3D Ultrasound-guided Labor Epidural Analgesia in the Morbid Obese Parturient

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

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).

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.

The control group (Group 2: Epidural) will receive the 'Blind/standard approach', which is the current standard of care using palpation in administering labor epidural analgesia. Additionally, an anesthesiologist will scan patient's back with Accuro device in turn off mode.

The treatment group (Group 1: Ultrasound and Epidural) will receive epidural analgesia using ultrasound pre-procedural scan with the ACCURO device.

The treatment group (Group 1: Ultrasound and Epidural) will receive epidural analgesia using ultrasound pre-procedural scan with the ACCURO device

The control group (Group 2: Epidural) will receive the 'Blind approach/palpation', which is using palpation in administering labor epidural analgesia. Additionally, anesthesiologist will scan patient's back with Accuro device in turned off mode

An epidural insertion attempt will be defined as advancement of the needle in an effort to enter the epidural space; a needle requiring withdrawal for redirection or reinsertion through the skin/another skin puncture will be counted as an additional attempt

Procedural difficulty will be rated by the performing anesthesiologist on a 10-point Likert scale from one (easy) to ten (extremely difficult).

Pressure pain thresholds will be obtained immediately prior to the epidural placement. The force that the patient will be indicated uncomfortable will be recorded. Each intervertebral level will be measured once. The PPT will be measured the next day after the discontinuation of the epidural.Twenty-four hours post-partum, pain with analgesia during labor was assessed using the Numerical Rating Scale (NRS).

Inclusion Criteria: American Society of Anesthesiologists physical status class I, II, or III. Term pregnancy. Requesting epidural analgesia for anticipated vaginal delivery. BMI>or = 40. Exclusion Criteria: Contraindication for epidural analgesia Inability to adequately understand the consent form. Incarcerated patients. Patients with known spinal deformities. Allergies to ultrasound gel. Allergies to local anesthetics