AUTHOR=Zhou Dan , Deng Li-Jing , Ling Yun-Fei , Tang Meng-Lin 

TITLE=Preoperative Hemoglobin Level, Oxygen Saturation and Postoperative Outcomes in Children With Cyanotic Congenital Heart Disease: A Propensity-Score Matching Analysis

JOURNAL=Frontiers in Pediatrics

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2021.762241

DOI=10.3389/fped.2021.762241

ISSN=2296-2360

ABSTRACT=<sec><title>Background</title><p>The optimal preoperative hemoglobin (Hb) level is difficult to define in children with cyanotic congenital heart disease (CHD) due to hypoxemia-induced secondary erythrocytosis. This retrospective study integrated preoperative Hb and pulse oxygen saturation (SpO<sub>2</sub>) using the product of Hb × SpO<sub>2</sub> to predict postoperative outcomes in children with cyanotic CHD.</p></sec><sec><title>Patients and Methods</title><p>Children aged &lt;18 years undergoing cardiac surgery with cyanotic CHD were included. The cutoff value of Hb × SpO<sub>2</sub> was the age-adjusted lower limit of normal Hb (aaHb) in healthy children. The main outcomes were in-hospital death and the composite outcome of severe postoperative events. Multivariate logistic regression analysis and propensity score matching analysis were used to adjust for important confounders.</p></sec><sec><title>Results</title><p>The presence of preoperative Hb × SpO<sub>2</sub> &lt; aaHb was observed in 21.6% of cyanotic children (<italic>n</italic> = 777). Children with Hb × SpO<sub>2</sub> &lt; aaHb had higher in-hospital mortality (12.5% vs. 4.6%, <italic>P</italic> &lt; 0.001) and composite outcome incidence (69.6% vs. 32.3%, <italic>P</italic> &lt; 0.001) than those with Hb × SpO<sub>2</sub> ≥ aaHb. After propensity score matching, 141 pairs of children were successfully matched. Multivariate analysis showed that preoperative Hb × SpO<sub>2</sub> &lt; aaHb was significantly associated with the composite outcome in the entire population (odds ratio = 4.092, 95% confidence interval = 2.748–6.095, <italic>P</italic> &lt; 0.001) and the matched cohorts (odds ratio = 2.277, 95% confidence interval = 1.366–3.795, <italic>P</italic> = 0.002).</p></sec><sec><title>Conclusion</title><p>Our results suggest that a preoperative Hb × SpO<sub>2</sub> value below the lower limit of normal hemoglobin is a prognostic factor in cyanotic children undergoing cardiac surgery and is a potential criterion to evaluate preoperative anemia in this population.</p></sec>