Implementation of standard setting for high-stakes objective structured clinical examinations

BACKGROUND AND PURPOSE

To describe one institution's approach to transformation of high-stakes objective structure clinical examinations (OSCEs) from norm-referenced to criterion-referenced standards setting and to evaluate the impact of these changes on OSCE performance and pass rates.

EDUCATIONAL ACTIVITY AND SETTING

The OSCE writing team at the college selected a modified Angoff method appropriate for high-stakes assessments to replace the two standard deviation method previously used. Each member of the OSCE writing team independently reviewed the analytical checklist and calculated a passing score for active stations on OSCEs. Then the group met to determine a final pass score for each station. The team also determined critical cut points for each station, when indicated. After administration of the OSCEs, scores, pass rates, and need for remediation were compared to the previous norm-referenced method. Descriptive statistics were used to summarize the data.

FINDINGS

OSCE scores remained relatively unchanged when switched to a criterion-referenced method, but the number of remediators increased up to 2.6 fold. In the first year, the average score increased from 86.8% to 91.7% while the remediation rate increased from 2.8% to 7.4%. In the third year, the average increased from 90.9% to 92% while the remediation rate increased from 6% to 15.6%. Likewise, the fourth-year average increased from 84.9% to 87.5% while the remediation rate increased from 4.4% to 9%.

SUMMARY

Transition to a modified Angoff method did not impact average OSCE score but did increase the number of remediations.

Brincidofovir for disease progression due to suspected tecovirimat resistance in association with advanced HIV

A man with advanced HIV presented with verrucous plaques 2-3 months after initial mpox infection. He received two courses of tecovirimat without resolution of initial mpox lesions and development of new lesions raising concern for resistance. He was treated with two doses of brincidofovir and demonstrated improvement 6 months later.

Cefepime pharmacokinetics in adult extracorporeal membrane oxygenation patients

BACKGROUND

The impact of extracorporeal membrane oxygenation (ECMO) on the pharmacokinetics/dynamics (PK/PD) of beta-lactam antibiotics have not been well studied in general, but cefepime specifically has the least amount of data. We aimed to investigate whether ECMO alters the PK of cefepime in adult intensive care unit (ICU) patients.

METHODS

This single-center, retrospective case-control study evaluated cefepime therapeutic drug monitoring (TDM) results from ECMO patients that were matched 1:1 with TDM results in non-ECMO patients for drug regimen and renal function. The primary outcome was the difference in PK/PD of cefepime in ECMO compared with non-ECMO ICU patients. Secondary outcomes included hospital length of stay, treatment failure, superinfection, bacterial resistance, and survival to discharge.

RESULTS

Eighty-two patients were included with 44 matched cefepime concentrations in each group. ECMO patients had higher free maximum concentrations (fCmax) (p = 0.003), lower free minimum concentration (fCmin)/1x minimum inhibitory concentration (MIC) ratios (p = 0.040), and lower attainment of free Cmin/4x MIC (p = 0.010). There were no differences between the groups for free Cmin, time above 1xMIC or 4x MIC, and pharmacokinetic parameters (ke, half-life, and Vd). Of those who survived to discharge, hospital length of stay was longer in the ECMO group (p < 0.001). Patients on ECMO were more likely to experience treatment failure (p = 0.036). The incidence of bacterial resistance, superinfection, or survival were similar among the groups.

CONCLUSION

These data suggest that more aggressive empiric dosing may be warranted in patients on ECMO. Therapeutic drug monitoring and future prospective studies would provide more evidence to guide decision making regarding dose adjustments.

A Randomized Clinical Trial of Bayesian-Guided Beta-Lactam Infusion Strategy and Associated Bacterial Resistance and Clinical Outcomes in Patients With Severe Pneumonia

BACKGROUND

Antimicrobial resistance is a growing health concern worldwide. The objective of this study was to evaluate the effect of beta-lactam infusion on the emergence of bacterial resistance in patients with severe pneumonia in the intensive care unit.

METHODS

Adult intensive care patients receiving cefepime, meropenem, or piperacillin-tazobactam for severe pneumonia caused by Gram-negative bacteria were randomized to receive beta-lactams as an intermittent (30 minutes) or continuous (24 hours) infusion. Respiratory samples for culture and susceptibility testing, with minimum inhibitory concentrations (MIC), were collected once a week for up to 4 weeks. Beta-lactam plasma concentrations were measured and therapeutic drug monitoring was performed using Bayesian software as the standard of care.

RESULTS

The study was terminated early owing to slow enrollment. Thirty-five patients were enrolled in this study. Cefepime (n = 22) was the most commonly prescribed drug at randomization, followed by piperacillin (n = 8) and meropenem (n = 5). Nineteen patients were randomized into the continuous infusion arm and 16 into the intermittent infusion arm. Pseudomonas aeruginosa was the most common respiratory isolate (n = 19). Eighteen patients were included in the final analyses. No differences in bacterial resistance were observed between arms ( P = 0.67). No significant differences in superinfection ( P = 1), microbiological cure ( P = 0.85), clinical cure at day 7 ( P = 0.1), clinical cure at end of therapy ( P = 0.56), mortality ( P = 1), intensive care unit length of stay ( P = 0.37), or hospital length of stay ( P = 0.83) were observed. Achieving 100% ƒT > MIC ( P = 0.04) and ƒT > 4 × MIC ( P = 0.02) increased likelihood of clinical cure at day 7 of therapy.

CONCLUSIONS

No differences in the emergence of bacterial resistance or clinical outcomes were observed between intermittent and continuous infusions. Pharmacokinetic/pharmacodynamic target attainment may be associated with a clinical cure on day 7.

Association of piperacillin and vancomycin exposure on acute kidney injury during combination therapy

Objectives

Acute kidney injury (AKI) is a well-documented adverse effect observed with piperacillin/tazobactam in combination with vancomycin. The pharmacokinetics of these antibiotics when given in combination have not been previously evaluated. The purpose of this study was to compare the exposure of vancomycin + piperacillin/tazobactam in patients with and without AKI.

Methods

Ninety adult patients, who received at least 72 h of vancomycin + piperacillin/tazobactam combination therapy and had available serum concentrations of vancomycin and piperacillin were included in the study. Nephrotoxicity was defined as a 1.5-fold increase in serum creatinine within 7 days from baseline. Median daily AUCs were calculated in those with nephrotoxicity (vancomycin + piperacillin/tazobactam 'N') versus those without nephrotoxicity (vancomycin + piperacillin/tazobactam 'WN') during the first 7 days of combination therapy.

Results

The overall incidence of AKI in those receiving vancomycin + piperacillin/tazobactam was 20% (18/90). The median daily vancomycin AUCs did not differ between the vancomycin + piperacillin/tazobactam 'WN' and vancomycin + piperacillin/tazobactam 'N' groups. Although not statistically significant, the median daily vancomycin AUCs in the vancomycin + piperacillin/tazobactam 'N' group were numerically greater on Day 5 and trended downwards thereafter. For the piperacillin group, the median daily AUCs did not vary between groups, except on Day 7 where the vancomycin + piperacillin/tazobactam 'WN' group had statistically greater median piperacillin AUC than the vancomycin + piperacillin/tazobactam 'N' group (P = 0.046).

Conclusions

Utilizing serum creatinine-defined AKI, our study did not find any significant differences in vancomycin and piperacillin/tazobactam exposure between the groups with and without nephrotoxicity. These data indicate that vancomycin + piperacillin/tazobactam should not be avoided due to the risk of overexposure; instead, clinicians should continue to use these therapies cautiously.

