Understanding the role of antibiotic-associated adverse events in influencing antibiotic decision-making

Objective

To (1) understand the role of antibiotic-associated adverse events (ABX-AEs) on antibiotic decision-making, (2) understand clinician preferences for ABX-AE feedback, and (3) identify ABX-AEs of greatest clinical concern.

Design

Focus groups.

Setting

Academic medical center.

Participants

Medical and surgical house staff, attending physicians, and advanced practice practitioners.

Methods

Focus groups were conducted from May 2022 to December 2022. Participants discussed the role of ABX-AEs in antibiotic decision-making and feedback preferences and evaluated the prespecified categorization of ABX-AEs based on degree of clinical concern. Thematic analysis was conducted using inductive coding.

Results

Four focus groups were conducted (n = 15). Six themes were identified. (1) ABX-AE risks during initial prescribing influence the antibiotic prescribed rather than the decision of whether to prescribe. (2) The occurrence of an ABX-AE leads to reassessment of the clinical indication for antibiotic therapy. (3) The impact of an ABX-AE on other management decisions is as important as the direct harm of the ABX-AE. (4) ABX-AEs may be overlooked because of limited feedback regarding the occurrence of ABX-AEs. (5) Clinicians are receptive to feedback regarding ABX-AEs but are concerned about it being punitive. (6) Feedback must be curated to prevent clinicians from being overwhelmed with data. Clinicians generally agreed with the prespecified categorizations of ABX-AEs by degree of clinical concern.

Conclusions

The themes identified and assessment of ABX-AEs of greatest clinical concern may inform antibiotic stewardship initiatives that incorporate reporting of ABX-AEs as a strategy to reduce unnecessary antibiotic use.

An Electronic Algorithm to Identify Vancomycin-Associated Acute Kidney Injury

Background

The burden of vancomycin-associated acute kidney injury (V-AKI) is unclear because it is not systematically monitored. The objective of this study was to develop and validate an electronic algorithm to identify cases of V-AKI and to determine its incidence.

Methods

Adults and children admitted to 1 of 5 health system hospitals from January 2018 to December 2019 who received at least 1 dose of intravenous (IV) vancomycin were included. A subset of charts was reviewed using a V-AKI assessment framework to classify cases as unlikely, possible, or probable events. Based on review, an electronic algorithm was developed and then validated using another subset of charts. Percentage agreement and kappa coefficients were calculated. Sensitivity and specificity were determined at various cutoffs, using chart review as the reference standard. For courses ≥48 hours, the incidence of possible or probable V-AKI events was assessed.

Results

The algorithm was developed using 494 cases and validated using 200 cases. The percentage agreement between the electronic algorithm and chart review was 92.5% and the weighted kappa was 0.95. The electronic algorithm was 89.7% sensitive and 98.2% specific in detecting possible or probable V-AKI events. For the 11 073 courses of ≥48 hours of vancomycin among 8963 patients, the incidence of possible or probable V-AKI events was 14.0%; the V-AKI incidence rate was 22.8 per 1000 days of IV vancomycin therapy.

Conclusions

An electronic algorithm demonstrated substantial agreement with chart review and had excellent sensitivity and specificity in detecting possible or probable V-AKI events. The electronic algorithm may be useful for informing future interventions to reduce V-AKI.

Anemia prevalence time trends and disparities in the US population: examination of NHANES 1999-2020

While a rising prevalence of anemia in the United States was reported in older studies, recent data are lacking. To estimate the prevalence and time trends of anemia in the United States and to examine how these estimates differ by gender, age, race, and household income to poverty threshold ratio (HIPR), we used the National Health and Nutrition Examination Surveys from 1999 to 2020. The presence of anemia was determined using the World Health Organization criteria. Survey-weighted raw and adjusted prevalence ratios (PRs) were determined using generalized linear models for the overall population and by gender, age, race, and HIPR. In addition, an interaction between gender and race was explored. Complete data on anemia, age, gender, and race were available on 87,554 participants (mean age = 34.6 years, women = 49.8%, Whites = 37.3%). Anemia prevalence increased from 4.03% during the 1999-2000 survey cycle to 6.49% during 2017-2020. In adjusted analyses, anemia prevalence was higher in >65 than in 26-45 years old (PR = 2.14, 95% confidence interval (CI) = 1.95, 2.35), in Blacks than Whites (PR = 3.97, 95% CI = 3.63, 4.35), in women than men (PR = 1.98, 95% CI = 1.83, 2.13), and in those with HIPR ≤ 1 than >4 (PR = 0.68, 95% CI = 0.61, 0.75). Gender modified the relationship between anemia and race; when compared to their male counterparts, Black, Hispanic, and other women had higher anemia prevalence than White women (all interaction p values <0.05). The anemia prevalence in the United States has risen from 1999 to 2020 and remains high among the elderly, minorities, and women. The difference in anemia prevalence between men and women is larger in non-Whites.

