Predicting the difficulty in performing a neuraxial blockade

BACKGROUND Traumatic placement of a needle during a neuraxial blockade has been related to many complications such as postdural puncture headache, trauma to neural structures and even spinal hematoma, causing permanent neurologic deficits. Although efforts to minimize the complications caused by traumatic neuraxial blockade have been made, nothing was found to be clear. The authors investigated the predictors of difficult neuraxial blockade using the first puncture success and number of attempts as measures to assess the difficulty. METHODS In this prospective observational study, 253 patients scheduled for elective surgery underwent spinal or epidural anesthesia. Patient data (age, sex, height, weight, body mass index, and quality of anatomical landmarks), the provider's level of experience, type of blockade (spinal or epidural), needle type/gauge and the distance from skin to subarachnoid or epidural space were recorded. Significant variables were first determined by Student's t-test and Pearson's chi square test and then logistic and Poisson regression tested the association of the first puncture success and number of attempts with the significant variables. RESULTS The provider's level of experience and the distance from skin to subarachnoid or epidural space were significant in logistic and Poisson regression. Body mass index was significant only in Poisson regression and the quality of anatomical landmarks was significant only in logistic regression. CONCLUSIONS Provider's level of experience and the distance from skin to subarachnoid or epidural space influenced the difficulty in performing a neuraxial blockade.