Ordering Blood Cultures Research Articles

Improving Antibiotic Use in Pediatric Preseptal Cellulitis Using a Clinical Practice Guideline.

The purpose of this study was to evaluate the impact of a clinical practice guideline (CPG) on antibiotic use and resource utilization for pediatric preseptal cellulitis. This retrospective quasiexperimental study included patients between the age of 2 months and 17 years admitted for preseptal cellulitis between January 2013 and December 2023. The preseptal cellulitis CPG was implemented in December 2020 using a multifaceted strategy that included buy-in from key stakeholders, education of frontline providers, the official CPG launch, and stakeholder check-ins. The primary outcome was the use of broad-spectrum antibiotics, including dual/triple therapy and methicillin-resistant Staphylococcus aureus (MRSA) active antibiotics. The secondary outcome was resource utilization including blood testing and imaging. Outcomes were compared pre- and post-CPG implementation using the Fisher exact test and logistic regressions. Of 236 patients meeting inclusion criteria, 175 and 61 patients composed the pre- and post-CPG cohorts, respectively. Median age (interquartile range) was 4.0 (1.8-8.3) years and 46% of the population were female. Post-CPG implementation changes in empirical antibiotic use included decreases in broad-spectrum use from 100% to 66% (P < .001), dual/triple therapy from 47% to 16% (P < .001), and MRSA active agents from 86% to 26% (P < .001). There was a decrease in complete blood count and blood culture orders from 75% to 57% (P = .014) and 32% to 18% (P = .047), respectively. Use of broad-spectrum antibiotics, including dual/triple therapy and MRSA active antibiotics for the treatment of pediatric preseptal cellulitis, decreased after CPG implementation.

Blood Culture Ordering After Sepsis Alerts and Subsequent Patient Outcomes: An Electronic Health Record-Based Study.

Sepsis is a global health priority associated with high mortality. Clinical decision support systems have been developed to support clinicians with sepsis management. Ordering blood cultures (BCs) for suspected sepsis patients are strongly recommended by clinical guidelines. However, limited evidence exists investigating BC ordering following sepsis alerts and subsequent patient outcomes. This study aimed to investigate this issue using electronic health record data from an acute care hospital in Australia. Of 4,092 patients, only 16.6% had a BC ordered following a sepsis alert. The median time from the first sepsis alert to a BC order was 15.3 hours. Patients had 5.89 times higher odds of being diagnosed with sepsis if a BC was ordered following a sepsis alert than those without BC ordered (p<0.0001). Further investigation is needed to understand reasons behind the delay or failure to order a BC despite receiving electronic sepsis alerts and how decision support can be optimized to improve patient outcomes.

Use of Electronic Clinical Data to Track Incidence and Mortality for SARS-CoV-2–Associated Sepsis

Efforts to quantify the burden of SARS-CoV-2-associated sepsis have been limited by inconsistent definitions and underrecognition of viral sepsis. To describe the incidence and outcomes of SARS-CoV-2-associated sepsis vs presumed bacterial sepsis using objective electronic clinical criteria. This retrospective cohort study included adults hospitalized at 5 Massachusetts hospitals between March 2020 and November 2022. SARS-CoV-2-associated sepsis was defined as a positive SARS-CoV-2 polymerase chain reaction test and concurrent organ dysfunction (ie, oxygen support above simple nasal cannula, vasopressors, elevated lactate level, rise in creatine or bilirubin level, and/or decline in platelets). Presumed bacterial sepsis was defined by modified US Centers for Disease Control and Prevention adult sepsis event criteria (ie, blood culture order, sustained treatment with antibiotics, and organ dysfunction using identical thresholds as for SARS-CoV-2-associated sepsis). Trends in the quarterly incidence (ie, proportion of hospitalizations) and in-hospital mortality for SARS-CoV-2-associated and presumed bacterial sepsis were assessed using negative binomial and logistic regression models. This study included 431 017 hospital encounters from 261 595 individuals (mean [SD] age 57.9 [19.8] years, 241 131 (55.9%) females, 286 397 [66.5%] from academic hospital site). Of these encounters, 23 276 (5.4%) were from SARS-CoV-2, 6558 (1.5%) had SARS-CoV-2-associated sepsis, and 30 604 patients (7.1%) had presumed bacterial sepsis without SARS-CoV-2 infection. Crude in-hospital mortality for SARS-CoV-2-associated sepsis declined from 490 of 1469 (33.4%) in the first quarter to 67 of 450 (14.9%) in the last (adjusted odds ratio [aOR], 0.88 [95% CI, 0.85-0.90] per quarter). Crude mortality for presumed bacterial sepsis was 4451 of 30 604 patients (14.5%) and stable across quarters (aOR, 1.00 [95% CI, 0.99-1.01]). Medical record reviews of 200 SARS-CoV-2-positive hospitalizations confirmed electronic health record (EHR)-based SARS-CoV-2-associated sepsis criteria performed well relative to sepsis-3 criteria (90.6% [95% CI, 80.7%-96.5%] sensitivity; 91.2% [95% CI, 85.1%-95.4%] specificity). In this retrospective cohort study of hospitalized adults, SARS-CoV-2 accounted for approximately 1 in 6 cases of sepsis during the first 33 months of the COVID-19 pandemic. In-hospital mortality rates for SARS-CoV-2-associated sepsis were high but declined over time and ultimately were similar to presumed bacterial sepsis. These findings highlight the high burden of SARS-CoV-2-associated sepsis and demonstrate the utility of EHR-based algorithms to conduct surveillance for viral and bacterial sepsis.

Derivation and External Validation of the Ottawa Bloodstream Infection Model for Acutely Ill Adults.

