A Propensity-Matched Cohort Assessing Impact of a Neutralizing Monoclonal Antibody in Mild-to-Moderate Coronavirus Disease 2019.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoaV-2) is responsible for the coronavirus disease 2019 (COVID-19) pandemic. In randomized clinical trials, patients who were treated with the anti-spike monoclonal antibody bamlanivimab had fewer COVID-19-related hospitalizations or emergency department (ED) visits than the control group. Methods: A retrospective cohort was assembled across a multisite healthcare system between November 20, 2020 and March 31, 2021. Ambulatory COVID-19 patients treated with bamlanivimab (n = 209) were propensity score matched without replacement (1:1) to a pool of 1024 eligible control patients who received similar care without bamlanivimab. The primary endpoint was all-cause mortality or admission at 30 days. Secondary endpoints included hospitalization, critical care admission, oxygenation requirements, and infusion-related reactions. Propensity score matching (PSM) analysis was used to assess the effect of bamlanivimab infusion on the composite endpoint and secondary endpoints. Results: A total of n = 209 matched patients were included in each arm of the study. The absolute standardized difference (stddiff) was calculated and indicated a balance between the groups. Almost all variables had a stddiff of less than 0.10, except for respiratory rate (RR) (stddiff = -0.11). For the primary composite endpoint of the matched cohort, 10.1% (n = 21) of patients in the intervention group were hospitalized or deceased within 30-day postbamlanivimab infusion versus 27.8% (n = 58) in the control group (adjusted odds ratio [aOR]: 0.29, 95% confidence interval [CI]: 0.17 to 0.51, P < .001). Conclusion: Patients with ambulatory COVID-19 who received bamlanivimab in the outpatient setting had a statistically significant reduction on the odds of admission postinfusion. Despite bamlanivimab's lack of efficacy on newer SARS-CoV-2 variants, this study demonstrates that neutralizing monoclonal antibodies can be effective against specific variants. If variant identification becomes a more accessible tool in outpatient centers or EDs, more targeted therapeutic options may be considered.

Antibiotic Overuse After Hospital Discharge: A Multi-hospital Cohort Study.

BACKGROUND: Antibiotics are commonly prescribed to patients as they leave the hospital. We aimed to create a comprehensive metric to characterize antibiotic overuse after discharge among hospitalized patients treated for pneumonia or urinary tract infection (UTI), and to determine whether overuse varied across hospitals and conditions. METHODS: In a retrospective cohort study of hospitalized patients treated for pneumonia or UTI in 46 hospitals between 1 July 2017-30 July 2019, we quantified the proportion of patients discharged with antibiotic overuse, defined as unnecessary antibiotic use, excess antibiotic duration, or suboptimal fluoroquinolone use. Using linear regression, we assessed hospital-level associations between antibiotic overuse after discharge in patients treated for pneumonia versus a UTI. RESULTS: Of 21 825 patients treated for infection (12 445 with pneumonia; 9380 with a UTI), nearly half (49.1%) had antibiotic overuse after discharge (56.9% with pneumonia; 38.7% with a UTI). For pneumonia, 63.1% of overuse days after discharge were due to excess duration; for UTIs, 43.9% were due to treatment of asymptomatic bacteriuria. The percentage of patients discharged with antibiotic overuse varied 5-fold among hospitals (from 15.9% [95% confidence interval, 8.7%-24.6%] to 80.6% [95% confidence interval, 69.4%-88.1%]) and was strongly correlated between conditions (regression coefficient = 0.85; P < .001). CONCLUSIONS: Antibiotic overuse after discharge was common and varied widely between hospitals. Antibiotic overuse after discharge was associated between conditions, suggesting that the prescribing culture, physician behavior, or organizational processes contribute to overprescribing at discharge. Multifaceted efforts focusing on all 3 types of overuse and multiple conditions should be considered to improve antibiotic prescribing at discharge.

Pharmacokinetics and investigation of optimal dose ertapenem in intermittent hemodialysis patients.

