Biomedical subjects

Alan C Elliott

Publications and source records attributed to Alan C Elliott.

5 recordsLinked to original sources

PubMed2006

Prospective comparison of methicillin-susceptible and methicillin-resistant community-associated Staphylococcus aureus infections in hospitalized patients.

BACKGROUND: We sought to determine the proportion of community-associated Staphylococcus aureus infections due to methicillin-resistant S. aureus (CA-MRSA) at a large county hospital. In addition, we sought to identify the demographic and clinical risk factors associated with CA-MRSA infection. METHODS: Patients were prospectively enrolled if they were admitted to Parkland Hospital and had a positive culture for S. aureus isolated within 72 h of admission. The patients were interviewed using a standardized data questionnaire. Data collected included patient demographics, clinical history, as well as health care and non-health care associated MRSA risk factors. Bacterial susceptibilities were verified through review of microbiology laboratory and pharmacy records. Isolates were tested for Panton-Valentine leukocidin (PVL) gene, SCCmec type, and for inducible clindamycin resistance. RESULTS: One hundred and ninety-eight patients were interviewed prospectively, of which eight had colonization without active infection. One hundred and nineteen patients were infected with MRSA and 71 patients were infected with methicillin-susceptible S. aureus (MSSA). Patients with MRSA were more likely to be African-American and unemployed. Patients with MRSA most commonly presented with a skin or soft tissue infection (SSTI): 69% versus 45%, p=0.0012, while patients with MSSA were more likely to have infection of the respiratory tract: 11% versus 3%, p=0.02. Patients with MRSA were more likely to have used antibiotics in the past six months, been homeless, have a history of incarceration, have abused alcohol and have a history of infection with MRSA. In multivariate analysis, African-American race, antibiotics in the past six months, and a history of being homeless were associated with MRSA infection. Only 11 of 119 (9%) MRSA patients did not have at least one of these risk factors. PVL gene was present in 72 of 74 (97%) MRSA isolates and SCCmec type IV was present in 63 of 75 (84%) MRSA isolates. CONCLUSIONS: The majority of patients hospitalized with community-associated S. aureus infections were due to MRSA, most of which involved an SSTI. African-American race, recent antibiotics and past homeless status predicted infection with MRSA; however, no clinical profile could reliably exclude MRSA. Clinicians should be aware of the increasing prevalence of CA-MRSA.

Adolescent↗

PubMed2006

Systemic hypotension is a late marker of shock after trauma: a validation study of Advanced Trauma Life Support principles in a large national sample.

BACKGROUND: Systolic blood pressure is used extensively to triage trauma patients as stable or unstable, contrary to Advanced Trauma Life Support recommendations. We hypothesized that systemic hypotension is a late marker of shock. METHODS: The National Trauma Data Bank was queried (n = 115,830). Base deficit was used as a measure of circulatory shock. Systolic blood pressure was correlated with the presence and the severity of base-deficit derangement. RESULTS: Systolic blood pressure correlated poorly with base deficit (r = .28). There was wide variation in systolic blood pressure within each base-deficit group. The mean and median systolic blood pressure did not decrease to less than 90 mm Hg until the base deficit was worse than -20, with mortality reaching 65%. CONCLUSIONS: We validated the Advanced Trauma Life Support principle that systemic hypotension is a late marker of shock. A normal blood pressure should not deter aggressive evaluation and resuscitation of trauma patients.

Adult↗

PubMed2006

Effect of trauma systems on motor vehicle occupant mortality: A comparison between states with and without a formal system.

BACKGROUND: Population-based studies using a "before-and-after" methodology report a reduction in motor vehicle collision mortality with implementation of statewide trauma systems (TS). However, concurrent improvements in roads, cars, restraint systems, and changes in rates of drunk driving, socioeconomics, speed limits, urban or rural mix, and traffic density may also be responsible for the progressive reduction in mortality rates. We hypothesized that a statewide TS independently reduces injury mortality, irrespective of other factors. METHODS: Data were acquired from several federal agencies including the Centers for Disease Control (CDC), The National Highway Traffic Safety Administration (NHTSA), the United States Department of Transportation (DOT), and the United States Census Bureau. Age-adjusted motor vehicle occupant (MVO) death rates per 100,000 population were compared in states with and without a TS. Negative binomial regression was used to calculate risk ratios (RR) comparing mortality in TS and non-TS states after adjusting for effects of gender, race, primary seat belt laws, seat belt use, alcohol use, miles traveled, population density, per capita income, types of registered vehicles, and rural or urban mix. RESULTS: : The number of states with a TS increased from 7 in 1981 to 36 in 2002. Concurrently, nationwide MVO death rates decreased by 2.6 per 100,000 (95% confidence interval 1.2-3.9; p < 0.001). Income, primary seat belt laws, restraint use, speed limits, and rural or urban population distribution (p < 0.05 for all), were independent predictors of MVO mortality, but not presence of a TS (RR 0.95, 95% confidence interval 0.73-1.23; p = 0.68). CONCLUSIONS: MVO death rates have declined over time, and are lower in TS states. However, the cause is multi-factorial, and cannot be attributed solely to presence of TS. Further studies are needed to identify beneficial components of a statewide trauma system.

Accidents, Traffic↗

PubMed2006

Preparing data for analysis using microsoft Excel.

A critical component essential to good research is the accurate and efficient collection and preparation of data for analysis. Most medical researchers have little or no training in data management, often causing not only excessive time spent cleaning data but also a risk that the data set contains collection or recording errors. The implementation of simple guidelines based on techniques used by professional data management teams will save researchers time and money and result in a data set better suited to answer research questions. Because Microsoft Excel is often used by researchers to collect data, specific techniques that can be implemented in Excel are presented.

Biomedical Research↗

PubMed2005

Is hypothermia simply a marker of shock and injury severity or an independent risk factor for mortality in trauma patients? Analysis of a large national trauma registry.

BACKGROUND: Successful application of induced hypothermia (HT) after stroke and cardiac arrest has led to a resurgence of interest in its potential protective effects in trauma patients. Although clinical studies demonstrate an adverse effect, they consist of small studies from single institutions. We tested the hypothesis that HT is associated with improved survival in trauma patients by analyzing a large, national trauma database. METHODS: The study included all patients in the National Trauma Data Bank (1994-2002) aged 18 to 55 years old with temperature at presentation to the emergency department and base deficit (BD) recorded. Hypothermic (temperature, <35 degrees C; n = 3267) patients and patients with normothermia (temperature, > or =35 degrees C; n = 35,283) patients were compared. Two analyses were conducted to control for the association between HT and injury severity. First, hypothermic and normothermic (NT) patients were stratified by injury severity score (ISS) and shock (blood pressure < or = 90 mm Hg). Next, logistic regression was used to control for effects of age, sex, mechanism, ISS, head, chest, and abdominal injuries, BP, Glasgow Coma Scale score, and BD, with survival as the dependent and HT as the predictor variable. RESULTS: Although HT was more common in more seriously injured patients, stratified analysis revealed that hypothermic patients have significantly higher mortality than patients with the same severity of injury who remain NT. Even after controlling for injury severity and the other potential confounders listed above, HT remained a strong, independent predictor of mortality (odds ratio, 1.19; 95% confidence interval, 1.05-1.35). CONCLUSION: There is no apparent protective effect of HT in trauma patients. HT itself, not just its association with shock, injury severity, and other cofactors lead to a significant increase in mortality in injured patients. Continued, aggressive efforts to prevent and treat HT are warranted.

Adolescent↗