Epidemiology and therapeutic aspects of burn injuries in Slovakia (1993-2003)

The authors analyze the epidemiology and trend of thermal injuries in Slovakia since 1990. The article includes statistics from both of the burn injury workplaces in Bratislava and Kosice. The article contains conclusions and proposals for preventive measures which have contributed to the decrease of thermal injuries in Slovakia since 2000.

Skin grafting options at the Burn and Reconstructive Surgery Department of the Faculty Hospital in Bratislava

Replacement of devastated or severely damaged skin presents a key problem in the treatment of extensive deep burns in humans. The skin is an organ serving many functions, which can be replaced with skin transplants or temporary skin replacements only up to a certain extent. At the Burn and Reconstructive Surgery Department of the Faculty Hospital in Bratislava, located in Ruzinov, we have been concerned with the problem of skin replacement since its establishment in 1987. In this article we review skin replacement options and our experience with indications and use of various types of skin substitutes, mainly of biological origin, such as allotransplants, xenotransplants and amnion.

Temozolomide and interferon alpha 2b in metastatic melanoma stage IV

BACKGROUND

A multicentre, centrally randomized, open-labelled study with temozolomide and interferon (IFN)-alpha 2b was carried out to study the therapeutic effect in patients with metastatic melanoma stage IV.

OBJECTIVES

The response rate, efficacy, side-effects, reasons for discontinuation of therapy and survival rate of 47 patients treated with temozolomide in combination with two different dosing regimens of IFN-alpha 2b were documented.

PATIENTS/METHODS

Twenty-nine male and 18 female patients (mean age 57.6 years, range 34-74) were centrally randomized to two different arms: 20 patients received a treatment schedule with temozolomide 150 mg m(-2) on days 1-5 orally every 28 days in combination with IFN-alpha 2b 10 MIU m(-2) every other day and 27 patients received temozolomide 150 mg m(-2) on days 1-5 every 28 days in combination with IFN-alpha 2b in a fixed dose of 10 MIU every other day.

RESULTS

We observed an overall response rate of 27.6% comprising five complete remissions (10.6%: one patient group A, four patients group B), in two of these five patients at the last follow-up in the study (4.3%, both in group B); and eight partial remissions (17%: six patients in group A, two patients in group B), in three of these eight patients at the last follow-up in the study (6.4%, two patients in group A, one patient in group B). Three patients showed stable disease (6.4%: one patient in group A, two patients in group B). Mean survival was 14.5 months [95% confidence interval (CI) 10-19] with no significant differences between treatment groups. However, there was a significant correlation with response after three cycles (log rank test, P < 0.03). Within the 32 patients who completed at least three cycles of therapy, seven patients (three in group A and four in group B) with a partial or complete response showed a significantly better mean survival of 30.6 months (95% CI 19.1-42) compared with 25 patients who did not respond (13.7 months 95% CI 9.2-18.3). In total, patients with at least one complete remission showed the longest survival (37.1 months 95% CI 26.3-47.9), followed by patients with at least one partial response (17.4 95% CI 10.9-23.9). Major side-effects of the treatment were nausea, vomiting, headache, leucopenia, thrombopenia, elevation of liver function parameters and neurological symptoms. In five patients, the side-effects led to a discontinuation of treatment: neurological symptoms (two patients), sepsis (one patient), brain haemorrhage (one patient) and exanthema (one patient). There were no treatment-related deaths.

CONCLUSIONS

The combination of temozolomide and IFN-alpha 2b can easily be administered and shows tolerable toxicity. When an objective response occurs after three cycles, it indicates a significant survival advantage.

Information access at the point of care: what can we learn for designing a mobile CPR system?

OBJECTIVES

Hospitals have started to migrate their paper-based records to computerized patient records (CPR). The majority of today's CPR systems are stationary, which means that physicians use a clinical workstation to access CPR information. But health care professionals need to request and enter information at different locations, for example, on their daily ward round. This suggests the use of mobile computers, enabling an ubiquitous access to needed data. Different studies show that health care professionals are reluctant to use poorly designed mobile CPR systems, as the work at the point of care is very time-pressured and hectic. To design a system with high acceptance, it is essential to obtain empirical insight into the work practices and context in which the mobile CPR system will be used.

