Parálisis diafragmática asociada al bloqueo interescalénico en cirugía de hombro: la utilidad de la ecografía diafragmática como herramienta diagnóstica

Abstract

Introduction: the interscalene block is used in a standardized way during major shoulder surgery, however, no technique performed above the clavicle has been shown to reduce the rate of phrenic nerve block below 20%. The interest for a diagnostic test to allows identifying the involvement of the phrenic nerve has been increasing in recent years and several diagnostic tests have been used. The purpose of this article is to evaluate the clinical utility of ultrasound to identify hemidiaphragmatic paralysis after interscalene block for shoulder surgery.

Materials and methods: prospective observational diagnostic study in thirty-three patients scheduled for shoulder surgery. A forced spirometry was performed and the thickness of the diaphragm muscle was evaluated with ultrasound. These determinations were made before and twenty minutes after performing the interscalene block.

Results: all the patients studied (100%) presented phrenic nerve block according to one or the two methods used in this study for its diagnosis. All patients presented variations in the diaphragm thickness ratio on the side of the phrenic block below 1.2.

Conclusion: the ultrasound examination of the diaphragm is a great tool for the examination of a viscera whose alteration implies serious disorders in the critical patient, in turn, the diaphragm thickness index <1.2 can be useful in the diagnosis of phrenic paresis associated with interscalene brachial plexus block.