Exploring Trends in Social Vulnerability for Pharmacy Students at a Large Public University

OBJECTIVE

This study aimed to describe trends in social vulnerability (SV) among pharmacy students at a large public college of pharmacy, and to describe differences in SV by race and ethnicity using the Centers for Disease Control and Prevention Social Vulnerability Index (SVI).

METHODS

The SVI was determined for each student admitted between Fall 2017 and Fall 2022 using the submitted permanent address for each student in a deidentified fashion. International students and students not from the 50 US states were excluded from the analysis.

RESULTS

During the study period, 1427 pharmacy students met the study inclusion criteria and were included in the final analysis. Students from historically minoritized populations accounted for 53.4% (n = 763/1427) of students. The median SVI score for all students was 0.4091 (interquartile range [IQR]: 0.2091-0.6395), which is consistent with low/moderate SV risk. When considering SVI by race, students from historically minoritized populations had a higher median SVI (0.4807 [IQR: 0.2791-0.7071] vs 0.3562 [IQR: 0.1561-0.5523]), and were more likely to come from moderate/high SV regions compared with White students (odds ratio 2.00 [95% confidence interval: 1.609-2.486]).

CONCLUSION

Among pharmacy students at a large public university, a substantial proportion of students had moderate/high SV risk, particularly those from historically minoritized backgrounds. Colleges and schools of pharmacy need to consider the unique needs of students from high SV backgrounds and provide intentional equity-based mitigation strategies to maximize the potential for student success for all.

Utilization of cefepime therapeutic drug monitoring in febrile neutropenia patients with hematologic malignancies

INTRODUCTION

Cefepime is a fourth-generation cephalosporin and is a workhorse for the empiric treatment of febrile neutropenia (FN). Beta-lactam therapeutic drug monitoring (TDM) has emerged as a dose optimization strategy in patient populations with altered kinetics. Prior literature has demonstrated that patients with FN exhibit augmented renal clearance which may lead to subtherapeutic drug concentrations with standard dosing regimens. The aim of this study was to evaluate pharmacokinetic/pharmacodynamic (PK/PD) target attainment and clinical outcomes in patients with hematologic malignancies and FN who were treated empirically with cefepime.

METHODS

This was a prospective, single-center study of adults with hematologic malignancies and FN admitted to the inpatient unit. The primary outcome was PK/PD target attainment (defined as 100% free time greater than minimum inhibitory concentration (100% fT > MIC)). Secondary clinical outcomes were time to defervescence, time to ANC recovery, in-hospital mortality, and cefepime failure.

RESULTS

There were 55 patients in our study. Forty-three (78%) patients achieved the primary outcome of PK/PD target attainment. The mean time to defervescence was similar between those that achieved PK/PD target attainment and those that did not (95% CI -0.75 to 1.25, p = 0.62).

CONCLUSIONS

This study showed that standard cefepime dosing in patients with hematologic malignancies and FN does not result in achievement of 100% fT > MIC in all patients. Patients in the group that did not achieve PK/PD target attainment were younger with increased creatinine clearance, indicating that cefepime TDM may be especially beneficial in these patients.

Making the case for precision dosing: visualizing the variability of cefepime exposures in critically ill adults

OBJECTIVE

To investigate and describe the variability in cefepime exposures among 'real-world', critically ill patients by using population pharmacokinetic modelling and simulations, and with translation of these findings to visualizations.

METHODS

A cohort of adult medical ICU patients who received cefepime with therapeutic drug monitoring was studied. Two compartment models were developed to estimate cefepime clearance (Model 1) and simulate cefepime exposures among 1000 patients, each with identical creatinine clearance of 60 mL/min and receiving a regimen of cefepime 1 gram IV over 30 minutes, every 8 hours (Model 2). Variability in the relationship between cefepime clearance and creatinine clearance (CrCL) was visualized, and a random, representative sample of 10 simulated patients was utilized to illustrate variability in cefepime exposures.

RESULTS

A total of 75 adult medical ICU patients (52% female) and 98 serum cefepime samples were included in the study. Population parameter estimates for cefepime displayed a wide range of variation in Model 1 (CV: 45% to 95%), with low bias at the individual level at 0.226 mg/L but high bias in the population model 10.6 mg/L. Model 2 displayed similar fits, demonstrating that correcting for individual patient creatinine clearance slightly improves the bias of the population model (bias = 4.31 mg/L). Among 10 simulated patients that a clinician would deem similar from a dosing perspective (i.e. equivalent creatinine clearance), maximum concentrations after three simulated doses varied more than 8-fold from 41.2 to 339 mg/L at the 5th and 95th percentiles, and clearance profiles were highly different.

CONCLUSION

Creatinine clearance estimates alone are inadequate for predicting cefepime exposures. Wide variations in cefepime exposure exist among ICU patients, even for those with similar kidney function estimates. Current population adjustment schemes based solely on creatinine clearance will result in unintended high and low exposures leading to safety and efficacy concerns, respectively.

Oral fluoroquinolones and risk of aortic aneurysm or dissection: A nationwide population-based propensity score-matched cohort study

STUDY OBJECTIVE

To investigate risk of aortic aneurysm or dissection in patients using oral fluoroquinolones compared to those using macrolides in real-world clinical practice among a large US general population.

DESIGN

Retrospective cohort study design.

DATA SOURCE

MarketScan commercial and Medicare supplemental databases.

PATIENTS

Adults patients with at least one prescription fill for fluoroquinolone or macrolide antibiotics.

INTERVENTION

Fluoroquinolone or macrolide antibiotics.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was estimated incidence of aortic aneurysm or dissection associated with the use of fluoroquinolones compared with macrolides during a 60-day follow-up period in a 1:1 propensity score-matched cohort. We identified 3,174,620 patients (1,587,310 in each group) after 1:1 propensity score matching. Crude incidence of aortic aneurysm or dissection was 1.9 cases per 1000 person-years among fluoroquinolone users and 1.2 cases per 1000 person-years among macrolide users. In multivariable Cox regression, compared with macrolides, the use of fluoroquinolones was associated with an increased risk of aortic aneurysm or dissection (aHR: 1.34; 95% CI: 1.17-1.54). The association was primarily driven by a high incidence of aortic aneurysm cases (95.8%). Results of sensitivity (e.g., fluoroquinolone exposure ranging from 7 to 14 days (aHR: 1.47; 95% CI: 1.26-1.71)) and subgroup analyses (e.g., ciprofloxacin (aHR: 1.26; 95% CI: 1.07-1.49) and levofloxacin (aHR: 1.44; 95% CI: 1.19-1.52)) remained consistent with main findings.

CONCLUSIONS

Fluoroquinolone use was associated with a 34% increased risk of aortic aneurysm or dissection compared with macrolide use among a general US population.

Re-evaluation of cefepime or piperacillin/tazobactam to decrease use of carbapenems in ESBL-producing Enterobacterales urinary tract infections (REDUCE-UTI)

Objectives

To re-examine the use of non-carbapenems (NCBPs), specifically piperacillin/tazobactam and cefepime, for ESBL-producing Enterobacterales (ESBL-E) urinary tract infections (UTIs).

Patients

Retrospective cohort study of adults hospitalized between January 2016 and June 2020 with pyuria on urinalysis, a urine culture positive for ESBL-E treated with a study antibiotic (meropenem, ertapenem, cefepime or piperacillin/tazobactam) and did not meet criteria for study exclusion.

Methods

To compare carbapenems (CBPs) with cefepime or piperacillin/tazobactam for the treatment of ESBL-E UTI. The primary outcome was clinical cure, defined as complete resolution of signs and symptoms of infection. Secondary outcomes included in-hospital mortality, recurrence within 30 days and resistance emergence within 30 days.

