Back to the future: Retrograde alcohol calculations an uncertain science.

Retrograde extrapolations, known as back calculations are widely used in forensic toxicology to estimate the blood alcohol concentration of an individual at some prior time. In the UK guidelines have been issued by the United Kingdom and Ireland Association of Forensic Toxicologists) and the Organization of Scientific Area Committees (OSAC) for Forensic Science. However, these guidelines are not fully agreed and open tointerpretation. Alcohol elimination rates have been discussed in numerous publications since Widmark's original data was published. The current guidance from UKIAFT, is to report the most likely back calculated result together with a range of results based on the 95% confidence limit elimination rates (9 to 29 mg/100 mL/hour).The Divisional Court, upheld by the House of Lords, ruled that in order to convict someone for being over the prescribed limit on the basis of any back calculation, the case must be proven beyond reasonable doubt. A 99.73% confidence interval increased to 3 standard deviations at the lower end would provide a greater factual basis for the court and cover alarger proportion of the population, this can be achieved by increasing the elimination range to 8 to 29 mg/100 mL/hour. Retrograde extrapolations also rely on the subject being post absorptive at the prior time. In the UK, back calculations are validif the subject has not eaten or consumed alcohol withinonehour ofthe back calculation time. Where the subject has eatenprior to the back calculation, experts are instructed to consider whether the back calculation is applicable. In Germany and the United States back calculations are not permitted to a time within 2 h after last drink consumed. The 2 h limit would better meet the highest standard of 'beyond reasonable doubt' burden of proof, and should be used. These proposed changes would decrease the uncertainty associated with retrograde calculations carried out by UK toxicologists.

Crystal-induced arthritis in prosthetic joints: a systematic review of clinical features, diagnosis, management, and outcomes.

BACKGROUND: To summarize clinical presentations, baseline characteristics, diagnosis, treatment, and treatment outcomes through a systematic review of cases of crystal-induced arthritis in prosthetic joints in the literature. METHODS: A systematic review of case reports and case series was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search was performed through PubMed/MEDLINE, Google Scholar, Embase, Cumulative Index to Nursing & Allied Health, and Web of Science. We identified case reports/case series in English of adult patients presenting with crystal-induced arthritis (gout, calcium pyrophosphate deposition disease) in prosthetic joints. Articles that met the inclusion criteria were utilized for qualitative data synthesis. RESULTS: We found 44 cases of crystal-induced arthritis in prosthetic joints from 1984 to 2021. Crystal-induced arthritis in periprosthetic joints most frequently affects patients who had knee arthroplasty and most often presents as monoarticular arthritis that is usually acute in onset. However, several cases in the literature involved patients who had bilateral knee replacements and presented with a concurrent flare of gout or calcium pyrophosphate deposition disease in bilateral knees. Patients with crystal-induced arthritis in prosthetic joints show elevated white blood cell counts with neutrophil predominance and respond favorably to anti-inflammatory treatments, usually within one week. In many cases, crystal-induced arthritis was challenging to differentiate from prosthetic joint infection, with approximately one-third of patients undergoing surgical intervention and 35% receiving antibiotic treatment. CONCLUSION: Crystal-induced arthritis in prosthetic joints can mimic prosthetic joint infections and should always be considered in the differential diagnoses of joint pain in prosthetic joints. We present the first systematic review of crystal-induced arthritis in prosthetic joints to increase awareness of the diagnosis and proper management.

Risk factors associated with 1-year mortality after osteoporotic hip fracture in Hawai'i: higher mortality risk among Native Hawaiians and other Pacific Islanders.

