Maximum inferior vena cava diameter predicts post-induction hypotension in hypertensive patients undergoing non-cardiac surgery under general anesthesia: A prospective cohort study

Hanying Zhang; Hongguang Gao; Yuanjun Xiang; Junxiang Li

doi:10.3389/fcvm.2022.958259

Maximum inferior vena cava diameter predicts post-induction hypotension in hypertensive patients undergoing non-cardiac surgery under general anesthesia: A prospective cohort study

Front Cardiovasc Med. 2022 Oct 4:9:958259. doi: 10.3389/fcvm.2022.958259. eCollection 2022.

Authors

Hanying Zhang¹, Hongguang Gao¹, Yuanjun Xiang¹, Junxiang Li¹

Affiliation

¹ Department of Anesthesiology, Third Affiliated Hospital of Chengdu Medical College and Pidu District People's Hospital Chengdu, Chengdu, Sichuan, China.

Abstract

Background: Inferior vena cava (IVC) ultrasonography is a reliable variable that predicts post-induction hypotension (PIH) in patients undergoing surgery under general anesthesia. However, in patients with hypertension, the predictive performance of ultrasound IVC measurements needs further exploration.

Methods: This is a prospective cohort study. Adult patients with existing hypertension scheduled to undergo non-cardiac surgery under general anesthesia were eligible. An abdominal ultrasound examination was conducted immediately prior to anesthesia induction (0.03 mg kg^-1 midazolam, 0.3 mg kg^-1 etomidate, 0.4 μg kg^-1 sufentanil, and 0.6 mg kg^-1 rocuronium). IVC collapsibility index (IVC-CI) was calculated as (dIVC_max-dIVC_min)/dIVC_max, where dIVC_max and dIVC_min represent the maximum and minimum IVC diameters at the end of expiration and inspiration, respectively. PIH was defined as a reduction of mean arterial pressure (MAP) by >30% of the baseline or to <60 mmHg within 10 min after endotracheal intubation. The diagnostic performance of IVC-CI, dIVC_max, and dIVC_min in predicting PIH was also examined in a group of normotensive patients receiving non-cardiac surgery under the same anesthesia protocol.

Results: A total of 51 hypertensive patients (61 ± 13 years of age, 31 women) and 52 normotensive patients (42 ± 13 years of age, 35 women) were included in the final analysis. PIH occurred in 33 (64.7%) hypertensive patients and 19 (36.5%) normotensive patients. In normotensive patients, the area under the receiver operating curve (AUC) in predicting PIH was 0.896 (95% confidence interval [CI]: 0.804-0.987) for IVC-CI, 0.770 (95% CI: 0.633-0.908) for dIVC_max, and 0.868 (95% CI: 0.773-0.963) for dIVC_min. In hypertensive patients, the AUC in predicting PIH was 0.523 (95% CI: 0.354-0.691) for IVC-CI, 0.752 (95% CI: 0.621-0.883) for dIVC_max, and 0.715 (95% CI: 0.571-0.858) for dIVC_min. At the optimal cutoff (1.24 cm), dIVC_max had 54.5% (18/33) sensitivity and 94.4% (17/18) specificity.

Conclusion: In hypertensive patients, IVC-CI is unsuitable for predicting PIH, and dIVC_max is an alternative measure with promising performance.

Clinical trial registration: [http://www.chictr.org.cn/], identifier [ChiCTR2000034853].

Keywords: general anesthesia; hypertension; inferior vena cava; post-induction hypotension; ultrasound.