Reliability of pleth variability index in predicting preload responsiveness of mechanically ventilated patients under various conditions: a systematic review and meta-analysis

Background: Goal-directed volume expansion is increasingly used for fluid management in mechanically ventilated patients. The Pleth Variability Index (PVI) has been shown to reliably predict preload responsiveness; however, a lot of research on PVI has been published recently, and update of the meta-analysis needs to be completed.

Methods: We searched PUBMED, EMBASE, Cochrane Library, Web of Science (updated to November 7, 2018) and the associated references. Relevant authors and researchers had been contacted for complete data.

Results: Twenty-five studies with 975 mechanically ventilated patients were included in this meta-analysis. The area under the curve (AUC) of receiver operating characteristics (ROC) to predict preload responsiveness was 0.82 (95% confidence interval (CI) 0.79-0.85). The pooled sensitivity was 0.77 (95% CI 0.67-0.85) and the pooled specificity was 0.77 (95% CI 0.71-0.82). The results of subgroup of patients without undergoing surgery (AUC =0.86, Youden index =0.65) and the results of subgroup of patients in ICU (AUC =0.89, Youden index =0.67) were reliable.

Conclusion: The reliability of the PVI is limited, but the PVI can play an important role in bedside monitoring for mechanically ventilated patients who are not undergoing surgery. Patients who are expanded with colloid may be more suitable for PVI.