Comparison of stroke volume variation with pulse pressure variation as a diagnostic indicator of fluid responsiveness in mechanically ventilated critically ill patients

OBJECTIVE: To compare the diagnostic accuracy of stroke volume variation (SVV) and pulse pressure variation (PPV) in studies that examined both parameters in the same patient population.

METHODS: Literature search was conducted in PubMed, EMBASE, CINAHL, and Google Scholar. Receiver operator characteristic (ROC) curves were examined, and summary ROC curves were plotted.

RESULTS: The study was conducted from January to July 2013 in The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, China. The meta-analysis of 19 studies published during the years 2005 and 2013 revealed a high degree of diagnostic accuracy of both SVV and PPV in predicting fluid responsiveness. The sensitivity and specificity of both the parameters were observed above 80% in a heterogeneous group of over 850 patients of which 55% responded to fluid challenge. The following values along with 95% confidence interval were noticed: SVV - sensitivity 82 (59-93%) and specificity 84 (62-95%), PPV - sensitivity 84 (62-95%) and specificity 83 (58-94%). Area under the curve values obtained in the pooled analysis were 0.84 (0.79-0.89) for SVV, and 0.88 (0.84-0.92) for PPV.

CONCLUSION: Both SVV and PPV exhibit a high degree of diagnostic accuracy in predicting the success or failure of a fluid challenge in hemodynamically unstable critically ill patients under controlled mechanical ventilation.