Knowing the probability that patients have a bloodstream infection (BSI) could influence the ordering of blood cultures and interpretation of their preliminary results. Many previous BSI probability models have limited applicability and accuracy. This study used currently recommended modeling techniques and a large sample to derive and validate the Ottawa BSI Model. At a tertiary care teaching hospital, we retrieved a random sample of 4180 adults having blood cultures in our emergency department or during the initial 48h of the encounter. Variable selection was based on clinical experience and a systematic review of previous model performance. Model performance was measured in a temporal external validation group of 4680 patients. A total of 327 derivation patients had a BSI (8.0%). BSI risk increased with increased number of culture sets (2 sets: adjusted odds ratio [aOR] 1.52 [1.10-2.11]; 3 sets: 1.99 [0.86-4.58]); with indwelling catheter (aOR 2.07 [1.34-3.20); with increasing temperature, heart rate, and neutrophil-lymphocyte ratio; and with decreasing systolic blood pressure, platelet count, urea-creatinine ratio, and estimated glomerular filtration rate. In the temporal external validation group, model discrimination was good (c-statistic 0.71 [0.69-0.74]) and calibration was very good (integrated calibration index .016 [.010-.024]). Exclusion of validation patients with acute SARS-CoV-2 infection improved discrimination slightly (c-statistic 0.73 [0.69-0.76]). The Ottawa BSI Model uses commonly available data to return an expected BSI probability for acutely ill patients. However, it cannot exclude BSI and its complexity requires computational assistance to use.

The power of written word: Reflection reduces errors of omission.

Medical trainees are expected to perform complex tasks while experiencing interruptions, which increases susceptibility to errors of omission. In our study, we examine whether documentation of clinical encounters increases reflective thinking and reduces errors of omission among novice learners in a simulated setting. In 2021, 56 senior medical students participated in a simulated paging curriculum involving urgent inpatient cross-cover scenarios (sepsis and atrial fibrillation). Students responded to pages from standardized registered nurses (SRNs) via telephone, gathered history, and discussed clinical decision-making. Following the phone encounter, students documented a brief note (documentation encounter). A 'phone' score (number of checklist items completed in the phone encounter) and a 'combined' score (number of checklist items completed in the phone and documentation encounters) were calculated. Data were analyzed for differences between the phone scores (control) and combined scores using T-tests and McNemar test of symmetry. Fifty-four students (96%) participated. Combined scores were higher than phone scores for sepsis (72.8 ±11.3% vs. 67.9 ±11.9%, p < 0.001) and atrial fibrillation (74.0 ± 10.1% vs. 67.6 ± 10.0%, p < 0.001) cases. Important items, such as ordering blood cultures for sepsis (p = 0.023) and placing the patient on telemetry for atrial fibrillation (p = 0.013), were more likely to be present when a note was documented. This study suggests that documentation provides a mechanism for learners to reflect, which could increase important diagnostic and therapeutic interventions. Documentation by novice medical learners may improve patient care by allowing for reflection and reducing errors of omission.

Sepsis Prediction Model for Determining Sepsis vs SIRS, qSOFA, and SOFA

The Sepsis Prediction Model (SPM) is a proprietary decision support tool created by Epic Systems; it generates a predicting sepsis score (PSS). The model has not undergone validation against existing sepsis prediction tools, such as Systemic Inflammatory Response Syndrome (SIRS), Sequential Organ Failure Assessment (SOFA), or quick Sepsis-Related Organ Failure Asessement (qSOFA). To assess the validity and timeliness of the SPM compared with SIRS, qSOFA, and SOFA. This retrospective cohort study included all adults admitted to 5 acute care hospitals in a single US health system between June 5, 2019, and December 31, 2020. Data analysis was conducted from March 2021 to February 2023. A sepsis event was defined as receipt of 4 or more days of antimicrobials, blood cultures collected within ±48 hours of initial antimicrobial, and at least 1 organ dysfunction as defined by the organ dysfunction criteria optimized for the electronic health record (eSOFA). Time zero was defined as 15 minutes prior to qualifying antimicrobial or blood culture order. Of 60 507 total admissions, 1663 (2.7%) met sepsis criteria, with 1324 electronic health record-confirmed sepsis (699 [52.8%] male patients; 298 [22.5%] Black patients; 46 [3.5%] Hispanic/Latinx patients; 945 [71.4%] White patients), 339 COVID-19 sepsis (183 [54.0%] male patients; 98 [28.9%] Black patients; 36 [10.6%] Hispanic/Latinx patients; and 189 [55.8%] White patients), and 58 844 (97.3%; 26 632 [45.2%] male patients; 12 698 [21.6%] Black patients; 3367 [5.7%] Hispanic/Latinx patients; 40 491 White patients) did not meet sepsis criteria. The median (IQR) age was 63 (51 to 73) years for electronic health record-confirmed sepsis, 69 (60 to 77) years for COVID-19 sepsis, and 60 (42 to 72) years for nonsepsis admissions. Within the vendor recommended threshold PSS range of 5 to 8, PSS of 8 or greater had the highest balanced accuracy for classifying a sepsis admission at 0.79 (95% CI, 0.78 to 0.80). Change in SOFA score of 2 or more had the highest sensitivity, at 0.97 (95% CI, 0.97 to 0.98). At a PSS of 8 or greater, median (IQR) time to score positivity from time zero was 68.00 (6.75 to 605.75) minutes. For SIRS, qSOFA, and SOFA, median (IQR) time to score positivity was 7.00 (-105.00 to 08.00) minutes, 74.00 (-22.25 to 599.25) minutes, and 28.00 (-108.50 to 134.00) minutes, respectively. In this cohort study of hospital admissions, balanced accuracy of the SPM outperformed other models at higher threshold PSS; however, application of the SPM in a clinical setting was limited by poor timeliness as a sepsis screening tool as compared to SIRS and SOFA.

