Sydney Jablonski, PharmD1, William Cahoon, PharmD, BCPS, BCCP, BCCCP1, Cassandra Baker, PharmD1 Virginia Commonwealth University (VCU) Health System Department of Pharmacy Services1 Learning Objective: Describe thiocyanate monitoring and factors associated with accumulation in patients receiving sodium nitroprusside. Background/objective: The purpose of this project is to characterize current thiocyanate monitoring in patients receiving sodium nitroprusside. Results will be utilized to update thiocyanate monitoring practices and optimize resource utilization. Methods: This project is a retrospective, single-center review from January 2022 to July 2025. Adult Coronary ICU patients who received intravenous sodium nitroprusside for at least 24 hours, and had at least one thiocyanate level obtained were included. Baseline characteristics, including age, sex, race, renal function, liver function, and mechanical circulatory support, were collected. Patients were categorized into two groups: those with and those without thiocyanate accumulation. Thiocyanate accumulation was defined as at least one thiocyanate level >30 mcg/mL. Nitroprusside factors, including cumulative nitroprusside dose, duration of nitroprusside therapy, peak nitroprusside infusion rate, peak thiocyanate level, and number of thiocyanate levels were obtained for all included patients. Symptoms of thiocyanate toxicity were assessed for each patient via Epic chart review. Results: Sixty-nine patients were included in this study with only 10 patients (14.5%) demonstrating thiocyanate accumulation. Patients with thiocyanate accumulation had a higher dosing weight (103 kg vs. 83.3 kg), a higher cumulative nitroprusside dose (23.08 vs. 4.25 mg/kg), a longer duration of nitroprusside infusion (588.5 vs. 213 hours), and a higher peak nitroprusside infusion rate (0.8 vs. 0.5 mcg/kg/min) compared to those without accumulation. Six patients (8.7%) had symptoms of thiocyanate toxicity documented. A total of 625 thiocyanate levels were collected, of which 46.6% were undetectable (< 5 mcg/ml) and 10.1% were greater than 30 mcg/mL. Conclusions: This project found an association between dosing weight, cumulative nitroprusside dose, duration of nitroprusside therapy, and peak nitroprusside infusion rate with thiocyanate accumulation. Given that a large percentage of thiocyanate levels obtained were undetectable, opportunities exist to decrease the frequency of thiocyanate monitoring to improve resource utilization and provide cost savings. Self-Assessment Question: What factor was associated with thiocyanate accumulation in patients receiving nitroprusside? a) Liver function b) Sex c) Age d) Duration of nitroprusside infusion
