Fig. 1From: A spray-as-you-go airway topical anesthesia attenuates cardiovascular responses for double-lumen tube tracheal intubationUltrasound-guided SLN block and transtracheal injection. Note: a The tissue structure around the SLN under sagittal ultrasound, b the sagittal out-of-plane puncture under ultrasound. 2Â ml of 2% lidocaine solution was injected into the thyroglossal membrane. c The location of the cricothyroid membrane under coronal ultrasoundBack to article page