Prevalence of Multidrug-Resistant Pathogens Causing Neonatal Early and Late Onset Sepsis, a Retrospective Study from the Tertiary Referral Children's Hospital.

Sepsis is the most severe infectious disease with the highest mortality rate, particularly among neonates admitted to the neonatal intensive care unit (NICU). This study retrospectively analyzed the epidemiology, antibiotic resistance profiles, and prevalence of multidrug-resistant (MDR) bacteria isolated from blood or cerebrospinal fluid (CSF) cultures in order to evaluate the appropriateness of initial empirical therapy for neonatal sepsis. A retrospective study was conducted in the NICU from January 1, 2015, to December 31, 2022. Microbiological data from patients admitted to the NICU were anonymously extracted from the Laboratory of Microbiology database. Neonatal sepsis was classified into two types: early-onset sepsis (EOS), which occurs within the first 72 hours of life, and late-onset sepsis (LOS) for those begins later. A total of 679 bacterial strains, 543 from blood and 136 from CSF, were detected in 631 neonates. Among these, 378 isolates (55.67%) were Gram-positive bacteria, and 301 isolates (44.33%) were Gram-negative bacteria. The most frequently isolated pathogens were Coagulase-negative staphylococci (CoNS) (36.52%), followed by Klebsiella pneumoniae (20.47%) and Escherichia coli (13.84%). In EOS, 121 strains were found, CoNS represented the majority (33.88%), followed by Klebsiella pneumoniae (23.97%) and Escherichia coli (8.26%). Early-onset septicemia exhibited 67 (55.37%) MDR bacteria. In LOS, 558 strains were isolated, CoNS represented the majority of pathogens (37.10%), followed by Klebsiella pneumoniae (19.71%) and Escherichia coli (15.05%). Late-onset septicemia showed 332 (59.50%) MDR bacteria. High rates of MDR were found in CoNS (76.21%), carbapenem-resistant Klebsiella pneumoniae (66.91%), and MRSA (33.33%). The study revealed an alarming prevalence of MDR strains isolated from neonatal sepsis, emphasizing the necessity of finding effective prevention and treatment measures. Colistin can be used for MDR Gram-negative bacteria, while vancomycin and teicoplanin can be considered treatment therapies for staphylococcal infections.

Implementation of diagnostic stewardship in two surgical ICUs: Time for a blood-culture change

Background: Blood cultures are commonly ordered for patients with low risk of bacteremia. Liberal blood-culture ordering increases the risk of false-positive results, which can lead to increased length of stay, excess antibiotics, and unnecessary diagnostic procedures. We implemented a blood-culture indication algorithm with data feedback and assessed the impact on ordering volume and percent positivity. Methods: We performed a prospective cohort study from February 2022 to November 2022 using historical controls from February 2020 to January 2022. We introduced the blood-culture algorithm (Fig. 1) in 2 adult surgical intensive care units (ICUs). Clinicians reviewed charts of eligible patients with blood cultures weekly to determine whether the blood-culture algorithm was followed. They provided feedback to the unit medical directors weekly. We defined a blood-culture event as ≥1 blood culture within 24 hours. We excluded patients aged &lt;18 years, absolute neutrophil count &lt;500, and heart and lung transplant recipients at the time of blood-culture review. Results: In total, 7,315 blood-culture events in the preintervention group and 2,506 blood-culture events in the postintervention group met eligibility criteria. The average monthly blood-culture rate decreased from 190 blood cultures per 1,000 patient days to 142 blood cultures per 1,000 patient days (P &lt; .01) after the algorithm was implemented. (Fig. 2) The average monthly blood-culture positivity increased from 11.7% to 14.2% (P = .13). Average monthly days of antibiotic therapy (DOT) was lower in the postintervention period than in the preintervention period (2,200 vs 1,940; P &lt; .01). (Fig. 3) The ICU length of stay did not change before the intervention compared to after the intervention: 10 days (IQR, 5–18) versus 10 days (IQR, 5–17; P = .63). The in-hospital mortality rate was lower during the postintervention period, but the difference was not statistically significant: 9.24% versus 8.34% (P = .17). The all-cause 30-day mortality was significantly lower during the intervention period: 11.9% versus 9.7% (P &lt; .01). The unplanned 30-day readmission percentage was significantly lower during the intervention period (10.6% vs 7.6%; P &lt; .01). Over the 9-month intervention, we reviewed 916 blood-culture events in 452 unique patients. Overall, 74.6% of blood cultures followed the algorithm. The most common reasons overall for ordering blood cultures were severe sepsis or septic shock (37%), isolated fever and/or leukocytosis (19%), and documenting clearance of bacteremia (15%) (Table 1). The most common indications for inappropriate blood cultures were isolated fever and/or leukocytosis (53%). Conclusions: We introduced a blood-culture algorithm with data feedback in 2 surgical ICUs and observed decreases in blood-culture volume without a negative impact on ICU LOS or mortality rate.Disclosure: None

Evaluation of interprovider consistency in interpretation of blood culture guidelines at an academic medical center

