Influence of lumbosacral cerebrospinal fluid density, velocity, and volume on extent and duration of plain bupivacaine spinal anesthesia.

Background: The current study was designed to investigate the influence of lumbosacral cerebrospinal fluid (CSF) density, velocity, and volume on the extent and duration of plain bupivacaine spinal anesthesia.

Methods: Forty-one patients scheduled to undergo orthopedic surgery with spinal block were enrolled. Lumbosacral CSF volumes were calculated from low thoracic, lumbar, and sacral axial magnetic resonance images.