Fragility Index and Trial Sequential Analysis for Randomized Controlled Studies Testing IV Vitamin C in Critically Ill Patients

Abstract

might be limited and dependent on the specific device. Third, rSo 2 only assess frontal cerebral areas and might be inadequate to assess global rSo 2 . Also, positioning of the probe cannot be adjusted as in the case of Pbto 2 catheter, which could be placed close to the "at risk areas" for ischemia (6) according to brain imaging.These concerns clearly indicate that the use of invasive or noninvasive brain oxygenation monitoring to guide RBCs transfusion in ABI patients remains an interesting and valuable approach, but more data on its feasibility and reliability are required before recommending it in clinical practice.

The authors reply

“…Next, Vargas et al (1) performed TSA of overall mortality but omitted one study (Fowler 2019). We performed a TSA with all studies ( n = 15) using the following variables: an alpha of 5%, power of 80%, intervention and control event rate of 20.92% (265/1,267), and 23.96% (293/1,223), respectively; heterogeneity correction based on model variance; and DerSimonian-Laird random-effect model.…”

“…We thank Vargas et al (1) for their interest in our recently published study in Critical Care Medicine (2). By analyzing the fragility index (FI) of all randomized controlled trials (RCTs) included in our systematic review and performing a trial sequential analysis (TSA) of our meta-analysis of overall mortality, they agreed with our position that a definitive conclusion regarding the efficacy of IV vitamin C cannot be made.…”