Gravity Flow Technique to Validate Proper Location of Epidural Needle Tip on Obese Parturients

Pregnant women, with a Body Mass Index (BMI) greater than 30 kg/m2, who receive epidural analgesia/anesthesia for childbirth will have epidural catheter placement per our standard procedure, which includes using the gravity flow technique to confirm that the tip (aperture) of the epidural needle is indeed located within the epidural space. The study procedure will be to use a cold stimulus (ice) to assess the subjects for hypesthesia the dermatomes of the lower abdomen between 10 and 30 minutes after the epidural catheter is inserted. Hypesthesia to cold will be taken a sign of successful lumbar epidural block.