Influence of mechanical ventilation and loading modifications on left ventricular global longitudinal strain in patients undergoing general anesthesia: a pilot study

Abstract

The modifications of left ventricular systolic function assessed with global longitudinal strain (GLS) after general anesthesia and invasive mechanical ventilation are poorly described. This was a single-center observational study. ASA I-II patients undergoing routine surgical procedures requiring anesthesia with invasive mechanical ventilation had serial trans-thoracic speckle-tracking echocardiography: at baseline, five minutes after anesthesia and invasive mechanical ventilation, one minute after passive leg raising and after extubation. The primary objective was to evaluate the modification of left ventricular systolic function, assessed with GLS, under anesthesia and mechanical ventilation. Secondary objectives were to evaluate the alterations of GLS after pre-load modifications with passive leg raising and after extubation. From November 2016 to July 2017, 27 patients were included. Baseline left ventricular ejection fraction (LVEF: 60% [56-63]) and GLS (-20.6% [-23.2/-19.2]) were within normal ranges. After anesthesia, LVEF was not altered but GLS showed a significant decrease (-18.2% [-20.4/-17.1], P<0.05). After passive leg raising, GLS was significantly impaired compared with baseline (-17.6% [-19.7/-15], P<0.05) and seven (26%) patients presented systolic function impairment (GLS >-16%). GLS was similar to baseline after extubation (-21.7% [-23.1/-19.5], P>0.05). Systolic function assessed with GLS is impaired after general anesthesia and invasive mechanical ventilation in patients without cardiovascular co-morbidities but remains within normal range.