A New Technique for the Quantification of Peripheral Edema with Application in both Unilateral and Bilateral Cases

Current noninvasive techniques for the routine and frequent quantification of peripheral lymphedema in patients are total limb volume measurement (by water immersion or by circumferential measurements) and bioelectrical impedance analysis (BIA). However both of these techniques require standardizing the measurement using a contralateral measurement from the unaffected limb. Hence these techniques are essentially restricted to unilateral lymphedema. This paper describes the results from a preliminary study to investigate an alternative approach to the analysis of the data from multiple frequency BIA to produce an index of lymphedema without the need for normalization to another body segment. Twenty patients receiving surgical treatment for breast cancer were monitored prior to surgery and again after diagnosis with unilateral lymphedema. The data recorded were total limb volume, by circumferential measurements; and BIA measurements of both limbs. From these measurements total limb volumes and extracellular fluid volumes were calculated and expressed as ratios of the affected limb to that of the unaffected limb. An index of the ratio of the extracellular fluid volume to the intracellular fluid volume was determined. This ECW/ICW index was calculated for both the affected and unaffected limbs at both measurement times. Results confirmed that the established techniques of total limb volume and extracellular fluid volume normalized to the unaffected contralateral limb were accurate in the detection of lymphedema (p < 10(-6)). Comparison of the ECW/ICW index from the affected limb after diagnosis with that from the pre-surgery measurement revealed a significant (p < 10(-6)) and considerable (75%) increase. The results of this pilot study suggest that by using multiple frequency bioelectrical impedance analysis, an index of the ECW/ICW ratio can be obtained and this index appears to have an equal, or better, sensitivity than the other techniques in detecting lymphedema. More importantly, this index does not require normalization to another body segment and can be used to detect all types of peripheral edema including both unilateral and bilateral lymphedema

Estudo da confiabilidade e validade da utilização do hidropletismômetro para medida de edema no tornozelo Study of the reliability and validity of the water plethysmographer for use in measurement of the edema at the ankle/foot

Instrumentos confiáveis e válidos são necessários para avaliar a efetividade das técnicas de reabilitação. O objetivo deste estudo foi avaliar a confiabilidade e a validade do Hidropletismômetro. Quatorze sujeitos com idade entre 18 e 59 anos foram selecionados para participar do estudo. Os tornozelos foram avaliados por dois examinadores treinados com o Hidropletismômetro. Três medidas de cada tornozelo foram obtidas pelos examinadores de forma aleatória para investigar a confiabilidade intra e inter-examinadores. Foram também obtidas vinte e seis medidas com o Hidropletismômetro e comparadas com as medidas obtidas com o Deslocador de Água considerado "padrão ouro", através de provetas de vidro graduadas de 10 ml a 1000 ml. A confiabilidade intra e inter-examinadores foi realizada através do Coeficiente de Correlação Intraclasse (CCI) e a validade através do teste t pareado. O Coeficiente de Correlação de Pearson foi utilizado para estabelecer a associação entre os dois instrumentos. Os dados demonstraram níveis de confiabilidade intra e inter-examinadores com (CCI)3,1 = 0,99 e (CCI)3,2 = 0,99, respectivamente. Nenhuma diferença foi encontrada entre as medidas obtidas com o Hidropletismômetro e as obtidas com as provetas (p=0,404). A Correlação de Coeficiente de Pearson mostrou alta magnitute e nível de significância entre as medidas (r=1,0; p<0,0001). Os resultados evidenciaram que o Hidropletismômetro é um instrumento confiável e válido para medida de volume do tornozelo/pé.<br>Reliable and valid instruments are necessary to evaluate the effectiveness of the rehabilitation techniques.The objective this study was to evaluate the reliability and the validity of the water plethysmography. Fourteen subjects between the ages of 18 and 59 years were selected to participate in the study. Ankles were assessed by two trained examiners with the water plethysmography. Three measures of each ankle were obtained by the two investigators to evaluate intra- and inter-raters reliability. Twenty-six measures were obtained with the water plethysmography and compared with measurements obtained by graduated cylinders from 10 to 1000 ml, water displacement device (gold standart). Intraclass correlation coefficients (ICCs) evaluated intra- and inter-raters reliability, whereas paired Student t-tests and Pearson's correlation coefficients were used to establish validity of the water plethysmography.The results demonstrated excellent intra- and inter-rater reliability levels with levels with CCI3,1=0.99 and CCI3,2=0.99 respectively. No differences were found between the measures obtained with the water plethysmography compared to those of the water displacement device (p=0.40). Pearson's correlation coefficient showed a high magnitude and significance level between the measures (r=1,0; p<0.0001).The findings demonstrated that the water plethysmography is a reliable and valid instrument for measuring ankle/foot volume