METHOD

We investigated the physicians' work with the patient record during their daily round. With the help of a compact notation method, the physicians' interaction with the information system was recorded in real time. Fourteen physicians from three different departments (internal medicine, surgery, and geriatrics) of a middle-sized Swiss hospital participated in our study.

RESULTS

Physicians have clear access preferences when they interact with the patient record during their daily round. There exists a clear profile of access frequencies and patterns, respectively. As an example, approximately 50% of all patient record accesses concern information about medications, vital signs and lab test results.

DISCUSSION/CONCLUSION

A CPR system which is designed to reflect the access frequencies and patterns should improve the efficiency of data entry and retrieval and thus result in a system with high acceptance among physicians in the demanding environment during hospital rounds.

Biocompatibility studies of modified collagen/Hyaluronan membranes after implantation

Two varieties of collagen/sodium hyaluronan membranes were used as dermal substitutes in a biocompatibility implantation study on rats. In order to improve especially the physical and mechanical properties of the material, the membranes were chemically modified using a combination of hexamethylenediisocyanate (HMDC) as a crosslinker and polyoxy-ethylene (POE) as a spacer. According to both macroscopic and microscopic histological observations, the membranes were well accepted by the surrounding host tissue in all the animals. No major differences in relation to the outgrowth of the material by host tissue have been observed between the implant varieties A and B. The most important finding was that no pathological changes or important alterations of the host tissues were detected.

Topical treatment of partial thickness burns by silver sulfadiazine plus hyaluronic acid compared to silver sulfadiazine alone: a double-blind, clinical study

Since its introduction into clinical practice in 1967 by Charles Fox Jr., silver sulfadiazine has been the gold standard for topical burn therapy. The addition to it of hyaluronic acid, which forms a substantial part of the human tissue intercellular matrix, is aimed at overcoming one of its very few disadvantages, i.e. prolongation of the wound re-epithelialization process. Since both hyaluronic acid and silver sulfadiazine have been used in therapy for decades and their efficacy is well documented, a topical treatment combining these two agents was formulated. The aim of the study was to investigate the efficacy and tolerability of a cream containing a hyaluronic acid/silver sulfadiazine fixed combination, compared with silver sulfadiazine cream alone, for the treatment of superficial and deep second-degree burns in a prospective, double-blind, controlled clinical study. The findings of the study confirmed that the association of the two compounds in a new topical treatment significantly reduced the healing time and significantly accelerated the reduction of local edema occurring shortly after injury. Furthermore, this new hyaluronic acid and silver sulfadiazine formulation has proven to have favorable antibacterial, anti-edematous and local analgesic effects, together with a clear stimulatory activity on the re-epithelialization process. This product may, therefore, significantly enrich the assortment of topical medications available for the treatment of burns and skin defects of other origin.

Thoracic epidural catheter placement via the caudal approach in infants by using electrocardiographic guidance

We examined the success of inserting epidural catheters via the caudal route in infants by using electrocardiographic guidance. A case series of 20 patients with thoracic epidural analgesia was studied. After the induction of general anesthesia, an 18-gauge IV catheter was inserted into the caudal space to allow threading of a 20-gauge epidural catheter. The electrocardiogram (ECG) tracings via the epidural catheter, as well as the surface ECG at the target spine level, were recorded simultaneously with a modified two-channel five-lead ECG system. The epidural catheter was advanced from the caudal space until the tip reached the target level as demonstrated by a match in the configuration of the epidural ECG tracing to that of the surface ECG tracing at the target level. The catheter tip location was verified by postoperative radiographs. All catheter tips were located within two vertebrae of the target level, and satisfactory intraoperative epidural anesthesia was achieved in all subjects.

IMPLICATIONS

Epidural electrocardiography may be used to guide the positioning of the thoracic epidural catheter tip via the caudal approach to the appropriate dermatome for optimum analgesia.