To wait or not to wait: Optimal time interval between the first and second blood-culture sets to maximize blood-culture yield

The optimal timing of blood culture (BCx) sets collection has not been evaluated with continuous BCx detection systems. The yield of BCx was similar between short intervals (median, 3 minutes) and longer intervals (median, 16 or 43 minutes) among 5,856 BCx, except for improved polymicrobial bacteremia detection with long-interval BCx.

Improving antimicrobial prescribing for upper respiratory infections in the emergency department: Implementation of peer comparison with behavioral feedback

OBJECTIVE

To reduce inappropriate antibiotic prescribing for acute respiratory infections (ARIs) by employing peer comparison with behavioral feedback in the emergency department (ED).

DESIGN

A controlled before-and-after study.

SETTING

The study was conducted in 5 adult EDs at teaching and community hospitals in a health system.

PATIENTS

Adults presenting to the ED with a respiratory condition diagnosis code. Hospitalized patients and those with a diagnosis code for a non-respiratory condition for which antibiotics are or may be warranted were excluded.

INTERVENTIONS

After a baseline period from January 2016 to March 2018, 3 EDs implemented a feedback intervention with peer comparison between April 2018 and December 2019 for attending physicians. Also, 2 EDs in the health system served as controls. Using interrupted time series analysis, the inappropriate ARI prescribing rate was calculated as the proportion of antibiotic-inappropriate ARI encounters with a prescription. Prescribing rates were also evaluated for all ARIs. Attending physicians at intervention sites received biannual e-mails with their inappropriate prescribing rate and had access to a dashboard that was updated daily showing their performance relative to their peers.

RESULTS

Among 28,544 ARI encounters, the inappropriate prescribing rate remained stable at the control EDs between the 2 periods (23.0% and 23.8%). At the intervention sites, the inappropriate prescribing rate decreased significantly from 22.0% to 15.2%. Between periods, the overall ARI prescribing rate was 38.1% and 40.6% in the control group and 35.9% and 30.6% in the intervention group.

CONCLUSIONS

Behavioral feedback with peer comparison can be implemented effectively in the ED to reduce inappropriate prescribing for ARIs.

Postoperative biliary anastomotic strictures after pancreaticoduodenectomy

BACKGROUND

Biliary anastomotic stricture (BAS) is an uncommon complication of pancreaticoduodenectomy (PD). As PDs are performed more frequently, BAS may become a more common pathologic entity requiring clinical engagement. The aim of this study was to report the incidence of BAS in the modern era of pancreatic surgery and identify risk factors associated with it.

METHODS

Patients undergoing PD at the Johns Hopkins Hospital between 2007 and 2016 were identified using an institutional registry and clinicopathological features were analyzed to identify risk factors associated with BAS.

RESULTS

Of 2125 patients identified, 103 (4.9%) developed BAS. Factors independently associated with BAS included laparoscopic approach (HR:2.83,95%CI:1.35-5.92, p = 0.006), postoperative pancreatic fistula (HR:2.45,95%CI:1.56-4.16,p < 0.001), postoperative bile leak (BL) (HR:5.26,95%CI:2.45-11.28,p < 0.001), and administration of adjuvant radiation therapy (HR:6.01,95%CI:3.19-11.34,p < 0.001). Malignant pathology was associated with lower rates of BAS (HR:0.52,95%CI:0.30-0.92, p = 0.025). BL was associated with higher rates of early-BAS (HR:16.49,95%CI:3.28-82.94, p = 0.001) while use of Vicryl suture for biliary enteric anastomosis was associated with lower rates of early-BAS (HR:0.20,95%CI:0.05-0.93, p = 0.041).

CONCLUSION

Approximately 5% of patients undergoing PD experience BAS. Multiple factors are associated with the development and timing of BAS.

Comparison of radiographic and necropsy findings of lung lesions in calves after challenge exposure with Pasteurella multocida

OBJECTIVES

To test suitability of radiographic evaluation of lung lesions as a substitute for lung lesion scores derived by examination at necropsy in challenge-exposure models of bovine pneumonia.

ANIMALS

10 calves selected by body weight from 20 multiple-source male Holstein calves approximately 1 to 2 months old enrolled in a Pasteurella multocida challenge-exposure study.

