Is ethnicity a risk factor for mortality in major trauma? A single-centred cohort study.

INTRODUCTION: Many studies have found varying health outcomes in patients from different minority ethnic groups. There has been limited research into the outcomes in major trauma dependent on ethnicity. The aim was to analyse whether ethnicity was an independent risk factor for 30-day mortality in patients presenting to a major trauma centre when adjusting for confounders. METHODS: This was a retrospective review of all patients presenting to a single major trauma centre from 2010 to 2020. Data were collected on patient demographics and variables including mechanism and injury severity score. Logistic regression was used to determine significant predictors of mortality. RESULTS: There were 10,668 data sets with ethnicity data; of these 9,098 were of White ethnicity, 1,143 were Asian and 427 were classified as Black. The 30-day mortality rate was 7.76% for White ethnicities, 6.91% for Asian ethnicity and 5.15% for people of Black ethnicity. On multivariate logistic regression, ethnicity (p = 0.076) was not associated with 30-day mortality. Age, Injury Severity Score (ISS), Probability of Survival (PS) score, shock and Glasgow Coma Scale (GCS; p < 0.001) were associated with 30-day mortality. White ethnicity had an odds ratio (OR) of mortality of 1.16 (95% confidence interval [CI] 0.658-2.040) (p = 0.609) compared with Black ethnicity and an OR of 0.74 (95% CI 0.546-1.001) (p = 0.050) compared with Asian patients. Black patients had an OR of mortality of 0.65 (95% CI 0.351-1.193) (p = 0.164) compared with the Asian population. CONCLUSION: Ethnicity is not a significant risk factor for 30-day mortality in trauma patients.

Hip arthroplasty practice across the Organisation for Economic Co-operation and Development (OECD) over the last decade.

INTRODUCTION: There are large variations in the number of hip replacements performed between countries, demonstrating large health inequalities; however, there has been limited research on this variation. The aims of this paper were to compare rates of hip replacements using Organisation for Economic Co-operation and Development (OECD) data for the period 2008-2018. The study also compared changes in the number of hip replacements in the total population and in only those aged over 65, and looked for a correlation of health expenditure and gross domestic product (GDP) with rates of hip replacements. METHODS: The OECD collects annual data from all member countries on the numbers of hip replacements, healthcare expenditure and GDP. Data analysis was undertaken using STATA. Descriptive statistics and Pearson's correlation coefficient were performed. RESULTS: The mean number of hip replacements performed in OECD countries in 2018 was 191.5 per 100,000 population per year. The largest number was 310.6 in Germany and the lowest was 8.6 in Mexico. There has been a 21.7% increase in the mean number of hip replacements across OECD countries. There was a moderate and significant Pearson coefficient of 0.468 (p = 0.009) between the number of hip replacements performed per 100,000 population in 2018 and GDP per person, and a strong and significant correlation with health expenditure (R = 0.784, p < 0.001). There was a moderate correlation (R = 0.645, p = 0.003) between the percentage change in the number of hip replacements performed per 100,000 population and the percentage change in healthcare expenditure per person between 2008 and 2018. CONCLUSIONS: There is 36-fold variation in the practice of hip replacements across the OECD and the number of hip replacements has increased by more than 20% over the past decade. The number of hip replacements performed appears to be correlated with health expenditure in each country and may indicate a need that can only be met by increasing health expenditure.

Fracture admission trends in England over a ten-year period.

INTRODUCTION: Fractures are a common reason for admission to hospital around the world. Varying incidences have been reported but these are mainly based on small studies from individual centres. The aim of our study was to analyse fracture admissions in England over a ten-year period. METHODS: Data were collated from the Hospital Episodes Statistics database. Since 2004, data have been collected for all admitted patients in England using the International Classification of Diseases codes for the primary diagnosis. Data were analysed for the ten-year period between 2004-2005 and 2013-2014. RESULTS: There were 2,489,052 fracture admissions in England over the 10-year study period. The risk of admission for fracture was 47.84 per 10,000 population. The rate of fracture admission has remained stable. Hip fractures were the most common fracture requiring hospitalisation (n=641,263), followed by distal radius fractures (n=406,313), ankle fractures (n=332,617) and hand fractures (n=244,013). Hip fractures accounted for 58% of hospital bed days, ankle fractures for 10%, and femoral shaft fractures and subtrochanteric femoral fractures for 5% each. The number of bed days per year for hip fractures has reduced from 1,549,939 bed days in 2004-2005 to 1,319,642 in 2013-2014. CONCLUSIONS: This study provides an updated picture of the incidence of fractures that required hospital admission over a ten-year period in England. It may be used as a platform from which the effect of modern patient treatment pathways can be monitored.

