[Comparative study of detection methods in epidural anesthesia: Episensor and loss of resistance]. / Estudio comparativo del método de detección en anestesia epidural: Episensor y pérdida de resistencia.

The aim of the present study is to evaluate an electronic detector of negative pressure (Episensor, Palex, Spain) designed for the identification of epidural space. Ninety patients were randomly assigned to two groups: group 1 (n = 47) received epidural anesthesia as perioperative analgesic technique with Episensor method and group 2 (n = 43) received epidural anesthesia with the classic method of loss of resistance with gas mandrin. The following parameters were studied: a) demographic features, b) characteristics of epidural anesthesia, and c) complications occurring during space detection. There were no statistical differences in the analysis of demographic variables neither in the quality of the epidural anesthesia achieved in both groups. With respect to complications, group I presented the highest number of complications although only the lack of detection of epidural space achieved statistical significance (8.5%, p less than 0.05); the incidence was lower than that reported in the literature as physiologically possible in the lumbar epidural segment. We conclude that progressive knowledge of Episensor may decrease the initial incidence of complications with a success rate similar to that of classic techniques of identification of epidural space.

[Localization of lumbar epidural space by loss of resistance and using the Episensor: a comparative study]. / Localización del espacio epidural lumbar por pérdida de resistencia y mediante el Episensor: estudio comparativo.

Since the existence of negative pressure in the epidural space was reported, its technique of localization has undergone changes directed to improve objectivity, reliability and safety. The aim of the present study was to evaluate a new electronic divide to localize the epidural space, i.e. the Episensor (Palex, Spain). To this end, 71 patients, both males and females, undergoing elective urological surgery and in whom catheterization of the lumbar epidural space had been planned, were prospectively evaluated and randomly assigned to two homogeneous groups. In group I (n = 35) the epidural space was localized by the classical technique of loss of resistance, while in group II the Episensor was used. In both groups several technical parameters, the qualification of the operator and the complications of the procedure were evaluated. There were no significant differences between both groups regarding the quality of epidural blockade or the subjective technical difficulty of the operator. The incidence of complications of the technique of puncture was significantly higher in group II (p less than 0.05); the most common were dura mater puncture in 13 group II patients and in one group I patient (p less than 0.001). There was no correlation between the qualification of the operator and the development of complications. It was concluded that the use of Episensor to localize lumbar epidural space did not improve the effectiveness of blockade but increased the iatrogenic effects of the puncture. Our lack of experience with this new technique and the low negative pressure of lumbar epidural space might have been the causes of the poor results, that we consider as initial in the evaluation of this new method.