Background: Blood cultures are a fundamental tool in the diagnosis of infections, but they can lead to clinical confusion and waste resources when they yield false results. To optimize blood-culture orders at our institution, we developed an evidence-based clinical guideline (Fig. 1) to be used by frontline providers on nonneutropenic hospitalized adult inpatients. We retrospectively reviewed charts of patients with positive blood cultures to evaluate whether frontline providers and infectious diseases (ID) attending physicians were able to consistently interpret the guidelines to determine whether blood cultures were drawn appropriately. Methods: In total, 95 nonneutropenic adults with an initial positive blood culture collected while on an inpatient unit were identified through a query of the electronic medical record from January 2021 through June 2022. Patients with polymicrobial bacteremia and bacteremia due to Enterococcus, Streptococcus, and gram-positive rods were excluded. Moreover, 4 medical resident physicians reviewed all patients and 2 ID attending physicians reviewed one-quarter of cases; all were blinded to the culture results. Blood cultures were determined to be either appropriately or inappropriately performed based on our institution’s guideline. The free-marginal multirater κ statistics with 95% CIs were calculated to evaluate interrater agreement. Results: Baseline patient demographics are shown in Table 1. Immune compromise without neutropenia was noted in 21 of 95 patients. Most patients were at high risk for bacteremia (72%) per our institutional guideline, most of whom were septic (67.7%). Low risk for bacteremia was found in only 12.3% of reviews. Medical resident physicians, ID attending physicians, and all reviewers combined agreed on whether blood cultures were drawn appropriately or inappropriately (84.2%, 92%, and 86.4% agreement rates, respectively). The free-marginal κ statistic was highest for ID attending physicians (0.84; 95% CI, 0.62–0.78), followed by attending physicians and resident physicians combined (0.73; 95% CI, 0.56–0.90), and resident physicians alone (0.68; 95% CI, 0.58–0.78). In the 21 patients with immune compromise, the agreement rates on blood culture appropriateness remained high among all reviewers, resident physicians, and ID attending physicians were 86.6%, 90.5%, and 95%, respectively. Conclusions: In our retrospective study of nonneutropenic hospitalized adult inpatients, frontline providers and ID attending physicians interpreted blood-culture guidelines consistently, largely agreeing on which patients had cultures drawn appropriately. Agreement among ID attending physicians was excellent and remained substantial among medical resident physicians. Guidelines on the appropriate use of blood cultures are vital to limiting unnecessarily collected cultures, which can lead to extended length of stay and increase cost across hospital systems. Further analyses on the clinical impact of this guideline are ongoing.Disclosures: None

Causal Association of Physician-in-Triage with Improved Pediatric Sepsis Care: A Single-Center, Emergency Department Experience.

A multidisciplinary sepsis task force formed in the Spring of 2020 aimed to assess and improve pediatric sepsis care in the pediatric emergency department (ED). The electronic medical record identified pediatric sepsis patients from September 2015 to July 2021. Data for time to sepsis recognition and antibiotic delivery were analyzed using statistical process control charts (X̄-S charts). We identified special cause variation, and Bradford-Hill Criteria guided multidisciplinary discussions to identify the most probable cause. In the fall of 2018, the average time from ED arrival to blood culture orders decreased by 1.1 hours, and the time from arrival to antibiotic administration decreased by 1.5 hours. After qualitative review, the task force hypothesized that initiation of attending-level pediatric physician-in-triage (P-PIT) as a part of ED triage was temporally associated with the observed improved sepsis care. P-PIT reduced the average time to the first provider exam by 14 minutes and introduced a process for physician evaluation before ED room assignment. Timely assessment by an attending-level physician improves time to sepsis recognition and antibiotic delivery in children who present to the ED with sepsis. Implementing a P-PIT program with early attending-level physician evaluation is a potential strategy for other institutions.

Overcultured? Blood cultures on discharged ED patients were ordered more frequently after the SEP-1 bundle initiation

IntroductionIn 2015, the Severe Sepsis and Early Septic Shock Management Bundle (SEP-1) tied hospital reimbursement to performance on a series of time sensitive indicators, including ordering blood cultures on patients with severe sepsis or septic shock. This metric could have broadly shaped ordering practices in the Emergency Department (ED), including for patients who did not have severe sepsis or septic shock. In this study, we sought to evaluate whether the frequency of blood culture orders on adult patients discharged from the ED changed after the SEP-1 metric, whether the rates of positivity for pathogens or contaminants changed after the SEP-1 metric, and whether similar changes were seen in orders for other laboratory tests. MethodsThis was a retrospective evaluation of blood culture orders from discharged adult ED patients from a suburban academic hospital between January 1, 2012 and June 30, 2019. We compared the number of blood cultures per discharged adult patient before and after the SEP-1 metric. We categorized each culture that grew an organism as a pathogen or a contaminant, and we compared rates of pathogen and contaminant growth before and after SEP-1. We compared rates of orders of blood cultures and lactates as labs related to SEP-1 with rates of orders of D-dimers, lipases, human chorionic gonadotropins (HCGs), and brain natriuretic peptides (BNPs) as labs unrelated to SEP-1 before and after the implementation of the SEP-1 metric. ResultsThere were 144,343 adult patients discharged from the ED during the study period. A total of 6754 blood cultures were drawn from 3827 of those patient visits. The rate increased from 43.1 cultures per 1000 discharged patients before the SEP-1 metric to 75.9 blood cultures per 1000 discharged patients, an increase of 76.2% (p < 0.001). The cultures had a decreased rate of positivity (from 3.93% before SEP-1 to 3.03% after SEP-1, p = 0.044) and an unchanged rate of blood cultures resulting in a contaminant (2.49% to 1.85%, p = 0.071). Overall, orders of the labs unrelated to SEP-1 increased by an average of 16.8% after the SEP-1 metric and orders of the labs related to SEP-1 increased by an average of 81.0%. ConclusionAfter the SEP-1 bundle, blood cultures were ordered more frequently on discharged ED patients. These cultures had a lower rate of positivity for pathogens and an unchanged rate of growth of contaminants. This increase was not matched by a similar increase in other labs. Taken together, these findings suggest that the SEP-1 metric had the unintended consequence of increasing orders of blood cultures on patients healthy enough to be discharged from the ED.

