Preoperative anemia is an important modifiable risk factor for red blood cell (RBC) transfusion in a variety of surgical populations. The primary objective of this study was to examine the association between preoperative anemia and 1) Within 72 hours of surgery and 2) postoperative clinical outcomes in children undergoing spine arthrodesis surgery.

The researchers assembled a retrospective cohort of children included in the American College of Surgeons National Quality Improvement Program (ACSNSQIP) Pediatric database who underwent spine arthrodesis surgery from 2012 to 2016. Anemia was defined using age- and sex-specific hematocrit thresholds.

Data collected included demographic and surgical characteristics, RBC transfusion within 72 hours, and 30-day postoperative outcomes (postoperative mechanical ventilation, infection, readmission, hospital length of stay, mortality). Multivariable logistic regression analyses were used to identify independent predictors of RBC transfusion and postoperative outcomes.

Preoperative anemia

They included 9,095 patients in the analysis. Preoperative anemia was present in 14% (n = 1,233) of the population and 67% (n = 6,135) of patients were transfused. Our multivariable logistic regression showed anemia, surgical time > 350 minutes, > 7 vertebral levels fused, neuromuscular disease, and cerebral palsy were all independent predictors of RBC transfusion. Preoperative anemia was also associated with prolonged hospital LOS (adjusted OR: 1.31, 95%CI: 1.11-1.54, p = 0.002).

In this study of 9,095 children undergoing spine surgery, preoperative anemia was associated with an increased risk of RBC transfusion and prolonged LOS. Further studies are needed to determine if treatment of preoperative anemia can effectively reduce intraoperative RBC transfusion.

ACS NSQIP Pediatric does not include any information regarding perioperative management of anemia at the center level and whether PBM programs existed or were implemented during the study period. Further studies are therefore needed to assess the effect of implementation of a PBM program on the incidence of transfusion and outcome in the studied population.

Differences in outcomes (e.g., LOS) could also be confounded by standardized clinical practices in individual hospitals, but ACS NSQIP does not allow comparisons between centers.

Thus, the analysis could not account for clustering and we were not able to test for intercenter variability in outcomes. Although the multivariable logistic regression models adjusted for potential confounding factors, there could still be unmeasured covariates that may still bias our results.

In conclusion, the study shows that in the pediatric population undergoing spine surgery preoperative anemia increases the risk of perioperative RBC transfusion and postoperative hospital LOS. Therefore, identifying patients with preoperative anemia might decrease intraoperative blood transfusion as well as LOS.

The development of a blood management program in this specific population is urgently needed, and further studies are needed to assess the best treatment of preoperative anemia, identify patients at higher risk of transfusion (e.g., > 7 levels fused, prolonged surgeries) as well as to develop protocols for intraoperative blood management. Further studies are also needed to determine if preoperative treatment of anemia can reduce intraoperative transfusion and LOS.