Via Research Recognition Day 2024 VCOM-Carolinas

Educational Reports

Hypophosphatemia, A Predictor of Outcomes in Critically Ill Trauma Patients Nichole Tackett, MA, Robyn Sawyers, BS, Caleb Glass, BS, Lana Maniakhina, BS, Siena Lombardozzi, David Redden, PhD, TJ Mack. RN, Michael Mount DO, Kristine Lombardozzi, MD Spartanburg Regional Healthcare System, Division of Surgery, Spartanburg, SC VCOM Carolinas Campus, Spartanburg, SC Abstract Results Conclusions

References Importance of Phosphate • Vital electrolyte in multiple intracellular pathways such as ATP, DNA and protein synthesis • In patients with depleted phosphate in the surgical ICU, there is an increased risk of procedures like tracheostomy and secondary complications such as PNA and AKI. • The pathophysiology behind these findings may be secondary to depleted muscle energy resulting in poor respiratory mechanics and subsequent prolonged ventilator dependent time. Implications of Hypophosphatemia in Critically Ill Trauma Patients • Traumatic injuries are a leading cause of morbidity and mortality. These patients often experience metabolic disturbances during their admission. • Hypophosphatemia is associated with adverse outcomes but not mortality in a critically ill trauma population. • Phosphate levels should be routinely monitored in the ICU. • An ideal replacement protocol should be established for critically ill trauma patients • From a scientific perspective, further studies should work to elucidate the cytologic milieu that results in hypophosphatemia to develop new targeted therapeutics in the surgical ICU 1.Martino C, Russo E, Santonastaso DP, et al. Long-term outcomes in major trauma patients and correlations with the acute phase. World Journal of Emergency Surgery. 2020;15(1). doi:10.1186/s13017-020-0289-3 2.Trauma facts and links. The American Association for the Surgery of Trauma. July 22, 2020. https://www.aast.org/resources/trauma-facts. 3.Lee JW. Fluid and electrolyte disturbances in critically ill patients. Electrolyte Blood Press. 2010;8(2):72-81. doi:10.5049/EBP.2010.8.2.72 4.Qadeer HA, Bashir K. Physiology, phosphate. Statpearls Publishing. January 2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560925/. We would like to thank David Redden for his assistance with statistical analysis. Our IRB was approved by Spartanburg Regional Heatlhcare system on 12/2/2022. Acknowledgements

Traumatic injuries are a major cause of morbidity and mortality in all age groups. 1,2 Often, trauma necessitates Intensive Care Unit (ICU) admission, where patients are at an increased risk for developing metabolic derangements that can further contribute to poor outcomes. 3 Phosphorus is essential for many of the body's most integral biological processes including energy metabolism and cellular operations. 4 Our previous study showed a correlation between hypophosphatemia (HP) and severity of illness in traumatic brain injury with increased likelihood of brain death. Building on these findings, this study seeks to investigate the potential association between low serum phosphate levels at any point during admission and adverse outcomes in a broader population. A retrospective chart review was performed on a total of 213 adult patients admitted to the ICU after traumatic injury. We evaluated daily phosphate levels from day 1 and up to 30 days post admission, identifying those that were found to have hypophosphatemia with phosphate level of <2.5 mg/dL on laboratory findings. The primary outcome of the study was to determine overall mortality rates, with our secondary outcomes focusing on the impact of correcting hypophosphatemia, infectious complications, acute kidney injury (AKI), tracheotomy, and mortality within 30 days of discharge. After the data was collected and analyzed, the results indicated no significant association between minimum phosphorus and mortality based on outcome group. However, there is a statistically significant negative association between minimum phosphorus and number of ICU days, indicating that as the minimum observed phosphorus level increased, the number of days in the ICU decreased. Another significant correlation showed higher minimum phosphorus levels are associated with lower odds of tracheotomy, AKI and pneumonia. Retrospective Study • Conducted at Spartanburg Regional Healthcare System (SRHS), Spartanburg Medical Center (SMC)- Church Street Campus, Spartanburg, South Carolina • Total of 216 patients were identified, aged 18 years and older, were identified as trauma patients admitted to the surgical intensive care unit (SICU) between 09/1/2020 and 8/31/2022 • Three patients were excluded from analysis secondary to age or not requiring SICU admission criteria, data analysis was performed on 213 patients. Data Collection and Analysis • Baseline demographics, laboratory studies including daily serum phosphate levels, minimum and maximum phosphate level,hemodynamic parameters, illness severity score, infectious complications, need for tracheotomy, acute kidney injury (AKI), total ventilator days, and mortality were collected and analyzed • Analysis of variance was utilized to analyze correlations between outcome groups and overall mortality • Spearman’s correlation analyzed relationships with SICU and total ventilator days. • Logistic regression analyses were used to analyze correlations with secondary Methods

Table 1. Comparison of Minimum Phosphorus across Outcome Groups • Significant difference found between mean phosphate replacement of those expiring during index hospitalization and those surviving greater than 30 days post-discharge (Table 3). • Higher minimum phosphate levels in the ICU were correlated with lower odds of tracheotomy, AKI, and pneumonia (Table 4). • No significant association found between minimum phosphorus levels and mortality (Table 1). • Negative correlation discovered between total ICU days and minimum recorded phosphorus (Table 2).

Table 2. Spearman Correlation between Minimum Phosphorus and Total Days in ICU, Total Vent Days

Table 3. Logistic Regression Models for Predicting 30 Day Mortality vs Reference Groups

Table 4. Secondary Outcomes

outcomes such as infectious complications and AKI. • A p-value of 0.05 was deemed statistically significant.

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2024 Research Recognition Day