The Optimal Distance That a Multiorifice Epidural Catheter Should Be Threaded into the Epidural Space

Abstract

Complications can occur during epidural placement for women in labor. As many as 23% of epidural anesthetics may not provide satisfactory analgesia. The cause of this may be technical. This study was undertaken to determine the optimal distance that a multiorifice catheter should be threaded into the epidural space to maximize analgesia and minimize complications. One hundred women in labor were enrolled in this prospective, randomized, and double-blind study. Patients were randomly assigned to have the epidural catheter threaded 3, 5, or 7 cm into the epidural space. After placement of the catheter and administration of a test dose with 3 mL of 0.25% bupivacaine, an additional 10 mL of 0.25% bupivacaine was administered in two divided doses. Fifteen minutes later, the adequacy of the analgesia was assessed by a blinded observer. We found that catheter insertion to a depth of 7 cm was associated with the highest rate of insertion complications while insertion to a depth of 5 cm was associated with the highest incidence of satisfactory analgesia. For women in labor who require continuous lumbar epidural anesthesia, we recommend threading a multiorifice epidural catheter 5 cm into the epidural space.

Insertion length and resistance during advancing of epidural catheter

“…Cesur et al [6] reported an 8.2% incidence of intravascular placement with 3-cm catheter insertion in normal healthy adult patients, while Beilin et al [8] reported an 8.3% incidence of intravascular location in healthy parturients, with the highest frequency occurring in the 7-cm group, as compared to a 7.5% incidence of intravascular placement in our study. Beilin et al [8] had performed aspiration to rule out intravascular placement after the entire 7 cm had been advanced into the epidural space.…”

“…Beilin et al [8] had performed aspiration to rule out intravascular placement after the entire 7 cm had been advanced into the epidural space. It is possible that intravascular placement had occurred earlier and it was only by chance that these patients were part of the 7-cm group.…”

“…The optimal length of an epidural catheter to be threaded into the epidural space is controversial [7][8][9][10]. It is suggested to thread in a length of at least 4 cm inside the epidural space to prevent inadequate block that might occur due to the movement of the catheter out of the epidural space during traction applied by fi xation to the skin [8].…”

“…As a result, anesthetists tend to push in an extra length to avoid dislodgement, especially in obese patients [9]. Insertion lengths of 7 and 8 cm were reported to have a higher incidence (8%-8.3%) of intravascular placement than shorter lengths [7,8], while in another study, the incidence of intravascular location remained the same with a 3-cm insertion length [6].…”

“…An optimal length, varying from 2 to 4 cm, has been suggested for epidural catheter insertion, but this length is associated with the risk of catheter dislodgement during fi xation to the skin and patient positioning [6][7][8][9]. As a result, anesthetists tend to push in an extra length to avoid dislodgement, especially in obese patients [9].…”