The following is a summary of “Diagnostic accuracy of left ventricular outflow tract velocity time integral versus inferior vena cava collapsibility index in predicting post-induction hypotension during general anesthesia: an observational study,” published in the February 2024 issue of Critical Care by Sharma, et al.

Researchers started a prospective study to assess the effectiveness of point-of-care ultrasound (POCUS) measurements like inferior vena cava collapsibility index (IVC-CI) and left ventricular outflow tract velocity time integral (LVOT-VTI) in predicting fluid responsiveness preoperatively and guiding PIH (Post-Induction Hypotension) treatment.

They measured the LVOT-VTI and IVC-CI in 100 adult patients undergoing surgery. (LVOT-VTI stands for Left Ventricular Outflow Tract Velocity Time Integral, and IVC-CI stands for Inferior Vena Cava Collapsibility Index). LVOT-VTI and IVC-CI were measured 15 minutes before surgery. Post-anesthesia induction, they measured PIH for 20 minutes.

The results showed that 24% of patients experienced PIH. When considering the accuracy of the two methods, IVC-CI scored 0.613 for the area under the curve, with sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at 30.4%, 93.3%, 58.3%, 81.4%, and 73.6%, respectively. LVOT-VTI scored 0.853 for the area under the curve, with sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at 83.3%, 80.3%, 57.1%, 93.8%, and 77.4%, respectively. In the multivariate analysis, the predictive threshold for IVC-CI was >51.5, and for LVOT-VTI, it was ≤17.45. The OR for IVCCI was 8.491 (P=0.025), and for LVOT, it was 17.427 (P<0.001). LVOT-VTI assessment was possible in all patients, while 10% had difficulty with IVC measurements.

Investigators concluded that POCUS using LVOT-VTI emerged as a more accurate method (77.4% accuracy) than IVC-CI for predicting PIH in surgical patients, potentially reducing complications.

Source: accjournal.org/journal/view.php?number=1511