of central circulatory hypovolemia, however, support more rapid infusion of fluid at the beginning of treatment.

Aim: The aim of the study was to examine the central and peripheral cardiovascular adaptation and its coupling during increasing levels of hyperoxaemia. We hypothesized a dose-related effect of hyperoxaemia on left ventricular performance and the vascular properties of the arterial tree.

Methods: Oscillometrically calibrated arterial subclavian pulse trace data were combined with echocardiographic recordings to obtain non-invasive estimates of left ventricular volumes, aortic root pressure and flow data. For complementary vascular parameters and control purposes whole-body impedance cardiography was applied. In nine (seven males) supine, resting healthy volunteers, aged 23–48 years, data was collected after 15 min of air breathing and at increasing transcutaneous oxygen tensions (20, 40 and 60 kPa), accomplished by a two group, random order and blinded hyperoxemic protocol.

Results: Left ventricular stroke volume [86 ± 13 to 75 ± 9 mL (mean ± SD)] and end-diastolic area (19.3 ± 4.4 to 16.8 ± 4.3 cm²) declined (P < 0.05), and showed a linear, negative dose–response relationship to increasing arterial oxygen levels in a regression model. Peripheral resistance and characteristic impedance increased in a similar manner. Heart rate, left ventricular fractional area change, end-systolic area, mean arterial pressure, arterial compliance or carbon dioxide levels did not change.

Conclusion: There is a linear dose–response relationship between arterial oxygen and cardiovascular parameters when the systemic oxygen tension increases above normal. A direct effect of supplemental oxygen on the vessels may therefore not be excluded. Proximal aortic and peripheral resistance increases from hyperoxaemia, but a decrease of venous return implies extra cardiac blood-pooling and compensatory relaxation of the capacitance vessels.

Atherosclerotic cardiovascular disease is a major problem despite the availability of drugs that influence major risk factors. New treatments are needed, and there is growing interest in therapies that may have multiple actions. Thyroid hormone modulates several cardiovascular risk factors and delays atherosclerosis progression in humans. However, use of thyroid hormone is limited by side effects, especially in the heart. To overcome this limitation, pharmacologically selective thyromimetics that mimic metabolic effects of thyroid hormone and bypass side effects are under development. In animal models, such thyromimetics have been shown to stimulate cholesterol elimination through LDL and HDL pathways and decrease body weight without eliciting side effects. We report here studies on a selective thyromimetic [KB2115, (3-[[3,5-dibromo-4- [4-hydroxy-3-(1-methylethyl)-phenoxy]-phenyl]-amino]-3-oxopropanoic acid)] in humans. In moderately overweight and hypercholesterolemic subjects KB2115 was found to be safe and well tolerated and elicited up to a 40% lowering of total and LDL cholesterol after 14 days of treatment. Bile acid synthesis was stimulated without evidence of increased cholesterol production, indicating that KB2115 induced net cholesterol excretion. KB2115 did not provoke detectable effects on the heart, suggesting that the pharmacological selectivity observed in animal models translates to humans. Thus, selective thyromimetics deserve further study as agents to treat dyslipidemia and other risk factors for atherosclerosis. © 2007 by The National Academy of Sciences of the USA.

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The ICU-diary concept is associated with less post-traumatic stress syndrome and improved perceived health-related quality-of-life (HRQoL) after critical illness, but little is known about its effect on the coping- mastery process, or whether it reduces hopelessness.

Objective: To see if the ICU-diary concept improves the patient’s ability to master his/her situation after critical illness, and if it reduces the feeling of hopelessness.

Design: Case control study (subgroup analysis of a multi-centre study on health-related quality-of-life (HRQoL).

Setting: Non-academic 8-bed general ICU.

Patients: Adults admitted between March 2002 and June 2004.

Measurements: Mastery and hopelessness were determined using validated questionnaires (the Mastery-Coping scale and a consolidated 2–item hopelessness questionnaire) which were sent home to patients 6 months after critical illness. Responses were compared between patients that received (Cases: n=38) or did not receive an ICU-diary (Controls: n=76) . Diaries were used when a long and complicated stay on the ICU was expected. Controls were matched with diary patients by gender and age. The effect of the ICU-diary was also examined using a multiple regression model.

Results: The ICU-diary concept group scored significantly higher than the No-diary group in mastery (22.1 vs. 20.4, P<0.05) and lower in hopelessness scores (1.3 vs. 1.6, P<0.05). The positive influence of the ICU-diary disappeared after adjustment for confounding factors in a multiple regression model.

Conclusion: We were unable to verify any positive influence of the ICU-diary concept on mastery and hopelessness 6 months after critical illness.

Background Critically ill patients often spend time in the intensive care unit (ICU) either unconscious or sedated. On recovery, they are often in a state of confusion with memory loss that may be associated with a longstanding reduction in health-related quality of life (QoL). We hypothesised that the ICU-diary concept could improve their QoL by filling in their memory gaps. Methods A non-randomised, prospective study in a non-academic eight-bedded general ICU. A group of patients (n=38) were selected to receive the ICU-diary concept (keeping a diary with photos while on the ICU plus a follow-up meeting) when a long and complicated course was expected. Health-related QoL at 6, 12, 24 and 36 months was compared with a group that did not receive the ICU-diary (n=224). The Medical Outcomes Study 36-Item Short-Form (SF-36) was used to measure health-related QoL. Multiple regression models adjusted for age, sex, illness severity, pre-existing disease and diagnostic category was used to analyse the effects of the ICU-diary concept at 6 months, and changes over time were analysed using repeated measures MANOVA. Results Crude and adjusted scores for two dimensions of SF-36 (general health and vitality) and the physical component summary score were significantly higher at 6 months in the ICU-diary group (P andlt; 0.05) and some of the effects remained during the 3-year follow-up period (P andlt; 0.05). Conclusion The ICU-diary concept was associated with improved health-related QoL during the 3-year follow-up period after a critical illness. The effect of this intervention needs to be confirmed in a larger randomised study.

Treatment of necrotizing fasciitis (NF) includes radical surgical debridement often resulting in large wounds that need to be closed with methods including split-thickness skin grafts (STSG), local flaps, or guided tissue regeneration procedures. In this case report, a 45 year-old Caucasian male was surgically treated for a benign left groin hernia, developed NF, and was transferred to the authors burn unit. The wound was treated initially with wide debridement and with a brief delay before finally closing the wound. A collagen matrix such as Integra (R) Dermal Regeneration Template (Integra LifeSciences, Plainsboro, NJ) in combination with STSG and negative pressure wound treatment, can provide fast recovery resulting in pliable, functional skin.

