Transthoracic Echocardiography for Assessing the Preoperative Hypovolemia in Patients with Aneurysmal Subarachnoid...

Volume disturbances frequently occur after aneurysmal subarachnoid hemorrhage (a-SAH). Both hypovolemia and hypervolemia are associated with poor outcomes. Hence, we planned this study to determine preoperative volume status using echocardiography.

The primary objective was to determine the incidence of preoperative hypovolemia in a-SAH patients with echocardiography. The secondary objectives include association between hypovolemia and induction hypotension and relative risk, and relative sensitivity and specificity of echocardiographic indices in predicting induction hypotension.

Ninety-eight ASA-I or -II patients, aged 18-65 years, undergoing aneurysmal clipping surgery were included. Hypovolemia was assessed by inferior vena cava (IVC) diameter, IVC collapsibility index in subcostal view, left ventricular end-diastolic area and kissing-papillary sign in parasternal short axis view, and variations in left-ventricular outflow tract velocity-time integral (LVOT-VTI) in apical view. Induction-hypotension was defined as mean arterial pressure <70 mm of Hg until 10 min after induction.

Out of 98 patients, 69 (70%) were hypovolemic and 59 (60%) developed induction hypotension with a relative risk of 2.26. The IVC-Cx and LVOT-VTI were the most sensitive parameters for determining induction hypotension (76% and 91%, respectively). A combination of IVC-Cx and kissing-papillary signs were most reliable for determining induction hypotension (P = 0.010).

We conclude that the incidence of preoperative hypovolemia was 70%, and 60% of patients had induction hypotension. Dynamic parameters including IVC-Cx and VTI-variations are more reliable in predicting induction hypotension. We emphasize that preoperative screening of patients using ultrasound helps identify the hypovolemic patients in the preoperative area.