Factors Associated With Unintended Dural Puncture and Failed Neuraxial Anesthesia in Obstetric Anesthesia

Unintended dural puncture (UDP) and failed neuraxial anesthesia increase risks for conversion to general anesthesia, procedural delays, and patient dissatisfaction. Additionally, UDP can result in a postdural puncture headache (PDPH) with significant maternal morbidity. Factors such as clinician experience, multiple attempts, anatomical variation, and technical difficulty are modifiable areas for quality improvement. We aim to identify specific factors associated with UDP and failed regional at our institution.

A one-year (July 2024-July 2025) retrospective electronic medical record-deidentified cohort study was conducted as a quality-improvement registered project. Controls (n = 126) were compared with UDP (n = 41) and failed neuraxial anesthesia (n = 38). Factors analyzed included demographic data (age, height, weight, BMI, gravidity, parity, and gestation) American Society of Anesthesiologists physical status classification, trial of labor, anesthesia type (spinal, epidural, combined spinal-epidural (CSE), dural puncture epidural, and general), intrathecal catheter placement, conversion to general anesthesia, preeclampsia diagnosis, block attempts, provider status (resident, certified registered nurse anesthetist (CRNA), and attending), failed regional anesthetic, and PDPH. Interval data were analyzed using the t-test; nominal data were analyzed using the chi-square test, including odds ratios. Assumption corrections included Mann-Whitney nonparametric testing, unequal variance corrections on t-tests, and Fisher's exact tests, as needed. Alpha was set to 0.05.

Over this one-year period, 1,429 obstetrical cases were performed, with a UDP rate of 41 (2.9%) and a failed regional rate of 38 (2.7%). Factors significant for UDP included age, CSE anesthesia technique, provider status (more likely for a resident than a CRNA), more block attempts, intrathecal catheter placement, preeclampsia diagnosis, and PDPH. Factors significant for failed regional included older age, younger gestation, trial of labor, spinal anesthesia technique more likely than epidural, more block attempts, cesarean delivery, general anesthesia conversion, and preeclampsia diagnosis.

Our analysis identifies older maternal age, preeclampsia, multiple block attempts, and provider experience as key risk factors for UDP and failed regional, highlighting modifiable residency training targets to improve obstetric anesthetic outcomes.