Iontophoresis of vasoactive substances is a promising tool for studying pharmacological aspects of the (patho)physiology of the microvasculature. However, nonspecific microvascular responses are a common problem in most protocols used. We studied the effect of current density (mA/cm²), charge density (mC/cm²), drug concentration (mass %) and vehicle concentration (M) on the nonspecific vasodilatation during iontophoresis of sodium chloride, acetylcholine (ACh) and sodium nitroprusside (SNP).

We found that nonspecific vasodilatation depended on current density and charge density in both anodal and cathodal iontophoresis. The responses to ACh and SNP were dependent on current density, charge density and drug concentration. We found that by limiting current density (<0.01 mA/cm²) and charge density (<7.8 mC/cm²) and with adjusted concentrations for drugs and vehicles, it is possible to prevent nonspecific effects during iontophoresis of ACh and SNP, while maximum drug effects (plateaus in the dose–response curves) are still obtained. These new findings are important for future iontophoresis studies in which vasoactive drugs are used to assess microvascular function because the presented approach has advantages compared to older techniques, which mainly have attempted to suppress or compensate for the nonspecific responses during iontophoresis by the use of local anaesthetics or the measurement of drug-minus-vehicle responses, both of which present well-known experimental shortcomings.

We used laser Doppler perfusion imaging (LDPI) to study nonspecific vasodilatation during iontophoresis. In iontophoresis studies, nonspecific vasodilatation occurs as a result either of galvanic currents or of the applied voltage over the skin. We made dose–response measurements to study the effect of ionic strength of the vehicle on the nonspecific vasodilatation during iontophoresis of sodium chloride and deionized water, while we monitored the voltage over the skin. We found that anodal and cathodal ionotophoresis induced a voltage over the skin that was dependent on the ionic strength of the test solution. The nonspecific vasodilatation during anodal iontophoresis was less pronounced than during cathodal iontophoresis, and was independent of the voltage over the skin. The nonspecific vasodilatation in cathodal iontophoresis was related to the voltage over the skin, and was possibly mediated by depolarization of local sensory nerves. In experiments using cathodal iontophoresis, therefore, the ionic strengths of the vehicle and the drug are important when vasoactive drugs are examined, as the nonspecific vasodilatation needs to be controlled for. As the vasodilatation that we observed was heterogeneously distributed within the area of iontophoresis, LDPI may provide more accurate measurements than conventional laser Doppler perfusion monitoring.

Aims: To investigate the pharmacodynamics, pharmacokinetics and safety of the glucokinase activator AZD6370 after 1 day of administration under fed and fasted conditions in patients with type 2 diabetes mellitus (T2DM). less thanbrgreater than less thanbrgreater thanMethods: This was a two-part study. In Part A, patients received a single oral dose of AZD6370 (20, 60 or 180 mg) or placebo in the fasted or fed states (both n = 8). In Part B, patients (n = 8) received placebo and a total dose of AZD6370 180 mg given in one, two or four divided doses. Plasma glucose, insulin and C-peptide changes versus placebo were assessed. less thanbrgreater than less thanbrgreater thanResults: AZD6370 provided dose-dependent reductions in plasma glucose of up to 30% versus placebo in both fasted and fed patients (p andlt; 0.001 at 60 and 180 mg doses). Insulin secretion increased with dose, but absolute increases were relatively small in the fasted versus fed state (0-4 h). Dosing AZD6370 twice or four-times over 1 day gave a smoother 24-h glucose profile than single-dose. AZD6370 was rapidly absorbed. Pharmacokinetics of AZD6370 were dose-independent and unaffected by food. AZD6370 was generally well tolerated. less thanbrgreater than less thanbrgreater thanConclusions: AZD6370 produced dose-dependent glucose reductions and increased glucose-stimulated insulin secretion in patients with T2DM.

Pgreater thanIncreasing evidence suggests that local blood flow should be monitored during microdialysis (MD) as the recovery of analytes is affected by local blood flow. At present ethanol clearance is the standard technique for this purpose, but it is not functional at very low perfusion velocities. Here, we introduce a technique for MD whereby local tissue blood flow is recorded by the use of urea clearance (changes inflow/outflow concentration), in conjunction with measurements of tissue metabolism (glucose, lactate and puruvate). MD probes were inserted into the gracilis muscle of 15 rats and perfused with a medium containing urea (20 mmol l-1). Changes in muscle blood flow were made by addition of noradrenaline (5 mu g ml-1) to the perfusion medium at two perfusion velocities (0 center dot 6 and 0 center dot 4 mu l min-1). The clearance of urea from the perfusion medium was then calculated and examined in relation to the dose of noradrenaline and to the coexisting changes in extracellular metabolites. The results showed reproducible and dose-dependent changes in blood flow that were induced by noradrenaline. These were characterized by dose-dependent changes in the urea clearance as well as blood-flow-specific changes in the MD metabolic markers (reduction in glucose and increase in lactate). The sensitivity for blood flow changes as assessed by urea clearance (MD) was increased at 0 center dot 4 compared with the 0 center dot 6 mu l min-1 perfusion speed. The results indicate that inclusion of urea to the perfusion medium may be used to monitor changes in skeletal muscle blood flow at low perfusion velocities and in parallel assess metabolic variables with a high recovery (greater than 90%).

Delayed detection of ischemia is one of the most feared postoperative complications. Early detection of impaired blood flow and close monitoring of the organ-specific metabolic status may therefore be critical for the surgical outcome. Urea clearance is a new technique for continuous monitoring of alterations in blood flow and metabolic markers with acceptable temporal characteristics. We compare this new microdialysis technique with the established microdialysis ethanol technique to assess hepatic blood flow. Six pigs were used in a liver ischemia/reperfusion injury model. Microdialysis catheters were placed in liver segment IV and all circulation was stopped for 80 min, followed by reperfusion for 220 min. Urea and ethanol clearance was calculated from the dialysate and correlated with metabolic changes. A laser Doppler probe was used as reference of restoration of blood flow. Both urea and ethanol clearance reproducibly depicted changes in liver blood flow in relation to metabolic changes and laser Doppler measurements. The two techniques highly correlated both overall and during the reperfusion phase (r = 0.8) and the changes were paralleled by altered perfusion as recorded by laser Doppler.

Objective: The aim of this study was to evaluate the urea clearance technique for the measurement of drug-induced blood flow changes in human skin, and compare it with two non-invasive techniques: polarization light spectroscopy and laser Doppler perfusion imaging.

Methods: Fifteen microdialysis catheters were placed intracutaneously on the volar aspect of the forearms of healthy human subjects, and were perfused with nitroglycerine, noradrenaline, and again nitroglycerine, to induce local tissue hyperaemia, hypoperfusion, and hyperaemia, respectively.