PROCEDURE

Calves were paired on the basis of weight and randomly assigned within pairs to vaccine or control (saline solution) group. By use of deep tracheal cannulation, calves were challenge exposed with a culture of virulent P multocida, observed for 10 days, euthanatized, and necropsied, and the lungs were scored for pneumonic lesions. Radiographic views of the lung fields of the calves were taken before challenge exposure and before necropsy and were evaluated for alveolar disease by a veterinary radiologist. Lung lesion scores were compared with radiographic evaluations.

RESULTS

There was a strong and significant correlation (R2 = 0.91, P < 0.001) between results of the evaluation of postchallenge-exposure radiographs and necropsy results. There also was also strong and significant correlation (R2 = 0.90, P < 0.001) between evaluation of the prechallenge-exposure radiographs and necropsy results.

CONCLUSIONS

Radiographic evaluation of lung lesions correlates well with lung lesions found at necropsy. The findings emphasize the need for caution in interpreting the results of challenge-exposure studies of bovine respiratory tract disease in which small numbers of calves are studied.

Application of a polymerase chain reaction assay for detection of proliferative enteritis-affected swine herds

A polymerase chain reaction (PCR) assay was used to confirm the presence of ileal symbiont (IS) intracellularis in 3 swine herds with a history of proliferative enteritis (PE). Two pooled fecal specimens, each comprising 5 individual stool samples, were collected from pen floors to screen for the presence of IS intracellularis and determine the age range of pigs shedding the organism. IS intracellularis was detected in the feces of clinically normal 10-25-week-old grower/finisher pigs, indicating that this age range of pigs was the main source of infection for younger nursery pigs. Shedding continued without clinical disease when 10-100 g/ton of tylosin or 10 g/ton of chlortetracycline was added to the feed. PCR testing of pooled fecal samples can be used to identify groups of pigs affected with PE. The results of this study indicate that this PCR assay has the potential to accurately assess the IS intracellularis infection status of swine herds and the association of IS intracellularis with PE and growth performance.

Comparison of techniques for diagnosis of proliferative enteritis of swine

In an abattoir-based case-control study, histologic, and macroscopic examination of porcine intestines at slaughter and 2 molecular assays were compared for use as diagnostic tests of proliferative enteritis (PE). Fecal samples and intestinal specimens were collected from pigs with grossly thick ileum and from clinically normal pigs at slaughter. Tissue specimens were fixed in neutral buffered 10% formalin, and sectioned. Sections stained with H&E were examined for proliferative lesions by a pathologist unaware of the group to which the pig had been assigned on the basis of results of gross examination. Adjacent tissue sections, stained with Warthin-Starry (silver) stain, were examined for presence of the intracellular bacterium of PE, ileal symbiont (IS)-intracellularis, in the enterocytes of the intestinal crypts by the senior author, who was unaware either of the group to which the pig had been assigned or diagnosis by the pathologist. Bacterial DNA was extracted from the fecal samples and assayed by dot-blot hybridization and polymerase chain reaction (PCR) for presence of IS-intracellularis DNA, without knowledge of results of the other examinations. The PCR assay for IS-intracellularis was a specific and sensitive diagnostic test for PE, and dot-blot hybridization was sensitive, but was less specific. Macroscopic examination of intestines at slaughter was a sensitive, but not specific, test. Association between IS-intracellularis and proliferative lesions was statistically examined in the same study. There was a highly significant (P = 0.0078) association between presence of naturally acquired proliferative lesions and intracellular infection induced by IS-intracellularis.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between Ileal symbiont intracellularis and porcine proliferative enteritis

The relationship between Ileal symbiont (IS) intracellularis, formerly known as a Campylobacter-like organism, and porcine proliferative enteritis (PE) was studied by use of pigs with experimentally transmitted PE. Twenty one pigs were experimentally inoculated with homogenized ileal mucosa from a pig that died with PE, and 7 were maintained as uninoculated controls. Fecal samples were collected, and pigs were necropsied weekly postinoculation. Light microscopy and electron microscopy were used to examine tissues for lesions of PE and infectious agents. DNA was extracted from the fecal samples and assayed for the presence of sequences specific for IS intracellularis by dot blot hybridization and polymerase chain reaction amplification. IS intracellularis was detected by the polymerase chain reaction in the feces of 20 of 21 inoculated pigs but not in the feces of uninoculated pigs. Seven inoculated pigs but no uninoculated pigs were detected shedding IS intracellularis by dot blot hybridization. Shedding was detected 1 to 5 weeks after inoculation, and clinical signs were seen in the second to fifth weeks after inoculation. Few pigs without lesions of PE were found to shed IS intracellularis. There was a highly significant association between the presence of IS intracellularis in feces or tissue and the presence of microscopic proliferative lesions and between the severity of the lesions of PE and the percentage of IS intracellularis-infected intestinal crypts. Pigs that ceased shedding IS intracellularis were significantly less likely to have proliferative lesions. These and previous reports are consistent with the hypothesis that IS intracellularis is a necessary causative agent of PE.

