Understanding the Risk of Infection after Ultra Massive Blood Product Transfusion

Authors:
Courtney Meyer, Jason Sciarretta, Jonathan Nguyen, Lucy Hart, Randi Smith, Will Dunne, Zachary Grady

Body of Abstract:
Background
Ultra massive transfusion (UMT), defined as the transfusion of > 20 units of red blood cell product, is utilized for trauma patients in severe hemorrhagic shock. Patients requiring UMT have high rates of mortality and survivors are at risk for infectious complications. Yet, the exact risk remains unknown. The aim of this study was to quantify the risk of infections after UMT by evaluating the incidence, type, causative organisms, treatment and outcomes in trauma survivors.
Methods
A retrospective review was conducted at a Level 1 trauma center from 05/2018- 11/2021 of all trauma patients who received UMT. Data were collected from prospectively maintained registries & chart review including demographics, comorbidities, infection type (bacteremia, fungemia, surgical site infection (SSI), osteomyelitis, pneumonia (PNA), urinary tract infection, empyema, & Clostridioides difficile infection), culture data, and antibiotic administration & duration. Outcomes of hospital & intensive care unit (ICU) length of stay and mortality were also evaluated.
Results
A total of 193 patients were included in the study period with an overall mortality rate of 54.4%. Infection occurred in 25.4% of patients and at least one antibiotic dose was administered for 93.8% of patients. For those that survived at least 48 hours, 50.9% had an infection. There was no difference in age, sex, comorbidities, injury mechanism, injury severity, initial vital signs & laboratory values, and operative interventions required between those with and without an infection. Patients without an infection had more bowel injuries (49.0% vs. 20.7%, p<0.05). In these patients, the most frequent infections were PNA (33%), bacteremia (19.8%), and deep SSI (9.4%). There were 55 unique organisms with the most frequent being Enterobacter cloacae (8.9%), Pseudomonas aeruginosa (8.1%), Enterobacter aerogenes (7.0%), and Enterococcus faecalis (7.0%). In the entire cohort, there were 1,182 unique antibiotic courses with an average antibiotic duration of 3.5 days. The most frequently administered antibiotics were cefazolin (27.6%), vancomycin (17.0%), and metronidazole (11.3%). Infectious disease consultation occurred for 22.6% of patients who survived at least 48 hours. Patients with infection had more ventilator days (14.5 vs. 4 days, p<0.001) and longer ICU (24.5 vs. 6 days, p<0.001) and hospital (41 vs. 13 days, p<0.001) length of stay. Patients without an infection had higher rates of mortality (32.7% vs. 12.1%, p=0.01). Conclusion Patients who require UMT following traumatic injury have high rates of infection, most frequently pneumonia, bacteremia, & deep surgical site infections caused by a variety of microorganisms. Though this high rate exists, it may be similar to other critically injured patients who do not require UMT such that once a patient is stabilized from a resuscitation standpoint, their infection rates may be similar to their non-UMT counterparts.