Bacteremia in Subjects with Sickle Cell Disease: High Rate of Gram-Negative Isolates in the West African Context

Background: Sickle cell disease is one of the most common monogenic diseases in the world, affecting approximately 70 million people, 80% in sub-Saharan Africa and 1 in 10 in Senegal. Sickle cell anemia causes functional asplenia (associated with repeated thrombosis of splenic vessels), resulting in increased susceptibility to infection. However, several studies have reported differences in the spectrum of bacterial infections in malaria-endemic areas. Therefore, we proposed to conduct a study to determine the rate of positive blood cultures and the bacteriological spectrum in sickle cell patients. Materials and Method: This is a descriptive cross-sectional study of blood culture samples from patients who received a request for hemoglobin electrophoresis as part of their treatment at the Principal’s hospital in Dakar. The study took place from January 2008 to December 2021. For each patient, we collect demographic information, including age, gender, and the service from which the analysis request originated. Data were collected in the laboratory’s computer system and entered into Microsoft Excel (2007). Statistical analyzes were performed using Epi-Info 7 software. Results: Our study included 1419 patients. The most common types of hemoglobin profiles were: normal profile (n = 1025), AS profile (n = 283), SS profile (n = 104), SC profile (n = 7). This corresponds to the proportions of 72%, 20%, 0.5% and 7.5% for the profiles Normal, AS, SC and SS. The male proportion was 61.1%, 61.5%, 57.1, respectively %, 55.8% for Normal, SA, SC, and SS profiles. A total of 19,090 individual blood culture bottles were collected from 1419 impatient patients as follows: Normal profile (n = 18,042 bottles), AS profile (n = 677 culture bottles), SS profile (n = 362 bottles). The majority of blood culture orders come from pediatric services, accounting for 70% of the total number of orders. Of 19,090 vials examined in this current study, 19.6% developed a positive blood culture. Overall, the most commonly isolated bacteria were Staphylococci (41.1%), Enterobacteriaceae (36.7%), Bacillaceae (10.2%), unfermented (6.30%), Streptococci (5.01%), and a small proportion of yeast (0.75%). There is no significant difference in bacterial spectrum between the SS profile and the normal profile of individuals (p = 0.104). Coagulase-negative staphylococci accounted for 32%, 24%, and 40% of the species isolated in the normal AS and SS profiles. respectively. Coagulase-negative staphylococci were the most commonly isolated organisms in SS. Group E and sptagged streptococci each account for less than 2% of the organisms isolated in SS. Pneumococci were not found. Bacillus accounts for 25% of isolates in SS subjects compared to 9% in normal and AS subjects, respectively. Pseudomonas aeruginosa and Burkholderia cepacia then make up 10% of the isolates in the subjects of the SS profile as non-fermenters. Conclusion: Our study shows that enterobacteria and staph are prevalent in people with sickle cell disease. There is no significant difference in bacterial spectrum between SS subjects compared to subjects with a normal profile. The rarity of Streptococcus pneumoniae in bacteremia isolates underlines the need for further studies with larger patient numbers to better understand the spectrum of bacterial infections in patients with sickle cell disease in West Africa.

Multidrug-Resistant Bacteria Isolated from Blood Culture Samples in a Moroccan Tertiary Hospital: True Bacteremia or Contamination?

PurposeTo demonstrate the relevance of clinico-biological correlation in the interpretation of positive blood cultures (BC) for multidrug-resistant (MDR) bacteria, among adult and pediatric patients, in order to distinguish between true bacteremia (TB) and contaminations and to evaluate the impact on patient management.Patients and MethodsThis six-month study was conducted at Mohammed VI University Hospital in Marrakech. All MDR bacteria isolated from BCs carried out on hospitalized patients during this period were included. For each positive BC to MDR microorganism, demographic and clinical characteristics, laboratory findings, therapeutic and evolution data were collected.ResultsTB was considered in 157 (94.6%) of the 166 positive-culture episodes for MDR bacteria, while 9 (5.4%) were classified as false-positive. Contamination rate was 0.2% (9/3824). TB and contaminations occurred mainly in intensive care units (ICUs), with the neonatal ICU being the most concerned (p = 0.016). Clinical signs of sepsis were present in all TB patients, with a significant difference between the two groups (p = 0.000). CRP values were higher in the TB group (p = 0.000). The most isolated true pathogens were ESBL-producing Enterobacterales (50%) and carbapenem-resistant Enterobacterales (33.3%). They also predominated in contaminated BCs. Isolation of the same microorganism from other sites was significantly associated with TB (p = 0.012). In contrast to the contaminations group, the difference in the clinical course of TB patients, according to whether or not they received appropriate probabilistic antibiotics, was statistically significant (p = 0.000). These patients had longer hospital stays and longer durations of antibiotic therapy. The overall mortality rate was 39.6%.ConclusionDistinguishing between MDR-positive BCs representing clinically significant bacteremia or simple contamination requires a careful clinical, biological, and microbiological confrontation of each MDR positive BC in order to avoid unnecessary overuse of broad-spectrum antibiotics and thus reduce resistance selective pressure.

