Preoperative Ultrasonographic Evaluation of Caval Aorta Diameter Index as a New Predictor for Hypotension after Induction of General Anesthesia in Geriatric Patients: A Prospective Observational Study.

Objectives: are the assessment of the prognostic performance of preoperative US determination of the inferior vena cava (IVC) collapsibility index (IVCCI) and the index of IVC to the abdominal aorta diameters (IVCD/AAD) for the development of post-induction hypotension (PIH) in elderly patients receiving general anesthesia (GA).Patients & Methods: 105 patients aged >60 years underwent preoperative US determination of ICVCI and IVCD/AAD index. Patients were invasively observed for the systolic blood pressure (SBP) and mean arterial pressure (MAP), and the development of PIH during 15 minutes after induction of anesthesia (Post-induction) using slow intravenous propofol (1.5 mg/kg) injection. Fentanyl (1 µg/kg) and Cis-atracurium (0.2 mg/kg) were injected, endotracheal intubation was performed, and anesthesia was maintained with sevoflurane 2%.Results: 58 patients (55.2%) developed PIH (PIH group). SBP and MAP were significantly lower compared to the baseline measures, and in the PIH than in the No-PIH groups. The estimated IVCDs were significantly narrower, while the AAD was significantly wider, and the IVCCI% was significantly higher, but the IVCD/AAD index was significantly lower in patients of PIH group. The IVCCI% (>45%) and IVCD/AAD (≤0.84) predicted the PIH with an accuracy rate of 91.7% and 93.8%, respectively. The IVCD/AAD index showed high specificity (97.6%). The IVCD/AAD demonstrated insignificant superiority in predictive accuracy for PIH.Conclusion: Preoperative IVCCI% and IVCD/AAD can define patients liable for PIH with a high accuracy rate. The IVCD/AAD showed superiority with high specificity and positive predictive value. ROC curve analysis ensured minor prognostic superiority for the IVCD/AAD.