CARE STUDY: audit of complications of regional anesthesia. A prospective multicenter cohort study

BACKGROUND: Regional techniques are not risk-free. The aim of the study was to determine the complications associated with peripheral regional anesthesia and to identify factors that could increase the risk, to try to correct or prevent them. METHODS: This prospective observational study formed part of the CARE audit. Thirty-one hospitals across Spain participated in the study, 1528 patients scheduled for surgical procedures involving nerve and/or fascial plane blocks were included in the analysis. Data on demographics, block type and location, safety and the surgery was collected. The form also collected data on perioperative complications (e.g. local anesthetic toxicity) and long-term complications (1 month), as well as treatment required. RESULTS: Of 1546 consecutives patients, 1528 (99%) with complete follow-up were analyzed. Orthopedic procedures were predominant in the study (85%). Axillary block was the most frequently performed (21%), followed by interscalene (16.5%). Fascial blocks accounted for 16% of all blocks. Of these, transverse plane block was the most frequent (4.4%), followed by serratus anterior (3.75%). The cumulative percentage of immediate complications was 4,9%. Of these, bleeding (0.39%) and Horner's Syndrome (0.39%) were 'the most frequent. Diabetes or interscalene block has been shown as risk factor. However, ultrasound guidance showed to be a significant protective factor (P=0.002, OR 0.4, 95% CI 0.2-0.7), along with pressure control (OR 0.3-0.6). CONCLUSIONS: The study supports the belief that performing peripheral blocks is safe and has a low complication rate, with ultrasound providing protection.