Blood-culture ordering practices in patients with a central line at an academic medical center–Iowa, 2020

Background: The IDSA has a clinical definition for catheter-related bloodstream infection (CRBSI) that requires ≥1 set of blood cultures from the catheter and ≥1 set from a peripheral vein. However, because blood cultures obtained from a central line may represent contamination rather than true infection, many institutions discourage blood cultures from central lines. We describe blood culture ordering practices in patients with a central line. Methods: The University of Iowa Hospitals &amp; Clinics is an academic medical center with 860 hospital beds. We retrospectively collected data for blood cultures obtained from adult patients (aged ≥18 years) in the emergency department or an inpatient unit during 2020. We focused on the first blood cultures obtained during each admission because they are usually obtained before antibiotic initiation and are the most important opportunity to diagnose bacteremia. We classified blood-culture orders as follows: CRBSI workup, non-CRBSI sepsis workup, or incomplete workup. We defined CRBSI workup as ≥1 blood culture from a central line and ≥1 peripheral blood culture (IDSA guidelines). We defined non-CRBSI sepsis workup as ≥2 peripheral blood cultures without cultures from a central line because providers might have suspected secondary bacteremia rather than CRBSI. We defined incomplete workup as any order that did not meet the CRBSI or non-CRBSI sepsis workup. This occurred when only 1 peripheral culture was obtained or when ≥1 central-line culture was obtained without peripheral cultures. Results: We included 1,150 patient admissions with 4,071 blood cultures. In total, 349 patient admissions with blood culture orders (30.4%) met CRBSI workup. 62.8% were deemed non-CRBSI sepsis workup, and 6.9% were deemed an incomplete workup. Stratified by location, ICUs had the highest percentage of orders with incomplete workups (8.8%), followed by wards (7.2%) and the emergency department (5.1%). In total, 204 patient admissions had ≥1 positive blood culture (17.7%). The most frequently isolated organisms were Staphylococcus epidermidis (n = 33, 16.2%), Staphylococcus aureus (n = 16, 7.8%), and Escherichia coli (n = 15, 7.4%) Conclusions: Analysis of blood culture data allowed us to identify units at our institute that were underperforming in terms of ordering the necessary blood cultures to diagnose CRBSI. Being familiar with CRBSI guidelines as well as decreasing inappropriate ordering will help lead to early and proper diagnosis of CRBSI which can reduce its morbidity, mortality, and cost.Funding: NoneDisclosures: None

Underutilization and Quality Gaps in Blood Culture Processing in Public Hospitals of Peru.

Correct processing of blood cultures may impact individual patient management, antibiotic stewardship, and scaling up of antimicrobial resistance surveillance. To assess the quality of blood culture processing, we conducted four assessments at 16 public hospitals across different regions of Peru. We assessed the following standardized quality indicators: 1) positivity and contamination rates, 2) compliance with recommended number of bottles/sets and volume of blood sampled, 3) blood culture utilization, and 4) possible barriers for compliance with recommendations. Suboptimal performance was found, with a median contamination rate of 4.2% (range 0-15.1%), with only one third of the participating hospitals meeting the target value of < 3%; and a median positivity rate of 4.9% (range 1-8.1%), with only 6 out of the 15 surveilled hospitals meeting the target of 6-12%. None of the assessed hospitals met both targets. The median frequency of solitary blood cultures was 71.9% and only 8.9% (N = 59) of the surveyed adult bottles met the target blood volume of 8 - 12 mL, whereas 90.5% (N = 602) were underfilled. A high frequency of missed opportunities for ordering blood cultures was found (69.9%, 221/316) among patients with clinical indications for blood culture sampling. This multicenter study demonstrates important shortcomings in the quality of blood culture processing in public hospitals of Peru. It provides a national benchmark of blood culture utilization and quality indicators that can be used to monitor future quality improvement studies and diagnostic stewardship policies.

Association Between Implementation of the Severe Sepsis and Septic Shock Early Management Bundle Performance Measure and Outcomes in Patients With Suspected Sepsis in US Hospitals

In October 2015, the Centers for Medicare & Medicaid Services began requiring US hospitals to report adherence to the Severe Sepsis and Septic Shock Early Management Bundle (SEP-1). To evaluate the association of SEP-1 implementation with sepsis treatment patterns and outcomes in diverse hospitals. This retrospective cohort study with interrupted time-series analysis and logistic regression models was conducted among adults admitted to 114 hospitals from October 2013 to December 2017 with suspected sepsis (blood culture orders, ≥2 systemic inflammatory response syndrome criteria, and acute organ dysfunction) within 24 hours of hospital arrival. Data analysis was conducted from September 2020 to September 2021. SEP-1 implementation in the fourth quarter (Q4) of 2015. The primary outcome was quarterly rates of risk-adjusted short-term mortality (in-hospital death or discharge to hospice). Secondary outcomes included lactate testing and administration of anti-methicillin-resistant Staphylococcus aureus (MRSA) or antipseudomonal β-lactam antibiotics within 24 hours of hospital arrival. Generalized estimating equations with robust sandwich variances were used to fit logistic regression models to assess for changes in level or trends in these outcomes, adjusting for baseline characteristics and severity of illness. The cohort included 117 510 patients (median [IQR] age, 67 years [55-78] years; 60 530 [51.5%] men and 56 980 [48.5%] women) with suspected sepsis. Lactate testing rates increased from 55.1% (95% CI, 53.9%-56.2%) in Q4 of 2013 to 76.7% (95% CI, 75.4%-78.0%) in Q4 of 2017, with a significant level change following SEP-1 implementation (odds ratio [OR], 1.34; 95% CI, 1.04-1.74). There were increases in use of anti-MRSA antibiotics (19.8% [95% CI, 18.9%-20.7%] in Q4 of 2013 to 26.3% [95% CI, 24.9%-27.7%] in Q4 of 2017) and antipseudomonal antibiotics (27.7% [95% CI, 26.7%-28.8%] in Q4 of 2013 to 40.5% [95% CI, 38.9%-42.0%] in Q4 of 2017), but these trends preceded SEP-1 and did not change with SEP-1 implementation. Unadjusted short-term mortality rates were similar in the pre-SEP-1 period (Q4 of 2013 through Q3 of 2015) vs the post-SEP-1 period (Q1 of 2016 through Q4 of 2017) (20.3% [95% CI, 20.0%-20.6%] vs 20.4% [95% CI, 20.1%-20.7%]), and SEP-1 implementation was not associated with changes in level (OR, 0.94; 95% CI, 0.68-1.29) or trend (OR, 1.00; 95% CI, 0.97-1.04) for risk-adjusted short-term mortality rates. In this cohort study, SEP-1 implementation was associated with an immediate increase in lactate testing rates, no change in already-increasing rates of broad-spectrum antibiotic use, and no change in short-term mortality rates for patients with suspected sepsis. Other approaches to decrease sepsis mortality may be warranted.

