Pulmonary circulatory changes after bilateral total knee arthroplasty during regional anesthesia

Study ObjectiveTo monitor the pulmonary hemodynamics of patients undergoing bilateral total knee arthroplasty (BTKA) intraoperatively and up to 24 hours following surgery.DesignProspective observational study.SettingUniversity-affiliated teaching hospital.Patients30 ASA physical status 2 and 3 patients scheduled for single-stage, cemented BTKA during epidural anesthesia.InterventionsPulmonary artery catheters were in all patients.MeasurementsSystemic vascular resistance (SVR), pulmonary vascular resistance (PVR), the ratio of PVR to SVR at baseline, at the beginning of surgery, and after each knee implantation were recorded and compared with measurements taken one day postoperatively (POD 1).Main ResultsOn POD 1, PVR/SVR was increased by 30% compared with baseline (P < 0.0001) and by 20% versus the end of surgery (P < 0.0001). Systemic vascular resistance decreased during surgery and was significantly lower than baseline at 24 hours after surgery (P < 0.0001). No significant change in PVR was noted during surgery.ConclusionThe PVR/SVR ratio on the day following BTKA was increased. This change may represent the different effects of inflammatory perioperative stresses on the pulmonary and systemic vasculature.