Does Ultrasound Help With Placement of Labor Analgesia in Pregnant Patients?
Condition: Pregnancy
Study type: Interventional

Summary: 
      The investigators believe that ultrasound guided CSE technique will accurately place the
      epidural needle in the midline position compared to epidural needle placement via palpation
      of anatomical landmarks. This will result in positive CSF in the spinal needle, correct
      placement of the catheter, and adequate symmetrical labor analgesia/anesthesia.
    

Detailed description: 
      Epidurals provide superior labor analgesia and anesthesia. Unfortunately, failure of epidural
      anesthesia and analgesia is a frequent clinical problem. In a heterogeneous cohort of 2,140
      surgical patients, a failure rate of 27% for lumbar epidural was described. However, the
      definition of a failed epidural is broad. Different definitions include insufficient
      analgesia to catheter dislodgement to conversion to general anesthesia. Epidural analgesia
      failures may result from technical difficulties, insufficiencies or overdosing of local
      anesthetics, epidural septum or midline adhesions, and placement of the epidural catheter
      through an intervertebral foramen or into the anterior epidural space. In an imaging study of
      failed epidurals, incorrect catheter placement accounted for half of the failures, while the
      remaining patients experienced suboptimal analgesia through a correctly positioned catheter.

      The incidence of overall failure was lower in patients receiving combined spinal-epidural
      (CSE) catheters versus epidural analgesia. In one study, the CSE technique provided decreased
      failure rates for labor analgesia and comparable or decreased failure rates for surgical
      anesthesia, when compared with reported failure rates for epidural anesthesia. It is believed
      that positive CSF flow in the spinal needle confirms correct epidural needle placement in the
      epidural space and also confirms the epidural needle to be in the midline position. Placement
      of the epidural needle in the midline position will minimize the incorrect placement of the
      catheter to one side, providing a symmetrical analgesia versus unilateral analgesia.

      However, the practice of CSE and epidural catheter placement relies on the palpation of
      anatomical landmarks that are not always easy to feel. Therefore, the epidural needle maybe
      placed "off midline" despite positive loss of resistance (LOR) that causes negative CSF flow
      in the spinal needle and an incorrectly placed catheter. As a result, the incorrect catheter
      placement will result in a "failed" or suboptimal epidural analgesia.

      Ultrasound has recently been utilized to facilitate lumbar epidurals and spinals. The US
      imaging of the lumbar spine in different scanning planes facilitates the identification of
      the landmarks necessary for appropriate epidural space location in pregnant patients. There
      are two acoustic windows that are effective for lumbar spine sonographic assessment: one seen
      on the transverse approach, and the other seen on the longitudinal paramedian approach. The
      ultrasound single-screen method using the transverse approach of the lumbar spine provides
      reliable information regarding the landmarks required for labor epidurals. The correct
      interspace and midline position are identified for correct placement of the CSE analgesia.
    

Intervention name(s): Use of Ultrasound; No ultrasound used
Intervention type(s): Device; Procedure
Intervention description(s): The ultrasound imaging of the lumbar spine in different scanning planes facilitates the identification of the landmarks necessary for appropriate epidural space location in pregnant patients. There are two acoustic windows that are effective for lumbar spine sonographic assessment: one seen on the transverse approach, and the other seen on the longitudinal paramedian approach. The ultrasound single-screen method using the transverse approach of the lumbar spine provides reliable information regarding the landmarks required for labor epidurals. The correct interspace and midline position are identified for correct placement of the CSE analgesia.; Palpation of anatomical landmarks is used for placement of labor analgesia
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Pregnant; labor; Epidural