Development of a pressure-measuring device to optimize compression treatment of lymphedema and evaluation of change in garment pressure with simulated wear and tear.

The use of compression garments in treating lymphedema following treatment of genital (penis, testes, uterus, cervical) and breast cancer treatment is a well-established practice. Although compression garments are classified in compression classes, little is known about the actual subgarment pressure exerted along the extremity. The aims of this study were to establish an in vitro method for measuring subgarment pressure along the extremity and to analyze initial and over time subgarment pressure of compression garments from three manufacturers. The measurements were performed with I-scan(®) (Tekscan Inc.) pressure measuring equipment once a week during a period of 4 weeks. Wear and tear was simulated by washing and putting on the garments on plastic legs every day. There was a statistically significant difference between the garments of some of manufacturers. There was no difference between garments from the same manufacturer. No significant decrease of subgarment pressure was observed during the trial period. The study demonstrated that Tekscan pressure-measuring equipment could measure subgarment pressure in vitro. The results may indicate that there was a difference in subgarment pressure exerted by garments from different manufacturers and that there was no clear decrease in subgarment pressure during the first four weeks of usage

Laser Doppler Perfusion Monitoring and Imaging especially as regards testing for sympathetic nerve function

The operating principle of all laser Doppler methods is based on the fact that incident photons shift in wavelength when interacting with moving blood cells passing through the microvascular network. After photodetection and further signal processing, the recorded parameter can be considered an arbitrary measure of tissue blood flow, and this is referred to as ?perfusion?. Laser Doppler perfusion monitoring with a probe (LDPM) gives a real-time recording from a small area, whereas imaging by use of a scanner (LDPI) creates an instant view of the spatial distribution over a wider area. Measurements are influenced by a variety of instrumental factors such as probe configuration and light wavelength. This thesis presents findings regarding changes of skin microcirculation when assessed by various technologies, and special attention was paid to those changes induced by sympathetically mediated vasoconstriction. Finger skin blood flow was investigated both in healthy subjects, and in patients with diabetes mellitus. Measurements with LDPM were performed with different probe configurations related to distance between emitting and detecting fibres. Measurements with LDPI were performed with different light wavelengths. In three experimental series, contra-lateral hand cooling induced vasoconstriction. In one series, the effects of local heating were explored. Besides the perfusion parameter, details regarding the concentration of moving blood cells and their average velocity were displayed and analysed. Our clinical findings are coherent with technical and theoretical assumptions. Hence, the wider fibre separation in LDPM the deeper the measurement and an increment in wavelength seem to have a similar effect. However, superficial capillary blood flow and deeper shunt blood flow cannot reliably be distinguished from one another by means of these different instrumental standards. Neither can the separation of the perfusion parameter into velocity and concentration with safety be used for this purpose. However, velocity and concentration may be used for clarifying various microcirculatory events from the physiological point of view. We found for instance that the two components act merely parallel at low and moderate perfusion rates, whereas a high perfusion rate primarily is associated with an increase in concentration. By applying frequency analysis, it was furthermore shown that the movement of the column of blood periodically reaches the peripheral vascular bed concurrently with the cardiac cycle whereas concentration remains the same. As microvascular blood flow cannot be measured quantitatively and due to varying instrumental design, the need for widely accepted and standardised test procedures and protocols is apparent. The cold pressor test used in this thesis is just one example. Under such given circumstances, the test parameter may be practically independent of the laser Doppler device used, as shown by the vasoconstriction index in the present studies. Diabetic patients showed an attenuated vasoconstriction response, and the index can reliably be used to monitoring peripheral sympathetic nerve function in these patients

Glucose concentration in seromas after plastic surgery: A pilot study.

Abstract Previously, glucose concentration has been presumed to be similar in seroma, lymph, and plasma. However, there are few studies actually measuring glucose concentration in seroma. The aim of this pilot study was to determine if the glucose concentration in seroma is similar to that in plasma, as it has previously been presumed. Biochemical analysis of seroma was performed on 11 patients that had undergone plastic surgery. Fluid was taken from the drains between postoperative day 3 and 6. The median glucose concentration was 3.09 millimolar (mM) (range 2.25-3.89 mM). Glucose concentration in seroma does not seem to be similar to that of plasma and lymph that has previously been presumed. The result of this pilot study warrants further investigation to determine the span of normal glucose concentration, its development over time, its relation to plasma glucose concentration, and how it is affected by infection

The influence of wavelength and probe configuration on findings of a skin vasoconstriction test when using laser Doppler perfusion devices.

The aim of this study was to establish the degree to which a standardized test based on laser Doppler blood flow measurement is dependent on the particular equipment set-up being used. For this purpose, we examined finger skin blood flow with laser Doppler instruments in 20 healthy subjects. In laser Doppler perfusion monitoring (LDPM), we used a custom-made probe with two detecting fibers placed 0.25 and 1.2 min from the illuminating fiber, respectively, and two laser Doppler perfusion imagers (LDPI) with a wavelength of 632.8 nm and 780 rim, respectively. Warming of the hand was achieved with a Peltier element, and reflex vasoconstriction was induced by immersing the other hand for 3 min into a water bath kept at 15 degrees C. As a measure for the change in skin blood flow, a vasoconstriction index (VAC: cooling/before cooling) was calculated and used for the comparison of the different devices. VAC values gathered around 0.6 for all devices. However, LDPI with a wavelength of 632.9 nm showed a slightly higher VAC index, and the difference was significant. We conclude that using a standardized test is the most appropriate for monitoring changes in blood flow rather than recording and comparing discrete values in intermittent recordings. Although a difference was noted when comparing the devices, different fiber separations and wavelengths seem then to be of little consequence. (c) 2005 Published by Elsevier Inc

Sympathetic and parasympathetic neuropathy are frequent in both type 1 and type 2 diabetic patients.

OBJECTIVE—The aim of this study was to evaluate the frequency of sympathetic versus parasympathetic neuropathy among type 1 and type 2 diabetic patients. RESEARCH DESIGN AND METHODS—There were 43 patients with type 1 and 17 with type 2 diabetes who were investigated. Sympathetic nerve function was assessed by measurement of the vasoconstriction (VAC) index by laser Doppler perfusion imaging of a locally heated finger followed by indirect cooling. Parasympathetic nerve function was assessed by R-R interval variation during deep breathing as measured by the expiration/inspiration (E/I) ratio. Results were expressed as age-corrected z scores in SD; VAC index >1.64 SD and E/I ratio <−1.64 SD were considered abnormal. RESULTS—VAC index was abnormal in 40% with type 1 and 41% with type 2 diabetes, whereas the E/I ratio was abnormal in 42% with type 1 and 65% with type 2 diabetes. There was a clear association between VAC index and E/I ratio among type 1 (rs = 0.525; P = 0.0002) but not among type 2 (rs = 0.10) diabetic patients. Among type 2 diabetic patients, the degree of dysfunction was most severe regarding parasympathetic function (P = 0.0167). CONCLUSIONS—Sympathetic and parasympathetic neuropathy were frequent in both type 1 and type 2 diabetic patients. However, there was a difference between the two types of diabetes. Sympathetic and parasympathetic nerve functions correlated in type 1 but not in type 2 diabetic patients. The explanation for this discrepancy might be that parasympathetic nerve function was most severely affected among type 2 diabetic patients

Development of a pressure-measuring device to optimize compression treatment of lymphedema and evaluation of change in garment pressure with simulated wear and tear

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