Ultrasoud-Guided Diaphragmatic Motility Evaluation in Patients Undergoing Orthopaedic Surgery of the Upper Limb Under Regional Anesthesia Using Infraclavicular Block

Introduction: Infraclavicular brachial-plexus block provides complete, effective and safe anesthesia for upper-limb surgical interventions from the distal third of the arm onwards. This study evaluated the possible compromise of diaphragmatic motility using standardized ultrasonographic evaluation in patients who underwent this anesthetic technique. Methods: 53 patients were recruited for upper-limb orthopedic surgery distal to the shoulder. Bilateral ultrasonographic exploration of the diaphragm was made both before and after the regional anesthesia was performed. Diaphragmatic motility measurements were taken in forced inspiration and expiration utilizing a Convex, low frequency transducer. The deepest point of diaphragmatic visualization was identified and followed during inspiration and expiration maneuvers using M Mode Ultrasonography. Results: A standardized measurement of diaphragmatic motility was performed in every patient both before and after the block was undertaken. We obtained both qualitative and quantitative measurements obtaining an average absolute value of 6.63 cm (SD +/- 0,35) and 6.75 cm (SD +/- 0.42), respectively. A statistical Student t test was performed demonstrating no significant difference in diaphragm movement before and after the anesthetic procedure. Discussion: The use of ultrasonography in the evaluation of diaphragmatic motility is a simple, non-invasive and reproducible tool. There is no evidence of diaphragmatic paralysis after infraclavicular brachial-plexus block. However, the result may be related toe the low prevalence of this complication and with the absence of normal, standardized values of the variables of interest.