Pulse pressure variation demonstrates dose-dependent response to volume resuscitation in pediatric craniosynostosis repair

BACKGROUND: Restoring intravascular volume in the face of hemorrhagic blood loss is a fundamental skill critical to the practice of anesthesiology. Predictors of fluid responsiveness in pediatric patients remain a challenge. Pulse pressure variation (PPV) is a valuable predictor of volume responsiveness in adults, but the utility in pediatric resuscitation remains controversial. Surgical correction of craniosynostosis occurs early in childhood and is commonly associated with significant, rapid blood loss intraoperatively. This study examines the relationship between blood product boluses with PPV and mean arterial pressure (MAP). METHODS: A retrospective, single center analysis of pediatric patients undergoing open cranial vault expansion over a four-year period was performed. Descriptive variables, blood product administrations, MAP, and PPV were extracted and analyzed using a linear mixed-effects model to characterize the association between blood product administration with MAP and PPV. To account for non-independence of repeated measures, the patient was modeled as a random effect with bolus events nested within the patient variable. RESULTS: A total of 798 bolus events from 111 patients met criteria. Patient ages ranged from 1-23 months (mean 10 months, SD 4.6 months). Transfusion of blood products was associated with increase in MAP by 1.60 mmHg [95% CI: 1.14, 2.06] and reduction in PPV by 0.82 percentage points [95% CI: 0.59, 1.06] (both p < 0.001). Notably, the magnitude of PPV reduction was dose-dependent: for each additional 10 mL/kg administered, post-bolus PPV decreased by an additional 0.4 percentage points [95% CI: 0.02, 0.07] (p = 0.002). In contrast, the MAP increase was not volume-dependent (interaction p = 0.918). CONCLUSION: This retrospective analysis of pediatric craniosynostosis repair cases at a single institution suggests that PPV is associated with a dose-dependent response to volume resuscitation, while MAP showed a fixed-magnitude response. These preliminary findings warrant further study in multicenter validity.