Results: Urea clearance, but not the other techniques, detected the changes in blood flow during all three periods of altered flow.  The last hyperaemic response was detected by all three methods.

Conclusion: Urea clearance can be used as a relatively simple method to estimate blood flow changes during microdialysis of vasoactive substances, in particular when the tissue is preconditioned in order to enhance the contrast between baseline and the responses to the provocations. Our results support that, in the model described, urea clearance was superior to the optical methods as it detected both the increases and decrease in blood flow, and the returns to baseline between these periods.

Microdialysis is a well-established technique for continuous sampling of small, water-soluble molecules within the extracellular fluid space in vivo. It also allows the use of microdoses of drugs, and the simultaneous evaluation of their related effects at the site of action. The present study was an experimental, randomized microdose trial to develop a human vascular model of dose response. We aimed to evaluate a microdialysis dosing method using urea clearance as a marker of druginduced changes in dermal blood flow and metabolism (glucose and lactate) in 12 healthy volunteers. We found that asymptomatic vasoconstriction can be detected by continuous microdialysis measurements of urea clearance in dermal tissue. More importantly, dose-effect relations using the E_max model could be constructed using the corresponding data on drug doses and both the urea clearance-based flow estimates and the changes in concentrations of tissue metabolites. This in vivo human experimental skin model offers an interesting tool with which both the dose-response effects on blood flow and concentrations of tissue metabolites of potent vasoactive substances can be evaluated.

Spider silk is an interesting biomaterial for medical applications. Recently, a method for production of recombinant spider silk protein (4RepCT) that forms macroscopic fibres in physiological solution was developed. Herein, 4RepCT and Mersilk(TM) (control) fibres were implanted subcutaneously in rats for seven days, without any negative systemic or local reactions. The tissue response, characterised by infiltration of macrophages and multinucleated cells, was similar with both fibres, while only the 4RepCT-fibres supported ingrowth of fibroblasts and newly formed capillaries. This in vivo study indicates that 4RepCT-fibres are well tolerated and could be used for medical applications, e. g., tissue engineering.

Silver is commonly used in wound dressings and topical formulations to assist in the management of wounds that are infected or at risk of becoming infected. They provide potent broad-spectrum antimicrobial activity, but should not cause sustained staining of the skin, dermal or systemic accumulation of silver, or discomfort to the patient. However, clinicians and healthcare personnel have been concerned about topical staining of the skin and complaints of additional pain from patients treated with certain silver dressings. Some delay in re-epithelialization has also been noticed and reported. The reasons for this are not clear, and the authors believed further study regarding the possible effects of silver accumulation and silver dressings effect on re-epithelialization was required. The authors studied possible silver accumulation and re-epithelialization in normal human dermal skin. The results showed that most of the dressings or treatments discolored the wound surface and that there was a dermal accumulation of what were assumed to be silver particles. Varying grades of accumulation were found in deep dermal tissue, particularly around blood vessels, depending on the dressing used. The results also indicated that all of the tested products delayed re-epithelialization in this model.

Transplantation of autologous cultured keratinocytes in single cell suspension is useful in the treatment of burns. The reduced time needed for culture, and the fact that keratinocytes in suspension can be transported from the laboratory to the patient in small vials, thus reducing the costs involved and be stored (frozen) in the clinic for transplantation when the wound surfaces are ready, makes it appealing. We found few published data in the literature about actual cell survival after transplantation of keratinocytes in single cell suspension and so did a comparative in vitro study, considering commonly used application techniques. Human primary keratinocytes were transplanted in vitro in a standard manner using different techniques. Keratinocytes were counted before and after transplantation, were subsequently allowed to proliferate, and counted again on days 4, 8, and 14 by vital staining. Cell survival varied, ranging from 47% to >90%, depending on the technique. However, the proliferation assays showed that the differences in numbers diminished after 8 days of culture. Our findings indicate that a great number of cells die during transplantation but that this effect is diminished if cells are allowed to proliferate in an optimal milieu. A burned patient’s wounds cannot be regarded as the optimal milieu, and using less harsh methods of transplantation may increase the take rate and wound closing properties of autologous keratinocytes transplanted in a single cell suspension.

Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on the normal breast, largely because of the lack of convenient models. We have developed a method of culturing normal breast tissue ex vivo. We have applied this method to investigate the effects of estradiol and progesterone on the key angiogenic mediator, vascular endothelial growth factor (VEGF), in the breast. Whole breast tissue was obtained from routine reduction mammoplasty. Tissue biopsies were cultured in vitro for 1–3 weeks, and the expression of luminal cytokeratin 18 was determined by immunohistochemistry. As an application, tissue biopsies were treated in vitro for 1 week with or without estradiol or estradiol and progesterone. Estrogen receptor, progesterone receptor, and Ki–67 were analyzed, and VEGF levels were examined by quantitative immunoassay and immunohistochemistry. Whole breast tissue was cultured ex vivo for 1 week with preserved morphology. Increased detachment of the luminal epithelium was observed after 2 weeks. Estradiol increased extracellular levels of VEGF in normal breast tissue biopsy medium. The addition of progesterone had neither stimulatory nor inhibitory effects on secreted VEGF. The method of whole breast tissue culturing thus provide a means by which to explore the biology of normal breast tissue. Our results suggest that estradiol exerts pro-angiogenic effects in normal breast by increasing levels of biologically active VEGF.

Studying microvascular responses to iontophoresis of vasoconstricting drugs contributes to a better understanding of the regulatory mechanisms of cutaneous vessels, but measuring these responses with laser-Doppler flowmetry at basal blood flow conditions is technically challenging. This study aimed to investigate whether the measurement of cutaneous vasoconstrictor responses to noradrenaline (NA) and phenylephrine (PE), delivered by iontophoresis, is facilitated by predilatation of the microvascular bed using local heating. We used different drug delivery rates (100 s x 0.12 mA, 200 s x 0.06 mA, 300 s x 0.04 mA) to investigate whether predilatation affects the local drug dynamics by an increased removal of drugs from the skin. In a predilatated vascular bed, iontophoresis of NA and PE resulted in a significant decrease in perfusion from the thermal plateau (p andlt; 0.001). The decrease was 25-33%, depending on drug delivery rate. In unheated skin, a significant vasoconstriction was observed (p andlt; 0.001), with 17% and 14% decrease from baseline for NA and PE, respectively. These results indicate that predilatating the cutaneous vascular bed by local heating facilitates measurement of vasoconstriction with laser-Doppler flowmetry and does not seem to significantly affect the result by an increased removal of drugs from the skin.

