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

Abstract 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. We also contacted relevant authors and researchers. Results: Twenty-five studies with 975 patients were included in this meta-analysis. All patients were mechanically ventilated. The area under the curve (AUC) of receiver operating characteristics (ROC) to predict preload responsiveness in patients 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.