The purpose of this study is to determine whether there is a difference in success outcome of the combined spinal epidural labor analgesia between air versus saline when used to identify the epidural space.

When the epidural needle is inserted initially, it is typically connected to a syringe filled with 2-3 ml or air or saline. This is used to help identify the placement of the epidural needle. Both air and saline are commonly used and it is not clear and debatable which is a better method to identify the correct placement of the needle. Some doctors like using air in the syringe because when a drop of clear fluid returned from the smaller spinal needle, it would be clear to indicate the correct space for first dose of medicine since no pre-existing fluid was used. In group Saline, 3 mL of saline will be used. In group Air, 3 mL of air will be used in the syringe during the procedure.

The medicine will be administered in the usual manner the doctor has identified the correct location for administration. The amount of pain during labor will be assessed the patient giving a number from 0 to 10 with 0 being no pain and 10 being the worst pain.

• Procedure: Air
• Procedure: Saline

• Active Comparator: Air 3 ml used to identify epidural space
• Active Comparator: Saline 3 ml used to identify epidural space

Inclusion Criteria:

• Pregnant females weighing less than or equal to 250 lbs
• Request for neuraxial labor analgesia

Exclusion Criteria:

• ASA physical status greater than II