Results

One-hundred and thirty-three patients were included, based on definitive therapy received; 69 (51.9%) received CBP and 64 (48.1%) received NCBP therapy. Of the total patient population, 17 (12.8%) were admitted to the ICU, 84 (63.1%) had a complicated UTI and 64 (48.1%) had pyelonephritis. There was no difference in clinical cure between the CBP and NCBP groups (95.7% versus 96.9%, P = 0.999). Additionally, no differences in secondary outcomes were observed.

Conclusions

When compared with CBPs, cefepime and piperacillin/tazobactam resulted in similar clinical cure, in-hospital mortality, recurrence and resistance emergence in the treatment of ESBL-E UTI.

Nephrotoxicity of Vancomycin in Combination With Beta-Lactam Agents: Ceftolozane-Tazobactam vs Piperacillin-Tazobactam

BACKGROUND

Vancomycin (VAN)-associated acute kidney injury (AKI) is increased when VAN is combined with certain beta-lactams (BLs) such as piperacillin-tazobactam (TZP) but has not been evaluated with ceftolozane-tazobactam (C/T). Our aim was to investigate the AKI incidence of VAN in combination with C/T (VAN/C/T) compared with VAN in combination to TZP (VAN-TZP).

METHODS

We conducted a multicenter, observational, comparative study across the United States. The primary analysis was a composite outcome of AKI and risk, injury, failure, loss, end stage renal disease; Acute Kidney Injury Network; or VAN-induced nephrotoxicity according to the consensus guidelines. Multivariable logistic regression analysis was conducted to adjust for confounding variables and stratified Kaplan-Meir analysis to assess the time to nephrotoxicity between the 2 groups.

RESULTS

We included VAN/C/T (n = 90) and VAN-TZP (n = 284) at an enrollment ratio of 3:1. The primary outcome occurred in 12.2% vs 25.0% in the VAN-C/T and VAN-TZP groups, respectively (P = .011). After adjusting for confounding variables, VAN-TZP was associated with increased odds of AKI compared with VAN-C/T; with an adjusted odds ratio of 3.308 (95% confidence interval, 1.560-6.993). Results of the stratified Kaplan-Meir analysis with log-rank time-to-nephrotoxicity analysis indicate that time to AKI was significantly shorter among patients who received VAN-TZP (P = .004). Cox proportional hazards analysis demonstrated that TZP was consistent with the primary analysis (P = .001).

CONCLUSIONS

Collectively, our results suggest that the AKI is not likely to be related to tazobactam but rather to piperacillin, which is a component in VAN-TZP but not in VAN-C/T.

Use of therapeutic drug monitoring to characterize cefepime-related neurotoxicity

STUDY OBJECTIVES

Data evaluating cefepime thresholds associated with neurotoxicity remain limited. The objectives of this study were to evaluate the incidence of cefepime-related neurotoxicity (CRN) in patients with plasma cefepime concentrations, assess the relationship between cefepime exposure and CRN, investigate clinical factors associated with CRN, and describe electroencephalogram (EEG) abnormalities in CRN.

DESIGN

This was a retrospective study of adult inpatients admitted between 2016 and 2018 who received cefepime therapeutic drug monitoring (TDM). Potential CRN cases were identified utilizing a standard definition. The primary outcomes of the study were to determine the incidence of CRN and evaluate the relationship between cefepime trough concentrations, the average daily AUC, and neurotoxicity. Bayesian posteriors were generated for each patient using a cefepime pharmacokinetic (PK) model, and the mean daily area under the concentration-time curve (AUC) was calculated. Multiple regression was performed to assess the association between CRN, cefepime PK, and clinical predictors of neurotoxicity.

MAIN RESULTS

Four hundred eighty-one patients with 503 hospital encounters received cefepime TDM and were included in the analysis. The incidence of CRN was 4.4% (22/503). Patients with CRN had a higher incidence of renal dysfunction, hypertension, and diabetes mellitus compared to patients without CRN (non-NT). The mean cefepime trough concentration was significantly greater in the CRN patients than in the non-NT group (61.8 ± 33.7 vs. 30 ± 27.7 mg/L, respectively, p = 0.0002). Cefepime trough concentration and renal dysfunction were independently associated with increased risk of CRN in the adjusted multiple regression model. Moderate generalized slowing of the background rhythm was the most common EEG pattern associated with CRN. Delaying cefepime TDM greater than 72 h after the initiation of cefepime was associated with a 3-fold increased risk of CRN.

CONCLUSION

Cefepime should be used cautiously in hospitalized patients with renal dysfunction due to the risk of neurotoxicity. Dose optimization utilizing TDM early in cefepime treatment may minimize adverse effects and improve patient safety.

Implementation of a β-lactam therapeutic drug monitoring program: Experience from a large academic medical center

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

To describe the implementation and operationalization of a β-lactam (BL) therapeutic drug monitoring(TDM) program at a large academic center.

SUMMARY

BLs are the most used class of antibiotics. Suboptimal antibiotic exposure is a significant concern in hospitalized patients, particularly in those with altered pharmacokinetics. BL-TDM provides clinicians the opportunity to optimize drug concentrations to ensure maximal therapeutic efficacy while minimizing toxicity. However, BL-TDM has not been widely adopted due to the lack of access to assays. The University of Florida Shands Hospital developed a BL-TDM program in 2015. This is a consultative service primarily run by pharmacists and is conducted in all patient care areas. An analysis was performed on the first BL-TDM encounter for 1,438 patients. BL-TDM was most frequently performed for cefepime (61%, n = 882), piperacillin (15%, n = 218), and meropenem (11%, n = 151). BL-TDM was performed a median of 3 days (interquartile range, 1-5 days) from BL initiation. Among patients with available minimum inhibitory concentration (MIC) values and trough concentrations, the pharmacokinetic/pharmacodynamic (PK/PD) target of 100% fT>MIC was attained in 308 patients (88%). BL-TDM resulted in a dosage adjustment in 25% (n = 361) of patients.

CONCLUSION

Implementation of a BL-TDM program requires the concerted efforts of physicians, pharmacists, nursing staff, phlebotomists, and personnel in the analytical laboratory. Standard antibiotic dosing failed to achieve optimal PK/PD targets in all patients; utilizing BL-TDM, dose adjustments were made in 1 of every 4 patients.

Evaluation of Susceptibility Patterns in Uropathogens and Empiric Antibiotic Therapy in the Emergency Department

Objectives: Urinary Tract Infections (UTIs) are the most common bacterial infections encountered in the Emergency Department (ED). Objectives of this study are to describe the urological pathogens associated with UTIs in the ED, report antibiotic susceptibilities, and assess empiric antibiotic treatment. Methods: A retrospective chart review of 154 patients with positive urine cultures from January to June 2016 were reviewed for inclusion in the study. Patients were excluded if less than 18 years of age, hospitalized, discharged from the ED without antibiotics or diagnosed with pyelonephritis. Patient demographics, uropathogens isolated, in-vitro susceptibility to commonly prescribed oral antibiotics (nitrofurantoin, ciprofloxacin, and sulfamethoxazole/trimethoprim), and antibiotics selected for treatment were recorded. Results: One hundred patients were included in the final analysis. Of the 106 bacterial isolates, Escherichia coli, Klebsiella pneumoniae, and Group B Streptococcus accounted for 62.5%, 8%, and 8% of pathogens, respectively. Overall susceptibilities were 88.1%, 87.9%, 85.4%, and 70.6% for nitrofurantoin, cefazolin, ciprofloxacin, and sulfamethoxazole/trimethoprim, respectively. Escherichia coli was most susceptible to nitrofurantoin at 96.9% followed by cefazolin at 94%. Ciprofloxacin was the most prescribed antibiotic followed by cephalexin, nitrofurantoin and sulfamethoxazole/trimethoprim. Conclusions: Based on bacterial susceptibility patterns, nitrofurantoin and cephalexin are reasonable first line agents in the empiric treatment of urinary tract infections identified in the emergency department. The most frequently prescribed antibiotic was ciprofloxacin, highlighting the importance of implementing antimicrobial stewardship initiatives and designing specific tools and educational programs for the emergency department targeted at minimizing fluoroquinolone use.

