///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47+00:00

Combined Spinal-Epidural: The "Untested Catheter"?

Abstract Number: T-18
Abstract Type: Original Research

Antonio Gonzalez MD1 ; Jaime Aaronson MD2; Adam Sachs MD3; Richard Smiley MD, PhD4

Introduction: Proponents of traditional epidural labor analgesia (EPI) commonly criticize the combined spinal epidural (CSE) technique using the argument of the “untested catheter.”1 This historical, unproven theory and belief has limited the use of this technique in some practices. We evaluate the theory of the “untested catheter” in our tertiary care academic practice.

Methods: Information about failed catheters (FC) placed via CSE and EPI techniques was collected prospectively from Oct. 2012-Sept. 2013 as part of our Quality Assurance program. IRB approval was obtained for analysis. FC was defined as any catheter that was replaced after being determined to be: intravascular, one sided or resulting in poor maternal analgesia after appropriate dosing based on the judgment of the attending obstetric anesthesiologist. Once identified, the following information was collected: age, height, weight, BMI, gravity, parity, skin to epidural space depth and catheter mark at skin, number of physician boluses, and time elapsed between placement to the identification of a FC. Kaplan-Meier surivival curves and Cox proportional hazards analysis was performed to determine if a difference exists between the times needed to recognize FC with CSE vs EPI.

Results: During the study period a total of 2780 neuraxial techniques were performed (853 Epi; 1927 CSE). A total of 38 CSE (1.97%) and 40 Epi (4.69%) catheters were replaced during labor (P< 0.001). The mean time to detect failed catheters was 405 min and 370 min for the Epi and CSE respectively, with no statistical difference. Survival analysis (Fig 1) demonstrates that the time course for detection of failure did not differ between CSE and EPI groups.

Conclusion: We were able to demonstrate that there was no difference in time elapsed between placement of catheters and detection of FC using CSE or EPI technique. The mean time for the recognition of a failed catheter was much more than the 1-2 hr period during which the catheter from a CSE could correctly be viewed as “untested.” On the other hand, catheters placed using a CSE technique were less likely to fail during labor. These results are consistent with those of Norris et al2 and Gambling et al1. Our findings validate CSE as a reliable technique for labor analgesia and tend to refute the theory of the “untested catheter.”

1. Gambling D, Anesth Analg 2013;116:636–43.

2. Norris MC. Int J Obstet Anesth 2000;9:3–6.



SOAP 2014