Response Patterns to the Electric Stimulation of Epidural Catheters in Term Pregnant Women
Condition: Labor Pain
MeSH terms: Labor Pain
Study type: Interventional

Summary: 
      Lumbar epidural analgesia is commonly used for labor pain relief due to its effectiveness and
      safety. Despite its very high success rate, the epidural technique remains a rather blind
      technique and failures continue to occur. The correct placement of an epidural catheter,
      however, remains a clinical problem, since there is no imaging technique that could be used
      at the bedside to determine the exact positioning of the catheter. The technique of a
      trans-catheter electric stimulation test (TCEST) has been successfully used to detect the
      proper epidural catheter location for pediatric, post-operative and laboring obstetric
      patients. The response to the TCEST with the uniport (single hole) epidural catheters has
      been well described. There is a growing body of evidence that multiport epidural catheters
      provide an advantage to uniport catheters, since additional ports likely allow for an
      enhanced distribution of the local anesthetic solution. This was shown to result in a lower
      incidence of inadequate analgesia, including unilateral sensory blockade and missed sensory
      segments. The characteristics of the TCEST response using a multiport catheter remain to be
      determined. The aim of this study is to compare the response patterns to the TCEST using a
      single port versus multiport wire reinforced epidural catheters. The hypothesis of this study
      is that the incidence of a bilateral response to the TCEST will be higher in the multiport
      catheter as compared to the uniport catheter.
    

Detailed description: 
      This will be a randomized double-blind controlled study. After recruitment of the patient,
      epidural anesthesia will be performed in the standard fashion employed in the investigators
      institution by a resident, fellow, or staff. Spinal ultrasound will be used prior to
      performing the epidural catheter insertion. Patients will be randomly allocated into two
      different groups to receive either a 19 gauge uniport catheter or a 19 gauge multiorifice
      catheter (Arrow Flextip plus, Arrow International Inc., Reading, PA). After securement of the
      catheter, the TCEST will be performed. The test will be repeated at 5 minutes, following a
      test dose, to determine the change in intensity of current required to elicit the motor
      response. Following the second testing, a loading dose of the standard anesthetic solution
      will be administered. The sensory level to ice will be tested at 20 minutes following
      injection of the loading dose of bupivacaine and fentanyl. The sensory level will be assessed
      from the sacral to the thoracic levels, bilaterally Failure of the epidural analgesia will be
      assessed, defined as no evidence of a sensory block to ice and absent pain relief. The need
      for catheter replacement will be determined within 2 hours of the completion of the loading
      dose.
    

Intervention name(s): Trans-catheter electric stimulation test
Intervention type(s): Device
Other intervention name(s): Tsui test
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Tsui Test; Labour; Epidural catheter