Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Racial disparity in early graft failure after infrainguinal bypass

Background: Racial disparities have been shown to be associated with increasing health-care costs. We sought to identify racial disparities in 30-d graft failure rates after infrainguinal bypass in an effort to define targets for improved health care among minorities. Methods: The 2005-2011 National Surgical Quality Improvement Program database was queried for patients with peripheral arterial disease who underwent infrainguinal bypass as their primary procedure. A bivariate analysis was done to assess pre and intraoperative risk factors across race (whites, blacks, and Hispanics). Multivariate logistic regression was performed to assess the independent association of race with 30-d graft failure. Results: Of a total of 16,276 patients, 12,536 (77.0%) were whites, 2940 (18.1%) blacks, and 800 (4.9%) Hispanics. Black patients were more likely to be younger, female, current smokers, and on dialysis (P\u3c0.001, all). In addition, whites were less likely to present with critical limb ischemia compared with blacks and Hispanics (44.2 versus 55.4 versus 52.8%, respectively; P\u3c0.001). Similarly, fewer whites underwent femoral-tibial (31.4 vs. 34.7 vs. 38.6% respectively) or popliteal-tibial level bypasses (8.9 versus 13.4 versus 16.1%, respectively) than blacks and Hispanics (P\u3c0.001, all). There was no difference in the use of autogenous conduit across the groups (P=0.266). Proportionally more blacks than whites developed early graft failure (6.7 versus 4.5%; P\u3c0.001) but there was no difference comparing Hispanics to whites (6.0 versus 4.5%; P=0.057). On multivariable analysis, black race remained independently associated with early graft failure (adjusted odds ratio=1.26, 95% confidence interval 1.05-1.51; P=0.011). Conclusions: More blacks and Hispanics present with critical limb ischemia, requiring distal revascularization. Even when controlling for anatomic differences and degree of peripheral arterial disease, black race remained independently associated with early graft failure after infrainguinal bypass. These results identify a target for improved outcome

Adjuvant and Salvage Radiotherapy after Prostatectomy: ASTRO/AUA Guideline Amendment 2018-2019.

PurposeThe purpose of this amendment is to incorporate newly-published literature into the original ASTRO/AUA Adjuvant and Salvage Radiotherapy after Prostatectomy Guideline and to provide an updated clinical framework for clinicians.Materials and methodsThe original systematic review yielded 294 studies published between January 1990 and December 2012. In April 2018, the guideline underwent an amendment and incorporated 155 references that were published from January 1990 through December 2017. Two new key questions were added. One on the use of genomic classifiers and the other on the treatment of oligo-metastases with radiation post-radical prostatectomy.ResultsA new statement on the use of hormone therapy with salvage radiotherapy after radical prostatectomy was added and long-term data was used to update an existing statement on adjuvant radiotherapy. The balance of the guideline statements were re-affirmed and references were added to the existing literature base. A discussion on the use of genomic classifiers as a risk stratification tool was added to the future research discussion. No relevant data on oligo-metastases was found.ConclusionsHormone therapy should be offered to patients who have had radical prostatectomy and who are candidates for salvage radiotherapy. The clinician should discuss possible short- and long-term side effects with the patient as well as the potential benefits of preventing recurrence. The decision to use hormone therapy should be made by the patient and a multi-disciplinary team of providers with full consideration of the patient's history, values, preferences, quality of life, and functional status

Undertriage of older trauma patients: is this a national phenomenon?

Background: Older age is associated with high rates of morbidity and mortality after injury. Statewide studies suggest significantly injured patients aged ≥55 y are commonly undertriaged to lower level trauma centers (TCs) or nontrauma centers (NTCs). This study determines whether undertriage is a national phenomenon. Materials and methods: Using the 2011 Nationwide Emergency Department Sample, significantly injured patients aged ≥55 y were identified by diagnosis and new injury severity score (NISS) ≥9. Undertriage was defined as definitive care anywhere other than level I or II TCs. Weighted descriptive analysis compared characteristics of patients by triage status. Multivariable logistic regression determined predictors of undertriage, controlling for hospital characteristics, injury severity, and comorbidities. Results: Of 4,152,541 emergency department (ED) visits meeting inclusion criteria, 74.0% were treated at lower level TCs or NTCs. Patients at level I and II TCs more commonly had NISS ≥9 (22.2% versus 12.3%, P \u3c 0.001), but among all patients with NISS ≥9, 61.3% were undertriaged to a lower level TC or a NTC. On multivariable logistic regression, factors independently associated with higher odds of being undertriaged were increasing age, female gender, and fall-related injuries. A subgroup analysis examined urban and suburban areas only where access to a TC is more likely and found that 55.8% of patients\u27 age were undertriaged. Conclusions: There is substantial undertriage of patients aged ≥55 y nationwide. Over half of significantly injured older patients are not treated at level I or II TCs. The impact of undertriage should be determined to ensure older patients receive trauma care at the optimal sit

Traumatic Spinal Cord Injury Emergency Service Triage Patterns and the Associated Emergency Department Outcomes

