Bacteremia in Trauma: A Contemporary Analysis of Blood Culture Results and Outcomes in 158,884 Patients

Author(s):
Samir Fakhry; Kimberly MacLeod; Jennifer Morse; Jeneva Garland; Nina Wilson; Laura McLean; Dorraine Watts

Background:

Bacteremia is a potentially lethal complication. Little contemporary research exists describing its incidence and associated outcomes in trauma patients.

Hypothesis:

The purpose of this descriptive study was to characterize incidence, risk factors and outcomes of Bacteremia in a large multi-institutional sample.

Methods:

Trauma activation/consultation, age>18, admitted 2017-20 to trauma centers in a hospital system were selected. Blood culture (BC) results reported by the laboratory were obtained from a system EMR repository. POS was defined as 2 BCs drawn within 2 hours of each other both growing the same organism. NEG was defined as above but with no growth, only 1 BC with growth, or growth of 2 different organisms. POS and NEG patients were compared to NO BC on univariate measures. Logistic regression examined the relationship of BC results to outcomes, adjusting for age, sex, ISS and comorbidity count.

Results:

Of 158,884 trauma patients at 45 centers, 17,166 (10.8%) had a BC drawn and 1,214 were POS (7.1%). Compared to NO BC patients, POS patients were more likely to be male (70.4% vs. 57.8, p<0.001), with more comorbidities (2.1 vs. 1.6, p<0.001) and higher median ISS (14 vs 9, p<0.001). They also had higher ICU use rates (82.5% vs. 40.3, p<0.001), ventilation (61.6% vs. 9.5, p<0.001) and mortality (17.2% vs. 2.6, p<0.001). POS patients were 3.8 times as likely to die (aOR 3.8 [3.2-4.5], p<0.001) and exponentially more likely to have septic shock/severe sepsis (aOR 114.9 [95.1-138.9], p<0.001). In POS patients, the most commonly reported isolates were S. epidermidis (14%), non-MRSA S. aureus (12%), and E. coli (6%). Organisms associated with the highest mortality rates were K. pneumoniae (27.1%), E. coli (28.4%) and E. faecalis (30.0%).

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Conclusions:

This multicenter study shows that Bacteremia in adult trauma patients is relatively uncommon (<1%) but associated with increased hospital resource use and very poor outcomes. Increased age, co-morbidities and ISS were associated with worse outcomes. Bacteremia, or even suspicion thereof, identifies a population at exceedingly high risk and justifies aggressive empiric intervention to maximize survival.