Lumbar epidural space was narrower in parturients than that in nonpregnant women by ultrasound assessment

Abstract

Labor epidural is commonly used to provide both regional anesthesia and postoperative pain relief. Epidural space is supposed to be narrower and deeper in a parturient than that in a nonpregnant woman. The aim of this study was to explore the difference of epidural spaces between parturient and nonpregnant women by ultrasound assessment. Thirty nonpregnant female volunteers and 30 parturients undergoing labor epidurals were enrolled to receive ultrasound examination. A low-frequency (2-5 MHz) curved-array ultrasound probe was used to obtain spinal sonoanatomy for each subject. The longitudinal paramedian scanning plane was used to obtain optimal ultrasound image for spinal sonoanatomy. Primary outcome was evaluated by the diameter and depth of epidural space at three lumbar interspaces (from L2 to L5). The quality of ultrasound images was also compared between the groups by a numerical scoring system (from 0 to 3). The mean diameters of lumbar epidural spaces were 3.03 ± 0.45 mm and 4.44 ± 0.49 mm (p<0.05) for parturients and nonpregnant women, respectively. The mean depths of lumbar epidural spaces for parturients and nonpregnant women were 3.53 ± 0.62 cm and 3.25 ± 0.63 cm, respectively (p<0.05). The mean scores for epidural space image quality were 2.58 ± 0.58 and 2.63 ± 0.53 for parturients and nonpregnant women, respectively (p=0.08). Epidural space is narrower and deeper at lumbar interspaces in obstetrics by ultrasound examination. The quality of ultrasound images did not differ significantly between the groups. These quantitative results improve the understanding of the differences between two groups that have been previously known qualitatively and may help in avoiding complications.

Epidural Blood Patch as a Treatment Intervention in Post-Dural Puncture Headache: A Systematic Review of Randomised-Controlled Trials

“…Obstetric patients are thus particularly predisposed to PDPH. This is also due to the increased technical difficulty encountered when performing epidural anaesthesia due to the narrowed epidural space, which may require multiple attempts and also due to straining during delivery, which can lead to CSF leakage at the dural puncture orifice [16,19].…”

Ultrasound diagnosis and therapeutic intervention in the spine

“…This large quantity of patients may benefit from the reliable visualization offered by ultrasound compared to landmark identification (34,90,91). Epidural catheter placement can be aided by ultrasound, resulting in improved success rate for visualizing the dura and epidural space (49,57,59,74,85,88,(92)(93)(94). Chin et al found that ultrasoundaided imaging improves the success rate of spinal anesthesia in adults by 100% (70).…”

Soft catheters reduce the risk of intravascular cannulation during epidural block—A retrospective analysis of 1117 cases in a medical center

“…Whether spinal process was easily palpable or not was reported as a predictor of difficult epidural anesthesia [1]. In addition to loss of resistance technique, ultrasound or real‐time fiber‐optic‐guided technique was a new method to facilitate needle placement in the exact epidural space [2,3]. Inserting the epidural catheter is also an important step in such practices and is associated with several complications, including blood or wet tapping.…”