Biomedical subjects

Yuchiao Chang

Publications and source records attributed to Yuchiao Chang.

At least 19 recordsLinked to original sources

PubMed2006

A mechanism-based combination therapy reduces local tumor growth and metastasis in an orthotopic model of prostate cancer.

Therapy-induced stimulation of angiogenic molecules can promote tumor angiogenesis leading to enhanced tumor growth and cancer metastasis. Several standard and emerging therapies, such as radiation and photodynamic therapy (PDT), can induce angiogenic molecules, thus limiting their effectiveness. PDT is approved for the treatment of several cancers; however, its induction of vascular endothelial growth factor (VEGF) creates conditions favorable to enhanced tumor growth and metastasis, therefore mitigating its cytotoxic and antivascular effects. This is the first report showing that subcurative PDT in an orthotopic model of prostate cancer (LNCaP) increases not only VEGF secretion (2.1-fold) but also the fraction of animals with lymph node metastases. PDT followed by administration of an antiangiogenic agent, TNP-470, abolished this increase and reduced local tumor growth. On the other hand, administration of TNP-470 before PDT was less effective at local tumor control. In addition, animals in all groups, except in the PDT + TNP-470 group, had a weight loss of >3 g at the time of sacrifice; the weight of the animals in the PDT + TNP-470 group did not change. The significant reduction (P < 0.05) in tumor weight and volume observed between the PDT + TNP-470 group and the control group suggests that the combination of PDT and antiangiogenic treatment administered in the appropriate sequence was not only more effective at controlling local tumor growth and metastases but also reduced disease-related toxicities. Such molecular response-based combinations merit further investigations as they enhance both monotherapies and lead to improved treatment outcomes.

Angiogenesis Inhibitors↗

PubMed2006

The "gender gap" in authorship of academic medical literature--a 35-year perspective.

BACKGROUND: Participation of women in the medical profession has increased during the past four decades, but issues of concern persist regarding disparities between the sexes in academic medicine. Advancement is largely driven by peer-reviewed original research, so we sought to determine the representation of female physician-investigators among the authors of selected publications during the past 35 years. METHODS: Original articles from six prominent medical journals--the New England Journal of Medicine (NEJM), the Journal of the American Medical Association (JAMA), the Annals of Internal Medicine (Ann Intern Med), the Annals of Surgery (Ann Surg), Obstetrics & Gynecology (Obstet Gynecol), and the Journal of Pediatrics (J Pediatr)--were categorized according to the sex of both the first and the senior (last listed) author. Sex was also determined for the authors of guest editorials in NEJM and JAMA. Data were collected for the years 1970, 1980, 1990, 2000, and 2004. The analysis was restricted to authors from U.S. institutions holding M.D. degrees. RESULTS: The sex was determined for 98.5 percent of the 7249 U.S. authors of original research with M.D. degrees. The proportion of first authors who were women increased from 5.9 percent in 1970 to 29.3 percent in 2004 (P<0.001), and the proportion of senior authors who were women increased from 3.7 percent to 19.3 percent (P<0.001) during the same period. The proportion of authors who were women increased most sharply in Obstet Gynecol (from 6.7 percent of first authors and 6.8 percent of senior authors in 1970 to 40.7 percent of first authors and 28.0 percent of senior authors in 2004) and J Pediatr (from 15.0 percent of first authors and 4.3 percent of senior authors in 1970 to 38.9 percent of first authors and 38.0 percent of senior authors in 2004) and remained low in Ann Surg (from 2.3 percent of first authors and 0.7 percent of senior authors in 1970 to 16.7 percent of first authors and 6.7 percent of senior authors in 2004). In 2004, 11.4 percent of the authors of guest editorials in NEJM and 18.8 percent of the authors of guest editorials in JAMA were women. CONCLUSIONS: Over the past four decades, the proportion of women among both first and senior physician-authors of original research in the United States has significantly increased. Nevertheless, women still compose a minority of the authors of original research and guest editorials in the journals studied.

Authorship↗

PubMed2006

INCOMING!--A web tracking application for PACU and post-surgical patients.