Prognostic factors for survival and factors associated with long-term remission in patients with advanced melanoma receiving cytokine-based treatments: second analysis of a randomised EORTC Melanoma Group trial comparing interferon-alpha2a (IFNalpha) and interleukin 2 (IL-2) with or without cisplatin

The aim of this study was to define prognostic factors for survival, and especially for long-term survival in a mature data-set of patients with stage IV melanoma treated within a randomised trial of cytokine-based protocols. Long-term follow-up data on patients enrolled into a European Organization for Research and Treatment of Cancer (EORTC) trial comparing interferon-alpha (IFNalpha) plus interleukin-2 (IL-2) with or without cisplatin were collected. Univariate and multivariate Cox regression analyses were performed to define prognostic factors for survival. The characteristics of patients alive at 2 and 5 years after randomisation were compared with the entire cohort using the chi(2) test. The minimum potential follow-up of the 131 evaluable patients was 5 years. 18 patients (14%) were alive 2 years after randomisation, and 11 (8%) 5 years after randomisation. Pretreatment performance status (PS), serum lactate dehydrogenase (LDH) and tumour mass were significant predictors for survival, whereas site of metastases and number of sites were non-significant. PS and LDH were the only independent prognostic factors. All except 1 patient alive at 2 and 5 years had a pretreatment PS of 100%, and only three long-term survivors had elevated pretreatment LDH. There was no association between the site of metastases and long-term survival. Response to treatment was a major predictor for long-term survival, whereas addition of cisplatin did not impact upon overall survival probability or on long-term survival. The probability of long-term survival in stage IV melanoma patients after IL-2-based treatments is governed by pretreatment PS, serum LDH and response to treatment. Site of metastases, the basis for the M-subcategories of the new AJCC staging system, was not informative in this study.

The seventh prototype of the mini-spindle-pump: does it fulfill the expectations of a short-term pump?

According to recent trends to develop implantable nonpulsatile blood pumps for different function modes and times, our intention was and still is to build a Mini-Spindle-Pump for a pumping duration of about 14 days. Initial conception for this plan was the premise that the device in a mock circuit should move 4 L of water/min at a speed of 12,000 to 15,000 rpm against a pressure difference of 90 mm Hg between pump inlet and outlet. Despite the development of 6 different prototypes, this project was not realized. Under the above-mentioned conditions, the main problem of this type of blood pump, the blood trauma, could not be reduced to an adequate level, i.e., the Mini-Spindle-Pump is not a high speed pump. Therefore, a revision of the conception was necessary. The device in a mock circuit should transport 5 L of water/min at a speed of about 9,000 rpm against a pressure difference of 90 mm Hg between its inlet and outlet. Considering the implantability of the blood pump, the following measurements for its components were arrived at. The U-shaped blockformed plexiglas housing was enlarged to 120 x 40 x 40 mm (length of blood chamber 86 mm, inner diameter 27 mm), and the rotor with 5 windings was redesigned at a length of 64 mm (outer diameter 25 mm, inner diameter 6.7 mm). In a mock circuit, this 7th prototype transported with a speed of 9,000 rpm about 10 L of water/min at an afterload of 80 mm Hg. In acute animal experiments with calves up to 15 h of pumping duration, the device showed the expected efficiency. Experiments with a longer pumping duration are necessary to confirm that this prototype will fulfill the criteria of a short-term pump according to Dr. Y. Nosé's advice.

Thoracic epidural analgesia via the caudal approach in pediatric patients undergoing fundoplication using nerve stimulation guidance

IMPLICATIONS

Epidural catheter placement using electrical stimulation guidance is an alternative approach for positioning the catheter into the thoracic region via the caudal space. This easily performed clinical assessment provides optimization of catheter tip positioning for achieving effective pain control.

