Hemodynamic Response to Low-dose Epinephrine Infusion during Hypotensive Epidural Anesthesia for Total Hip Replacement

85 elderly patients undergoing total hip replacement with epidural anesthesia to T4 or above, where mean arterial pressure (MAP) was allowed to decrease to 50-55 mmHg to minimize blood loss.

Low-dose intravenous epinephrine infusion (less than 1 microgram/minute, 1-2 micrograms/minute, or 2-5 micrograms/minute) to maintain MAP at 50-55 mmHg.

No epinephrine infusion (zero dose).

Hemodynamic response (mean arterial pressure, heart rate, stroke volume, cardiac index, pulmonary artery diastolic pressure, left ventricular stroke work index, and systemic vascular resistance) measured via radial artery and thermodilution pulmonary artery catheters.surrogate