A comparison of two different navigated hip replacement techniques on leg length discrepancy.

We hypothesised that a femoral array placed into bone or an external (pinless) reference marker made no difference to leg length discrepancy in patients undergoing navigated total hip arthroplasty. Consecutive patients undergoing navigated total hip arthroplasty. 162 patients. No statistical difference between preoperative leg length discrepancy (p = 0.524). Mean intraoperative change was 3.7 mm and 4.6 mm (p = 0.262). The mean change in leg length measure post operatively was 4.2 mm and 4.1 mm (p = 0.656). No significant difference in leg length discrepancy between a pinless reference markers and a femoral array placed into the bone.

Mortality in patients sustaining a periprosthetic fracture following a previous extracapsular hip fracture fixation.

BACKGROUND: Mortality rates following hip fractures are decreasing. As these outcomes improve, it increases the potential for further falls and the potential to sustain a periprosthetic fracture. The aim of this study was to analyse the 1 year mortality of periprosthetic fractures around an implant used to treat an extracapsular hip fracture. Secondary outcomes included 30 day mortality, complications and risk factors associated with mortality. METHODS: A retrospective case note and radiographic review of all patients who presented to a single institution with a periprosthetic femoral fracture around an implant previously used to treat an extracapsular hip fracture between 1st January and 2008 and 31st May 2015. RESULTS: 29 patients with a mean age of 75.8. 6 males and 23 females. 20 (69.0%) patients had capacity to consent for surgery. Pre-operatively 34.5% mobilised independently without any walking aids. 79.3% lived at home. 62.1% had a Charlson co-morbidity score of 0 or 1, 27.6% a score of 2 or 3, 6.9% a score of 4 and 5, and 3.4% a score of more than 5.3.4% was ASA grade 1, 13.8% ASA2, 65.5% ASA 3 and 17.2% were ASA 4. The previous implant a dynamic hip screw in 75.9% dynamic hip screws and an intramedullary nail in 24.1%. There were 4 (13.8%) in-patient deaths. The 30 day mortality 17.2% (5 patients) was and the 1 year mortality was 44.8% (13 patients). There were 0 complications that required return to surgery during admission. 1 patient with a revision intramedullary nail had dynamisation performed due to delayed union 7 months following surgery. 1 patient required removal of metalwork 2 years following surgery for infection. When comparing risk factors for mortality, there were no significant risk factors found in this study for 30 day and 1 year mortality. CONCLUSIONS: This paper suggests that periprosthetic fractures sustained after the surgical treatment of extra capsular neck of femur fractures have higher mortality rates than hip fractures. These patients should be given the same priority as these patients in there management.

Prevention of infection in external fixator pin sites.

Infection in external fixator pins is known to be a significant problem, with incidences between 3% and 80% reported in the literature. An infection occurs when planktonic bacteria adhere to external fixator pins and subsequently produce a biofilm which protects the bacteria from host defences. The most commonly implicated organisms are Staphylococcus aureus and Staphylococcus epidermidis. Once an infection occurs, treatment is difficult. Systemic antibiotics have limited benefits and considerable side-effects. The only definitive management is removal of the pin. This review will consider the current and potential future strategies for reducing pin site infection. Techniques to prevent infection must prevent bacterial adhesion, allow good osteointegration and have a low toxicity. Current areas of interest reviewed are titanium-copper alloys, nanosilver coatings, nitric oxide coatings, chitosan coatings, chlorhexidine and iodine, hydroxyapatite and antibiotic coatings. At present there is no consensus on the prevention of pin site infection, and there is a paucity of randomized controlled trials on which to draw a conclusion. Whilst a number of these strategies have potential future use, many of the above strategies need further studies in animal models to ensure no cytotoxicity and prevention of osteointegration. Following this, well-designed randomized controlled clinical trials are required to give future ways to prevent external fixator pin site infections.