BACKGROUND: Capacity constraints necessitate improving hospital efficiency. An integrated real time system facilitating patient flow between the post-anesthesia care unit (PACU) and surgical ward would ease PACU workload by reducing the effort of discharging patients. METHODS: We developed INCOMING!, a web-based platform that monitors patient progress from the operating room to the PACU. INCOMING! integrates available data, automatically determining when a patient enters the PACU. An automated paging system alerts clinical unit managers to 'pull' their patients from the PACU after a set recovery period. General surgery patients were included in the INCOMING! system in late 2004 with paging added in mid-March 2005. Mean PACU length of stay was calculated for the intervention group (general surgery patients with INCOMING!) and compared to a control group (general surgery patients without INCOMING!) and an orthopedic surgery group before and after paging. RESULTS: The system successfully gathers data and generates automated pages when events occur. After paging, there was a significant difference between the orthopedic surgery control group and the general surgery intervention group (235 min versus 185 min, P = 0.001). The mean PACU LOS decreased in the INCOMING! intervention group by 26 min while the mean LOS increased by 28 min in the general surgery control group (P = 0.27). CONCLUSION: Pilot implementation demonstrates that INCOMING! performs the desired integration and automatic notification. Given the minimal cost and potential large gains from a wider deployment, we plan to implement the system for all PACU patients and all post-PACU care units.

Computer Systems↗

PubMed2006

Regional pulmonary perfusion, inflation, and ventilation defects in bronchoconstricted patients with asthma.

RATIONALE: Bronchoconstriction in asthma leads to heterogeneous ventilation and the formation of large and contiguous ventilation defects in the lungs. However, the regional adaptations of pulmonary perfusion (Q) to such ventilation defects have not been well studied. METHODS: We used positron emission tomography to assess the intrapulmonary kinetics of intravenously infused tracer nitrogen-13 ((13)NN), and measured the regional distributions of ventilation and perfusion in 11 patients with mild asthma. For each subject, the regional washout kinetics of (13)NN before and during methacholine-induced bronchoconstriction were analyzed. Two regions of interest (ROIs) were defined: one over a spatially contiguous area of high tracer retention (TR) during bronchoconstriction and a second one covering an area of similar size, showing minimal tracer retention (NR). RESULTS: Both ROIs demonstrated heterogeneous washout kinetics, which could be described by a two-compartment model with fast and slow washout rates. We found a systematic reduction in regional Q to the TR ROI during bronchoconstriction and a variable and nonsignificant change in relative Q for NR regions. The reduction in regional Q was associated with an increase in regional gas content of the TR ROI, but its magnitude was greater than that anticipated solely by the change in regional lung inflation. CONCLUSION: During methacholine-induced bronchoconstriction, perfusion to ventilation defects are systematically reduced by a relative increase in regional pulmonary vascular resistance.

Adult↗

PubMed2006

Evidence of focal small-fiber axonal degeneration in complex regional pain syndrome-I (reflex sympathetic dystrophy).

CRPS-I consists of post-traumatic limb pain and autonomic abnormalities that continue despite apparent healing of inciting injuries. The cause of symptoms is unknown and objective findings are few, making diagnosis and treatment controversial, and research difficult. We tested the hypotheses that CRPS-I is caused by persistent minimal distal nerve injury (MDNI), specifically distal degeneration of small-diameter axons. These subserve pain and autonomic function. We studied 18 adults with IASP-defined CRPS-I affecting their arms or legs. We studied three sites on subjects' CRPS-affected and matching contralateral limb; the CRPS-affected site, and nearby unaffected ipsilateral and matching contralateral control sites. We performed quantitative mechanical and thermal sensory testing (QST) followed by quantitation of epidermal neurite densities within PGP9.5-immunolabeled skin biopsies. Seven adults with chronic leg pain, edema, disuse, and prior surgeries from trauma or osteoarthritis provided symptom-matched controls. CRPS-I subjects had representative histories and symptoms. Medical procedures were unexpectedly frequently associated with CRPS onset. QST revealed mechanical allodynia (P<0.03) and heat-pain hyperalgesia (P<0.04) at the CRPS-affected site. Axonal densities were highly correlated between subjects' ipsilateral and contralateral control sites (r=0.97), but were diminished at the CRPS-affected sites of 17/18 subjects, on average by 29% (P<0.001). Overall, control subjects had no painful-site neurite reductions (P=1.00), suggesting that pain, disuse, or prior surgeries alone do not explain CRPS-associated neurite losses. These results support the hypothesis that CRPS-I is specifically associated with post-traumatic focal MDNI affecting nociceptive small-fibers. This type of nerve injury will remain undetected in most clinical settings.

Adolescent↗

PubMed2006

Maximizing operating room and recovery room capacity in an era of constrained resources.