Paralysis is an indication for trauma patients to be preferentially triaged by emergency services to designated level I or II trauma centers (TC). We sought to describe triage practices for patients with acute traumatic spinal cord injury (TSCI) and its associated emergency department (ED) outcomes. Adults ages ≥ 18 years with a diagnosis of acute TSCI (International Classification of Diseases-9: 806 and 952) in the 2006-2011 United States Nationwide Emergency Department Sample were included in these analyses. Outcomes assessed include triage to non-trauma centers (NTC), which is referred to as under-triage, and ED mortality. Of 117,444 adults with TSCI, 33.4% were under-triaged to NTC. Under-triage was more prevalent with increasing age. Among patients under-triaged to NTC, 37.4% had new injury severity score (NISS) \u3e15, representing severe injuries or polytrauma. Among patients with NISS \u3e15, the odds of ED mortality in NTC were four-fold greater compared to level I trauma centers (TC-I) (adjusted odds ratio [AOR] = 4.06; 95% confidence interval = 1.87-8.79; p \u3c 0.001). In conclusion, under-triage of adults with acute TSCI occurred in at least one-third of the cases. Patients triaged to NTC rather than TC-I experienced higher likelihood of death in the ED even after controlling for personal and injury characteristics. Further research is necessary to elucidate detailed clinical and logistical factors that may be associated with under-triage of acute TSCI, to facilitate interventions aimed at improving patient experience and outcomes

Traumatic spinal cord injury emergency service triage patterns and the associated emergency department outcomes

Paralysis is an indication for trauma patients to be preferentially triaged by emergency services to designated level I or II trauma centers (TC). We sought to describe triage practices for patients with acute traumatic spinal cord injury (TSCI) and its associated emergency department (ED) outcomes. Adults ages ≥ 18 years with a diagnosis of acute TSCI (International Classification of Diseases-9: 806 and 952) in the 2006-2011 United States Nationwide Emergency Department Sample were included in these analyses. Outcomes assessed include triage to non-trauma centers (NTC), which is referred to as under-triage, and ED mortality. Of 117,444 adults with TSCI, 33.4% were under-triaged to NTC. Under-triage was more prevalent with increasing age. Among patients under-triaged to NTC, 37.4% had new injury severity score (NISS) \u3e15, representing severe injuries or polytrauma. Among patients with NISS \u3e15, the odds of ED mortality in NTC were four-fold greater compared to level I trauma centers (TC-I) (adjusted odds ratio [AOR] = 4.06; 95% confidence interval = 1.87-8.79; p \u3c 0.001). In conclusion, under-triage of adults with acute TSCI occurred in at least one-third of the cases. Patients triaged to NTC rather than TC-I experienced higher likelihood of death in the ED even after controlling for personal and injury characteristics. Further research is necessary to elucidate detailed clinical and logistical factors that may be associated with under-triage of acute TSCI, to facilitate interventions aimed at improving patient experience and outcomes

Halo effect in trauma centers: Does it extend to emergent colectomy?

Background: Trauma centers (TCs) have been demonstrated to improve outcomes for some nontrauma surgical conditions, such as appendicitis, but it remains unclear if this extends to all emergency general surgery procedures. Using emergent colectomy in patients with diverticulitis as index condition, this study compared outcomes between TCs and nontrauma centers (NTCs).Materials and methods: The Nationwide Emergency Department Sample (2006-2011) was queried for patients ≥16 y with diverticulitis who underwent emergency surgical intervention. Outcomes included mortality, total charges, and length of stay (LOS). Mortality in TC and NTC was compared using logistic regression, controlling for patient, procedure, and hospital-level characteristics. Adjusted total charges and LOS were analyzed using generalized linear models with gamma and Poisson distributions, respectively.Results: A total of 25,396 patients were included, 5189 (20.4%) were treated at TC and 20,207 (79.6%) at NTC. Median age and sex distribution were similar. Unadjusted proportional in-hospital mortality did not differ between TC and NTC; median charges and LOS were greater in TC. After adjusting, the odds of mortality were significantly higher in TC (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.02-1.51; P = 0.003) as were mean charges and LOS (P \u3c 0.001).Conclusions: The improved outcomes reported for other nontrauma conditions in TC were not observed for patients undergoing an emergent colectomy for diverticulitis after accounting for patient, procedure, and hospital-level characteristics. Future research is needed to assess differences in case mix between TC versus NTC and possible case-mix effects on outcomes to elucidate potential benefit of surgical care in a TC across the breadth of emergency general surgery conditions

Trends in incidence and severity of sports-related traumatic brain injury (TBI) in the emergency department, 2006-2011

Objective: To characterize and identify trends in sports-related traumatic brain injury (TBI) emergency department (ED) visits from 2006-2011.Methods: This study reviewed data on sports-related TBI among individuals under age 65 from the Nationwide Emergency Department Sample from 2006-2011. Visits were stratified by age, sex, injury severity, payer status and other criteria. Variations in incidence and severity were examined both between groups and over time. Odds of inpatient admission were calculated using regression modelling.Results: Over the period examined, 489 572 sports-related TBI ED visits were reported. The majority (62.2%) of these visits occurred among males under the age of 18. The average head Abbreviated Injury Severity score among these individuals was 1.93 (95% CI = 1.93-1.94) and tended to be lowest among those in middle school and high school age groups; these were also less likely to be admitted. The absolute annual number of visits grew 65.9% from 2006 until 2011, with the majority of this growth occurring among children under age 15. Hospitalization rates dropped 35.6% over the same period.Conclusion: Changes in year-over-year presentation rates vs. hospitalization rates among young athletes suggest that players, coaches and parents may be more aware of sports-related TBI and have developed lower thresholds for seeking medical attention