BACKGROUND: Previous pharmacokinetic studies demonstrated an increase in serum ertapenem concentrations with decreasing kidney function, including patients receiving renal replacement therapy. This study evaluated the pharmacokinetic parameters of ertapenem in patients receiving hemodialysis. METHODS: This prospective, single-center, open-label study examined the pharmacokinetics of a single intravenous (IV) dose of ertapenem 1 g in seven hospitalized noninfected patients undergoing hemodialysis. Blood samples were collected prior to ertapenem administration and at 0.5, 1, 2, 6, 12 and 48 hours (h) after administration. Ertapenem concentrations were determined by validated liquid chromatography mass spectrometry assay. RESULTS: Following an IV bolus of 1 g ertapenem, plasma concentrations declined relatively slowly with a mean ±standard deviation (SD) elimination half-life of 19.3 ±6.6 h. Plasma concentrations were similar in all subjects, with maximum mean plasma concentration observed of 343±48 µg/mL postdose. The mean ±SD values for systemic plasma clearance (CL) and volume of distribution at steady state (Vss) were 2±0.5 mL/min and 3295±1187 mL, respectively. The area under the curve for 0 h-∞ (AUCinf) was 7494 ±1424 h•µg/mL. No gender effect was observed and no serious adverse events were reported. CONCLUSIONS: Ertapenem half-life was prolonged in hemodialysis patients. Considering the nonrenal clearance and the expected 70% removal with high-efficacy hemodialysis, the dose of 1 g ertapenem, three times weekly, after hemodialysis may produce pharmacodynamically sufficient exposure for potential antimicrobial efficacy. Further studies are warranted to assess the clinical efficacy and safety of this dose with prolonged duration of therapy.

A Deeper Dive Into Antibiotic Stewardship Needs: A Multihospital Survey.

In a 2016 survey of 46 Michigan hospitals, we identified four key needs for antibiotic stewardship: clinically-relevant antibiotic data, monitoring compliance, syndrome-specific interventions, and discharge stewardship. A stewardship initiative now addresses these needs within the Michigan Hospital Medicine Safety Consortium.

Assessment of Testing and Treatment of Asymptomatic Bacteriuria Initiated in the Emergency Department.

BACKGROUND: Reducing antibiotic use in patients with asymptomatic bacteriuria (ASB) has been inpatient focused. However, testing and treatment is often started in the emergency department (ED). Thus, for hospitalized patients with ASB, we sought to identify patterns of testing and treatment initiated by emergency medicine (EM) clinicians and the association of treatment with outcomes. METHODS: We conducted a 43-hospital, cohort study of adults admitted through the ED with ASB (February 2018-February 2020). Using generalized estimating equation models, we assessed for (1) factors associated with antibiotic treatment by EM clinicians and, after inverse probability of treatment weighting, (2) the effect of treatment on outcomes. RESULTS: Of 2461 patients with ASB, 74.4% (N = 1830) received antibiotics. The EM clinicians ordered urine cultures in 80.0% (N = 1970) of patients and initiated treatment in 68.5% (1253 of 1830). Predictors of EM clinician treatment of ASB versus no treatment included dementia, spinal cord injury, incontinence, urinary catheter, altered mental status, leukocytosis, and abnormal urinalysis. Once initiated by EM clinicians, 79% (993 of 1253) of patients remained on antibiotics for at least 3 days. Antibiotic treatment was associated with a longer length of hospitalization (mean 5.1 vs 4.2 days; relative risk = 1.16; 95% confidence interval, 1.08-1.23) and Clostridioides difficile infection (CDI) (0.9% [N = 11] vs 0% [N = 0]; P = .02). CONCLUSIONS: Among hospitalized patients ultimately diagnosed with ASB, EM clinicians commonly initiated testing and treatment; most antibiotics were continued by inpatient clinicians. Antibiotic treatment was not associated with improved outcomes, whereas it was associated with prolonged hospitalization and CDI. For best impact, stewardship interventions must expand to the ED.