Patients can undergo lower extremity surgery by using the lumbar plexus block (LPB) technique. However, compared with central block, LPB problems were complex. For lower limb procedures, psoas compartment block is a suitable regional anaesthesia approach in place of central neuraxial blockade. As a peripheral nerve block, it is considered less dangerous than a central neuraxial block. However, it might result in some severe issues. Here, we describe a rare side effect of total spinal anaesthesia following psoas compartment block guided by a peripheral nerve stimulator.