[Ultrasonographic assessment of hemidiaphragm paralysis secondary to interscalene block]. / Evaluación ultrasonográfica de la parálisis hemidiafragmática secundaria a bloqueo interescalénico.

BACKGROUND: In shoulder surgery, interscalene brachial plexus block has an incidence of 100% hemidiaphragm palsy due to phrenic nerve block. Controling the hemidiaphragm becomes a security ventilation parameter. OBJECTIVE: identify and evaluate with ultrasound hemidiaphragm paralysis after interscalene block. METHODS: This prospective study included 50 patients scheduled for shoulder surgery with interscalene block using neurostimulation. Diaphragmatic movement was evaluated by ultrasound prior to placement of block and the end of the surgical procedure to make the comparison between the two measurements. RESULTS: Comparing the duration of the respiratory cycle at the start and the end of the surgical procedure, both normal and forced ventilation, there is a statistically significant difference of p < 0.001, as with the depth of the hemidiaphragm was found p < 0.001. 90% of patients had no adverse events, 8% had Horner's syndrome and 2% periauricular hypoesthesia. Hemidiaphragm paralysis was found in all cases, with a volume of 30 mL local anesthetic. CONCLUSIONS: Ultrasound is a reliable tool that allows real time viewing of the respiratory cycle and measurements of the diaphragm dome it serves to identify diaphragmatic hemiparesis.