Influence of the thoracic epidural anesthesia on the left ventricular function: an echocardiographic study.

BACKGROUND: Thoracic epidural anesthesia (TEA) is widely used for major surgery, but studies assessing its impact on left ventricular (LV) systolic and diastolic function are limited, and such studies have assessed patients already under general anesthesia and/or receiving volume expansion between examinations.

METHODS: Observational study at a secondary university hospital including consecutive awake patients undergoing major abdominal surgery without significant pre-existing cardiac disease. Patients received a pre-emptive intravenous volume loading before epidural catheter placement with puncture between T6-T7 and T8-T9. Hemodynamic and trans-thoracic echocardiography (TTE) parameters were assessed before and after establishing TEA with a 10 mL bolus of 2% lidocaine. Changes in heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac output (CO), LV systolic function (as evaluated by fractional shortening [FS]; ejection fraction [EF]; Simpson; S prime [S`]), and LV diastolic function were recorded.

RESULTS: Twenty-four awake patients were included. After TEA, HR, MAP, SV and CO significantly decreased (15.0%, 29.3%, 6.8% and 22%, respectively; all P<0.01); LV systolic function was also reduced by TEA (FS by 28%, EF-Simpson by 26%, S' by 15.3%, all P<0.001). TEA non-significantly reduced the incidence of diastolic dysfunction, from 65% (N.=15/23) to 43% (N.=10/23) patients (P=0.13) in the 23 complete diastolic function evaluations.

CONCLUSIONS: The net effect of TEA in awake patients is a reduction of HR and LV systolic function, which results in a reduction of the CO and the MAP. The effect of TEA on LV diastolic function remains to be addressed by larger studies.