Laser-Doppler flowmetry (LDF) is an attractive method to assess blood flow responses butlacks sensitivity to accurately measure low perfusion values during iontophoresis of vasoconstricting drugs without predilatation of the microvascular bed.

The aim of this study was to develop a protocol for iontophoresis of noradrenaline (NA) andphenylephrine (Phe) in the skin, using local heating to predilate the microvascular bed andLDF to measure blood flow responses. Three protocols with the same electrical charge (12mC) but different durations and current strengths (100 s x 0.12 mA, 200 s x 0.06 mA, 300 s x0.04 mA) were used to study the effect of pulse duration and current strength on the responses.

Skin perfusion decreased to 68-78% of the predilatated state with both NA and Phe. Doseresponse plateaus were not obtained with any protocol. The extent of the vasoconstriction depended on the protocol used.

These results suggest that predilatation by local heating appears less suitable duringiontophoresis of NA and Phe, due to limited vascular responses and especially absence of response plateaus, even at high current strengths. The latter leads to difficulties in performing proper dose response analyses. Another interesting finding was that the actual dose of NA and Phe given to the tissue was affected not only by the size of the electrical charge, but local blood flow as well.

Current knowledge about vascular function stems mainly from pharmacological in vitro studies using mounted vascular strips on a strain gauge. We know of no paper that has systematically examined the possibility of assessing the conventional dose–response effects of iontophoresis and laser Doppler investigation of vasoactive substances and compared those relations to data obtained from strips mounted on a strain gauge.

We used the vasoactive substances acetylcholine (endothelium dependent) and sodium nitroprusside (endothelium independent) and an antagonist (atropine) to enable further investigations in the receptor physiology of iontophoresis.

Dose–response curves from the iontophoresis experiments showed close similarity to those obtained by vascular strips mounted on a strain gauge. The coefficient of variation (CV) of the dose–response factors found in iontophoresis (both inter and intra experimental variability) was low. The iontophoretic effective dose of 50% (ED50) for acetylcholine and nitroprusside had only CVs of 25% and 26%, respectively, compared with 71% and 77% for the vascular strips. Acetylcholine-induced response was antagonized by iontophoresis of atropine. Contrary to expectations, this antagonism was not competitive.

The results show that iontophoresis in combination with laser Doppler technology produces reproducible and reliable dose–response curves that picture the vascular effects of vasoactive drugs.

When one is studying the physiology of the cutaneous microcirculation there is a need for relevant non-invasive and versatile techniques. In this study we used a new optical device, the tissue viability imager (TiVi), to map changes in cutaneous microvascular concentrations of red blood cells during iontophoresis of vasoactive substances (noradrenaline (NA) and phenylephrine (Phe) for vasoconstriction and acetylcholine (ACh) and sodium nitroprusside (SNP) for vasodilatation). We aimed to present data both individually and pooled, using a four-variable logistic dose response model that is commonly used in similar in vitro vascular studies. The accuracy of the TiVi was also investigated by calculating the coefficient of variation and comparing it with similar tests previously done using laser Doppler imaging.

Tests were also performed using the TiVi and LDPI simultaneously to further compare the two methods. Results showed that the TiVi is capable of quantifying vascular responses to iontophorised noradrenaline and phenylephrine without the need to increase background flow first. Fitting the TiVi data to the dose response model resulted in ED50-values with narrow confidence intervals and acceptable r2 values. Mean ED50-values for the TiVi did not differ significantly from similar values obtained using laser Doppler.

Results further seem to suggest that when the blood perfusion increases during vasodilatation in skin the initial phase relies mainly on an increase in red blood cell concentration whereas the further perfusion increase is due to an increase in red blood cell velocity.

Nonspecific vasodilatation during iontophoresis is an important confounding factor in experimental pharmacology. In this investigation, we studied the involvement of sensory nerves and histamine-related reactions in causing nonspecific vasodilatation in a model of anodal and cathodal iontophoresis of sodium chloride. Firstly, we applied a mixture of local anesthetic (EMLA) cream to confirm its suppressive effect on nonspecific vasodilatation and to measure its efficacy in three different dosages (duration: 1, 2, and 3 h). We then investigated the role of histamine in nonspecific vasodilatation by giving an oral antihistamine drug (cetirizine) to subjects who had and had not been given EMLA. We found substantial suppression of the nonspecific vasodilatation in all EMLA-treated groups (all dosages) compared with untreated controls (with suppression rates of 60–65%). Dosage had no significant effect. A further suppression of nonspecific vasodilatation was seen after oral cetirizine during anodal and cathodal iontophoresis in both EMLA-treated and untreated groups. The antihistamine effect was most pronounced during anodal iontophoresis. These results suggest a histaminergic increase in perfusion that may be independent of neurogenic mechanisms and depend on polarity (anode or cathode). Local nerve blocks (EMLA) together with cetirizine may therefore be used to reduce nonspecific vasodilatation in both anodal and cathodal iontophoresis.

Full thickness skin wounds in humans heal with scars, but without regeneration of the dermis. A degradable poly(urethane urea) scaffold (PUUR), Artelon® is already used to reinforce soft tissues in orthopaedics, and for treatment of osteoarthritis of the hand, wrist and foot. In this paper we have done in vitro experiments followed by in vivo studies to find out whether the PUUR is biocompatible and usable as a template for dermal regeneration. Human dermal fibroblasts were cultured on discs of PUUR, with different macrostructures (fibrous and porous). They adhered to and migrated into the scaffolds, and produced collagen. The porous scaffold was judged more suitable for clinical applications and 4 mm Ø, 2 mm-thick discs of porous scaffold (12% w/w or 9% w/w polymer solution) were inserted intradermally in four healthy human volunteers. The implants were well tolerated and increasing ingrowth of fibroblasts was seen over time in all subjects. The fibroblasts stained immunohistochemically for procollagen and von Willebrand factor, indicating neocollagenesis and angiogenesis within the scaffolds. The PUUR scaffold may be a suitable material to use as a template for dermal regeneration. ©2008 Landes Bioscience.

To correct, improve, and maintain tissues, and their functions, are common denominators in tissue engineering and reconstructive plastic surgery. This can be achieved by using autolo-gous tissues as in flaps or transplants. However, often autologous tissue is not useable. This is one of the reasons for the increasing interest among plastic surgeons for tissue engineering, and it has led to fruitful cross-fertilizations between the fields. Tissue engineering is defined as an interdisciplinary field that applies the principles of engineering and life sciences for development of biologic substitutes designed to maintain, restore, or improve tissue functions. These methods have already dramatically improved the possibilities to treat a number of medical conditions, and can arbitrarily be divided into two main principles:

> Methods where autologous cells are cultured in vitro and transplanted by means of a cell suspension, a graft, or in a 3-D biodegradable matrix as carrier.

