3D Ultrasound-guided Labor Epidural Analgesia in the Morbid Obese Parturient: A Randomized Control Trial

Worldwide obesity has become an epidemic. The obstetrical population is no exception. This made more challenging for anesthesiologists on labor and delivery units to administer epidural analgesia. According to the World Health Organization, more than 30% of U.S. adults are obese with a body mass index (BMI; in kg/m2) ≥ 30. Recent data has shown that increased BMI has been associated with increased neuraxial analgesic failure and difficulty with prolonged epidural placement time.

The 'Blind approach' is the current standard of care in administering neuraxial anesthesia. The physician palpates the patient's spinal bony landmarks; the needle is placed in relation to identified landmarks and inserted until loss of resistance is felt. In the obese population, the success rates are as low as 68%. Recently the FDA has approved a handheld device "The Accuro" as an adjunct for neuraxial analgesia (Rivanna Medical, LLC). It consists of a three-dimensional ultrasound device. By utilizing sound waves it constructs three-dimensional images of the spinal column, allowing the physician to better see the spine in order to perform spinal/epidural anesthesia.

Hypothesize that this device will enable clinicians to assess epidural spaces for epidural needle placement compared with the traditional Blind approach in the morbidly obese parturient.

This study will be a randomized control study, with the objective to evaluate epidural analgesia success rates between the two methods (Blind Approach versus Accuro Device). Also, will determine if ultrasound based landmarks would reduce the needle tract and thereby reduced the amount of post-procedure pain at the insertion site in the peripartum period by using the algometer.