Spread of anesthetic mixture as a predictor of clinical success of extraconal blockage

Abstract

Introduction: Cataract surgery is one of the most practiced worldwide, ocular anesthesia aims at analgesia, akinesia and normotonia, the effectiveness of peribulbar block is not very predictable and the administration of more anesthetic is necessary in more than half of the cases, the spread and extension of the anesthetic mixture within the content of the orbit is variable and this characteristic of inadequate reproducibility is the main disadvantage. Ultrasound supposes an improvement in the prediction of the anesthetic quality according to the analysis of the images obtained. Objective: To evaluate the efficacy of the peribulbar block according to the spread of the anesthetic mixture determined by ultrasound. Methods: This is an observational, descriptive, prospective and cross-sectional study with a sample of 52 patients who underwent peribulbar block and ultrasound visualization of the dispersion of the anesthetic mixture, who underwent cataract surgery. Results: The detection of the anesthetic mixture in the total extraconal, partial intraconal and total intraconal space results in a sensitivity of 92%, specificity of 78.57% and a positive predictive value of 92.11% with a confidence interval of 95%. Conclusion: Four propagation patterns of the anesthetic mixture in the retroocular space were described and an effectiveness projection was statistically calculated which correlated with the clinical conditions of the patients.