Improving ion mass ratio performance at low concentrations in methamphetamine GC-MS assay through internal standard selection.

In federally regulated drug testing, laboratories must identify and quantitate drugs and their breakdown products by gas chromatography-mass spectrometry (GC-MS) to a concentration that is at least 60% below the cutoff concentration for reconfirmation purposes. Use of methamphetamine-d5 as an internal standard in routine testing with derivatization by HFBA was found to contribute m/z 91 and 118 ions to the same ions from the nondeuterated methamphetamine in the specimen. This resulted in poor chromatography and occasionally caused the 91/254 and 118/254 ion mass ratios to exceed the +20% acceptance limit established in the calibration process at low concentrations. The analogues methamphetamine-d8 and -d11 were evaluated for contributions to the nondeuterated methamphetamine ion fragments. Methamphetamine-d8 produced m/z 91 and 118 ions, but in less abundance than methamphetamine-d5. Methamphetamine-d11 was found to produce little or no detectable m/z 91 or 118. Replacing methamphetamine-d5 with methamphetamine-d11 eliminates this problem and allows the assay to consistently produce ion mass ratios and acceptable chromatography sufficient for identifying and quantitating methamphetamine at 60% below the 500-ng/mL cutoff concentration.

A rapid gas chromatographic method quantitating clozapine in human plasma or serum for the purpose of therapeutic monitoring.

A gas chromatographic method using nitrogen-phosphorus detection was developed to quantitate clozapine in plasma or serum. Methyl clonazepam was used as an internal standard. Sample preparation included a single-step extraction with ethyl acetate, which was injected directly onto a wide-bore capillary column. Within-run and total precision, measured as percent coefficient of variation, were determined at low, therapeutic, and high clozapine plasma concentrations. The within-run precision for the low, therapeutic, and high clozapine plasma samples was 5.2, 2.7, and 2.4%, respectively. The total precision for the low, therapeutic, and high clozapine plasma samples was 10.0, 2.6, and 2.0%, respectively. Analytical accuracy was evaluated by comparing quantitative results with those obtained from a reference laboratory. Those samples containing therapeutic or high concentrations agreed within 3%; the sample containing a subtherapeutic concentration differed by 11.9%. The limit of quantitation was determined to be 35 ng/mL, and the upper limit of linearity was 3000 ng/mL. No significant interferences were detected after testing more than two dozen drugs and metabolites.

A high-performance liquid chromatographic method for quantitating bupropion in human plasma or serum.

We report a high-performance liquid chromatographic (HPLC) procedure for quantitating bupropion in serum or plasma for the purpose of therapeutic monitoring. Bupropion and its internal standard, a fluorinated analogue of bupropion, are extracted into hexane-isoamyl alcohol (96:4) after the addition of 400 microL 0.1N KOH. The organic phase is evaporated, reconstituted with 200 microL acetonitrile, and then analyzed on a silica column using a mobile phase consisting of 95% methanol and 5% NH4H2PO4. The ultraviolet detector is set to monitor 248 nm. Within-run and total precision at a therapeutic concentration of 30 ng/mL are 5.2 and 8.5%, respectively. The lower limit of quantitation is 5 ng/mL, and the upper limit of linearity is 400 ng/mL. More than two dozen drugs and metabolites were tested for interference; fluoxetine was the only analyte demonstrating a retention time that would interfere with bupropion quantitation. Chromatographic analysis time per injection is less than 7 min. This procedure combines a single-step extraction with HPLC analysis to provide rapid and reliable analysis of bupropion.

The reliability of a solid-phase extraction system for the analysis of benzoylecgonine in urine.

Gas chromatographic-mass spectrometric (GC-MS) analysis for benzoylecgonine (BE), a metabolite of cocaine, requires an initial extraction from urine. Although liquid-liquid extraction methods are frequently used, solid-phase extraction (SPE) may be preferable for obtaining reliable results and clean chromatograms. We describe a 12-month study that evaluates the accuracy, precision, variability between analysts, variability between column lots, and cleanliness of BE extracts using SPE columns followed by GC-MS analysis. The overall mean for a control urine sample prepared at 150 ng/mL is 151 ng/mL (N = 293) with a standard deviation of 8.59 and a coefficient of variation (CV) of 5.7%. Within-run precision (measured as CV) at 75, 150, and 2000 ng/mL is 4.0, 1.8, and 0.8%, respectively. Mean results from 10 different analysts vary a maximum of 4.6% from the overall mean of 151 ng/mL, and the CV for 9 out of 10 analysts is 7.0% or less. The CV for the remaining analyst is 10.4%. Quantitative results from nine different lots of SPE columns fluctuate 3.3% from the overall mean of 151 ng/mL, and the CV varies from 3.5 to 6.2%. GC-MS chromatograms following SPE are significantly cleaner (i.e., reduced baseline signal and no interfering peaks) than those from two types of liquid-liquid extractions.

