Pneumatic Pulse Simulation for Teaching Peripheral Plexus Blocks in Cadavers

To the Editor: Arterial pulses are anatomic landmarks for some frequently used regional anesthetic blocks. For teaching and training, we developed a compact, portable, pneumatically driven, and electronically controlled system to artificially generate palpable pulses in cadavers. A thrombectomy catheter is inserted into an artery and connected to a modified infant respirator (Dräger, Germany). To generate local pulses the catheter balloon is insufflated rhythmically at 0.75 to 1.2 bar. In a previous early postmortem study (1), artificial axillary, subclavian, and femoral artery pulses were palpable in 88% and recordable in 78% of attempts. Failure to palpate or record pulses was due to anatomic variants, arterial disease, or skin induration (1). In the present series, the system was used in eight anatomic cadavers embalmed with the method described by Thiel (2), an embalming process with which the flexibility of cadavers and lifelike consistence of tissue are preserved. Palpable pulses were found in 91% of attempts. The system was used to teach 189 students who evaluated it on a scale of 1 to 4. Overall, 164 students (87%) reported very good and 21 (11%) good improved learning experience. In summary, pulse simulation in specially embalmed cadavers appears to be effective in improving teaching of regional blocks. Gerhard Schwarz, MD Georg Feigl, MD Reinhold Kleinert, MD Christian Dorn, MD Gerhard Litscher, PhD Andreas Sandner-Kiesling, MD Norbert Bock, PhD