Real-world, Multicenter Experience With Meropenem-Vaborbactam for Gram-Negative Bacterial Infections Including Carbapenem-Resistant Enterobacterales and Pseudomonas aeruginosa

Background

We aimed to describe the clinical characteristics and outcomes of patients treated with meropenem-vaborbactam (MEV) for a variety of gram-negative infections (GNIs), primarily including carbapenem-resistant Enterobacterales (CRE).

Methods

This is a real-world, multicenter, retrospective cohort within the United States between 2017 and 2020. Adult patients who received MEV for ≥72 hours were eligible for inclusion. The primary outcome was 30-day mortality. Classification and regression tree analysis (CART) was used to identify the time breakpoint (BP) that delineated the risk of negative clinical outcomes (NCOs) and was examined by multivariable logistic regression analysis (MLR).

Results

Overall, 126 patients were evaluated from 13 medical centers in 10 states. The most common infection sources were respiratory tract (38.1%) and intra-abdominal (19.0%) origin, while the most common isolated pathogens were CRE (78.6%). Thirty-day mortality and recurrence occurred in 18.3% and 11.9%, respectively. Adverse events occurred in 4 patients: nephrotoxicity (n = 2), hepatoxicity (n = 1), and rash (n = 1). CART-BP between early and delayed treatment was 48 hours (P = .04). MEV initiation within 48 hours was independently associated with reduced NCO following analysis by MLR (adusted odds ratio, 0.277; 95% CI, 0.081–0.941).

Conclusions

Our results support current evidence establishing positive clinical and safety outcomes of MEV in GNIs, including CRE. We suggest that delaying appropriate therapy for CRE significantly increases the risk of NCOs.

Early therapeutic monitoring of β-lactams and associated therapy outcomes in critically ill patients

BACKGROUND

In the ICU, early and appropriate antimicrobial therapy is important to lower infection-related mortality.

OBJECTIVES

Assess whether achieving early β-lactam free concentration above the MIC 100% of the time (fT>MIC) is associated with positive outcomes in the ICU.

METHODS

This retrospective study was conducted in ICU patients admitted to UF Health Shands Hospital between 2016 and 2018. Adult patients who received β-lactam therapy and had drug concentration measured were included. Data collected included demographics, β-lactam regimens and concentrations, sources of infection, cultures and susceptibilities, mortality, length of stay, resistance acquisition for 30 days and clinical outcome at end of therapy. Multiple regression and time-to-event (TTE) analyses were performed.

RESULTS

Two-hundred and six patients were included. Clinical cure occurred in 71%, microbial eradication occurred in 58% and new resistance to the β-lactam received developed in 8% of patients. Hospital and 30 day mortalities were 17% and 14%, respectively. fT>MIC and fT>4×MIC were associated with clinical cure (P = 0.0303), microbial eradication (P = 0.0476) and suppression of resistance (P = 0.0043). Delay in measuring β-lactam concentration was associated with clinical failure (P = 0.0072), longer ICU stay (P < 0.0001) and higher mortality (P = 0.0387). In the TTE analysis, patients with 100% fT>MIC had a significantly shorter ICU stay (P = 0.0297). Patients who had clinical cure and microbial eradication had drug concentrations measured earlier (P = 0.0025 and 0.0254, respectively).

CONCLUSIONS

This study highlights the importance of early measurement of β-lactam concentration and confirms the association between fT>MIC and clinical cure, microbial eradication and emergence of resistance.

Resource Over-Utilization in Hospitalized Patients With Uncomplicated Skin and Soft Tissue Infections

BACKGROUND

Inpatient management of SSTIs utilizes considerable healthcare resources. The CREST+SEWS score categorizes patients with SSTIs into 4 severity classes. Hospitalizations can be avoided in Class I as they are treated as outpatients with oral antibiotics, whereas Class IV require hospitalization for intravenous antibiotics.

OBJECTIVE

The purpose of this study was to perform a budget impact analysis on CREST+SEWS Class 1 patients, to compare the medical costs of current treatment, in the inpatient setting with intravenous antibiotics, with a proposed alternative of using oral antibiotics in the outpatient setting. Further, resource utilization in Class I was evaluated.

METHODS

This was a retrospective study of adult patients hospitalized in 2015 for SSTIs who received >24 hours of antimicrobials. The CREST+SEWS scoring system was used to stratify patients into Class I to IV. Pharmacy and medical costs and resources associated with inpatient management of Class I SSTIs were derived from the itemized discharge records.

RESULTS

Of the 252 patients who met the inclusion criteria, 61 (24%) were classified as Class I. The total cost of treating Class I SSTI patients in the inpatient setting was $281,816 (cost per patient: $4,619) in 2015 USD. In the hypothetical situation of treatment with oral antibiotics in the outpatient setting, the cost savings were estimated to be $4,398 per patient. Fifty-three percent of patients had blood cultures, and on average, each patient received 2 radiographic tests.

CONCLUSIONS

Identifying outpatient candidates, and avoiding tests with low diagnostic can reduce the economic burden of SSTIs.

Impact of supplemental individual verbal defense on confidence, engagement, and performance in a team-based learning therapeutics course

BACKGROUND AND PURPOSE

Team-based learning (TBL) has been successfully applied to multiple healthcare education disciplines. A primary tenet of TBL is the development of solutions leveraging the collective knowledge of a team rather than the individual competency of any one student. In an effort to enhance individual student accountability, an individual verbal defense (IVD) format was implemented in a multi-campus TBL-based pharmacotherapeutics course. The study sought to investigate the use of TBL-IVD embedded within a traditional TBL format on student engagement, teaching style preferences, and exam performance compared to a TBL-only format.

EDUCATIONAL ACTIVITY AND SETTING

In this cross-sectional study, second-year pharmacy students enrolled in a pharmacotherapeutics course during fall 2019 completed an 11-item survey. The survey was designed to assess TBL-IVD on student engagement and teaching style preference. Free-response qualitative feedback was solicited to assess positive-negative themes related to the activity. Aggregate exam performance for community-acquired pneumonia (CAP) related content was compared to historical exam data to assess the impact on student performance.

FINDINGS

The majority of students (72%, n = 54) preferred the TBL-IVD compared to a TBL-only format. Students reported higher engagement with TBL-IVD (84%, n = 63). Correct exam responses for CAP related content were higher in the TBL-IVD group (67% vs. 55%, P < .001). Positive themes included an increased opportunity to defend recommendations verbally and increased interaction with an on-campus faculty member.

SUMMARY

The study demonstrates the addition of IVD can enhance student perceptions, confidence, and performance within a large, multi-campus, TBL-based pharmacotherapeutics course.

143. Modification of Linezolid Restriction Criteria Reduces ICU Gram-positive Antibiotic Consumption

Background

Antibiotic time out (ATO) policies have been proposed by the Centers for Disease Control and Prevention to limit unnecessary use of antibiotics. Critically ill patients are often treated empirically with MRSA-active agents for a prolonged duration. The objective of this study was to assess the impact of an ATO policy by targeting empiric gram-positive coverage.

