Intraoperative monitoring for safety of bilateral total knee replacement.

Cardiopulmonary hemodynamics in 79 consecutive patients who had one-stage bilateral total knee replacements were monitored prospectively with a pulmonary artery catheter. The pulmonary vascular resistance, wedge pressure, pulmonary artery pressure, and systemic vascular resistance were measured before skin incision, 5 to 10 minutes after implanting the first total knee replacement, and after the second knee replacement. The second knee replacement was cancelled in five patients because the pulmonary vascular resistance after the first knee replacement was more than double the baseline, or above 200 dyne/second/cm(5).