Resorption and calcification of chemically modified collagen/hyaluronan hybrid membranes

The objectives of this study were to characterize collagen/hyaluronan hybrid membrane before and after different chemical crosslinking, as well as to investigate the impact of the treatment method on resorption and calcification processes by in vivo tests. The kinetics study of resorption of collagen/hyaluronan membranes showed that after 28 days the membranes were completely resorbed. The modification of the membranes with glutaraldehyde comparing to the similar modification of pericardial tissue conducts higher calcification. Treatment with hexamethylene diisocyanate together with poly(oxyethylene) improved mechanical properties but the resorption process was similar. Additional treatments with diphenylphosphorylazide and 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide (EDAC) resulted in prolongation of the resorption time. Calcification was suppressed in case of treatment with EDAC.

Role of hydrogen bonding in the oxidation of thianthrene 5-oxide with peroxy acids

The oxidation of thianthrene 5-oxide, i.e., a mechanistic probe for the assessment of the electronic character of various oxidants, with peroxybenzoic acids in various oxygen bases as solvents was investigated. The nucleophilicity (X(SO)) of peroxy acids was increasing with increasing basicity of the oxygen base. A good linear correlation was observed by plotting X(SO) values vs either the Kamlet-Taft beta values or the OOH (1)H NMR chemical shifts of m-chloroperoxybenzoic acid (m-CPBA) in solvents of various basicity. These observations, together with the results of IR and (1)H NMR spectroscopic studies of peroxybenzoic acids, and DFT (B3LYP/6-311++G) studies of the intramolecular hydrogen bonding in peroxyformic, peroxyacetic, and m-CPBA, as well as the intermolecular hydrogen bonding in the complexes of the these peroxy acids with dimethyl ether as a model oxygen base, support the involvement of the peroxy acid-oxygen base complexes in the transition states of these reactions. The increased nucleophilicity (X(SO)) of peroxy acids in basic solvents is most likely due to the increased negative charge on the terminal "electrophilic" peroxycarboxylic oxygen atom (OH), and/or the increased LUMO and HOMO energies of the peroxy acid in the complexes, as compared to those parameters in the intramolecularly hydrogen-bonded form of peroxy acids, believed to be operative in inert solvents.

Reproducibility of lymphoscintigraphy in cutaneous melanoma: can we accurately detect the sentinel lymph node by expanding the tracer injection distance from the tumor site?

The aim of the study was to determine whether the sentinel lymph node (SLN) can be accurately detected in cutaneous melanoma patients when the injection distance from the tumor site is expanded.

METHODS

In 100 patients with cutaneous melanoma, lymphoscintigraphy was performed twice. First, we injected 37 MBq (99m)Tc nanocolloid intracutaneously at a 2- to 5-mm distance from either the melanoma or the biopsy scar. The injection was followed by dynamic imaging, which continued until the SLN became visible. On another day, we repeated the investigation, injecting the radiopharmaceutical intracutaneously exactly 10 mm from the previous injection site. The detected SLNs of both investigations were compared to determine the number and location of SLNs for each patient.

RESULTS

The SLN identification rate was 94% with close injection and 100% with 10-mm-distant injection. All SLNs detected with close injection were visible with distant injection. In 84 of 100 patients, the images of both investigations showed the same number and location of SLNs. In the remaining 16 patients, an additional SLN was detected with the distant injection.

CONCLUSION

The reproducibility of lymphoscintigraphy using different injection distances was 84%. The discordance in the remaining 16% was caused by detection of a lymph node in addition to the original SLN with distant injection. Diagnostic excision of the primary tumor before lymphoscintigraphy was possible without preventing detection of the original SLN. However, in 16% of our patients, excision of an additional lymph node had to be considered when lymphoscintigraphy was performed after diagnostic excision.

Whole-body scintigraphy in melanoma patients: comparison of 99Tcm-tetrofosmin and 201Tl

