Outcomes
paresthesia, pain, failure of labor, Labor pain, headache, bloody
SECONDARY, COMPLICATIONS, PARESTHESIA
Primary outcome was the procedural time of CSE anesthesia, defined as the sum of the identification time and performance time (Fig. The secondary outcomes were the epidural success rate (overall, at the first skin puncture attempt, and at the first needle pass without redirections), success rate of dural puncture through the NTN technique (overall and at the first spinal needle pass without redirections), number of needle passes (defined as the number of needle redirections without removing the needle from the skin, including the first pass) for the first successful epidural placement, number of epidural needle insertion attempts (defined as the number of each needle punctures through the skin) for the successful CSE placement, number of epidural needle redirections for success of NTN technique, use of alternative methods, number of interspace levels at which insertion was attempted, depth to the ligamentum flavum-dura mater complex measured by handheld ultrasound, actual needle depth at LOR, and actual spinal needle depth at CSF return. We measured the spinal needle depth using the scale marked on the CSE needle (Portex CSEcure). We also assessed periprocedural complications, including radicular pain, paresthesia, bloody tapping, inadvertent dural puncture with the epidural needle, failure of labor analgesia (defined as the need to reinsert a new epidural catheter owing to lack of sufficient analgesia within 2 h of the primary insertion), post-dural puncture headache, and incidence of back pain at the site of epidural insertion. Labor pain before and after analgesia (11-point numeric scale, 0 = no pain, 10 = worst pain imaginable), back pain during the procedure (0 = no pain, 10 = worst pain imaginable), discomfort during the procedure (0 = no discomfort, 10 = most discomfort imaginable), and patient satisfaction score with overall labor analgesia (0 = very unsatisfied, 10 = very satisfied) were also evaluated.The successful epidural placement was confirmed by the LOR to air, and the successful spinal placement was defined as the presence of CSF return with the spinal needle placed through the epidural needle. The time of each component of the CSE procedure was also recorded as follows (Fig. Two independent observers recorded the outcomes. The intra-procedural outcome assessor could not be blinded to the group allocation owing to the presence of skin markings in the ultrasound group. However, a blinded observer entered the room after completing the CSE procedure and evaluated the post-procedural outcomes. An electronic timer was used to accurately record each time interval. Independent research staff pressed the lap button of the stopwatch at each time point and recorded the time intervals.