Application of the Technicon Chem 1+ chemistry analyzer to the Syva Emit ethyl alcohol assay in plasma and urine.

The performance of the Technicon Chem 1+ chemistry analyzer with the Syva Emit ethyl alcohol assay in plasma and urine was evaluated. Spiked specimens from 0 to 600 mg/dL were tested, and expected versus measured concentrations were monitored. Linear regression line equations of y = 0.9314x + 5.4 and y = 0.9005x + 4.6, and correlation coefficients (r) of 0.9997 and 0.9995, were obtained for plasma and urine, respectively. A limit of detection of 5 mg/dL for plasma and urine, and a limit of quantitation of 20 mg/dL for plasma and 15 mg/dL for urine were obtained. Recovery was within 10% of expected concentration from 20 to 600 mg/dL. Precision was evaluated, giving the following coefficients of variation: within-run precision: plasma, 1.31-2.20; urine, 1.16-1.21; total precision: plasma, 2.72-3.38; urine, 2.98-4.64. No carry-over was detected when alternating 600 mg/dL and negative specimens. No interference from acetone, isopropanol, or methanol was detected. No significant differences in evaporation of alcohol at two concentrations, or from the two matrices were observed. Evaporation from a small cup (200 microL) was more than twice as great as from a large cup (2 mL). The Chem 1+ was compared to a gas chromatographic method. Plasma specimens of 0-352 mg/dL produced a linear regression line of y = 1.0112x + 6.0, r = 0.9859; urine specimens of 0-313 mg/dL produced a line of y = 1.0493x - 0.3, r = 0.9910. The capability to separate positive and negative specimens at 20% around a cutoff concentration of 20 mg/dL was examined. Four hundred specimens were analyzed, with only one specimen incorrectly classified (a false positive). The Chem 1+ chemistry analyzer demonstrated reliable performance of the Emit ethyl alcohol assay of plasma and urine specimens.

The quantitative conversion of morphine 3-beta-D glucuronide to morphine using beta-glucuronidase obtained from Patella vulgata as compared to acid hydrolysis.

Methods to confirm morphine in urine require hydrolysis to liberate morphine from its 3-beta-D glucuronide (M-3G) conjugate. Lengthy enzyme hydrolysis procedures prolong testing turnaround time whereas rapid enzyme methods may produce a low conversion of M-3G to morphine. The purpose of this study was to evaluate the quantitative conversion of M-3G to morphine in human urine using a thermally stable beta-glucuronidase isolated from Patella vulgata; to compare these findings with those obtained from acid hydrolysis; and to compare between-run imprecision for both hydrolysis methods. We found both enzyme and acid hydrolysis techniques to be efficient, giving 90.4% and 92.8% conversion of M-3G to morphine, respectively. Also, both methods were found to be reproducible. Over a 14 week period, 20 opiate confirmation batches were analyzed by each hydrolysis method; the coefficient of variation for morphine liberated from M-3G was 5.5% for enzyme hydrolysis and 2.7% for acid hydrolysis.

Investigation of interference by nonsteroidal anti-inflammatory drugs in urine tests for abused drugs.

Anecdotal and uncontrolled studies have suggested that nonsteroidal anti-inflammatory drugs produce false-positive results in immunoassay urine tests for some drugs of abuse. This study was performed in 60 volunteers who took ibuprofen as either a single 400-mg dose, or 200 mg three times a day, or 400 mg three times a day, and in 42 patients taking ibuprofen, naproxyn, or fenoprofen in therapeutic regimens for more than 30 days. Of the 510 urines collected from 102 individuals during these dosage regimens, two gave false-positive tests for cannabinoid by enzyme-mediated immunoassay (EMIA), one after 1200 mg of ibuprofen in three divided doses for one day and one in a patient taking naproxyn on a chronic basis; none was falsely positive for benzodiazepines. Two urines were false-positive for barbiturates by fluorescence polarization immunoassay (FPIA), one in a patient taking ibuprofen and one in a patient taking naproxyn. These data, collected prospectively, demonstrate the small likelihood of a false-positive immunoassay test result for cannabinoids, benzodiazepines, or barbiturates after the acute or chronic ingestion of ibuprofen, or after the chronic ingestion of naproxyn or fenoprofen.

