We performed a systematic review and meta-analysis of studies investigating the diagnostic accuracy of respiratory variation in inferior vena cava diameter (ΔIVC) for predicting fluid responsiveness in patients receiving mechanical ventilation.
MEDLINE, EMBASE, the Cochrane Library, and Web of Science were screened from inception to February 2017. The meta-analysis assessed the pooled sensitivity, specificity, diagnostic odds ratio, and area under the receiver operating characteristic curve. In addition, heterogeneity and subgroup analyses were performed.
A total of 12 studies involving 753 patients were included. Significant heterogeneity existed among the studies, and meta-regression indicated that ventilator settings were the main sources of heterogeneity. Subgroup analysis indicated that ΔIVC exhibited better diagnostic performance in the group of patients ventilated with tidal volume (TV) ≥8 mL/kg and positive end-expiratory pressure (PEEP) ≤5 cm H2O than in the group ventilated with TV <8 mL/kg or PEEP >5 cm H2O, as demonstrated by higher sensitivity (0.80 vs 0.66; P = .02), specificity (0.94 vs 0.68; P < .001), diagnostic odds ratio (68 vs 4; P < .001), and area under the receiver operating characteristic curve (0.88 vs 0.70; P < .001). The best ΔIVC threshold for predicting fluid responsiveness was 16% ± 2% in the group of TV ≥8 mL/kg and PEEP ≤5 cm H2O, whereas in the group of TV <8 mL/kg or PEEP >5 cm H2O, this threshold was 14% ± 5%.
ΔIVC shows limited ability for predicting fluid responsiveness in distinct ventilator settings. In patients with TV ≥8 mL/kg and PEEP ≤5 cm H2O, ΔIVC was an accurate predictor of fluid responsiveness, while in patients with TV <8 mL/kg or PEEP >5 cm H2O, ΔIVC was a poor predictor. Thus, intensivists must be cautious when using ΔIVC.
From the *Department of Surgical Intensive Care Unit, The First Affiliated Hospital
†Department of Intensive Care Unit, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People’s Republic of China.
Published ahead of print May 21, 2018.
Accepted for publication April 16, 2018.
Funding: This study was supported by the grants from Sun Yat-Sen University Clinical Research 5010 Program (2007015).
The authors declare no conflicts of interest.
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X. Si and H. Xu contributed equally and share first authorship.
Reprints will not be available from the authors.
Address correspondence to Xiangdong Guan, PhD, MD, Department of Surgical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan No. 2 Rd, Guangzhou, People’s Republic of China. Address e-mail to firstname.lastname@example.org.