PROTEIN-CONCENTRATION OF SUBCUTANEOUS INTERSTITIAL FLUID IN THE HUMANLEG - A COMPARISON BETWEEN THE WICK TECHNIQUE AND THE BLISTER SUCTIONTECHNIQUE

The wick technique and the blister suction technique are the most comm on methods for sampling of subcutaneous interstitial tissue fluid in m an. The blister suction technique has the advantage of being less inva sive than the wick technique, but the reliability of this method is st ill controversial. The aim of this study was to evaluate whether the s impler blister suction technique using large (8 mm) blisters could rep lace the wick technique in the investigation of patients with postreco nstructive leg edema. Fifteen patients with ipsilateral leg edema foll owing infrainguinal bypass surgery for lower limb atherosclerosis were investigated. The two different fluid sampling techniques were applie d simultaneously on both legs. The concentration of total protein and albumin as well as colloid osmotic pressure of the subcutaneous inters titial tissue fluid in the leg were measured in all fluid samples. Agr eement analysis was applied to compare the two methods, while the corr espondence between the methods was estimated with linear regression an alysis. The agreement index was found to be positive for all variables from the operated as well as from the contralateral control limb. Fur thermore, all values were within the agreement limit. The best agreeme nt between the two methods was found for colloid osmotic pressure on t he operated side. According to the equation of linear regression, ther e was a slight overestimation of the wick values compared to the obser ved blister values. In conclusion, there was a good methodological agr eement between the blister suction technique and the wick technique. T he less invasive blister suction technique should be regarded as the m ethod of choice for the investigation of subcutaneous interstitial tis sue fluid in patients with postreconstructive leg edema.