135. Association Between Implementation of the Centers for Medicare &amp; Medicaid Services Sepsis Performance Measure (SEP-1) and Outcomes in U.S. Hospitals

BackgroundIn October 2015, CMS began requiring U.S. hospitals to report compliance with the Severe Sepsis/Septic Shock Early Management Bundle (SEP-1). We evaluated the impact of SEP-1 implementation on sepsis treatment patterns and outcomes using detailed clinical data from diverse hospitals.MethodsWe conducted a quasi-experimental interrupted time-series analysis of adults admitted to 114 hospitals in the Cerner HealthFacts dataset from October 2013-December 2017 with suspected sepsis (defined by blood culture orders, SIRS criteria, and acute organ dysfunction) within 24 hours of hospital arrival. The primary outcome was quarterly short-term mortality rates (in-hospital death or discharge to hospice). Secondary outcomes included lactate testing and administration of anti-MRSA or anti-Pseudomonal beta-lactam antibiotics within 24 hours of hospital arrival. Generalized estimating equations with robust sandwich variances were used to fit logistic regression models to assess for immediate SEP-1 impact and changes in quarterly trends after October 2015, adjusting for baseline characteristics and severity-of-illness. ResultsThe cohort included 117,510 patients with suspected sepsis on admission. Lactate testing rates increased over the study period (61.9% pre-SEP-1 vs 77.9% post-SEP-1) with a significant immediate increase in risk-adjusted testing rates after SEP-1 (OR 1.34, 95% CI 1.04-1.74) (Figure 1). There was also an increase in utilization of anti-MRSA (20.6% pre vs 23.2% post-SEP-1) and anti-Pseudomonal antibiotics (30.1% vs 39.8%), %), but these trends began before SEP-1 implementation. Unadjusted short-term mortality was similar in the pre vs post-SEP-1 periods (20.3% vs 20.4%). SEP-1 was not associated with either an immediate change (OR 0.94, 95% CI 0.68-1.29] or quarterly trend change (OR 1.00, 95% CI 0.97-1.04] in risk-adjusted short-term mortality (Figure 2). Figure 1. Quarterly risk-adjusted rates of A) lactate testing, B) anti-MRSA antibiotic administration, and C) anti-Pseudomonal beta-lactam antibiotic administration within 24 hours of hospital presentation for patients with suspected sepsis before and after SEP-1 implementation in Q4 2015. All models included time (in quarters), an indicator of the post-SEP-1 implementation period (starting Q12016, to allow for evaluation of an immediate policy effect), and a two-way interaction term to assess whether SEP-1 implementation resulted in a change in trend. When data suggested no change in trend, models were also fit without this interaction term; this yielded a significant association for an immediate level change in lactate testing (OR 1.34 [95% CI 1.04-1.74]) but not antibiotic utilization. All analyses were adjusted for patient severity of illness and baseline characteristics including age, sex, race, initial vital signs (systolic blood pressure, temperature, respiratory rate, heart rate), and initial laboratory results (creatinine, platelet count, bilirubin, white blood cell count) if done within 24 hours.Figure 2. Quarterly risk-adjusted outcomes of patients with suspected sepsis before and after SEP-1 implementation in Q4 2015: A) In-hospital death or discharge to hospice, and B) In-hospital death alone. Models included time (in quarters), an indicator of the post-SEP-1 implementation period (starting Q12016, to allow for evaluation of an immediate policy effect), and a two-way interaction term to assess whether SEP-1 implementation resulted in a change in trend. Analyses were adjusted for patient severity of illness and baseline characteristics including age, sex, race, initial vital signs (systolic blood pressure, temperature, respiratory rate, heart rate), and initial laboratory results (creatinine, platelet count, bilirubin, white blood cell count) if done within 24 hours.ConclusionSEP-1 implementation was associated with an immediate increase in lactate testing rates, no significant change in already-rising rates of broad-spectrum antibiotic use, and no change in short-term mortality rates for patients with suspected sepsis in a large cohort of hospitals. Other approaches to decrease sepsis mortality may be warranted. Disclosures Chanu Rhee, MD, MPH, UpToDate (Other Financial or Material Support, Chapter Author) Sameer S. Kadri, MD, MS, FIDSA, Nothing to disclose Michael Klompas, MD, MPH, UpToDate (Other Financial or Material Support, Chapter Author)

