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

Study Overview
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Brief Summary
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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.

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

Conditions
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Labor Pain

Intervention / Treatment
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* Device: color flow Doppler ultrasonography


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients who had an epidural placed for labour<br>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<br>* Doppler ultrasonography<br>|

What is the study measuring?
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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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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epidural catheter, epidural analgesia, labor epidural, ultrasound, Doppler