Tsui Test as a Predictor of Bupivacaine Consumption in Labour Epidurals

Study Overview
=================
Brief Summary
-----------------
Low current electrical stimulation test, also called the Tsui test, has been used successfully to confirm the catheter location in the epidural space in various patient populations. The results of this study will show whether or not doing a Tsui test can predict inadequate epidural analgesia early in the course of placing the epidural, so that the appropriate measures could be applied immediately upon gathering unfavorable results.

Detailed Description
-----------------
Despite its very high success rate, the epidural technique remains a rather blind technique, and failures continue to occur. The incidence and reasons for failure are not well understood. The Tsui test is not routinely performed with each epidural catheter insertion, but rather it is used when there is suspicion about the catheter location. In this study, the Tsui test will be performed twice during the epidural procedure, and bupivacaine consumption will be recorded for the first 2 hours. Information gained from this study could have great impact in clinical practice, since the incidence of inadequate labor analgesia is still relatively high (10-20%), leading to maternal distress and disappointing labor experience.

Official Title
-----------------
Tsui Test as a Predictor of Bupivacaine Consumption in Labour Epidurals

Conditions
-----------------
Pain

Intervention / Treatment
-----------------
* Procedure: Tsui test


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Women over 18 years of age requesting an epidural for labor and delivery Cervix dilated 0-5 cm and pain VAS>6 Able to communicate in English Informed consent Exclusion Criteria: Refusal to provide written informed consent Patients unable to communicate in English Contraindication to regional anesthesia Allergy or hypersensitivity to lidocaine, bupivacaine or fentanyl Sedatives or opioids received prior to insertion of epidural catheter Abnormal vertebral anatomy, such as previous spine surgery and scoliosis Coexisting neurological disorders Patients with implanted electronic devices

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tsui test<br>Tsui test administration. | Procedure: Tsui test<br>* The stimulator is set at frequency of 1Hz with 200ms pulse width and the current output ranging from 0 to 20 mA. The current output will be carefully increased from zero until motor activity is detected up to a maximum of 20 mA.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Consumption of bupivacaine in mg/hour in the first 2 hours of epidural anesthesia |  | 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of inadequate epidural block. |  | 2 hours | 
| Current (mA) needed to elicit motor response; 1. before test dose and 2. 5 minutes after test dose. |  | 5 minutes | 
| Contraction pattern elicited by the Tsui test at baseline and after test dose. |  | 5 minutes | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Tsui test, Epidural Analgesia