Use of a DNA probe to detect the intracellular organism of proliferative enteritis in swine feces

A method of extracting bacterial DNA from swine feces was developed and used in a molecular assay for the presence of ileal symbiont (IS) intracellularis, formerly known as the Campylobacter-like organism associated with swine with proliferative enteritis. Hybridization with a digoxigenin-labeled, IS intracellularis-specific probe detected the presence of IS intracellularis at a concentration of 10(7) organisms/g of feces. This method was sufficient to detect IS intracellularis in the feces of swine with experimentally induced and naturally acquired infection. Results of the hybridization were in agreement with those from histologic postmortem examination.

Enhanced detection of intracellular organism of swine proliferative enteritis, ileal symbiont intracellularis, in feces by polymerase chain reaction

A sensitive assay based on amplification of a 319-bp DNA fragment of the intracellular bacterium of swine proliferative enteritis was developed for the detection of the organism in the feces of swine. A vernacular name, ileal symbiont intracellularis (IS-intracellularis), has recently been published for the intracellular bacterium, which was formerly known as a Campylobacter-like organism (C.J. Gebhart, S.M. Barnes, S. McOrist, G.F. Lin, and G.H.K. Larson, Int. J. Syst. Bacteriol. 43:533-538, 1993). As few as 10(1) IS-intracellularis organisms purified from intestinal mucosa, or 10(3) IS-intracellularis per g of feces, were detected. No amplification product was produced from a polymerase chain reaction performed on DNA extracted from the feces of healthy pigs. A 319-bp DNA fragment specific for IS-intracellularis was produced on amplification of DNA from the feces of pigs with experimental and naturally occurring proliferative enteritis.

Transmission of proliferative enteritis to swine by use of embryonating chicken eggs

Embryonating eggs were inoculated with filtered porcine ileal mucosa containing intracellular curved rods (ICR) and incubated for 4 to 6 days. Three of 12 pigs given the eggs per os developed microscopic lesions of proliferative enteritis (PE). Nonchallenge-exposed control pigs did not develop lesions of PE. Four of six positive control pigs given ileal mucosa from pigs with PE also developed microscopic lesions of PE. All of the PE lesions were found in pigs necropsied 10 to 29 days after challenge exposure. None of the swine in the study had clinical signs or gross lesions of PE. Campylobacter spp were isolated from pigs with and without exposure to the ileal mucosa from pigs with PE. There was no relationship between Campylobacter spp isolation and development of lesions. Deoxyribonucleic acids extracted from embryonating chicken eggs injected with the equivalent of 0.5 mg of mucosal lesions and incubated for 4 days hybridized to a DNA probe specific for the ICR, whereas DNA extracted from 1.5 mg of mucosal homogenates of the same proliferative tissue did not hybridize with the same probe. Results of these experiments indicated that ICR injected into eggs remained infective for pigs and suggest replication of ICR in the first-passage eggs.

Use of embryonating eggs for isolation of Campylobacter species from intestines of swine with proliferative enteritis

Intestinal tissues from swine affected with proliferative enteritis were ground, filtered through a 0.65-micron pore membrane filter, diluted, and injected into 7-day-old embryonated hens' eggs via the yolk sac. At 2, 4, and 7 days later, yolk sac swab specimens taken from live embryos were cultured for Campylobacter species. Campylobacter hyointestinalis was recovered from eggs injected with tissues of swine with acute hemorrhagic proliferative enteritis at dilutions up to 10(-4). Campylobacter mucosalis was recovered from eggs injected with tissues of swine with chronic proliferative enteritis at dilutions up to 10(-6). Campylobacter coli was recovered from several specimens without lesions of proliferative enteritis and also from some specimens with lesions of proliferative enteritis. Two previously undescribed hemolytic Campylobacter species designed as hemolytic number 1 and hemolytic number 2 were recovered from normal and experimentally inoculated swine tissues. Few contaminating organisms grow in eggs and these were usually recovered at dilutions of 10(-2) or less. Recovery of Campylobacter species by use of these techniques was seldom successful in tissues stored at -70 C for more than 6 months.