We studied factors affecting osteoporotic hip fracture mortality in Hawai'i, a region with unique geography and racial composition. Men, older adults, higher ASA score, lower BMI, and NHPI race were associated with higher mortality. This is the first study demonstrating increased mortality risk after hip fracture in NHPI patients. PURPOSE: To estimate mortality rates and identify specific risk factors associated with 1-year mortality after osteoporotic hip fracture in Hawai'i. METHODS: A retrospective review of adults (≥ 50 years) hospitalized with an osteoporotic hip fracture at a large multicenter healthcare system in Hawai'i from 2011 to 2019. The Kaplan-Meier curves and log-rank tests examined survival probability by sex, age group, race/ethnicity, primary insurance, body mass index (BMI), and American Society of Anesthesiologists (ASA) physical status classification. After accounting for potential confounders, adjusted hazard ratios (aHR) and 95% confidence intervals (CI) were obtained from Cox proportional hazards regression models. RESULTS: We identified 1755 cases of osteoporotic hip fracture. The cumulative mortality rate 1 year after fracture was 14.4%. Older age (aHR 3.50; 95% CI 2.13-5.76 for ≥ 90 vs 50-69), higher ASA score (aHR 5.21; 95% CI 3.09-8.77 for ASA 4-5 vs 1-2), and Native Hawaiian/Pacific Islander (NHPI) race (aHR 1.84; 95% CI 1.10-3.07 vs. White) were independently associated with higher mortality risk. Female sex (aHR 0.64; 95% CI 0.49-0.84 vs male sex) and higher BMI (aHR 0.35; 95% CI 0.18-0.68 for obese vs underweight) were associated with lower mortality risk. CONCLUSION: In our study, men, older adults, higher ASA score, lower BMI, and NHPI race were associated with significantly higher mortality risk after osteoporotic hip fracture. NHPIs are an especially vulnerable group and comprise a significant portion of Hawai'i's population. Further research is needed to address the causes of higher mortality and interventions to reduce hip fractures and associated mortality.

Utility of D-dimer in predicting pulmonary embolism in patients with COVID-19 presenting to the emergency department.

Objectives: While our understanding of coronavirus disease 2019 (COVID-19) has evolved, uncertainty remains regarding utility of previously established pulmonary embolism (PE) screening guidelines in patients with COVID-19. Many studies have investigated the efficacy of D-dimer (DD) screenings for patients with COVID-19 admitted to inpatient services, but few have evaluated patients in the emergency department (ED). The purpose of this study was to investigate utility of DD threshold for PE screening in patients with COVID-19 presenting to the ED. Methods: This was a retrospective, multicenter cohort including patients presenting to three EDs between March 1, 2020 and February 1, 2021 who tested positive for COVID-19 during ED visit or in 60 days prior to presentation and had DD ordered in ED. Patients were grouped by those who underwent computed tomography pulmonary angiogram (CTPA) to evaluate for PE and those who did not, and descriptive statistics were performed. Those who underwent CTPA were further divided into PE-positive and PE-negative groups. The discriminative ability of DD in predicting PE in patients with COVID-19 was analyzed using the receiver operating characteristic (ROC) curve. Results: A total of 570 patients with COVID-19 were included in the study, of which 107 underwent CTPA to evaluate for PE. History of diabetes, elevated glucose, elevated lactate dehydrogenase, elevated white blood cell count, elevated platelets, elevated respiratory rate, and lower temperature were associated with increased risk for PE. Compared to those without PE, patients with PE were significantly more likely to be hospitalized (100% vs. 82%, p = 0.020) and admitted to the ICU (64% vs. 24%, p = 0.002). Those with PE had a significantly higher median DD value (21,177 ng/mL) compared to PE-negative group (952 ng/mL, p < 0.001). The ROC curve for DD in predicting PE had an area under the curve of 0.91 (95% confidence interval [0.84, 0.98]). In our study population, the optimal DD threshold for predicting PE was 1815 ng/mL (sensitivity 93% and specificity 80%). A conservative threshold of 1089 ng/mL could be used with sensitivity 100% and specificity 58%. Conclusion: DD is often elevated in patients with COVID-19, regardless of PE. While the classically used DD cutoff is 500 ng/mL, our study demonstrated a threshold of 1089 ng/mL safely predicted PE in patients with COVID-19 .