air in epidural space
ProcedureThe epidural puncture will be performed in the L3-L4 or L4-L5 interspinous space in a seated position. A local anaesthesia with 2-5 mL of 2% lidocaine will be applied subcutaneously using a 25Gm 25mm needle. The epidural space will be localized using a Perifix® set by inserting the Tuohy needle in the ligamentum flavum or the interspinous space. The obturator will be then withdrawn and the low resistance syringe filled with 3-5mL of air will be connected. After localizing the epidural space, the catheter will be inserted 3-5 cm. An aspiration test will be performed through the catheter in a decline position with a 2 mL syringe, and a 3mL test dose with bupivacaine 0,25% plus epinephrine 1/200.000 will be administered to exclude an intradural or an intravascular position of the catheter.