46 - Rate of laboratory correction as predictor of severity of brain injury in hypoxic-ischemic encephalopathy (HIE)

Publication Number: 1039.46

Shannon T. Vice, University of Florida College of Medicine, Gainesville, FL, United States; James L. Wynn, University of Florida College of Medicine, Gainesville, FL, United States; Shamil Sheth, University of Florida College of Medicine, Wildwood, FL, United States; Kaitlyn Lagnese, University of Florida College of Medicine, Gainesville, FL, United States; Juan C. Roig, University of Central Florida College of Medicine, Gainesville, FL, United States; Dhanashree Rajderkar, University of Florida College of Medicine, Gainesville, FL, United States; Michael D.. Weiss, University of Florida, Gainesville, FL, United States

Background: HIE remains a leading cause of morbidity and mortality in neonates. Although therapeutic hypothermia (TH) has significantly reduced long-term neurodevelopmental impairment among infants with moderate-to-severe HIE, approximately 30% still experience adverse outcomes. This highlights the need for reliable bedside indicators that can predict brain injury severity on MRI. Routine laboratory measures reflect systemic responses to hypoxia-ischemia and are monitored during TH. This study investigates the association between the time to normalization of these laboratory values and MRI-defined brain injury severity.

Objective: We hypothesize that infants with faster normalization of laboratory parameters will exhibit less severe brain injury on MRI compared to those with slower rates of normalization.

Design/Methods: This retrospective cohort study included 122 infants born at UF Health who met established criteria for therapeutic hypothermia (TH) between January 2012 and April 2023. Data were extracted from the institution's Integrated Data Repository, which contains comprehensive electronic health record information. Twenty-nine laboratory parameters-blood gases, liver function tests, electrolytes (including ionized calcium), coagulation factors, and troponin-were collected for each infant from birth until normalization, measured in hours from birth. Brain MRIs obtained after completion of TH were scored using the Weeke MRI scoring system. Based on these scores, infants were categorized into none-mild (NM; 0 - 4) and moderate-severe (MS; >/= 5) injury groups. Comparisons between groups were performed using the two-tailed Mann-Whitney U test.

Results: Of the 29 parameters analyzed, five demonstrated a significant association between the rate of normalization and MRI-defined brain injury severity. Blood gas base deficit (BD), prothrombin time (PT), sodium (Na), and creatinine (Cr) normalized faster in infants with NM Weeke scores compared with those with MS scores (p = 0.0318, 0.0454, 0.0246, and 0.0018, respectively). In contrast, phosphorus levels normalized more rapidly in infants with MS injury (p = 0.0178). There was no difference between the two groups in the rate of pH normalization (p = 0.3779). These findings are depicted in Figure 1 (scatterplot with median and interquartile ranges).

Conclusion(s): Our results suggest that early laboratory trends during therapeutic hypothermia may provide valuable bedside indicators of brain injury severity and merit further investigation for clinical implementation.

Figure 1
Scatterplot depicting the rate of normalization of six key laboratory parameters in hours from birth in none-mild and moderate-severe Weeke groups.