Outcomes after the administration of hydroxocobalamin

Background: Hydroxocobalamin is frequently administered to patients after injures sustained during structure fires or fires in enclosed spaces, prior to confirming inhalation injury with bronchoscopy. Hydroxocobalamin is generally considered safe. However, over the last several years, the safety of hydroxocobalamin has been called into question by case reports of crystalline nephropathy and interference with renal replacement therapies. Objectives: The aim of this project was to describe the population in which hydroxocobalamin was administered and assess clinical outcomes such as mortality and need for renal replacement therapy. We hypothesized that there is a relationship between the administration of hydroxocobalamin and the development of acute kidney injury (AKI). Methods: This was a retrospective chart review that was approved by our institution's research and regulatory compliance division as a performance improvement (PI) project (H-19-019nr). All patients admitted to the burn ICU at a large, government medical center between July 1, 2016 and April 30, 2019 were considered for inclusion. Patients were included if they received hydroxocobalamin after burn ICU admission. Patients who received hydroxocobalamin in the pre-ICU or pre-hospital setting were not included. Data were collected from the electronic medical record and included demographic information, number of hydroxocobalamin doses administered, burn size (%TBSA), presence and grade of inhalation injury, lactate levels during the first 72 hours of hospitalization, carboxyhemoglobin levels, duration of mechanical ventilation, and in-hospital mortality. Development of acute kidney injury (AKI) as per the AKIN criteria, as well as need for and duration of continuous renal replacement therapy (CRRT) were also collected. Results: Thirty five patients received at least 1 dose of hydroxocobalamin after ICU admission; 31 patients received 1 dose and 4 patients received 2 doses. Twenty nine (82.9%) patients who received hydroxocobalamin in the ICU were diagnosed with inhalation injury via bronchoscopy. The median fluid resuscitation requirement was 7.4 mL/kg/%TBSA (IQR 4.6, 12.7). Twenty two (63%) patients who received hydroxocobalamin developed an acute kidney injury (AKI) during the first 72 hours of admission, with the average time from burn to AKI being approximately 20 hours. Twenty one (60%) patients required CRRT at some point during their hospital stay, with 42.8% of patients being initiated on CRRT during the resuscitation period. On average, lactate clearance occurred in 34.6 hours; 11 (31.4%) patients did not clear lactate within 72 hours. One patient had a carboxyhemoglobin level greater than 10% on admission and 4 patients had a carboxyhemoglobin level greater than 3% on admission. The average time to carboxyhemoglobin level less than 3% was 3.4 ± 2.6 hours. The average duration of mechanical ventilation was 11 ± 7 days. Ten (28.9%) patients died during their hospital stay. Conclusions: Most patients who receive at least 1 dose of hydroxocobalamin after ICU admission developed AKI within the first 72 hours, with 42.8% of patients requiring CRRT during the initial resuscitation period. One-third of patients who received hydroxocobalamin after ICU admission died during their hospital stay. Further studies on the relationship between the administration of hydroxocobalamin and the development of AKI and in-hospital mortality are warranted.