Methods

Before this intervention, linezolid required pre-approval by the antimicrobial stewardship program or infectious diseases (ID) consult service before dispensing, and no automatic ATO policy was in place for any agent. In 2018, restriction of linezolid was modified to allow 72 hours of empiric use in the intensive care unit (ICU). This retrospective, single-center, pre- post-intervention study looked at eight ICUs at our institution from two equal periods. Adults (age ≥ 18 years) were included who received an IV gram-positive antibiotic (IVGP-AB), specifically linezolid or vancomycin, used for empiric therapy and were admitted to the ICU. The primary outcome was antimicrobial consumption of IVGP-AB defined as days of therapy (DOT) per patient. Secondary outcomes included in-hospital length of stay (LOS), ICU LOS, in-hospital mortality, 30-day readmission, and incidence of acute kidney injury (AKI).

Figure 1. Flowchart of patient inclusion into the study

Results

2718 patients met criteria for inclusion in the study. 1091 patients were included in the pre-intervention group and 1627 patients were included in the post-intervention group. Baseline characteristics between the two groups were similar, with ID consults being higher in the pre-intervention group. Total mean DOT of IVGP-AB in pre- and- post-intervention groups was 4.97 days vs. 4.36 days, p&lt; 0.01. Secondary outcomes of in-hospital LOS, ICU LOS, and in-hospital mortality did not vary significantly between groups. Thirty-day readmission was lower in the post-intervention group (12.9% vs. 3.9%, p&lt; 0.01). AKI did not differ significantly between groups, however the need for renal replacement therapy was higher in the pre-intervention group (1.2% vs. 0.2%, p&lt; 0.01).

Conclusion

This study assessed the impact of an ATO policy allowing 72 hours of empiric linezolid in the ICU. We found a statistically significant reduction in days of therapy of IVGP-AB without increases in LOS, mortality, readmission, and AKI.

Disclosures

All Authors: No reported disclosures

1575. Predictors of Negative Clinical Outcomes among Patients treated with Meropenem-Vaborbactam for Serious Gram-Negative Bacterial Infections: Impact of Delayed Appropriate Antibiotic Selection

Background

Numerous number of studies have found a positive correlation between delayed appropriate antibiotic therapy and negative clinical outcomes (NCO) in Gram-negative bacterial infections (GNBI). The combination of meropenem with vaborbactam (MVB) received Food and Drug Administration approval for the treatment of complicated urinary tract infections and acute pyelonephritis caused by susceptible organisms in August 2017. We sought to determine the impact of delayed appropriate therapy with MVB on NCO among patients with GNBI.

Methods

Multi-center, retrospective cohort study from October 2017 to March 2020. We included adult patients treated with MVB for &gt;72 hours. We excluded patients who received alternative appropriate antibiotics for GNB prior to MVB and patients with unknown dates for index culture. NCO were defined as 30-day mortality and/or microbiological recurrence. All outcomes were measured from MVB start date. Classification and regression tree analysis (CART) was used to identify the time breakpoint (BP) that delineates the risk of NCO. Multivariable logistic regression analysis (MLR) was used to examine the independent association between the CART-derived-BP and NCO. Variables were retained in the model if P&lt; 0.2 and removed in a backward stepwise approach.

Results

A total of 86 patients were included from 13 institutions in the United States: median(IQR) age 55 (37-67) years, 67% male, and 48% Caucasian. Median(IQR) APACHE II and Charlson Comorbidity index scores were 18(11-26) and 4(2-6), respectively. Common sources of infection were respiratory (37%) and intra-abdominal (21%). The most common pathogens were carbapenem-resistant Enterobacterales (83%). CART-derived BP between early and delayed treatment was 48 hours, where NCO was increased (36% vs.7%; P=0.04). Delayed MVB initiation was independently associated with NCO in the MLR (aOR=7.4, P=0.02).

Results of Regression Analysis of Variables Associated With Negative Clinical Outcomes and Delayed Appropriate Therapy with Meropenem-vaborbactam

Conclusion

Our results suggest that delaying appropriate antibiotic therapy with MVB for &gt;48 hours significantly increases the risk of NCO in patients with GNBI. Clinicians must ensure timely administration of MVB to assure best outcomes in patients with GNBI.

Disclosures

Kevin W. Garey, PharMD, MS, FASHP, Merck & Co. (Grant/Research Support, Scientific Research Study Investigator) Michael J. Rybak, PharmD, MPH, PhD, Paratek (Grant/Research Support)

1576. Re-Evaluation of cefepime or piperacillin-tazobactam to Decrease Use of Carbapenems in ESBL-Producing Enterobacterales BloodStream Infections (REDUCE-BSI)

Background

The ideal therapy for treatment of bloodstream infections (BSI) due to ESBL-producing organisms is widely debated. Although prior studies have demonstrated efficacy of non-carbapenems (CBPNs) for ESBL infections, results from the MERINO study group found increased mortality associated with piperacillin/tazobactam (PT) when compared with meropenem for treatment of ESBL BSI. The goal of this study was to investigate patient outcomes associated with the use of CBPN-sparing therapies (PT and cefepime (CEF)) for ESBL BSI. The primary outcome was in-hospital mortality between non-CBPN (PT and CEF) and CBPN groups. Secondary outcomes included clinical cure, microbiologic cure, infection recurrence, and development of resistance.

Methods

This was a retrospective observational study of patients admitted to the hospital from May 2016 - May 2019 with a positive blood culture for an ESBL-producing organism. Patients receiving meropenem, ertapenem, PT, or CEF were included. Patients were excluded if < 18 years old, receiving antibiotics for < 24 hours, treated for a polymicrobial BSI, or receiving concomitant antibiotic therapy for another gram-negative (non-ESBL) infection.

Results

One hundred and fourteen patients were analyzed; 74 (65%) patients received CBPN therapy compared with 40 (35%) patients that received a non-CBPN (CEF N=30, PT N=10). There were no statistically significant differences in baseline characteristics between groups. The overall in-hospital mortality rate was 6% (N=7). Eight percent of patients (N=6) in the CBPN arm died compared to 3% (N=1) of patients in the non-CBPN arm, P = 0.42. No difference in mortality was detected between groups when evaluating subgroups with Pitt bacteremia score ≥4 (N=25), requiring ICU admission (N=50), non-genitourinary source (N=50), or by causative organism (N=76 E. coli; N=38 Klebsiella spp.). There was no difference between groups for secondary outcomes.

Conclusion

CEF and PT are reasonable options for the treatment of ESBL BSI and did not result in increased mortality or decreased clinical efficacy when compared to CBPNs in this cohort.

Disclosures

All Authors: No reported disclosures

A Comparative Randomized Prospective Clinical Study on Modified Erich Arch Bar with Conventional Erich Arch Bar for Maxillomandibular Fixation

Introduction

Erich arch bar used for maxillomandibular fixation (MMF) since decades has several disadvantages such as risks of injury, additional operating room time, and gingival trauma. To overcome these downsides, modified Erich arch bar was introduced; however, there is not much available literature, indicating the efficacy of modified Erich arch bar over that of conventional arch bar wire. Therefore, the present study focuses on comparing efficiency of modified arch bar with conventional arch bar.

Materials and Methods

This comparative randomized study was conducted on 32 patients that required MMF and were divided into Group A patients who received intermaxillary fixation (IMF) with modified Erich arch bars and Group B patients with conventional Erich arch bars. The parameters recorded were average surgical time required, wire prick injuries, IMF stability, occlusal stability, screw loosening, oral hygiene status, and vitality response of the teeth. The variables were statistically analyzed using Student's t-test and Wilcoxon signed-rank test.

Results

The wire prick injury, intraoperative time noted in Group A was significantly reduced in comparison to Group B (P < 0.0001). Debris indices were significantly good in Group A in comparison to Group B (P < 0.0001). Nonvitality response of tooth was significantly more in Group B than in Group A patients (P < 0.05).

