The Effect of Depth of Anaesthesia on the Severity of Mitral Insufficiency by Transesophageal Echocardiography

Abstract

he assessment of mitral regurgitation (MR) is complex and complicated by the dynamic nature of this valvular abnormality. Intraoperative transesophageal echocardiography (TEE) is a well-established tool that is used to assess the mitral regurgitation (MR) before and after mitral valve reconstruction. Although TEE can accurately define the mitral anatomy and mechanism of MR, general anaesthesia may have profound effects on loading conditions on left ventricle. This unloading effect of general anaesthesia on the left ventricle is dependent on the depth of anaesthesia; it increases as the depth of anaesthesia deepens. It is known that there is an effect with loading condition that affects severity of mitral regurgitation. This study conducted in the National Heart Institute in Cairo aimed at assessing the effect of depth of anaesthesia guided by bispectral index on the severity of mitral insufficiency as measured by transesophageal echocardiography. Anaesthetic induction and maintenance were standardized. On arrival in the operating room, ECG leads, pulse oximeter were applied to monitor any electrical changes heart rate and peripheral oxygen saturation. Under local infiltration of anaesthesia (lidocaine 2%) a wide bore intravenous cannula was inserted, patient received initial sedation with intravenous midazolam 0.05 mg/kg, followed by insertion of invasive arterial cannula in radial artery of the non-dominant hand after performing modified Allen’s test, invasive arterial cannula was inserted for monitoring of blood pressure and arterial blood gases sampling.