The ability of left ventricular end-diastolic volume variations measured by TEE to monitor fluid responsiveness in high-risk surgical patients during craniotomy: a prospective cohort study

Background: This study was aimed to evaluate the ability of left ventricular end-diastolic volume variations (LVEDVV) measured by transesophageal echocardiography (TEE) compared with stroke volume variation (SVV) obtained by the FloTrac/Vigileo monitor to predict fluid responsiveness, in patients undergoing craniotomy with goal direct therapy. Methods: We used SVV obtained by the FloTrac/Vigileo monitor to manage intraoperative hypotension in adult patients undergoing craniotomy (ASA III - IV) after obtaining IRB approval and informed consent. The LVEDVV were measured by TEE through the changes of left ventricular short diameter of axle simultaneously. When cardiac index (CI) <= 2.5 and SVV >= 15%, comparisons were made between the two devices before and after volume expansion. Results: We enrolled twenty-six patients referred for craniotomy in this study and 145 pairs of data were obtained. Mean Vigileo-SVV and TEE-LVEDVV were 17.8 +/- 2.78% and 22.1 +/- 7.25% before volume expansion respectively, and were 10.95 +/- 2.8% and 13.58 +/- 3.78% after volume expansion respectively (P < 0.001). The relationship between Vigileo-SVV and TEE-LVEDVV was significant (r2 = 0.55; p < 0.001). Agreement between Vigileo-SVV and TEE-LVEDVV was 3.3% +/- 3.9% (mean bias +/- SD, Bland-Altman). Conclusions: For fluid responsiveness of patients during craniotomy in ASA III-IV, LVEDVV measured by left ventricular short diameter of axle using M type echocaidiographic measurement seems an acceptable monitoring indicator. This accessible method has promising clinical applications in situations where volume and cardiac function monitoring is of great importance during surgery.