Identification of the Epidural Space: Loss of Resistance with Air, Lidocaine, or the Combination of Air and Lidocaine

Abstract

The ideal technique for identifying the epidural space remains unclear. Five-hundred-forty-seven women in labor who requested epidural analgesia were randomly allocated to three groups according to the technique by which the epidural space was identified: 1) loss-of-resistance with air (air; n = 180), 2) loss-of-resistance with lidocaine (lidocaine; n = 185), and 3) loss-of-resistance with both air and lidocaine (air-plus-lidocaine; n = 182). We assessed ease of epidural catheter insertion, characteristics of the blockade, quality of analgesia, and complications. The inability to thread the epidural catheter occurred in 16% of the air, 4% of the lidocaine, and 3% of the air-plus-lidocaine patients (P < 0.001). More patients from the air group had unblocked segments (6.6% versus 3.2% and 2.2%, respectively; P < 0.02). The incidence of accidental dural puncture was greater in the air group (1.7% versus 0% in the other two groups; P < 0.02). Pain scores, time to onset of analgesia, upper sensory level, motor blockade, and the incidence of hypotension, transient neurological deficits, postpartum urinary retention, and postdural puncture headache were comparable. Identification of the epidural space with air was more difficult and caused more dural punctures than with lidocaine or air plus lidocaine. Additionally, sequential use of air and lidocaine had no advantage over lidocaine alone.

The use of patient‐controlled epidural fentanyl in elderly patients*

“…Before induction of general anaesthesia, an epidural catheter was positioned at a vertebral level corresponding to the dermatomal level of the anticipated surgical incision. The epidural space was identified by using loss of resistance with a glass syringe filled with 1.5% mepivacaine [8]. The epidural catheter was inserted 5 cm into the epidural space.…”

Anatomy and Clinical Importance of the Epidural Space

“…Additionally, sequential use of air and lidocaine had no advantage over lidocaine alone (Evron et al, 2004). The techniques of LOR to air or saline are also associated with some complications.…”

Identification of epidural space - which technique should I adopt?

“…Saline as a medium has advantages if we select it especially in a parturient patient 10 . Some anaesthesiologists prefer using Lignocaine as a medium instead of normal saline as it was blamed for causing delayed onset of action of local anaesthetics 11 .…”