WITHDRAWAL FORCES DURING REMOVAL OF LUMBAR EXTRADURAL CATHETERS

After performing successful continuous lumbar extradural conduction bl ock, we investigated the effects of the extradural insertion technique (midline (M) or paramedian (P)) and patient position during extradura l catheter removal (flexed lateral (L) or sitting (S)) on the force re quired to remove extradural catheters. One hundred parturients were al located randomly to four groups: ML, MS, FL, PS. The results indicated that neither the midline nor paramedian approach affected withdrawal forces. However, more than 2.5 times as much force was required to rem ove the catheters when patients were in the flexed sitting compared wi th the lateral position (P < 0.005). For ease of removal of catheters from the lumbar extradural space, we therefore strongly recommend the flexed lateral position.