The aim of this study was to determine the diagnostic value of 99Tcm-tetrofosmin whole-body imaging in comparison to 201Tl scintigraphy in patients with metastatic melanoma. In 27 patients with known or suspected melanoma metastases we performed 201Tl scintigraphy and 99Tcm-tetrofosmin scintigraphy using a 1-day protocol. In five patients with known locoregional metastasis the in vivo uptake kinetics of both radiotracers were compared. The final diagnosis was confirmed by surgical histology in 39 lesions (group I) and computed tomography (CT) and clinical course in 14 lesions (group II). In group I, containing mainly locoregional metastases, 201Tl scintigraphy correctly identified 36 of 39 metastases and 99Tcm-tetrofosmin 35 of 39 resulting in a sensitivity of 92% and 90% respectively. The T/B ratios of 201Tl (1.4-4.0, mean 2.15) were statistically significantly higher in comparison to tetrofosmin (1.3-3.0, mean 1.88). However, both radiotracers showed similar uptake and washout kinetics with a maximum of tracer uptake between 1 and 5 min p.i. In group II, containing mainly cerebral and pulmonary metastases, both methods correctly identified six of 14 metastases resulting in a sensitivity of only 43%. We conclude that the uptake of 99Tcm-tetrofosmin and 201Tl in melanoma metastases is very similar. The T/B ratios with 99Tcm-tetrofosmin are significantly lower than with 201Tl. In locoregional melanoma metastases the sensitivity of tetrofosmin scintigraphy is identical with 201Tl imaging and amounts to 90%. In cerebral and lung metastases the sensitivity of both methods is limited when using whole-body scintigraphy.

[Detection of melanoma metastases with Tc-99m-tetrofosmin]

AIM

The aim of this study was to evaluate Tc-99m-tetrofosmin whole-body imaging in the detection of metastases in patients with malignant melanoma.

METHODS

In 30 patients with suspected melanoma metastases we performed whole body imaging. After administration of about 600 MBq Tc-99m-tetrofosmin dynamic images up to 10 min were performed in 7 patients (1 image per 10 sec) to evaluate the optimal tracer uptake in the metastases. In all patients whole-body images were performed 5-10 min p.i. using an acquisition time of 5 min per image. The final diagnosis was confirmed by surgical histology in 30 lesions, by computertomography and clinical course in the remaining lesions.

RESULTS

Out of 64 melanoma metastases 49 were detected using Tc-99m-tetrofosmin scintigraphy (49 rp., 15 fn.). The overall sensitivity for the detection of malignant lesions was 77%. Referring only to the lymph node metastases, the sensitivity was 87% (26 rp.; 4 fn.). The maximal tracer uptake was reached 1 min after injection, with a slow decrease in the following 10 minutes. The size of the lesions ranged between 0.5 and 7.0 cm and the T/B ratios between 1.3 and 3.0 (mean 1.88).

CONCLUSIONS

Tc-99m-tetrofosmin whole body imaging is a simple and side-effectless method for the detection of melanoma metastases especially of lymph node metastases. The results are comparable to Tc-99m-sestamibi and Tl-201 scintigraphy.

Changing pattern of infection in the Bratislava Burn Center

Infection still remains one of the major problems in burn treatment. The authors investigated the occurrence of burn wound pathogens in burn wound biopsies and/or semiquantitative wound surface off-prints. As the results have shown, trends of a decreased contribution of "classical pathogens", like Staphylococcus aureus and Pseudomonas aeruginosa, to burn wound infections were observed. The role of "other pathogens", like Enterobacter, Acinetobacter, etc., which were quite rare in the past, is on the opposite, increasing. One of the explanations can be the increasing rate of early surgical treatment methods of deep burns. The results were in accordance with similar studies from other burn centres.

17O NMR spectroscopic characterization and the mechanism of formation of alkyl hydrotrioxides (ROOOH) and hydrogen trioxide (HOOOH) in the low-temperature ozonation of isopropyl alcohol and isopropyl methyl ether: water-assisted decomposition

