Early heart rate variability changes during acute fetal inflammatory response syndrome: An experimental study in a fetal sheep model.

INTRODUCTION: Fetal infection during labor with fetal inflammatory response syndrome (FIRS) is associated with neurodevelopmental disabilities, cerebral palsy, neonatal sepsis, and mortality. Current methods to diagnose FIRS are inadequate. Thus, the study aim was to explore whether fetal heart rate variability (HRV) analysis can be used to detect FIRS. MATERIAL AND METHODS: In chronically instrumented near-term fetal sheep, lipopolysaccharide (LPS) was injected intravenously to model FIRS. A control group received saline solution injection. Hemodynamic, blood gas analysis, interleukin-6 (IL-6), and 14 HRV indices were recorded for 6 h. In both groups, comparisons were made between the stability phase and the 6 h following injection (H1-H6, respectively) and between LPS and control groups. RESULTS: Fifteen lambs were instrumented. In the LPS group (n = 8), IL-6 increased significantly after LPS injection (p < 0.001), confirming the FIRS model. Fetal heart rate increased significantly after H5 (p < 0.01). In our FIRS model without shock or cardiovascular decompensation, five HRV measures changed significantly after H2 until H4 in comparison to baseline. Moreover, significant differences between LPS and control groups were observed in HRV measures between H2 and H4. These changes appear to be mediated by an increase of global variability and a loss of signal complexity. CONCLUSION: As significant HRV changes were detected before FHR increase, these indices may be valuable for early detection of acute FIRS.

Antioxidants other than vitamin C may be detected by glucose meters: Immediate relevance for patients with disorders targeted by antioxidant therapies.

Owing to their ease of use, glucose meters are frequently used in research and medicine. However, little is known of whether other non-glucose molecules, besides vitamin C, interfere with glucometry. Therefore, we sought to determine whether other antioxidants might behave like vitamin C in causing falsely elevated blood glucose levels, potentially exposing patients to glycemic mismanagement by being administered harmful doses of glucose-lowering drugs. To determine whether various antioxidants can be detected by seven commercial glucose meters, human blood samples were spiked with various antioxidants ex vivo and their effect on the glucose results were assessed by Parkes error grid analysis. Several of the glucose meters demonstrated a positive bias in the glucose measurement of blood samples spiked with vitamin C, N-acetylcysteine, and glutathione. With the most interference-sensitive glucose meter, non-blood solutions of 1 mmol/L N-acetylcysteine, glutathione, cysteine, vitamin C, dihydrolipoate, and dithiothreitol mimicked the results seen on that glucose meter for 0.7, 1.0, 1.2, 2.6, 3.7 and 5.5 mmol/L glucose solutions, respectively. Glucose meter users should be alerted that some of these devices might produce spurious glucose results not only in patients on vitamin C therapy but also in those being administered other antioxidants. As discussed herein, the clinical relevance of the data is immediate in view of the current use of antioxidant therapies for disorders such as the metabolic syndrome, diabetes, cardiovascular diseases, and coronavirus disease 2019.