Accuracy of preoperative evaluation of inferior vena cava collapsibility index and caval aorta index for prediction of hypotension after induction of general anesthesia: a prospective observational study

Abstract

Background & Objective: Post general anesthesia induction hypotension (PGAH) is not a rare event. Almost every induction agent has been incriminated to a variable extent. Preoperative ultrasound assessment of Inferior Vena Cava Collapsibility Index (IVCCI) has been investigated for predicting hypotension with mixed results. Inferior vena cava to aorta diameter index (IVC/Ao) hasn’t been studied before as a predictor for PGAH. We studied the comparative accuracy of preoperative IVCC and IVC/Ao index for PGAH prediction.

Methodology: This observational prospective blinded study involved 102 participants undergoing different surgeries under general anesthesia. Preoperative ultrasound assessment of IVCCI and IVC/Ao index was done. Mean arterial pressure (MAP) was assessed 6 times; before induction, 1 min and 3 min after induction and 1, 5 and 10 min after endotracheal intubation. The area under the receiver operating characteristic curve (AUROC) was calculated for the ability of IVCC and IVC/Ao index to predict PGAH. Stepwise, backward logistic regression model was constructed to detect and quantify the predictive factors of PGAH.

Results: A total of 80 (78.43%) patients developed PGAH. ROC curve analysis for PGAH prediction demonstrated better diagnostic accuracy for IVC/Ao index than IVCCI, as the AUC of both were 0.666 (P < 0.017) and 0.487 (P = 0.852) respectively. IVC/Ao index cutoff value was 0.852

Conclusions: Inferior vena cava collapsibility index and inferior vena cava to aorta diameter ratio (IVC/Ao) index are both reliable indicators of post general anesthesia induction hypotension. IVC/Ao index is a more accurate and reliable indicator than inferior vena cava collapsibility index.

Abbreviations: CVP: Central Venous Pressure; IVCCI: Inferior Vena Cava Collapsibility Index; IVC/Ao: Inferior Vena Cava to Aorta Diameter Index; IVCD: Inferior Vena Cava Diameter; PAOP: Pulmonary Artery Occlusion Pressure; PGAH: Post General Anesthesia Induction Hypotension

Key words: Hypotension; General Anesthesia; Ultrasound; IVCCI; Aorta

Citation: Omar H, Moamen A, Abdelhamid BM, Rady A, Farouk I. Accuracy of preoperative evaluation of inferior vena cava collapsibility index and caval aorta index for prediction of hypotension after induction of general anesthesia: a prospective observational study. Anaesth. pain intensive care 2023;27(4):449−455; DOI: 10.35975/apic.v27i4.2255

Received: October 12, 2022; Reviewed: March 03, 2023; Accepted: May 20, 2023