HYPOTHESIS: Three parallel processing operating rooms (ORs) (concurrent induction and turnover) with a dedicated 3-bed mini-recovery room (mini-postanesthesia care unit [PACU]) will optimize patient throughput and main PACU workload when compared with 4 traditional ORs or 4 parallel processing ORs. DESIGN: Statistical and mathematical models projected the impact of parallel processing on case throughput and PACU use. SETTING: Academic medical center with 48 traditional ORs using serial induction and turnover and 1 experimental OR, the operating room of the future, with parallel processing. PARTICIPANTS: All surgical cases from October 2002 through March 2004 (N = 49 887). INTERVENTIONS: A statistical model projected the duration of induction, surgery, turnover, and PACU stay for cases performed in a traditional OR (n = 48 667) based on the operating room of the future (n = 1220) experience. A fluid queuing model compared each combination using specific probability density functions. MAIN OUTCOME MEASURES: Each OR configuration was evaluated for case throughput and minutes of work sent to the PACU. RESULTS: Although all cases save OR time with parallel processing, only select surgeon-case combinations translate time saved into additional cases per day (26%). Without additional PACU slots, output from 4 parallel processing ORs further stresses the PACU. Three parallel processing ORs and a mini-PACU balances incremental volume by offsetting PACU utilization in 84% of cases. CONCLUSION: In a PACU-constrained environment, 3 parallel processing ORs with a mini-PACU configuration offers increased throughput and decreased PACU workload.

Academic Medical Centers↗

PubMed2006

Bupropion for smokers hospitalized with acute cardiovascular disease.

PURPOSE: Smoking cessation after myocardial infarction reduces cardiovascular mortality, but many smokers cannot quit despite state-of-the-art counseling intervention. Bupropion is effective for smoking cessation, but its safety and efficacy in hospitalized smokers with acute cardiovascular disease is unknown. METHODS: A five-hospital randomized double-blind placebo-controlled trial assessed the safety and efficacy of 12 weeks of sustained-release bupropion (300 mg) or placebo in 248 smokers admitted for acute cardiovascular disease, primarily myocardial infarction and unstable angina. All subjects had smoking counseling in the hospital and for 12 weeks after discharge. Cotinine-validated 7-day tobacco abstinence, cardiovascular mortality, and new cardiovascular events were assessed at 3 months (end-of-treatment) and 1 year. RESULTS: Validated tobacco abstinence rates in bupropion and placebo groups were 37.1% vs 26.8% (OR 1.61, 95% CI, 0.94-2.76; P=.08) at 3 months and 25.0% vs 21.3% (OR, 1.23, 95% CI, 0.68-2.23, P=.49) at 1 year. The adjusted odds ratio, after controlling for cigarettes per day, depression symptoms, prior bupropion use, hypertension, and length of stay, was 1.91 (95% CI, 1.06-3.40, P=.03) at 3 months and 1.51 (95% CI, 0.81-2.83) at 1 year. Bupropion and placebo groups did not differ in cardiovascular mortality at 1 year (0% vs 2%), in blood pressure at follow-up, or in cardiovascular events at end-of-treatment (16% vs 14%, incidence rate ratio [IRR]1.22 (95% CI: 0.64-2.33) or 1 year (26% vs 18%, IRR 1.56, 95% CI 0.91-2.69). CONCLUSIONS: Bupropion improved short-term but not long-term smoking cessation rates over intensive counseling and appeared to be safe in hospitalized smokers with acute cardiovascular disease.

Acute Disease↗

PubMed2006

Efficacy of telephone counseling for pregnant smokers: a randomized controlled trial.

OBJECTIVE: Reducing tobacco use in pregnancy is a public health priority. Brief smoking counseling during prenatal care is effective but generates modest cessation rates. Telephone counseling is an effective smoking cessation method that could offer pregnant women convenient access to more intensive smoking cessation counseling. METHODS: The efficacy of proactive pregnancy-tailored telephone counseling for smoking cessation was compared with a "best-practice" brief-counseling control in a randomized controlled trial of 442 pregnant smokers referred by prenatal providers and a managed care plan. Trained counselors using cognitive-behavioral and motivational interviewing methods called intervention subjects throughout pregnancy and for 2 months postpartum (mean = 5 calls, mean total contact = 68 minutes). Controls received one 5-minute counseling call. RESULTS: Cotinine-validated 7-day tobacco abstinence rates in intervention and control groups were 10.0% and 7.5% at end of pregnancy (odds ratio [OR] 1.37, 95% confidence interval [CI] 0.69-2.70; number needed to treat = 40) and 6.7% versus 7.1% at 3 months postpartum (OR 0.93, 95% CI 0.44-1.99). The intervention increased end-of-pregnancy cessation rates among 201 light smokers (< 10 cigarettes/day at study enrollment) (intervention 19.1% versus control 8.4%; OR 2.58, 95% CI 1.1-6.1; number needed to treat = 9.3) and among 193 smokers who attempted to quit in pregnancy before enrollment (intervention 18.1% versus control 6.8%; OR 3.02, CI 1.15-7.94; number needed to treat = 8.8); 63% of the sample (n = 267) was in one of these subgroups. CONCLUSION: Proactive pregnancy-tailored telephone counseling did not outperform a brief "best practice" intervention among pregnant smokers. The intervention had efficacy in light smokers and in women who had attempted cessation earlier in pregnancy. Future studies should confirm whether telephone counseling benefits these groups of pregnant smokers. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, #NCT00181909. LEVEL OF EVIDENCE: I.

