2025 Southeastern Residency Conference

Title: Characterizing 24-hour pharmacist response to rapid multiplex polymerase chain reaction (rmPCR) blood culture results. 


Authors:
Noah Sanford
Elizabeth Covington
Rachel Friend
Mary Kate Lackey
Sarah Grace Gunter


Background: Rapid molecular polymerase chain reaction (rmPCR)-based blood cultures provide organism identification within hours of initial organism detection with proven positive impact on time-to-appropriate antimicrobial therapy and clinical outcomes. Pharmacist-driven rapid response programs to bacteremia identified by rmPCR have been studied with differing means of communication and limited hours of pharmacist coverage. Our study aimed to characterize 24-hour pharmacist response to rmPCR blood culture results with a focus on response differences between shifts and on time-to-appropriate antibiotics in patients hospitalized with resultant positive blood cultures.


Methods: This study was a single-center, retrospective chart review conducted on patients ≥19 years-old with positive blood cultures from November 25, 2022, to June 30, 2024, admitted to East Alabama Medical Center (EAMC). Patients were excluded if they were pregnant, prisoners, discharged or transitioned to comfort care within 8 hours of blood culture notification, or if they died within 24 hours of blood culture notification. Pharmacist shifts were divided into first (0700 to 1459), second (1500 to 2259), and third shift (2300 to 0659). The pharmacists at EAMC are alerted via Cerner when blood cultures result and review each positive result. Patients were identified using TheraDoc clinical surveillance software and randomized prior to screening for inclusion. Our primary outcome was percentage of patients requiring therapy modification after positive blood culture notification. Secondary outcomes included number and type of pharmacist intervention documented, time to pharmacist intervention, and time to optimal therapy. Between group comparisons were performed using the Chi-square, Fisher’s exact test, Mann-Whitney U test, and Kruskal Wallis depending on the data type and distribution. Normality was assessed by Shapiro-Wilk. To assess variables associated with a pharmacist intervention, a bivariate analysis was performed and variables with P<0.200 were included in logistic regression analysis. Statistical significance was defined by a 2-tailed p-value of less than 0.05. All statistical tests were performed using SPSS statistics software.


Results: After randomization, 150 patients were screened, and 30 patients were excluded leaving 120 patients for analysis. Baseline characteristics, including age, gender, race, Pitt bacteremia score, and Charlson Comorbidity Index, were similar among the three groups (first, second, and third shift). There was no difference in the primary outcome: 17 patients required therapy modification in the first shift group (31%), 15 (38%) in second shift, and 6 (24%) in third shift (p=0.516). Across the three shifts, there was no difference in number of patients with a pharmacist intervention documented (p=0.966), type of pharmacist intervention documented (p=0.175), time to pharmacist intervention (p=0.062) or time to optimal therapy (p=0.219). Pharmacists were more likely to intervene on patients with methicillin-susceptible Staphylococcus aureus bacteremia (odds ratio [OR] 5.7, 95% confidence interval [CI] 1.60 to 20.74) and less likely to intervene on patients with an infectious disease consult (OR 0.21, 95% CI 0.084 to 0.530). Pharmacist shift was not associated with likelihood of intervention.


Conclusion: Our study showed a similar need for therapy modification across shifts, with no difference in number or type of pharmacy interventions. Strengths of our study include assessing 24-hour pharmacist services and having all pharmacists intervening rather than just antimicrobial stewardship pharmacists. Limitations include a small sample size, potential delays in pharmacist documentation, reliance on manual intervention documentation, and the retrospective nature of the study. Future studies should further explore the benefit of 24-hour pharmacist response to positive rmPCR blood culture notifications.