Discussion

The efficiency of modified Erich arch bar group was superior to the conventional arch bar with very limited restrictions.

Real-world Multicenter Analysis of Clinical Outcomes and Safety of Meropenem-Vaborbactam in Patients Treated for Serious Gram-Negative Bacterial Infections

Fourty patients were treated with meropenem-vaborbactam (MEV) for serious Gram-negative bacterial (GNB) infections. Carbapenem-resistant Enterobacteriaceae (CRE) comprised 80.0% of all GNB infections. Clinical success occurred in 70.0% of patients. Mortality and recurrence at 30 days were 7.5% and 12.5%, respectively. One patient experienced a probable rash due to MEV.

Impact of an antimicrobial stewardship initiative on time to administration of empirical antibiotic therapy in hospitalized patients with bacteremia

PURPOSE

The impact of an antimicrobial stewardship initiative on time to first antibiotic dose and clinical outcomes in bacteremic patients was evaluated.

METHODS

A single-center, retrospective study was conducted for adult inpatients who received antibiotics before and after implementation of a rapid administration of antimicrobials by an infectious diseases specialist (RAIDS) protocol. Patients admitted to an inpatient service from June to October 2011 (pre-RAIDS protocol) and from December 2011 to February 2012 (post-RAIDS protocol) were eligible for inclusion if (1) they were age 18 years or older, (2) their infection occurred two or more days after hospital admission, and (3) they had a blood culture growing an organism other than common skin contaminants (i.e., coagulase-negative staphylococci, Bacillus species). The primary outcome was the time to the first antibiotic dose (TFAD), defined as the time that elapsed from a positive blood culture result to administration of the first empirical antimicrobial dose.

RESULTS

A total of 111 bacteremic patients were included in the analysis. Implementation of the RAIDS protocol led to significantly faster antibiotic order entry, verification, and administration of empirical antibiotics in patients with bacteremia. The median TFAD was approximately 8 hours faster in the post-RAIDS group than in the pre-RAIDS group (9:09 hr:min versus 1:23 hr:min, p < 0.001). Patients in the post-RAIDS group had a significant reduction in infection-related mortality (p = 0.047), though all-cause 30-day mortality was similar.

CONCLUSION

Early notification of an infectious diseases pharmacist about positive blood cultures using the RAIDS protocol led to increased appropriateness of empirical drug selection and a dramatic reduction in the administration of antibiotics and was associated with decreased infection-related mortality.

2425. Clinical and Microbiologic Outcomes Among Patients With Monomicrobial Stenotrophomonas maltophilia Infections

Background

Stenotrophomonas maltophilia is an opportunistic pathogen observed in nosocomial infections. Due to biofilm production and intrinsic resistance to numerous antimicrobials, organism eradication is difficult and morbidity and mortality remain high. Unfortunately, study outcomes are often confounded by co-infecting organisms. Therefore, clinical and microbiologic outcome data for monomicrobial infections is warranted.

Methods

Single-center, retrospective chart review of adult patients receiving treatment for S. maltophilia between January 2012 and October 2016. Polymicrobial infections and cystic fibrosis patients were excluded. Primary endpoint was clinical cure (CC) at end of therapy. Secondary endpoints included microbiological eradication (ME), 28-day mortality, and resistance selection. An exploratory analysis was performed in patients receiving trimethoprim-sulfamethoxazole (TMP/SMX) or levofloxacin (LVX).

Results

Seventy-six patients were included in the analysis. The population was 60 years of age, predominantly female (62%) with median APACHE score of 16. Infection onset occurred 6 days after admission with 71% located in the ICU. Approximately 2/third of ICU patients were intubated. Primary site of infection was the lung (92%). Treatment strategies included TMP/SMX (45 patients) or LVX (31 patients). Overall, CC, ME, and 28-day mortality was observed in 79%, 82%, and 14%, respectively. Adverse events were uncommon with three patients receiving TMP/SMX requiring alternate therapy. Comparative analysis revealed similar baseline characteristics except higher APACHE scores (18 vs. 14; P = 0.03) and frequency of mechanical ventilation in the TMP/SMX group (64% vs. 30%; P = 0.007). CC was similar between TMP/SMX and LVX (82% vs. 74%, respectively (P = 0.4)). ME was observed in 84% and 77%, respectively (P = 0.5). Resistance selection to primary treatment was observed in 29% (2/7) and 86% (6/7), respectively (P = 0.1).

Conclusion

Use of TMP/SMX or LVX for S. maltophilia infections resulted in high CC rates. No differences in primary or secondary outcomes were observed; however, a trend toward resistance selection with LVX was identified. Larger studies assessing outcomes and resistance selection are warranted to further delineate treatment.

Disclosures

K. Klinker, Melinta Therapeutics: Consultant, Speaker honorarium. Nabriva Therapeutics: Scientific Advisor, Consulting fee.

Training a Drug to Do New Tricks: Insights on Stability of Meropenem Administered as a Continuous Infusion

Background

The antibiotic armamentarium used to combat multi-drug resistant organisms (MDROs) include carbapenems. Continuous infusion (CI) dosing is frequently employed to maximize beta-lactam efficacy; however, use of meropenem CI has been limited due to concerns with product instability.

Objective

The primary objective of this study was to quantify meropenem serum concentrations to reflect drug stability when administered as CI over 8- or 12-h exchanges. In addition, a stability experiment was performed to further establish meropenem integrity over 12 h. The secondary objectives were to assess the ability of meropenem to achieve target pharmacokinetic/pharmacodynamic (PK/PD) exposures relative to the minimum inhibitory concentration (MIC) of the pathogen, and to determine clinical cure.

Methods

This was a retrospective, observational study on use of CI meropenem (infused either over 8- or 12- h) at a 1% concentration. The stability experiment was conducted on 1% meropenem at room temperature.

Results

In 22 patients, a median meropenem daily dose of 6 g/day (range 2-6 g/day) resulted in a median serum concentration of 17.8 mg/L (interquartile range, 9.3-27.8 mg/L). In 95% of cases, meropenem delivered as CI resulted in free drug concentrations at or above the MIC of the pathogen for the entire dosing interval. Clinical cure was achieved in 80% of patients included in this review. The stability experiment revealed negligible drug degradation at the end of the 12-h dosing interval.

Conclusions

The data from this study provides compelling evidence for the use of meropenem as CI utilizing either a 12- or 8-h exchange process.

Assessing antimicrobial stewardship initiatives: Clinical evaluation of cefepime or piperacillin/tazobactam in patients with bloodstream infections secondary to AmpC-producing organisms

Management of micro-organisms harbouring AmpC β-lactamases remains challenging. Carbapenems are often considered first-line agents. Due to growing concern regarding carbapenem-resistant Enterobacteriaceae, integrating non-carbapenem treatment strategies is being explored for these pathogens. The primary objective of this study was to evaluate clinical outcomes in patients with bacteraemia secondary to AmpC-producing organisms treated with cefepime or piperacillin/tazobactam (TZP). A retrospective study of adult patients receiving cefepime or TZP for the treatment of AmpC -producing organisms with positive cefoxitin screen (i.e. Citrobacter, Enterobacter or Serratia spp. along with cefoxitin resistance) isolated from blood cultures was conducted. The primary endpoint was clinical cure at end of therapy (EOT). Secondary endpoints included microbiological eradication, frequency of susceptibility changes following treatment, and 7- and 30-day all-cause mortality. Clinical cure at EOT was 87.1%, with 93.2% of patients achieving microbiological eradication. The 7- and 30-day mortality rates were 3.8% and 10.6%, respectively. Organism susceptibility was exceptionally high, with minimum inhibitory concentrations (MICs) of ≤2 μg/mL in 90% of patients treated with cefepime (n = 108). Selection for resistance to third-generation cephalosporins or primary antimicrobial therapy was infrequent at 6.1% (8/132). In conclusion, use of cefepime or TZP for management of AmpC bloodstream infections was associated with clinical and microbiological cure with infrequent selection for resistance.

