Cardiac output during hemiarthroplasty of the hip - A prospective controlled trial of cemented and uncemented prostheses

In a prospective, controlled study, we measured the effect on cardiac outpu t of the introduction of methylmethacrylate during hemiarthroplasty for dis placed fractures of the femoral neck. We treated 20 elderly patients who we re similar in age, height, weight and preoperative left ventricular functio n with either cemented or uncemented hemiarthroplasty, Using a transoesopha geal Doppler probe, we measured cardiac output before incision and at six s tages of the procedure: during the surgical approach, reaming and lavage of the femoral canal, the introduction of cement, the insertion of the prosth esis, and in reduction and closure. We found that before the cement was introduced, there was no difference in stroke volume or cardiac output (p > 0.25). Cementation produced a transien t but significant reduction in cardiac output of 33% (p < 0.01) and a reduc tion in stroke volume of 44% (p < 0.02). The introduction of cement did not affect the heart rate or mean arterial pressure, There was no significant difference in cardiac function on insertion of the prosthesis. Standard non -invasive haemodynamic monitoring did not detect the cardiovascular changes which may account for the sudden deaths that sometimes occur during cement ed hemiarthroplasty. The fall in stroke volume and cardiac output may be caused by embolism occu rring during cementation, but there was no similar fall during reaming or i nsertion of the prosthesis.