Pediatric Intensive Care Unit, Department of Women’s and Children’s Health, University Hospital of Padua, Padua, Italy Padova, Veneto, Italy
Abstract: Introduction/
Objective: Patients (pts) undergoing cardiovascular surgery experience a complex systemic inflammatory response syndrome with an important oxidative stress, generally associated with cardiopulmonary bypass (CBP). Vitamin C (vitC) is a water-soluble micronutrient, not synthetized by humans. It is known for its antioxidant properties, protecting biomolecules from reactive oxygen species and preserving endothelial function and microcirculation from oxidative stress. In some adult studies, cardiac surgery decreased vitC levels, consistent with increased oxidative stress. No data are available about vitC changes in children undergoing cardiac surgery. Aim of this study is to determine pre- and post-operative vitC plasma values in pediatric pts undergoing cardiac surgery.
Methods: A single-center prospective cohort study is being conducted since May 2021 on children undergoing cardiac surgery in our Pediatric Cardiac Surgery Unit in Padua, Italy. We excluded pts requiring renal replacement therapy and/or ECMO. Plasma concentration of vitC was measured pre- and post-operatively using high performance liquid chromatography and mass spectrophotometry. We considered vitC deficiency as a concentration < 11 μmol/L and hypovitaminosis when < 23 μmol/L. Demographic information, clinical history, surgical, intraoperative, and post-operative data were collected from pts’ records. Continuous variables were presented as median and interquartile range (IQR), discrete as data value and percentages. The Wilcoxon and the Fischer tests were used to test the difference between groups for continuous and discrete variables, respectively.
Results: We prospectively recruited 56 pediatric pts undergoing open heart surgery (M/F=23/33). Median age was 43 months (IQR 5–85.5). Median pre- and post-operative vitC were 59.5 (IQR 43–80.25) and 23.0 μmol/L (IQR 10.75–33), respectively. VitC decreased significantly by 60.51% (IQR 37.95–77.8, p< 0.01, Figure 1) corresponding to a median perioperative loss (Δ) of 29.5 μmol/L (IQR 20.75–52.25). Twenty-seven (48.2%) pts had post-operative hypovitaminosis C, 14 (25.0%) had vitC deficiency. Comparing pts according to their Δ (Table 1), duration of the surgical procedure, CBP and Aortic cross-clamp (AxC) were significantly higher in those pts that presented Δ>50%.
Conclusion: Our preliminary data suggest that cardiac surgery induces a significant reduction in perioperative vitC in the pediatric population, similar to what reported in adults. Longer surgical, CPB and AxC time were associated with vitC Δ>50%. Further studies may determine if post-operative hypovitaminosis is associated with significant changes in post-operative outcomes.
