Tsui Test as a Predictor of Bupivacaine Consumption in Labour Epidurals
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.
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||Tsui Test as a Predictor of Bupivacaine Consumption in Labour Epidurals|
- Consumption of bupivacaine in mg/hour in the first 2 hours of epidural anesthesia [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
- Incidence of inadequate epidural block. [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
- Current (mA) needed to elicit motor response; 1. before test dose and 2. 5 minutes after test dose. [ Time Frame: 5 minutes ] [ Designated as safety issue: No ]
- Contraction pattern elicited by the Tsui test at baseline and after test dose. [ Time Frame: 5 minutes ] [ Designated as safety issue: No ]
|Study Start Date:||November 2008|
|Study Completion Date:||August 2009|
|Primary Completion Date:||August 2009 (Final data collection date for primary outcome measure)|
Experimental: Tsui test
Tsui test administration.
Procedure: Tsui test
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.
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.
|Mount Sinai Hospital|
|Toronto, Ontario, Canada, M5G 1X5|
|Principal Investigator:||Jose CA Carvalho, MD||Mount Sinai Hospital, New York|