> Methods where the tissue of interest is stimulated and given the right prerequisites to regenerate the tissue in vivo/situ with the assistance of implantation of specially designed materials, or application of substances that regulate cell functions - guided tissue regeneration.

We have shown that human mammary epithelial cells and adipocytes could be isolated from tissue biopsies and that the cells kept their proliferative ability. When co-cultured in a 3-D matrix, patterns of ductal structures of epithelial cells embedded in clusters of adipocytes, mimicking the in vivo architecture of human breast tissue, were seen. This indicated that human autologous breast tissue can be regenerated in vitro.

The adipose tissue is also generally used to correct soft tissue defects e.g. by autologous fat transplantation. Alas 30-70% of the transplanted fat is commonly resorbed. Preadipocytes are believed to be hardier and also able to replicate, and hence, are probably more useful for fat transplantation. We showed that by using cell culture techniques, significantly more pre-adipocytes could survive and proliferate in vitro compared to two clinically used techniques of fat graft handling. Theoretically, a biopsy of fat could generate enough preadipocytes to seed a biodegradable matrix that is implanted to correct a defect. The cells in the matrix will replicate at a rate that parallels the vascular development, the matrix subsequently degrades and the cell-matrix complex is replaced by regenerated, vascularized adipose tissue.

We further evaluated different biodegradable scaffolds usable for tissue engineering of soft tissues. A macroporous gelatin sphere showed several appealing characteristics. A number of primary human ecto- and mesodermal cells were proven to thrive on the gelatin spheres when cultured in spinner flasks. As the spheres are biodegradable, it follows that the cells can be cultured and expanded on the same substrate that functions as a transplantation vehicle and scaffold for tissue engineering of soft tissues.

To evaluate the in vivo behavior of cells and gelatin spheres, an animal study was performed where human fibroblasts and preadipocytes were cultured on the spheres and injected intra-dermally. Cell-seeded spheres were compared with injections of empty spheres and cell suspensions. The pre-seeded spheres showed a near complete regeneration of the soft tissues with neoangiogenesis. Some tissue regeneration was seen also in the ‘naked’ spheres but no effect was shown by cell injections.

In a human pilot-study, intradermally injected spheres were compared with hyaluronan. Volume-stability was inferior to hyaluronan but a near complete regeneration of the dermis was proven, indicating that the volume-effect is permanent in contrast to hyaluronan which eventually will be resorbed. Further studies are needed to fully evaluate the effect of the macroporous gelatin spheres, with or without cellular pre-seeding, as a matrix for guided tissue regeneration. However, we believe that the prospect to use these spheres as an injectable, 3D, biodegradable matrix will greatly enhance our possibilities to regenerate tissues through guided tissue regeneration.

In the course of development of a new type of filler for the correction of small defects in soft tissues we studied macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues in vivo. We injected intradermally in nude mice gelatine spheres that had either been preseeded with human fibroblasts or preadipocytes, or left unseeded. We compared the extent of regenerated tissue with that found after injections of saline or single-cell suspensions of human fibroblasts or preadipocytes. Routine histological examinations and immunohistochemical staining for von Willebrand factor (indicating neoangiogenesis) were made after 7, 21, and 56 days. Injected saline or single-cell suspensions had no effect. However, a quick and thorough tissue regeneration with developing neoangiogenesis was elicited by the gelatine spheres and the effect of spheres preseeded with preadipocytes surpassed the effect of spheres preseeded with fibroblasts, which in turn surpassed the effect of unseeded gelatine spheres. We suggest that minor soft tissue defects such as wrinkles or creases can be corrected by injection of naked macroporous gelatine spheres, whereas larger defects are best corrected by injection of macroporous gelatine spheres preseeded with fibroblasts, or preadipocytes, or both.

Correcting soft tissue defects by autologous fat grafting is a routine procedure in plastic surgery. Its efficacy and safety has been discussed extensively and several techniques of lipoinjection have been developed. However, one is bound to overcorrect by 30%-70% or need to repeat the procedure because of resorption of the transplant. The reasons are that many of the transplanted cells are already differentiated, and also that there is no nutritional support to the inner cell layers when they are transplanted as fragments. By culturing autologous adipocytes one can ensure that only non-differentiated, but committed, preadipocytes are transplanted and the procedure can be done in a way that ensures optimal nutritional support for the cells. In the present study we have compared our cell culture technique with two common clinical ways of processing liposuction material and found that (pre)adipocytes survive and proliferate significantly better in cell culture.

Reconstruction of the female breast after cancer surgery is a demanding task where the methods used today suffer from several disadvantages. In the present study we have investigated the possibility to use tissue engineering methods to regenerate human autologous breast tissue. Human mammary epithelial cells and preadipocytes were derived from breast tissue biopsies from healthy women undergoing reduction mammoplasty, and the two celltypes were co-cultured with conventional cell culture methods as well as in 3-D matrices. The study shows that it is possible to harvest both human mammary epithelial cells and preadipocytes in a single session, propagate several subcultures, and that the cells maintain a normal intercellular distribution and growth-pattern when co-cultured in a 3-D collagen gel. We propose that growth and formation of a tissue closely resembling normal human breast tissue be readily obtained in the described in vitro cell culture set-up using basic tissue engineering principles. This concept may be of great importance in the development of new methods for reconstruction of the human breast.

Background: The increased vascular permeability seen after burn contribute to morbidity and mortality as it interferes with organ function and the healing process. Large efforts have been made to explore underlying pathophysiological mechanisms that generate increased vascular permeability after burns. Many different substances have been proposed as mediators of which histamine, serotonin and oxygen radicals are claimed most important. However, no specific blocker has convincingly been shown to be clinically effective. Early work has claimed increased histamine plasma-concentrations in humans after burn and data from animal models pointed at histamine as an important mediator. Modern human clinical studies investigating the role of histamine as a mediator of the generalized post burn increase in vascular permeability are lacking. less thanbrgreater than less thanbrgreater thanMethod: We examined histamine turnover by measuring the urinary excretion of histamine and methyl histamine for 48 h after burns in 8 patients (mean total burn surface area 24%). less thanbrgreater than less thanbrgreater thanResults: Over time, in this time frame and compared to healthy controls we found a small increase in the excretion of histamine, but no increase of its metabolite methylhistamine. less thanbrgreater than less thanbrgreater thanConclusion: Our findings do not support that histamine is an important mediator of the increased systemic vascular permeability seen after burn.

