Extradural block in obstetric patients: review of experience with gravity administration

Charts of 2284 obstetric patients who received extradural block with gravity administration of local anaesthetic were evaluated retrospectively. Despite a 1.3% incidence of vascular puncture and a 1.8% incidence of dural puncture, accidental intravascular or intrathecal injection of local anaesthetic did not occur. We propose that this method may be safer than the traditional "injection by needle" technique, and has a high degree of "visualization" of the otherwise "blind" extradural block procedure.