Use of an Anti-Infective Medication Review Process at Hospital Discharge to Identify Medication Errors and Optimize Therapy

BACKGROUND

Medication reconciliation is a major patient safety concern, and the impact of a structured process to evaluate anti-infective agents at hospital discharge warrants further review.

OBJECTIVE

The aim of this study was to (1) describe a structured, multidisciplinary approach to review anti-infectives at discharge and (2) measure the impact of a stewardship-initiated antimicrobial review process in identifying and preventing anti-infective-related medication errors (MEs) at discharge.

METHODS

A prospective study to evaluate adult patients discharged on anti-infectives was conducted from October 2013 to May 2014. The antimicrobial stewardship program (ASP) classified interventions on anti-infective regimens into predefined ME categories.

RESULTS

Forty-five patients who were discharged on 59 anti-infective prescriptions were included in the study. The most common indications for anti-infective regimens at discharge were pneumonia (22%, n = 10), bacteremia (18%, n = 8), and skin and soft tissue infections (16%, n = 7). An ME was identified in 42% (n = 19/45) of anti-infective regimens. Seventy percentage of ASP team recommendations were accepted which resulted in an avoidance of MEs in 68% (n = 13/19) of patients with an ME prior to discharge.

CONCLUSION

This study describes the outcomes of a stewardship-initiated review process in preventing MEs at discharge. Developing a systematic process for a multidisciplinary ASP team to review all anti-infectives can be a valuable tool in preventing MEs at hospital discharge.

Impact of an Extended Infusion Β-lactam Strategy on Outcomes in Critically Ill Patients with Pseudomonas Infections

Background

Pseudomonas aeruginosa (PSA) is frequently associated with nosocomial infections resulting in significant morbidity and mortality. High MICs in MDR strains highlights the need to maximize antibiotic exposure with the goal of improving patient outcomes. For β-lactams, optimal efficacy is achieved when free drug concentrations are above the MIC for ~ 40–60% of the dosing interval. Unfortunately, due to significant pharmacokinetic variability in the critically ill, achieving this target with standard intermittent infusions (II) is challenging, resulting in preference for extended (EI) or continuous infusion strategies. Additional data in patients with PSA infections are needed to understand the association between infusion strategy and clinical outcome.

Methods

A single-center, retrospective chart review. Adult patients with positive respiratory or blood cultures for PSA treated with cefepime or piperacillin/tazobactam managed in an ICU from January 2012 to May 2016 were included. Primary endpoint was clinical cure (CC) at end of therapy (EOT) between patients receiving EI or II. Secondary endpoints included microbiologic eradication (ME), 28-day mortality, length of ICU and hospital stay, and effect of baseline kidney function on clinical cure.

Results

Eighty-three patients were included in the analysis. Patient characteristics were well matched except for a higher frequency of malignancy in the EI arm (P = 0.02). CC was achieved in an overwhelming majority of EI patients compared with II (89.2% vs. 69.6%, P = 0.031). Further, patients with normal renal function (CrCL ≥ 60; P = 0.02) or APACHE II ≥ 17 (P = 0.04) receiving II experienced higher failure rates. In multivariate analysis, use of II associated with 4-fold higher incidence of clinical failure (OR 4.5 [1.3–16.3]). For other secondary endpoints, ME was observed in 73% of EI vs. 65% of II (P = 0.44) and 28-day mortality was observed in 13% of patients in both arms (P = 0.94). No significant differences were observed with other secondary variables.

Conclusion

Use of an EI strategy in critically ill patients with PSA infections improves CC. Further, EI benefitted those patients with normal to augmented renal clearance suggesting that improved exposure may play a role in clinical outcomes.

Disclosures

K. Klinker, The Medicines Company: Scientific Advisor, Consulting fee.

Management of skin and soft-tissue infections at a community teaching hospital using a severity-of-illness tool

OBJECTIVES

Skin and soft-tissue infections (SSTIs) encompass a diverse range of infections of varying severity. The Clinical Resource Efficiency Support Team (CREST) scoring system stratifies patients into four classes (I = least severe to IV = most severe) based on the Standardized Early Warning Score (SEWS). The objective of this study was to apply CREST to hospitalized patients with SSTIs in order to quantify disease severity and evaluate appropriateness of antibiotic management.

METHODS

This was a retrospective, hypothesis-generating, single-centre evaluation of hospitalized patients with SSTIs admitted in 2011. Based on CREST classification, the empirical antimicrobial choices were categorized as appropriate, over-treatment or under-treatment.

RESULTS

A total of 369 patients were screened and 200 met the inclusion criteria. The majority of patients were classified as either CREST class I (n = 68) or class II (n = 102). Over-treatment was more common in the less severe classes (88% and 32% in class I and class II, respectively; P < 0.05). Sixty-three percent of class I (n = 43) were over-treated due to both the use of intravenous antibiotics when oral therapy was sufficient and use of unnecessarily broad-spectrum antibiotics. In contrast, 25% (n = 26) of class II were over-treated due to use of unnecessarily broad-spectrum antibiotics. Overall clinical failure rates remained low with only 1%, 4% and 17% of patients unable to achieve initial response in class II, class III and class IV.

CONCLUSIONS

Retrospective application of CREST identified opportunities to improve the management of SSTIs. CREST can be of great value in discriminating less-severe SSTIs, which can be treated on an outpatient basis.

Preparing Students to Enter the Race for Postgraduate Training

PURPOSE

Exposure of pharmacy students to postgraduate training prior to clinical practice is currently endorsed by national professional organizations. To meet this goal, colleges and schools of pharmacy are developing residency preparation programs. In this descriptive report, we review published studies of curricular activities and structured programs from academic institutions across the United States aimed at preparing students for residency training and promoting postgraduate education. Additionally, we discuss our experience developing a residency preparation program at Touro College of Pharmacy (TCOP).

SUMMARY

A literature search yielded 15 residency preparation programs. While the format, content, and length of programs varied, there were common components such as curriculum vitae critique, mock interviews, and focused sessions on the residency application process. At TCOP, a 5-themed residency preparation workshop series was implemented during the third and fourth academic year. The workshops were modeled after existing programs and included several of the core components. One feature unique to the TCOP program was the addition of multiple mock interviews.

CONCLUSION

The growing focus on residency training has led to increased competition among applicants. To better prepare students for this rigorous application and interview process, development of structured residency preparation programs, similar to TCOP's, should be encouraged.

Administration of a survey to evaluate the attitudes of house staff physicians towards antimicrobial resistance and the antimicrobial stewardship programme at a community teaching hospital

Antimicrobial stewardship programmes (ASPs) are used in numerous institutions in an effort to promote safe and effective antimicrobial use. The objectives of this study were to (i) assess physicians' perceptions, attitudes and knowledge about antimicrobial use, resistance and the ASP at The Brooklyn Hospital Center (TBHC) and (ii) measure physicians' beliefs and attitudes to the current system of prior authorisation of antimicrobials. A 75-item, anonymous, voluntary, traditional paper and pencil survey was distributed to resident physicians at TBHC. Multiple-choice, 5-point Likert scale and knowledge-based questions were utilised. Of the 261 residents, 129 (49%) completed the survey. The respondents significantly believed that antibiotics are overused more frequently nationally vs. locally [117/129 (91%) vs. 91/129 (71%); P=0.0001]. Although 49% (63/129) felt that other providers overprescribe antibiotics, only 26% (34/129) agreed that they themselves were contributing to the current problem (P=0.0003). Fifty-seven percent of respondents agreed that individual patient care is improved by having an antibiotic approval programme; however, 45% of respondents reported that the antibiotic approval programme limits their autonomy in choosing antibiotics. Compared with surgical residents, medical residents were more likely (33% vs. 13%; P=0.02) to feel that the antibiotic approval programme forced them to choose an inappropriate antibiotic. On the antibiotic knowledge assessment segment of the survey, there was no difference in score when stratified by specialty or years of postgraduate training. Based on the survey results, house staff are supportive of antimicrobial stewardship and feel that the ASP is valuable for patient care.

