Ultrasound-guided dorsal penile nerve block for ED paraphimosis reduction

Adequate anesthesia for emergency department management of painful penile conditions such as paraphimosis or priapism is often both technically challenging and inconsistent using traditional landmark-based techniques of the dorsal penile block (DPB). The pudendal nerves branch to form the paired dorsal nerves of the penis providing sensory innervation to the skin of both the dorsal and ventral aspects of the penis. "Blind" DPB techniques tend to rely on subtle tactile feedback from the needle and visual landmark approximation to identify the appropriate subpubic fascial compartment for injection. The landmark-based DPB is not standardized with options including “10 o'clock and 2 o'clock” infrapubic injections with or without ventral infiltration or a ring block. Given the lack of standardization and inherent technical imprecision with the landmark-based DPB, large volumes of local anesthetic (up to 50 mL) are sometimes required to achieve a clinically adequate block. In addition, inadvertent injection into the corpora cavernosa may occur. More recently, an ultrasound-guided approach has been developed. Using ultrasound, the dorsal penile nerves can be precisely targeted in the fascial compartment just deep to Buck fascia, potentially increasing block success rate and reducing the need for large local anesthetic volumes. Herein, we report the first adult case of an ultrasound-guided dorsal penile nerve block performed in the emergency department for the reduction of a paraphimosis and review the relevant penile anatomy and technical details of the procedure.