Increased vascular permeability and oedema formation constitute a major clinical challenge following burns. Several clinical studies show that leukocytes are systemically activated following burns. Neutrophils have the capability to increase vascular permeability via mechanisms thought to involve the release of heparin binding protein (HBP). We hypothesised that HBP is elevated in plasma after major burns due to a systemic inflammatory response and investigated plasma-HBP concentrations in 10 severely burned patients daily for 1 week following the burn. Five-fold higher levels in plasma-HBP concentration compared to a control group were detected on the first day after injury, followed by a steep reduction in the time-period that corresponds to the last part of the hyperpermeability phase. These data are in accordance with the hypothesis that HBP may function as a mediator of the early bum-induced increase in vascular permeability, and call for further studies to confirm a possible cause-and-effect relationship between HBP and oedema formation following burns.

Background: Patients with burns are susceptible to organ failure, and there is indirect evidence that leukocytes may contribute to this process. They may change the expression of cell-surface receptors after certain stimuli, for example, the burn. We therefore aimed to assess the changes induced by the burn in the expression of leukocyte cell-surface receptors CD11b, CD14, CD16, and CD62L on the surface of PMNs and monocytes. We also wanted to examine the dynamics of this activation during the first week after the burn, and to relate it to the size of the injury. Methods: Ten patients with burns of andgt;15% (TBSA) were included in the study. Blood samples were collected on arrival and every consecutive morning during the first week. Healthy volunteers acted as controls. Results: PMN CD11b expression was increased. The extent of PMN CD11b expression correlated negatively to the size of the full thickness burn. Monocyte CD14 expression increased initially but there was no relation to the size of the burn. PMN CD16 expression decreased initially during the first days and the decrease was related to burn size. CD62L did not vary depending on the burn in either PMN or monocytes during the first week after the burn. Conclusion: This study showed that specific receptors on the surface of leukocytes (PMN CD11b, monocyte CD14 and PMN CD16) are affected by the burn. Expression of PMN CD11b and CD16 are related to burn size. Burn-induced effects on the expression of PMN receptors, such as PMN CD11b and CD16, may contribute to burn-induced infection susceptibility.

Introduction: The lung is affected soon after a major burn as indicated by a decreased Pa_O2:Fi_O2 ratio. The exact mechanism underlying this is not known. Polymorphonuclear leucocytes (PMN) are activated systemically and their numbers are largely increased soon after a burn followed by a rapid decline to low normal or subnormal numbers within 24 hours, possibly by increased extravasation. Experimental data have supported the hypothesis that an important target for this extravasation is the lungs. Other studies also show that when PMN adhere to endothelial cells they increase vascular permeability, and this effect is mediated, at least in part, by release of heparin binding protein (HBP, also known as CAP-37 and azurocidin). We hypothesised that there is a relation between early increased pulmonary vascular permeability or a decreased Pa_O2:Fi_O2 ratio and the dynamic change in blood leucocytes after a burn, possibly mediated by the local release of HBP.

Material and methods: This is a prospective, descriptive, exploratory, singlecentre study at a national burn centre. We investigated the dynamic changes of leucocytes in blood, plasma concentrations of HBP, pulmonary vascular permeability index (PVPI) by thermodilution, and PaO2:FiO2 ratios in 20 patients during the first 21 days after a major burn (20% >total burn surface area %).

Results: Median total burn surface area was 40% (IQR 25-52) and full thickness burn 28% (IQR 2-39). There was a correlation between the early (<24 hours) alteration in circulating white blood cell count and both early increased vascular permeability in the lung (r=0.63, p=0.004) and the decreased oxygenation index defined as Pa_O2:Fi_O2 < 27 kPa (p=0.004). There were no associations between plasma concentrations of HBP and measured pulmonary vascular permeability or Pa_O2:Fi_O2 ratios.

Conclusions: The results indicate that trapping of leucocytes in the lung may be an important factor in early increased pulmonary vascular permeability and decrease of the Pa_O2:Fi_O2 ratio. Our data do not support the idea that HBP, assessed by systemic plasma concentrations, mediate this effect.

We investigated the capacity of normal human dermal fibroblasts to alter their phenotype into an endothelialcell-like phenotype. By utilising in vitro cell culture models, the part played by different types of serum andmedium constituents in inducing a phenotypic change of fibroblasts was investigated. The experiments usedprimary cultures of human endothelial cells, human dermal fibroblasts and single-cell clone fibroblasts. Thelatter cell type was obtained by clonal expansion using a micromanipulator technique. The results showed thatthe presence of human serum in the cell culture medium caused both types of fibroblasts to express vonWillebrand factor, to incorporate fluorochrome-labelled LDL, and to start forming capillary-like networks in asimilar way to endothelial cells. The phenotypic shift was detectable after 4 days of cell culture and reached amaximum after 7-10 days. To our knowledge this is the first report to describe differentiation of humanfibroblasts towards an endothelial cell-like phenotype. The results also show that the underlying mechanism ofthe phenotypic shift is a change in gene expression in the dermal fibroblasts and not fusion between different celltypes. Collectively, the present results indicate that human dermal fibroblasts may be a novel cell source forcreating vascular endothelium.

Background: Hypothermia in burns is common and increases morbidity and mortality. Several methods are available to reach and maintain normal core body temperature, but have not yet been evaluated in critical care for burned patients. Our units ordinary technique for controlling body temperature (Bair Hugger®+ radiator ceiling + bed warmer + Hotline®) has many drawbacks e.g.; slow and the working environment is hampered.The aim of this study was to compare our ordinary heating technique with newly-developed methods: the Allon™2001 Thermowrap (a temperature regulating water-mattress), and Warmcloud (a temperature regulating air-mattress).Methods: Ten consecutive burned patients (andgt; 20% total burned surface area and a core temperature andlt; 36.0C) were included in this prospective, randomised, comparative study. Patients were randomly exposed to 3 heating methods. Each treatment/measuring-cycle lasted for 6 hours. Each heating method was assessed for 2 hours according to a randomised timetable. Core temperature was measured using an indwelling (bladder) thermistor. Paired t-tests were used to assess the significance of differences between the treatments within the patients. ANOVA was used to assess the differences in temperature from the first to the last measurement among all treatments. Three-way ANOVA with the Tukey HSD post hoc test and a repeated measures ANOVA was used in the same manner, but included information about patients and treatment/measuring-cycles to control for potential confounding. Data are presented as mean (SD) and (range). Probabilities of less than 0.05 were accepted as significant.Results: The mean increase, 1.4 (SD 0.6C; range 0.6-2.6C) in core temperature/treatment/measuring-cycle highly significantly favoured the Allon™2001 Thermowrap in contrast to the conventional method 0.2 (0.6)C (range -1.2 to 1.5C) and the Warmcloud 0.3 (0.4)C (range -0.4 to 0.9C). The procedures for using the Allon™2001 Thermowrap were experienced to be more comfortable and straightforward than the conventional method or the Warmcloud.Conclusions: The Allon™2001 Thermowrap was more effective than the Warmcloud or the conventional method in controlling patients temperatures. © 2011 Kjellman et al; licensee BioMed Central Ltd.

