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

Abstract

BackgroundInferior 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.MethodsThis 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 (dIVCmax–dIVCmin)/dIVCmax, where dIVCmax and dIVCmin 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, dIVCmax, and dIVCmin in predicting PIH was also examined in a group of normotensive patients receiving non-cardiac surgery under the same anesthesia protocol.ResultsA 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 dIVCmax, and 0.868 (95% CI: 0.773–0.963) for dIVCmin. 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 dIVCmax, and 0.715 (95% CI: 0.571–0.858) for dIVCmin. At the optimal cutoff (1.24 cm), dIVCmax had 54.5% (18/33) sensitivity and 94.4% (17/18) specificity.ConclusionIn hypertensive patients, IVC-CI is unsuitable for predicting PIH, and dIVCmax is an alternative measure with promising performance.Clinical trial registration[http://www.chictr.org.cn/], identifier [ChiCTR2000034853].

Preoperative Ultrasound for the Prediction of Postinduction Hypotension: A Systematic Review and Meta-Analysis

“…The results of our study showed that the cutoff and age > 60 years were associated with the accuracy of the IVC-CI, and meta-regression analysis revealed a significant decrease in sensitivity for the prediction of PIH when the cutoff of the IVC-CI exceeded 50%, which was consistent with the results from previous studies [13,44]. Several studies [65][66][67] have shown that the baseline inferior vena cava (IVC) diameter varies with age, gender, weight, body mass index (BMI), and body surface area.…”

“…The IVC-CI was reported in 27 studies [12,13,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][52][53][54][56][57][58] with 2467 patients. PIH was observed in 48.03% of the patients.…”

“…DIVCmax was reported in 18 studies [12,13,[27][28][29]31,33,34,[37][38][39][40][42][43][44][45]57,58] that included 1654 patients. The area under the receiver operating characteristic curve was 0.77 (95% CI = 0.73, 0.81) (Figure 2).…”

“…Almost all studies clearly stated that an ultrasound assessment was performed before anesthesia induction. The method of patient selection, whether consecutive or not, was not clearly reported in some studies [13,14,32,33,37,41,44,59]. There is also the presence of an unclear risk of bias in patient flow and timing because not all patients were analyzed due to poor ultrasound visualization, especially when examining the inferior vena cava.…”

Inferior vena cava collapsibility index as a predictor of hypotension after induction of general anesthesia in hypertensive patients

“…In contrast to the current finding, Zhang and associates demonstrated poor performance of IVCCI (best cutoff value 50%) before induction in predicting hypotension after induction of GA in hypertensive patients (AUC 0.523 vs. 0.908 in the current study), while they found a comparable predictivity in normotensive patients (AUC 0.896). The different findings from the current study may be due to different sample sizes (51 vs. 153 hypertensive patients in the current study), different outcome definitions (based on MAP only in Zhang’s study vs. considering both SAP and MAP in the current study) or the state of hypertension control in the included patients (heterogenous population in Zhang study vs. controlled hypertensive patients in the current study) [ 22 ].…”