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.

Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardiovascular magnetic resonance measurements of arterial and venous flow.

BACKGROUND: This study aims to present a novel method for using cardiovascular magnetic resonance (CMR) to non-invasively quantify the variation in pulmonary blood volume throughout the cardiac cycle in humans. METHODS: 10 healthy volunteers (7 males, 3 female, age range 21-32 years) were studied. The blood flow in the pulmonary artery and all pulmonary veins was quantified during free breathing using phase contrast velocity encoded CMR. The difference in flow between the pulmonary artery and the pulmonary veins was integrated to calculate the change in pulmonary blood volume throughout the cardiac cycle. RESULTS: The stroke volumes in the pulmonary artery and the sum of the pulmonary veins were (mean +/- SEM) 103 +/- 6 ml and 95 +/- 6 ml, respectively. The pulmonary blood volume variation (PBVV) was 48 +/- 5 ml, and the PBVV expressed as percent of the pulmonary artery stroke volume was 46 +/- 3%. The maximum increase in pulmonary blood volume occurred 310 +/- 12 ms after the R-wave from the ECG (32 +/- 2% of the cardiac cycle). PBVV did not correlate to change in cross-sectional area in the pulmonary artery (R2 = 0.03, p = 0.66). CONCLUSION: It is feasible to non-invasively quantify the change in pulmonary blood volume during the cardiac cycle in humans using CMR. The average pulmonary blood volume variation in healthy volunteers was approximately 50 ml and this was approximately 50% of the stroke volume. Further studies are needed to assess the utility of the pulmonary blood volume variation as a measure for identifying cardiac and pulmonary vascular disease.