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Currently, there is a lack of data related to differences in symptoms and infection across different types and anatomical sites of lymphedema. The objective of this study was to examine differences in symptoms and infection status among individuals with lymphedema of the upper or lower extremities. The National Lymphedema Network initiated an online survey of self-report lymphedema data from March 2006 through January 2010. Descriptive statistics, Mann-Whitney tests, and Chi-square tests were used to analyze data. 723 individuals with upper extremity lymphedema and 1114 individuals with lower extremity lymphedema completed the survey. Individuals with extremity lymphedema experienced high symptom burden and infectious complications. Compared with individuals with upper extremity lymphedema, individuals with lower extremity lymphedema experienced more frequent and more severe symptoms (p<.001), infection episodes (p<.001), and infection-related hospitalizations (p<.001). No statistically significant differences of symptom burden and infection status were identified between individuals with lower extremity primary and secondary lymphedema. Individuals with extremity lymphedema experience substantial symptom burden and infectious complications; however, those with lower extremity lymphedema have more severe symptoms and more infections than those with upper extremity lymphedema.
Skeletal muscle adaptation to chronic hypoxia includes loss of oxidative capacity and decrease in fiber size. However, the diaphragm may adapt differently since its activity increases in response to hypoxia. Thus, we hypothesized that chronic hypoxia would not affect endurance, mitochondrial function, or fiber size in the mouse diaphragm. Adult male mice were kept in normoxia (control) or hypoxia (hypoxia, FIO(2) = 10%) for 4 weeks. After that time, muscles were collected for histological, biochemical, and functional analyses. Hypoxia soleus muscles fatigued faster (fatigue index higher in control, 21.5 ± 2.6% vs. 13.4 ± 2.4%, p < 0.05), but there was no difference between control and hypoxia diaphragm bundles. Mean fiber cross-sectional area was unchanged in hypoxia limb muscles, but it was 25% smaller in diaphragm (p < 0.001). Ratio of capillary length contact to fiber perimeter was significantly higher in hypoxia diaphragm (28.6 ± 1.2 vs. 49.3 ± 1.4, control and hypoxia, p < 0.001). Mitochondrial respiration rates in hypoxia limb muscles were lower: state 2 decreased 19%, state 3 31%, and state 4 18% vs. control, p < 0.05 for all comparisons. There were similar changes in hypoxia diaphragm: state 3 decreased 29% and state 4 17%, p < 0.05. After 4 weeks of hypoxia, limb muscle mitochondria had lower content of complex IV (cytochrome c oxidase), while diaphragm mitochondria had higher content of complexes IV and V (F (1)/F (0) ATP synthase) and less uncoupling protein 3 (UCP-3). These data demonstrate that diaphragm retains its endurance during chronic hypoxia, apparently due to a combination of morphometric changes and optimization of mitochondrial energy production.
Reperfusion injury is characterized by significant oxidative stress. F(2)-isoprostanes (F(2)-IsoP's) and isofurans (IsoF's), the latter preferentially produced during increased oxygen tension, are recognized markers of in vivo oxidative stress. We aimed to determine whether increasing oxygen tension during reperfusion modified levels of plasma total IsoF's and F(2)-IsoP's. Forty-five patients undergoing upper-limb surgery were randomized to receive inspired oxygen concentrations of 30, 50, or 80% during the last 15 min of surgery. Venous blood samples were taken before the change in inspired oxygen, after 10 min (before reperfusion), and after 15 min (5 min after reperfusion). IsoF's and F(2)-IsoP's were measured by gas chromatography-mass spectrometry. Venous oxygen tension and hemoglobin concentrations were also measured. Plasma IsoF and F(2)-IsoP levels in the 50 and 80% O(2) groups were not significantly different from those of the 30% O(2) group. In secondary analyses, using data combining all groups, levels of IsoF's, but not F(2)-IsoP's, associated with higher venous oxygen tension (P=0.038). Hemoglobin negatively modified the influence of oxygen tension on levels of IsoF's (P=0.014). This study has shown, for the first time, that plasma IsoF levels associate with higher oxygen tension in a human model of reperfusion, and this effect is significantly attenuated by hemoglobin.
Copyright © 2011 Elsevier Inc. All rights reserved.
BACKGROUND - In this study, we performed the infraclavicular block with combined ultrasound guidance and neurostimulation to selectively target cords to compare the success rates of placing a single injection of local anesthetic either in a central or peripheral location.
METHODS - Two hundred eighteen patients were enrolled in a consecutive, prospective study. Patients were randomized to injection of local anesthetic either centrally (posterior cord) or peripherally (medial or lateral cord) using ultrasound guidance and neurostimulation. Supervised senior anesthesiology residents or attending anesthesiologists performed the blocks. Both intent-to-treat and treatment-received analyses were used to compare central and peripheral placement efficacy.
RESULTS - The overall success rate was significantly higher for the central placements than peripheral placements (96% vs 85%, P = 0.004). Individual cord success rates were as follows: posterior 99%, lateral 92%, and medial 84% (P = 0.001). The central group required attending physician intervention more frequently (27% vs 6%, P < 0.001). Postoperative pain scores of < or =3 were more likely with central placement (100% vs 94%, P = 0.012).
CONCLUSION - Central placement of a single injection of local anesthetic targeted at the posterior cord resulted in a higher success rate for infraclavicular block.
BACKGROUND - Single-frequency bioelectrical impedance has been used in clinical and research settings to measure extracellular fluid in arms. Its ease of use and low risk of user error suggests this measurement method may have advantages for use in nonlaboratory (community-based) environments when compared to other measurement methods. The purpose of this study was to evaluate the feasibility of using single-frequency bioelectrical impedance to detect upper limb lymphedema in nonlaboratory settings.
METHODS AND RESULTS - Using a standardized protocol, impedance ratios among healthy normal women, breast cancer survivors with lymphedema, and breast cancer survivors without lymphedema were compared with participants seated in an upright position conducive for use outside laboratory settings (community-based environments). Ratios of healthy normal controls and breast cancer survivor groups without lymphedema were very similar, with almost complete overlap in confidence intervals. However, those values were markedly different from the values assessed in the survivor group with lymphedema (p<0.001).
CONCLUSIONS - These findings suggest impedance ratios determined by single-frequency bioelectrical impedance can be used as markers for lymphedema in nonlaboratory settings when a standardized protocol is used.
Lymphedema is a problem for breast cancer survivors. The proliferation of limb measurement techniques makes it difficult to know how best to measure an at-risk limb. Using a sample of healthy volunteers and individuals with lymphedema, this study: 1) examined the relationship between more commonly used circumferential limb measurement methods and newer measurement methods of infrared laser perometry and bioelectrical impedance; 2) compared self-reported arm symptoms in healthy volunteers and breast cancer survivors with known lymphedema; and 3) explored the relationships among self-reported arm symptoms and circumferential tape measurement, infrared laser (perometry), and single and multi-frequency bioelectrical impedance. Lymphedema index ratios were calculated to allow comparison among measurement methods. Measurement methods correlated strongly with each other. Fourteen symptoms were reported by one or more participants in the lymphedema group while participants in the healthy volunteer group reported only eight symptoms over the same time frames. Using p < 0.001, all measurement methods correlated with self-reported arm swelling in the past year, while only circumferential and impedance measurements correlated with firmness. Future research needs to include serial arm measurements to explore arm volume variation in healthy and lymphedema volunteers and to further investigate possible lymphedema index ratios cut points as lymphedema diagnostic criteria.