Low-temperature ozonation of isopropyl alcohol (1a) and isopropyl methyl ether (1b) in [D6]acetone, methyl acetate, and tert-butyl methyl ether at -78 degrees C produced the corresponding hydrotrioxides, Me2C(OH)(OOOH) (2a) and Me2C(OMe)(OOOH) (2b), along with hydrogen trioxide (HOOOH). All the polyoxides investigated were characterized for the first time by 17O NMR spectroscopy of highly 17O-enriched species. The assignment was confirmed by GIAO/MP2/6-31++G* calculations of 17O NMR chemical shifts, which were in excellent agreement with the experimental values. Ab initio density functional (DFT) calculations at the B3LYP/ 6-31G*+ZPE level have clarified the transition structure (TS1, deltaE = 7.4 and 10.6 kcalmol(-1), relative to isolated reactants and the complex 1a-ozone, respectively) for the ozonation of 1a: this, together with the formation of HOOOH and some other products, indicates the involvement of radical intermediates (R*, *OOOH) in the reaction. The activation parameters for the decomposition of the hydrotrioxides 2a and 2b (Ea, = 23.5+/-1.5 kcalmol(-1), logA = 16+/-1.8) were typical for a homolytic process in which cleavage of the ROOOH molecule occurs to yield a radical pair [RO* *OOH] and represents the lowest available energy pathway. Significantly the lower activation parameters for the decomposition of HOOOH (Ea = 16.5+/-2.2 kcalmol(-1), logA = 9.5+/-2.0) relative to those expected for the homolytic scission of the HO-OOH bond [bond dissociation energy (BDE) = 29.8 kcalmol(-1), CCSD(T)/6-311++G**] are in accord with the proposal that water behaves as a bifunctional catalyst and therefore participates in a "polar" (non-radical) decomposition process of this polyoxide. A relatively large acceleration of the decomposition of the hydrotrioxide 2a in [D6]acetone, accompanied by a significant lowering of the activation energies, was observed in the presence of a large excess of water. Thus intramolecular 1,3-proton transfer probably also involves the participation of water and is similar to the mechanism proposed for the decomposition of HOOOH. This hypothesis was further substantiated by the B3LYP/6-31++ G*+ZPE calculations for the participation of water in the decomposition of CH3OOOH, which revealed two stationary points on the potential energy surface corresponding to a CH3OOOH-HOH complex and a six-membered cyclic transition state TS2. The energy barriers were comparable with those calculated for HOOOH, that is, deltaE = 15.0 and 21.5 kcalmol(-1) relative to isolated reactants and the CH3OOOH-HOH complex, respectively.

Accuracy of echocardiographic right ventricular parameters in patients with different end-stage lung diseases prior to lung transplantation

BACKGROUND

Because there are few data available on the accuracy of 2D-echocardiography to assess right ventricular (RV) size and function in patients with far-advanced lung disease, in this prospective study, we compared various echocardiographic RV parameters with RV volumes derived from magnetic resonance imaging (MRI).

METHODS

In 32 patients (18 male, 17 female) presenting for lung transplantation, we measured RV end-diastolic and end-systolic area as well as derived RV fractional area change, long-axis diameter, short-axis diameter, tricuspid valve anulus diameter (using 2D apical or sub-costal 4-chamber view), and RV end-diastolic diameter (using M-mode in the parasternal short-axis view). These values were compared with RV end-diastolic and end-systolic volumes derived by MRI, serving as the gold standard.

RESULTS

Right ventricular end-diastolic area was the most accurate echocardiographic parameter of RV size (correlation to MRI: r = 0.88, p < 0.001), followed by RV end-diastolic short-axis diameter (r = 0.75, p < 0.001), long axis diameter (r = 0.66, p < 0.001), and tricuspid valve anulus diameter (r = 0.63, p < 0.001). In contrast, M-mode measurement of RV end-diastolic diameter was possible in only 24/35 (68%) patients and showed a weak correlation to MRI-derived RV end-diastolic volume (r = 0.56, p = 0.004). Right ventricular fractional area change correlated well with MRI-derived RV ejection fraction (r = 0.84, p < 0.0001). In a sub-group analysis, patients with vascular lung disease showed best agreement between both methods for RV end-diastolic area and RV fractional area change compared with patients with restrictive or obstructive lung disease.

CONCLUSION

This study shows that in patients with far-advanced lung diseases, RV end-diastolic area demonstrated the best correlation with MRI-derived measurement of RV end-diastolic volume, and RV fractional area change compared favorably with MRI-derived ejection fraction. Despite reduced image quality, especially in patients with obstructive lung disease, these parameters can yield clinically valuable information.