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Updated: Aug 14, 2026
A Modified Method for Intrathecal Catheterization in Rats
Published on: February 14, 2025
Advancing an epidural catheter 10 cm then retracting it 5 cm is no more effective than advancing it 5 cm
Rafael Cartagena1, Robert R Gaiser
1Department of Anesthesia, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA.
Study Objective:
To determine whether threading an epidural catheter 10 cm then retracting it 5 cm affects its intravascular placement and paresthesias.
Design:
Prospective randomized study.
Setting:
Labor and Delivery Unit, University Medical Center.
Patients:
Eighty parturients.
Interventions:
All patients received epidural anesthesia. Patients were randomized to 1 of 2 groups: threading the epidural catheter 5 cm (5-cm group) or threading the epidural catheter 10 cm and retracting 5 cm (10-cm group). In the 10-cm group, the epidural catheter was threaded 10 cm and pulled back 5 cm. In the 5-cm group, the epidural catheter was threaded 5 cm.
Measurements And Main Results:
Placement of the epidural catheter intravascularly, the presence of a paresthesia, and bilateral sensory levels were measured. There was no difference in the frequency of intravascular placement between 10- and 5-cm groups, 10.2% vs 7.5%, respectively. Although not statistically significant, there was a trend toward a higher frequency of paresthesia in the 10-cm group, 15.4% vs 7.5%, and a lower frequency of uneven sensory levels in the 10-cm group, 15% vs 2.6%.
Conclusions:
There is no clear clinical benefit or disadvantage to threading an epidural catheter 10 cm into the epidural space then withdrawing it 5 cm. Further study is warranted.