81. Reducing Unnecessary Blood Cultures Through Diagnostic Stewardship

BackgroundAt our institution, we learned the frequency of blood cultures was sometimes being changed from “Once” to “Daily” without a defined number of days. We hypothesized this led to unnecessary blood cultures being performed.MethodsOver a 3 month period from 12/6/2019-3/6/2020, we retrospectively evaluated the charts of patients who had a blood culture frequency changed to “Daily”. We evaluated if there was an initial positive blood culture within 48 hours of the “Daily” order being placed and the number of positive, negative, or “contaminant” sets of cultures drawn with the order. Contaminant blood cultures were defined as a contaminant species, present only once in the repeat cultures, and not present in initial positive cultures.Results95 unique orders were placed with 406 sets of cultures drawn from 89 adults. ~20% of the time (17 orders) the order was placed without an initial positive blood culture. This led to 62 sets of cultures being drawn, only 1 of which came back positive. 78/95 orders had an initial positive blood culture. The most common initial organisms were Staphylococcus aureus (SA) (38), Candida sp (10), Enterobacterales sp (10), and coagulase negative staphylococci (7). 43/78 (55%) orders with an initial positive set had positive repeat cultures. SA (26) and Candida sp (8) were most common to have positive repeats. Central line associated bloodstream infections (CLABSI) were found in 5 of the orders and contaminant species were found in 4 of the orders. 54% of the patients who had a “Daily” order placed did not have positive repeat cultures. The majority of the cultures were drawn from Surgical (40 orders) and Medical (35 orders) services. Assuming that SA and Candida sp require 48 hours of negative blood cultures to document clearance and other species require 24 hours, it was estimated that 51% of the cultures drawn using the "Daily" frequency were unnecessary. Cost savings over a year of removing the "Daily" frequency would be ~&14,000. Data from "Daily" blood culture orders drawn at Oregon Health & Science University from 12/6/2019-3/6/2020ConclusionUnnecessary blood cultures are drawn when the frequency of blood cultures is changed to "Daily". Repeat blood cultures had the greatest utility in bloodstream infections due to SA or Candida sp, and with CLABSI where the line is still in place. These results led to a stewardship intervention to change blood culture ordering at our institution.Disclosures All Authors: No reported disclosures

Purposeful microbiology comment added to urine cultures with Staphylococcus aureus increases orders for follow-up blood cultures.

Introduction Patients with Staphylococcus aureus bacteriuria (SABU) often have underlying invasive disease, including S. aureus bacteremia (SAB). It has been proposed that most patients with SABU should have a blood culture done to rule out SAB. A preliminary audit suggested that our local hospitals had a low rate of follow-up blood culture orders for patients with SABU. In response to this, our microbiology laboratory changed the comment appended to urine cultures with growth of S. aureus to make a more assertive link between SABU and SAB and to recommend follow-up blood cultures.Aim We designed a retrospective quasi-experimental study to see if the change in microbiology comment wording had an effect on clinician behaviour. We hypothesized that this simple comment change to make a more assertive link between SABU and SAB would lead to an increase in follow-up blood culture orders.Methodology We used microbiology records to identify adult patients with urine cultures positive for Staphylococcus aureus at three acute-care hospitals in Hamilton, Ontario, Canada, for 1 year pre- and post-intervention. We recorded urine and blood culture results, timing, patient demographics, and in-hospital mortality.Results A total of 243 adult patients with urine cultures with S. aureus were identified for inclusion. The primary outcome was met, as there was a significant increase in blood culture orders between the pre-intervention and post-intervention groups (66.9 % vs 80.4 %). This difference was mainly driven by an increase for emergency department and urgent care patients (30.6 % vs 63.6 %). The inpatient group had a high baseline rate of blood culture orders that did not change significantly (80.0 % vs 84.7 %). There was no significant change in detection of SAB (23.5 % vs 32.7 %) or inpatient mortality (18.0 % vs 24.7 %).Conclusion Our study shows that a simple, purposeful comment appended to urine cultures with S. aureus leads to a significant increase in follow-up blood culture orders.

Determining the Electronic Signature of Infection in Electronic Health Record Data.

Recent sepsis studies have defined patients as "infected" using a combination of culture and antibiotic orders rather than billing data. However, the accuracy of these definitions is unclear. We aimed to compare the accuracy of different established criteria for identifying infected patients using detailed chart review. Retrospective observational study. Six hospitals from three health systems in Illinois. Adult admissions with blood culture or antibiotic orders, or Angus International Classification of Diseases infection codes and death were eligible for study inclusion as potentially infected patients. Nine-hundred to 1,000 of these admissions were randomly selected from each health system for chart review, and a proportional number of patients who did not meet chart review eligibility criteria were also included and deemed not infected. None. The accuracy of published billing code criteria by Angus et al and electronic health record criteria by Rhee et al and Seymour et al (Sepsis-3) was determined using the manual chart review results as the gold standard. A total of 5,215 patients were included, with 2,874 encounters analyzed via chart review and a proportional 2,341 added who did not meet chart review eligibility criteria. In the study cohort, 27.5% of admissions had at least one infection. This was most similar to the percentage of admissions with blood culture orders (26.8%), Angus infection criteria (28.7%), and the Sepsis-3 criteria (30.4%). Sepsis-3 criteria was the most sensitive (81%), followed by Angus (77%) and Rhee (52%), while Rhee (97%) and Angus (90%) were more specific than the Sepsis-3 criteria (89%). Results were similar for patients with organ dysfunction during their admission. Published criteria have a wide range of accuracy for identifying infected patients, with the Sepsis-3 criteria being the most sensitive and Rhee criteria being the most specific. These findings have important implications for studies investigating the burden of sepsis on a local and national level.