Intraoperative Asystole Induced by Intramedullary Reaming During Orthopedic Surgery

Intramedullary nailing has become the standard of care for the treatment of femoral diaphyseal fractures due to its low incidence of complications and return of limb function. We present a case of a rare complication that we believe deserves attention for further studies and research. A 71-year-old female with a past medical history of essential hypertension, hypothyroidism, and osteoarthritis of the bilateral knees presented after a ground-level fall resulting in a right intertrochanteric femoral fracture. The patient underwent operative repair with an intramedullary nail during orthopedic surgery. Preprocedural vitals were stable, and no abnormalities were seen on preprocedural EKG. During the procedure, the patient experienced two episodes of asystole that began with intramedullary reaming and spontaneously resolved with cessation of reaming. The patient remained hemodynamically stable throughout the procedure, and as the patient's asystole acutely resolved to normal sinus rhythm after intramedullary reaming was stopped, no acute interventions were necessary, such as cardiopulmonary resuscitation or pharmacological interventions. The procedure was successfully completed. The patient had an unremarkable postoperative course and was discharged on postoperative day one. The suspected etiology of this finding is a parasympathetic-mediated bradycardia caused by transmitted pressures from the reaming through the hip joint and into the abdominal cavity. Only a few case reports have focused on intraoperative asystole associated with intramedullary reaming. In this case report, we aim to present another case of this rare occurrence and discuss current hypotheses of the physiology, with the main objective of recognizing transient asystole as a possible complication of intramedullary reaming and suggesting further research into understanding this physiology.