Factors associated with brachial plexus regional anesthesia failure for upper limb surgery

Introduction Brachial plexus block as an anesthetic technique for upper limb surgery has some advantages over general anesthesia. The technique is widely used in our practice, with high effectiveness and adequate safety profile. However, the relationship between block failure and failure-determining factors has not been measured. Objectives To identify and quantify brachial plexus block failure-associated factors for upper limb surgery as an initial observation aimed at developing prevention-oriented risk profiles and strategies. Materials and methods An analytical observational study was conducted by collecting data from electronic medical records of upper limb surgery using brachial plexus block from the San Ignacio University Hospital between 2011 to 2012. Block failures were identified using standardized clinical criteria, measuring potentially associated factors. Dichotomous comparisons were made and uni- and multivariate logistic regression analysis was performed to identify potential statistically significant variables, based on failed cases and successful controls. Results None of the proposed factors was independently associated with failure of brachial plexus block. A qualitative description of failed cases presented confounding factors associated with local practices and the failure characteristics did not show a clinically plausible trend. Conclusions There were no factors determined by patient, anesthetic procedure, surgical procedure and operator that could be independently associated with brachial plexus block failure. The suggestion is to fine-tune the definition of failures, not just in the research environment, but in the current clinical practice; to improve the anesthesia records to rise the numbers and the quality of data bases for a quantitative determination of the risk of peripheral regional anesthesia failure and design prevention strategies focused on risk groups.