CHANGES IN THE POSITION OF EPIDURAL CATHETERS ASSOCIATED WITH PATIENTMOVEMENT

Background: Epidural catheter movement has been noted with change of p atient position and can result in inadequate anesthesia. This study wa s designed to measure movement and to develop a technique that minimiz es catheter displacement. Methods: In 255 parturients requesting epidu ral anesthesia for labor or cesarean section, a multiorificed lumbar e pidural catheter was inserted with the patient in the sitting flexed p osition. The distance to the epidural space, length of catheter insert ed, and amount of catheter position change as the patient moved from t he sitting flexed to sitting upright and then to the lateral decubitus position mere measured before the catheter was secured to the skin. A dequacy of analgesia, the need for catheter manipulation, and whether the patient was considered obese were noted. Data were grouped accordi ng to body mass index (BMT): < 25, 25-30, and > 30 kg/m(2). Results: T he groups did not differ with respect to the length of catheter initia lly inserted or changes in catheter position between initial taping an d removal. The distance to the epidural space differed significantly a mong the groups, increasing with greater BMI. Catheters frequently app eared to be drawn inward with position change from the sitting flexed to lateral decubitus position, with the greatest change seen in patien ts with BMI > 30. Only nine catheters were associated with inadequate analgesia, four of which were replaced. No analgesic failures occurred in the BMI > 30 group. In patients judged by the anesthesiologist to be obese or to have an obese back, BMI was greater, and the distance t o the epidural space and the magnitude of catheter movement with posit ion change were greater than in those who were not obese. Conclusions: Epidural catheters moved a clinically significant amount with referen ce to the skin in all BMI groups as patients changed position. Lf cath eters had been secured to the skin before position change, many would have been pulled partially out of the epidural space. To minimize the risk of catheter displacement, particularly in obese patients, Re reco mmend that multiorificed catheters be inserted at least 4 cm into the epidural space and that patients assume the sitting upright or lateral position before securing the catheter to the skin.