Validación de la posición de Vallejo por ultrasonografía para acceso neuroaxial difícil en pacientes obstétricas

Abstract

Introduction:The neuraxial technique for anesthesia in patients undergoing cesarean section is preferred by anesthesiologists due to its lower rate of complications and the advantages over the mother and the fetus, however, daily we face difficult neuraxial accesses due to changes in the of pregnancy, obesity, musculoskeletal deformations, etc., which can hinder the success of the blockade and therefore the satisfaction of the patient. The objective of this study is to validate the Vallejo position by ultrasound to achieve a successful spinal block in obstetric patients classified as difficult neuraxial access. Method: This is a descriptive, prospective cohort study, which was carried out on patients admitted for scheduled Cesarean section at Atlas Clinics, Quito-Ecuador during the month of July-August 2022. The patients were examined to classify them as NBA (Neural Axial Access Difficult) of intermediate and high difficulty who underwent ultrasonography of the lumbar spine comparing the measurement of the interspinous space L3-L4 with and without the Vallejo position. Results: 138 obstetric patients were included, of which 36 patients were classified as NBA score of intermediate difficulty and 14 patients as NBA score of high difficulty (total of 50 patients). Of the 50 patients, 5 patients achieved neuraxial blockade at the first attempt. Ultrasonography of the lumbar spine was performed on the remaining 45 patients, obtaining a mean interspinous space measurement of L3-L4 of 2.55 cm without the Vallejo position and a mean of 3.10 cm with the Vallejo position. So, the mean opening with Vallejo's position was 0.544 cm. Conclusion: The Vallejo position offers an alternative to achieve a successful neuraxial blockade in obstetric patients who have difficult access to the neuraxis.