Time-resolved digital holographic microscopy of laser-induced forward transfer process

We develop a method for time-resolved digital holographic microscopy to obtain time-resolved 3-D deformation measurements of laser induced forward transfer (LIFT) processes. We demonstrate nanometer axial resolution and nanosecond temporal resolution of our method which is suitable for measuring dynamic morphological changes in LIFT target materials. Such measurements provide insight into the early dynamics of the LIFT process and a means to examine the effect of laser and material parameters on LIFT process dynamics.

Incidence of Antiretroviral Drug Interactions During Hospital Course

Background: Human immunodeficiency virus (HIV) providers are treating more comorbid conditions with additional pharmacologic agents, resulting in patients with HIV being disproportionately at risk for clinically significant drug–drug interactions (CSDDIs). There is a potential to overlook these interactions and ultimately place patients at risk for drug toxicity, resistance, and virologic failure. Objective: To assess the burden of CSDDIs among patients receiving antiretroviral therapy (ART) within 24 hours of admission and to evaluate the effect of a clinical pharmacist operating through an antiretroviral stewardship (ARVSP) program in identifying and correcting potential drug interactions. Methods: Adult HIV-positive patients receiving ART who were admitted to The Brooklyn Hospital Center from November 2010 through January 2012 were included in the analysis. Drug interactions were categorized according to time frame (ie, within 24 hours of admission vs after 24 hours of admission) and type (ie, contraindicated combinations, dosage modifications, and frequency alterations). The Liverpool HIV drug reference, Micromedex drug database, and the Department of Health and Human Services Guidelines were used as comprehensive tools for identification of antiretroviral drug errors. Results: Eighty-four CSDDIs were identified from 252 admissions among 158 patients receiving ART during the study period. Of the identified CSDDIs, 61 (73%) occurred within 24 hours of admission and 23 (27%) later in the hospital course. Forty-eight drug interactions (57%) represented contraindicated drug combinations. Protease inhibitor–based regimens were associated with the highest percentage of CSDDIs (98%). Of all CSDDIs, the most common interacting drug class was acid-suppressive therapy (63%). Clinical pharmacists identified and intervened in 80% of the CSDDIs that occurred on patient admission with all interventions accepted. Conclusions: CSDDIs are common among patients receiving ART at the time of admission and throughout the hospital course. Interventions including medication review by clinical pharmacists are critical in the prevention of CSDDIs on admission.

Dynamics of primary and secondary microbubbles created by laser-induced breakdown of an optically trapped nanoparticle

Laser-induced breakdown of an optically trapped nanoparticle is a unique system for studying cavitation dynamics. It offers additional degrees of freedom, namely the nanoparticle material, its size, and the relative position between the laser focus and the center of the optically trapped nanoparticle. We quantify the spatial and temporal dynamics of the cavitation and secondary bubbles created in this system and use hydrodynamic modeling to quantify the observed dynamic shear stress of the expanding bubble. In the final stage of bubble collapse, we visualize the formation of multiple submicrometer secondary bubbles around the toroidal bubble on the substrate. We show that the pattern of the secondary bubbles typically has its circular symmetry broken along an axis whose unique angle rotates over time. This is a result of vorticity along the jet towards the boundary upon bubble collapse near solid boundaries.

Regulatory oversight and safety of probiotic use

Depending on intended use of a probiotic (drug vs. dietary supplement), regulatory requirements differ greatly. For dietary supplements, premarketing demonstration of safety and efficacy and approval by the Food and Drug Administration are not required; only premarket notification is required. Saccharomyces boulardii is a probiotic regulated as a dietary supplement intended for use by the general healthy population, not as a drug to prevent, treat, or mitigate disease. However, since recent increases in incidence and severity of Clostridium difficile infection, probiotics have been used to treat recurrent and/or refractory disease in hospitalized patients. Saccharomyces fungemia secondary to use of the probiotic has been described for patients who are critically ill, are receiving nutrition enterally, or have a central venous catheter. Before use of a probiotic is considered for hospitalized patients, careful assessment of risk versus benefit must be made. To ensure patient safety, probiotics should be properly handled during administration.

Trimethoprim-sulfamethoxazole exposure alters ex vivo function of B lymphocytes isolated from human immunodeficiency virus-infected patients receiving Zidovudine

STUDY OBJECTIVE

To determine if exposure to trimethoprim-sulfamethoxazole (TMP-SMX) causes a defect in peripheral B-cell function among patients with the human immunodeficiency virus (HIV) who are receiving zidovudine antiretroviral therapy.

DESIGN

Prospective, single-center, single-group, case-crossover design with a 4-week exposure period.

SETTING

University-affiliated infectious diseases outpatient clinic.

PATIENTS

Fourteen HIV-infected adult men receiving zidovudine, who had CD4(+) cell counts above 350 cells/mm(3) and undetectable viral loads.

INTERVENTION

Patients were administered a 28-day course of TMP 160 mg-SMX 800 mg/day (one double-strength tablet/day). Peripheral blood mononuclear cells (PBMCs) were obtained and isolated before and after exposure to TMP-SMX. Cells were cultured ex vivo with three mitogens of differing immunologic properties: pokeweed mitogen ([PWM] T-cell-dependent B-cell mitogen), Staphylococcus aureus Cowan ([SAC] T-cell-independent B-cell mitogen), and phytohemagglutinin A ([PHA] T-cell mitogen). Functionality of the B and T lymphocytes was then assessed.

MEASUREMENTS AND MAIN RESULTS

Proliferative capacity, cytokine secretion, and antibody production were measured and compared before and after TMP-SMX exposure. Reduced proliferative capacities of both PBMC and B cells stimulated with mitogens were observed at the 3-day culture time point in response to PWM, PHA, and SAC (p=0.029, 0.028, and 0.026, respectively). Proliferative capacity at day 7 of culture was not significantly different for any condition examined. Cytokine production was not altered by combination drug exposure after 10 days of culture when cells were stimulated with either PWM or PHA. Although antibody responses to PWM and PHA were similar, total immunoglobulin G concentration was lower in cells stimulated with SAC in samples obtained after TMP-SMX regimen completion compared with those obtained before exposure (p=0.005).

CONCLUSION

Although these data were affected by limitations in power and study design, they suggest that peripheral B-lymphocyte function is altered as a result of TMP-SMX exposure in HIV-infected patients concurrently receiving zidovudine. Further study of this effect is warranted.

Generation of laser-induced cavitation bubbles with a digital hologram

We demonstrate a method using a spatial light modulator (SLM) to generate arbitrary 2-D spatial configurations of laser induced cavitation bubbles. The SLM acts as a phase hologram that controls the light distribution in the focal plane of a microscope objective. We generate cavitation bubbles over an area of 380 x 380 microm(2) with a 20x microscope objective through absorption of the pulsed laser light in a liquid ink solution. We demonstrate the ability to accurately position up to 34 micrometer sized bubbles using laser energies of 56 microJ.