Evaluation of systemic administration of gentamicin for treatment of coliform mastitis in cows

Recovery of cows (n = 61) with mastitis caused by gram-negative bacteria and treated systemically with an antibiotic (gentamicin) to which the bacteria were susceptible in vitro, was compared with recovery of cows (n = 13) with similar infections treated with a systemically administered antibiotic (erythromycin) to which the bacteria were resistant in vitro or with recovery of cows (n = 12) not given an antibiotic systemically. In the first part of the study, cows were selected for treatment groups by use of a diagnostic scheme designed to predict whether the mastitis was caused by gram-negative or gram-positive bacteria. In the second part of the study, all cows were treated without systemic administration of an antibiotic. Significant difference was not observed in the outcome of the disease between cows given gentamicin and cows of the other 2 treatment groups at 24 hours or at 4 weeks after treatment. At 24 hours after initial treatment, 71.9% of cows treated with gentamicin, 92.3% of those treated with erythromycin, and 45.5% not treated systemically had improved appetite. At 4 weeks after initial treatment, of the cows treated with gentamicin, 11.5% died; in 32.8%, lactation ceased in the affected mammary gland; in 21.3%, lactation was decreased in the affected gland; and 34.4% returned to normal lactation and health. Of cows treated with erythromycin, none died; in 23%, lactation ceased in the affected mammary gland; in 23%, lactation decreased in the affected gland; and 54% returned to normal lactation and health.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of a scheme for predicting the gram-staining reaction of organisms causing bovine mastitis

The accuracy of a scheme for predicting the gram-staining reaction of organisms causing bovine mastitis in cows with systemic signs of disease (anorexia) was evaluated over 1 year. Criteria for making the predictions included: season of year, stage of lactation, appearance of milk, detection and duration of teat injuries, and milk odor. It was possible to determine the cause by microbiologic culture of specimens from 136 of the 147 cows of the study. Of 78 infections caused by gram-negative (mostly coliform) organisms, 62 (79%) were predicted accurately to be caused by gram-negative organisms. Of 57 infections caused by gram-positive organisms, 45 (79%) were predicted correctly to be caused by gram-positive organisms. Correctly predicted as gram-positive organisms causing infection were: Actinomyces pyogenes in 20 of 21 (95%) cows; Staphylococcus sp in 14 of 22 (64%) cows; Streptococcus sp in 10 of 13 (77%) cows and Bacillus sp in 1 cow. Overall accuracy, in those instances when bacteria were isolated (136 cows), was 78%.

Cause, occurrence, and clinical signs of mastitis and anorexia in cows in a Wisconsin study

Microbiologic culture revealed the following cause of mastitis and anorexia in 145 cows in Wisconsin to be Escherichia coli, 66 cows; Klebsiella spp, 3; Corynebacterium pyogenes, 27; streptococci, 21; staphylococci, 20; yeasts, 1; and no bacterial growth, 7. Mastitis was detected with approximately equal frequency throughout the year. Escherichia coli was isolated throughout the year, but was more common and was the predominant organism during the summer. Corynebacterium pyogenes was isolated most often in winter and spring; streptococci in fall, winter, and spring; and staphylococci throughout the year. Corynebacterium pyogenes caused most of the mastitis in nonlactating cows. Escherichia coli, C pyogenes, streptococci, and staphylococci were isolated with about equal frequency at parturition, whereas E coli was the predominant cause of mastitis in early and late lactation. Of cases of mastitis, 27% were seen 10 days before and after parturition. Local and systemic clinical signs of infection were similar for all causes, except that C pyogenes caused more (P less than 0.01) malodorous and purulent milk than did other organisms and was isolated more commonly from quarters with injured teats. Recovery was significantly (P less than 0.01) higher in cows with E coli infections, compared with recovery in cows with gram-positive organism infections. Cows with C pyogenes infections frequently had quarters that ultimately ceased lactation. A few cows were recumbent at initiation of antimicrobial therapy and a few were not eating 24 hours later; however, 50% of these cows recovered. Criteria such as season of year, stage of lactation, appearance of milk and udder, and appetite permitted the cause (gram-negative or gram-positive organisms) of the mastitis to be predicted with 77% accuracy.

A simple overlay system for data comparison in dental identification

A system for handling dental data in mass disasters and in individual cases is described. The basic method allows for a quick overlay comparison of antemortem and postmortem records. After systematic hole punching in the postmortem form, it can be placed over the antemortem form and nonmatches can be easily detected. Suggested uses in mass disaster and individual cases are discussed, as well as its potential for acquainting rural law enforcement with the value of dental data and its management.