Background: Chromogranin A (CgA) in plasma (P-CgA), a neuroendocrine marker of sympathetic stress, has been shown to predict mortality in medical intensive care. We hypothesized that the magnitude of CgA release would reflect stress load, and thereby injury severity in burn intensive care patients. Methods: Fifty-one consecutive patients with a burn area exceeding 10% were included. P-CgA was measured twice daily for seven days after injury. The point value at 24 h, the mean and maximum values and the AUC at days 1-7, were tested as possible predictors. Injury severity in the form of organ dysfunction was measured as SOFA score at day 7. Results: P-CgA could be classified into two types with respect to variability over time. Patients with high variability had more deep injuries and were older than those with low variability. All measures of CgA correlated with SOFA score at day 7, but not with total burn size. Univariate regressions showed that age, burn size and three of four measures of P-CgA predicted organ dysfunction. Multiple regressions showed that age, burn size, and either P-CgA at 24 h, the mean value up to day 7, or the maximum value up to day 7, were independent predictors for organ dysfunction. Significant organ dysfunction was best predicted by age, burn area and the CgA point value at 24 h with an AUC value of 0.91 in a ROC-analysis. Conclusions: The extent of neuroendocrine activation assessed as P-CgA after a major burn injury is independently related to organ dysfunction.

Background

The use of objective methods for assessment of burns is limited. Laser Speckle Contrast Imaging (LSCI) is a non-invasive technique for instant measurement of tissue perfusion, making it potentially valuable for early prediction of burn wound outcome.

Aim

To evaluate the influence of technical factors on perfusion and to measure perfusion in burns 0–14 days post-burn and compare this with the outcome of the burn wound at 14 days after burn.

Method

The effect of room light, camera distance and camera angle was studied using a suspension of polystyrene particles. LSCI measurements were performed on 45 scald burns and 32 uninjured areas 0–14 days after burn.

Result

Technical factors had no clinically relevant effect on measured perfusion. Burns that healed within 14 days had a higher perfusion during the first week post-burn than burns that healed after 14 days or underwent surgery. The difference in perfusion was largest 4–7 days after burn.

Conclusion

LSCI allows for robust, instant measurement of burns and can easily be applied in a clinical setting. Differences in perfusion during the first week post-burn are related to the outcome after 14 days.

The course of tissue swelling in human non-injured skin after burn injury was investigated with a non-invasive impression method that measures force and tissue fluid translocation during mechanical compression of the skin. Time-dependent changes in the fluid translocation and the interstitial-pressure related to impression force were measured on 11 occasions, during 3 weeks, in seven patients postburn. A mathematical model was fitted to the impression force curves and the parameters of the model depicted the time-dependent compartmental fluid shift in the postburn generalized oedema. Tissue fluid translocation increased significantly (P < 0.05) up to a maximum value after 6 days postburn and declined thereafter. This indicated a continuous increase in the generalized postburn oedema for the first 6 days postburn. Impression force at 3 weeks postburn was significantly lower (P < 0.001) as compared with the half-day postburn value, indicating an increased tissue pressure during the first days postburn. Parameter analysis indicated a flux of water-like fluid from the vasculature to the interstitial space during the first 6 days postburn. The spread of the values registered between different measurement sites was, however, large.

The orthogonal polarisation spectral (OPS) imaging technique is a method that enables intravital microscopy of the tissue microvasculature particularly including the erythrocytes and leucocytes. As a new finding we here report multi flow, i.e, several different laminar velocity profiles in each and separate veins (diameters < 200 μm) of the microcirculation of the rat brain cortex. The phenomenon was present in all 20 preparations studied and these different laminar velocity profiles were regularly maintained in length beyond 20 times the diameter of parent vessel. In single veins up to 9 different laminar velocity profiles were discernible, each with a different red blood cell velocity. These multi flow profiles may theoretically be anticipated based on what is known in rheological physiology as the Fahreus - Lindqvist effect. It may also be predicted in tissues that have both high and heterogeneous blood flows in conjunction with large local variations in metabolic activity as are present in the cortex of the brain. The new information is that the extent and magnitude of this multi laminar flow phenomenon especially in the venular network of the brain exceeds what has previously been known. The physiological importance of these finding warrants further studies.

The aim of this study was to evaluate pain relief for patients with burns during rest and mobilization with morphine according to a standard protocol for patient-controlled analgesia (PCA). Eighteen patients with a mean (SD) burned TBSA% of 26 (20) were studied for 10 days. Using a numeric rating scale (NRS, 0 = no pain and 10 = unbearable pain), patients were asked to estimate their acceptable and worst experienced pain by specifying a number on a scale and at what point they would like additional analgesics. Patients were allowed free access to morphine with a PCA pump device. Bolus doses were set according to age, (100 - age)/24 = bolus dose (mg), and 6 minutes lockout time. Degrees of pain, morphine requirements, doses delivered and demanded, oral intake of food, and antiemetics given were used as endpoints. Acceptable pain (mean [SD]) was estimated to be 3.8 (1.3) on the NRS, and additional treatment was considered necessary at scores of 4.3 (1.6) or more. NRS at rest was 2.7 (2.2) and during mobilization 4.7 (2.6). Required mean morphine per day was 81 (15) mg, and the number of doses requested increased during the first 6 days after the burn. The authors found no correlation between dose of morphine required and any other variables. Background pain can be controlled adequately with a standard PCA protocol. During mobilization, the pain experienced was too intense, despite having the already high doses of morphine increased. The present protocol must be refined further to provide analgesia adequate to cover mobilization as well.

Background

Widespread use of patient-controlled sedation (PCS) demands simplicity and a predictable outcome. We evaluated patients’ safety and ease of use of PCS for gynaecological outpatient procedures.

Methods

In a prospective double-blind study, 165 patients were randomized to use propofol or propofol with alfentanil as PCS combined with local anaesthetic for pain control. Data on cardiopulmonary function, consciousness, and need for interventions were collected at baseline and every fifth minute. The surgeons’ evaluation of the ease and the duration of the procedure were recorded.

