Association between cerebrospinal fluid confirmation during attempted combined spinal–epidural placement and documented early neuraxial analgesic failure: a retrospective cohort study

Background Combined spinal–epidural (CSE) analgesia is widely used in obstetric anesthesia, yet the clinical significance of cerebrospinal fluid (CSF) confirmation during attempted CSE placement remains uncertain. We evaluated whether CSF confirmation during attempted CSE placement was associated with documented early neuraxial analgesic failure during labor analgesia. Methods We performed a retrospective cohort study of patients undergoing attempted CSE placement for labor analgesia at a tertiary care center between June 2016 and January 2018. The primary analysis compared Any CSF Confirmation versus No CSF Confirmation. The primary outcome was documented early neuraxial analgesic failure within 3 hours of neuraxial placement. Multivariable logistic regression adjusted for demographic and procedural covariates. A secondary exploratory analysis evaluated CSF Confirmation at Initial Loss of Resistance, Eventual CSF Confirmation, and No CSF Confirmation groups. Results Among 1520 patients, documented early neuraxial analgesic failure occurred in 22 of 63 patients (34.9%) with No CSF Confirmation compared with 76 of 1457 patients (5.2%) with Any CSF Confirmation. After multivariable adjustment, absence of CSF confirmation remained strongly associated with documented early neuraxial analgesic failure (adjusted OR 10.30; 95% CI 5.71 to 18.58; p<0.001). In the secondary exploratory analysis, documented early neuraxial analgesic failure occurred in 5.0% of patients with CSF confirmation at initial loss of resistance, 10.1% with eventual CSF confirmation, and 34.9% with no CSF confirmation. Conclusions Absence of CSF confirmation during attempted CSE placement was strongly associated with documented early neuraxial analgesic failure during the subsequent 3-hour clinical management period. CSF-confirmation status was associated with early neuraxial analgesic outcomes but should not be interpreted as a direct measure of epidural catheter function or reliability.