An evaluation of the TDX fluorescence polarization immunoassays for procainamide and n-acetylprocainamide.

The TDX fluorescence polarization assays (FPIA) for procainamide (PA) and n-acetylprocainamide (NAPA) were evaluated. Coefficients of variation for within- and between-assay precision studies were less than 6%. Both methods correlated well with a referenced HPLC technique; r2 values for PA and NAPA were 0.980 and 0.986, respectively.

Twin transfusion syndrome: successful in utero treatment with digoxin.

A pregnancy complicated by twin transfusion syndrome is presented. When signs of cardiac failure (edema, ascites and hydramnios) persisted in the recipient twin, maternal digoxin therapy was instituted at 27 weeks' gestation. The signs of failure resolved, and the twins were delivered electively by cesarean section at 34 weeks. At birth, the syndrome was confirmed by examination of the infants and placenta. Both infants survived. Digoxin therapy is recommended for fetal heart failure from circulatory overload in twin transfusion.

Analysis of ethchlorvynol (Placidyl): evaluation of a comparison performed in a clinical laboratory.

Common techniques for analyzing ethchlorvynol (Placidyl) by colorimetry and gas liquid chromatography are evaluated. Matrix effects are thoroughly examined to determine their contribution to the validity of results.

Stability of delta 9-tetrahydrocannabinol (THC), 11-hydroxy-THC, and 11-nor-9-carboxy-THC in blood and plasma.

The stabilities of delta 9-tetrahydrocannabinol (THC) and two of its metabolites, 11-hydroxy-delta 9-tetrahydrocannabinol (HO-THC) and 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (COOH-THC), were determined in blood and plasma stored at -10 degrees C, 4 degrees C, and room temperature. Each of the cannabinoids was added to freshly-drawn blood and plasma to give concentrations of 20 ng/mL. Two-mL aliquots were stored in silanized tubes and the cannabinoid concentrations were monitored by gas chromatography/mass spectrometry over a 6-month period. No significant changes were observed in the concentrations of the cannabinoids for the first month of storage. However, the concentrations of THC and HO-THC in blood stored at room temperature had decreased significantly at 2 months. No statistically significant changes were detected in cannabinoid concentrations in plasma or blood stored at 4 degrees or -10 degrees C for up to 4 months. After 6 months at room temperature, the blood concentrations of THC and HO-THC had decreased by 90 and 44%, respectively, whereas the concentration of COOH-THC was not significantly different from the control. The possibility of loss of cannabinoids from blood due to adsorption onto the grey stoppers used in Venoject tubes was also investigated. Over a 24-hr period, no significant differences were detected in any of the cannabinoid concentrations regardless of sample size (1.3 or 8 mL), differences in temperature (-10 degrees C, 4 degrees C, or room temperature), or extent of contact with the tube's stoppers.

Formate concentrations in a case of methanol ingestion.

An eight-month-old infant ingested at least 3.5 g of methanol when he accidentally received 5 mL of amoxicillin suspended in 70% methanol. The serum methanol concentration 8 h later was 9.7 mmol/L (310 mg/L) and the formate concentration 23 mmol/L (1.0 g/L). At 18 h after the ingestion, total CO2 had decreased to 6.8 mmol/L. Throughout the second day, 21-32 h after the ingestion, the methanol concentration was 2.8-3.4 mmol/L (90-110 mg/L) and that of formate was 31-33 mmol/L (1.4-1.5 g/L). On the third day, 46 h after the ingestion, methanol was not detected and the formate concentration had declined to 16 mmol/L (720 mg/L). The patient was treated with activated charcoal 7 h after the ingestion and with ethanol, administered both orally and intravenously, 21 h after the ingestion. No abnormalities of the infant's eyes were noted upon ophthalmological examination approximately 55 h after the incident.