Assessment of Catheter Flow Direction Using Color Flow Doppler in Labor Epidurals

Assessment of Catheter Flow Direction Using Color Flow Doppler in Labor Epidurals: an Observational Study

Epidural analgesia is commonly used for pain relief in labor and involves placement of a catheter in the epidural space. Failure of epidural analgesia may occur in 12-16% of epidural catheter placements. It is defined as inadequate analgesia after the local anesthetic loading dose, despite use of appropriate dose/concentration of local anesthetic. Failure to provide adequate epidural analgesia is commonly caused by malposition of the epidural catheter. Many factors may influence the position of the tip of the epidural catheter and the resulting spread of local anesthetic into the epidural space, and consequently the quality of analgesia. Previously, X-ray exposure was required to assess catheter position in the epidural space. Recent developments have allowed the anesthesiologist to assess the catheter position at the bedside after its placement, using color flow Doppler ultrasonography.

The investigators will perform an observational study to determine epidural catheter flow direction in the obstetrical population using color flow Doppler ultrasound. Women who have delivered under epidural analgesia, either vaginal or caesarean delivery, will be approached for the study before the epidural catheter is removed.

The investigators aim to determine epidural flow relative to the insertion site, describe the findings and to correlate them with other clinical outcomes.

Study Overview

• Status: Completed
• Conditions: Labor Pain
• Intervention / Treatment: Device: color flow Doppler ultrasonography

• Study Type: Observational
• Enrollment (Actual): 45

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G1X5
      • Mount Sinai Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Women who have delivered under epidural analgesia, either with vaginal or caesarean delivery, will be approached for the study before the epidural catheter is removed.

Description

Inclusion Criteria:

• Women who have delivered under epidural analgesia
• Women who have vaginal or caesarean delivery
• Women with the epidural catheter still in place

Exclusion Criteria:

-Women who experience fetal or maternal complications during delivery

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients who had an epidural placed for labour; Patients who had an epidural placed for labour may take part. Study procedures will take place after delivery and prior to removal of the epidural catheter.	Device: color flow Doppler ultrasonography; Doppler ultrasonography

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visualization of flow relative to the interspace insertion level as assessed by color flow Doppler ultrasound	Visualization of flow relative to the interspace insertion level as assessed by color flow Doppler ultrasound (at insertion level [yes/no], above insertion level [yes/no], below insertion level [yes/no], no visualization of flow in any space).	15 min

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Level of epidural catheter insertion: questionnaire	The anesthesiologist will record the intervertebral level at which the epidural was placed: L2-L3, L3-L4	5 min
Epidural regimen: questionnaire	Settings for the epidural pump as charted by the anesthesiologist and the nurse.	5 min
Maximum upper sensory block to ice: questionnaire	Maximum upper sensory block to ice as charted by the nurse in the electronic charting system	5 min
Any anesthetic intervention for patchy or asymmetric block	The anesthetic record will be reviewed for any interventions done.	5 min
Number of manual epidural top ups	The number of top ups given by nurses or physicians manually will be recorded from the chart.	5 min
Number of PCEA (patient controlled epidural analgesia) boluses delivered	Number of PCEA (patient controlled epidural analgesia) boluses delivered will be collected from the chart.	5 min
Duration of epidural analgesia	Time of epidural placement to delivery or placement to top up for caesarean delivery.	5 min
Quality of analgesia questionnaire - 1st stage	Quality of analgesia during first stage as defined by the patient on a VNRS (verbal numerical rating scale) 0-10 : On a scale from 0-10 (where 0 is not at all and 10 is the best ever), how well did your epidural work from the start of your epidural until you were fully dilated?	5 min
Quality of analgesia questionnaire - 2nd stage	Quality of analgesia during second stage as defined by the patient on a VNRS (verbal numerical rating scale) 0-10: On a scale from 0-10 (where 0 is not at all and 10 is the best ever), how well did your epidural work from you were fully dilated until the delivery of your baby?	5 min

Collaborators and Investigators

• Sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Publications and helpful links

General Publications

• van den Bosch OFC, Gleicher Y, Arzola C, Siddiqui N, Downey K, Carvalho JCA. Color flow Doppler in spinal ultrasound: a novel technique for assessment of catheter position in labor epidurals. Reg Anesth Pain Med. 2022 Dec;47(12):775-779. doi: 10.1136/rapm-2022-103948. Epub 2022 Sep 7.

Study record dates

Study Major Dates

• Study Start (Actual): November 17, 2021
• Primary Completion (Actual): June 6, 2022
• Study Completion (Actual): June 6, 2022

Study Registration Dates

• First Submitted: October 25, 2021
• First Submitted That Met QC Criteria: November 18, 2021
• First Posted (Actual): November 19, 2021

Study Record Updates

• Last Update Posted (Actual): July 29, 2022
• Last Update Submitted That Met QC Criteria: July 27, 2022
• Last Verified: July 1, 2022

More Information

Terms related to this study

• Keywords: ultrasound; epidural analgesia; labor epidural; Doppler; epidural catheter
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Labor Pain
• Other Study ID Numbers: 21-07

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No