Results

One hundred and fifty-five patients used PCS for the entire procedure, 76 patients propofol, and 79 patients propofol/alfentanil. Fifteen procedures in the propofol group were limited or could not be done, compared with four in the propofol/alfentanil group (P = 0.02). The duration of surgery was not affected. The addition of alfentanil affected respiratory function compared with the propofol group: five patients compared with none were manually ventilated (P = 0.03), and two thirds, compared with a quarter, were given supplementary oxygen as their saturation decreased below 90% (P < 0.001). Overall cardiovascular stability was maintained. The propofol group had deeper conscious sedation as measured by the bispectral index (P  = 0.03), but all patients could be roused. In the propofol/alfentanil group, five patients became apnoeic and could not be roused.

Conclusions

PCS using propofol alone supports patients’ safety, as the addition of alfentanil increased the need for specific interventions to maintain respiratory stability. However, alfentanil increases the feasibility of the procedure, as complementary doses of propofol were not required.

Background: The aim was to evaluate safety aspects of patient-controlled sedation and analgesia (PCS) for extracor-poreal shockwave lithotripsy (ESWL) and PCS to be handled by non-anaesthesiology doctors. Methods: Thirty-four ASA I-III patients used PCS with propofol and alfentanil for ESWL in this interventional study. Strict safety limits were defined regarding respiratory rate (RR), heart rate (HR), mean arterial blood pressure (MAP), oxygen saturation from pulse oximetry (SpO2), and transcutaneous partial pressures of oxygen (PtcO2) and carbon dioxide (PtcCO2). The pa-tients’ levels of consciousness was graded on a five-point scale and monitored with Bispectral Index (BIS). A nurse anaesthetist was supervising the procedure but was instructed to intervene only if safety limits were breached. No sup-plementary oxygen was given. Results: All patients responded to verbal stimuli during treatment. Cardiovascular sta-bility was maintained, but respiratory variables were affected. Two patients with SpO2 < 90% and two cases of RR ≤ 8 were diagnosed, and seven patients became hypercarbic (PtcCO2 ≥ 6.5 kPa). In 18 patients hypoxaemia was indicated as PtcO2 ≤ 8.0 kPa. All these 18 patients were given supplementary oxygen. There was no correlation between dose of drugs, age, weight or any vital variable. The 34 patients would use PCS again in the case of future treatment. Conclu-sions: During ESWL treatment PCS can be used with good patients’ satisfaction, and maintained cardiovascular stabil-ity, but PCS had an indisputable effect on pulmonary function with hypoxemia (resulting in need for supplementary oxygen) or hypercarbia. The person in charge of PCS must therefore be trained to perform according to the guidelines for sedation and/or analgesia by non-anaesthesiology doctors.

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Background: Patient controlled sedation (PCS) enables patients to titrate doses of drugs by themselves during different procedures involving pain or discomfort. Methods: We studied it in a prospective crossover design using a fixed protocol without lockout time to examine it as an alternative method of sedation for changing dressings in burned patients. Eleven patients with >10% total burn surface area (TBSA) had their dressings changed, starting with sedation by an anaesthetist (ACS). The second dressing change was done with PCS (propofol/alfentanil) and the third time the patients had to choose ACS or PCS. During the procedures, data on cardiopulmonary variables, sedation (bispectral index), pain intensity (VAS), procedural details, doses of drugs, and patients' preferences were collected to compare the two sedation techniques. Results: The study data indicated that wound care in burned patients is feasible with a standardized PCS protocol. The patients preferred PCS to ACS on the basis of self-control, and because they had less discomfort during the recovery period. Wound care was also considered adequate by the staff during PCS. No respiratory (respiratory rate/transcutaneous PCO2) or cardiovascular (heart rate/blood pressure) adverse events were recorded at any time during any of the PCS procedures. The doses of propofol and alfentanil and BIS index decrease were less during PCS than ACS. Procedural pain was higher during PCS but lower after the procedure. Conclusion: We suggest that PCS using a standard protocol is an interesting alternative to anaesthetist-provided sedation during dressing changes. It seems effective, saves resources, is safe, and at same time is preferred by the patients. The strength of these conclusions is, however, hampered by the small size of this investigation and therefore further studies are warranted. © 2008 Elsevier Ltd and ISBI.

Objectives: To investigate the impact of comorbidity on general health-related quality of life (HRQoL) in a Swedish normal population using the Charlson Comorbidity Index (CCI), designed for mortality outcomes, and the new Health-Related Quality of Life Comorbidity Index (HRQL-CI, with physical and psychosocial subindexes) designed for HRQoL outcomes, and comorbidity analyses based on data from the Swedish national inpatient register.

Study design and setting:L In 1999, 6083 women (54%) and men aged 20-74 (mean 46, SD 15) responded to a public health survey in the county of Östergötland, Sweden, including measures of general HRQoL (the SF-36 and the EQ-5D).

Results: During 1987-1999, 478 (15 %) and 664 (21 %)/418 (13 %) persons had been registered with ≥1 hospital admission ICD-code included in the CCI and the HRQL-CI physical/psychosocial dimensions, respectively. Both indices discriminated between persons with different degrees of comorbidity regarding their HRQoL. The HRQL-CI received somewhat higher R2 values (e.g. SF-36 scales Physical Functioning 0.161 vs 0.067 and Mental Health 0.026 vs 0.004).

Conclusions: The new HRQL-CI, created on the basis of self-reports, proved to be a valid measure of comorbidity in a Swedish normal population using national register data.

A new and versatile method for tissue viability imaging based on polarization spectroscopy of blood in superficial tissue structures such as the skin is presented in this paper. Linearly polarized light in the visible wavelength region is partly reflected directly by the skin surface and partly diffusely backscattered from the dermal tissue matrix. Most of the directly reflected light preserves its polarization state while the light returning from the deeper tissue layers is depolarized. By the use of a polarization filter positioned in front of a sensitive CCD-array, the light directly reflected from the tissue surface is blocked, while the depolarized light returning from the deeper tissue layers reaches the detector array. By separating the colour planes of the detected image, spectroscopic information about the amount of red blood cells (RBCs) in the microvascular network of the tissue under investigation can be derived. A theory that utilizes the differences in light absorption of RBCs and bloodless tissue in the red and green wavelength region forms the basis of an algorithm for displaying a colour coded map of the RBC distribution in a tissue. Using a fluid model, a linear relationship (cc. = 0.99) between RBC concentration and the output signal was demonstrated within the physiological range 0–4%. In-vivo evaluation using transepidermal application of acetylcholine by the way of iontophoresis displayed the heterogeneity pattern of the vasodilatation produced by the vasoactive agent. Applications of this novel technology are likely to be found in drug and skin care product development as well as in the assessment of skin irritation and tissue repair processes and even ultimately in a clinic case situation.