Adult↗

PubMed2006

Increasing operating room efficiency through parallel processing.

OBJECTIVE: Because of rising costs and shrinking reimbursements, hospitals must continually find ways to improve efficiency and productivity. This study attempts to increase caseloads in ambulatory surgery operating rooms while maintaining patient satisfaction and safety. SUMMARY BACKGROUND DATA: In most hospitals, patients move through their operative day in a linear fashion, starting at registration and finishing in the recovery room. Given this pattern, only 1 patient may occupy the efforts of the operating room team at a time. By processing patients in a parallel fashion, operating room efficiency and patient throughput are increased while costs remain stable. METHODS: Patients undergoing hernia repairs under local anesthesia with intravenous sedation were divided into a control group and an experimental group. Patients in the control group received their local anesthesia in the operating room at the start of the surgery. The experimental group patients received their local anesthesia in the induction room by the surgeon while the operating room was being cleaned and set up. RESULTS: While operative time for the control group and the experimental group were nearly identical, the turnover time and the induction time were significantly shorter for the experimental group. The cumulative reduction in time during the operative day was sufficient to allow the addition of new operative cases. CONCLUSIONS: This study demonstrates a system of increasing operating room efficiency by changing patient flow rather than simply working to streamline existing steps. This increase in efficiency is not associated with the expansion of hospital budgets or a decrease in patient safety or satisfaction.

Ambulatory Surgical Procedures↗

PubMed2006

Is this "my" patient? Development and validation of a predictive model to link patients to primary care providers.

BACKGROUND: Evaluating the quality of care provided by individual primary care physicians (PCPs) may be limited by failing to know which patients the PCP feels personally responsible for. OBJECTIVE: To develop and validate a model for linking patients to specific PCPs. DESIGN: Retrospective convenience sample. PARTICIPANTS: Eighteen PCPs from 10 practice sites within an academic adult primary care network. MEASUREMENTS: Each PCP reviewed the records for all outpatients seen over the preceding 3 years (16,435 patients reviewed) and designated each patient as "My Patient" or "Not My Patient." Using this reference standard, we developed an algorithm with logistic regression modeling to predict "My Patient" using development and validation subsets drawn from the same patient set. Quality of care was then assessed by "My Patient" or "Not My Patient" designation by analyzing cancer screening test rates. RESULTS: Overall, PCPs designated 11,226 patients (68.3%, range per provider 15% to 93%) to be "My Patient." The model accurately categorized patients in development and validation subsets (combined sensitivity 80.4%, specificity 93.7%, and positive predictive value 96.5%). To achieve positive predictive values of > 90% for individual PCPs, the model excluded 19.6% of PCP "My Patients" (range 5.5% to 75.3%). Cancer screening rates were higher among model-predicted "My Patients." CONCLUSIONS: Nearly one-third of patients seen were considered "Not My Patient" by the PCP, although this proportion varied widely. We developed and validated a simple model to link specific patients and PCPs. Such efforts may help effectively target interventions to improve primary care quality.

Adult↗

PubMed2006

Age and the risk of warfarin-associated hemorrhage: the anticoagulation and risk factors in atrial fibrillation study.

OBJECTIVES: To assess whether older age is independently associated with hemorrhage risk in patients with atrial fibrillation, whether or not they are taking warfarin therapy. DESIGN: Cohort study. SETTING: Integrated healthcare delivery system. Thirteen thousand five hundred fifty-nine adults with nonvalvular atrial fibrillation. MEASUREMENTS: Patient data were collected from automated clinical and administrative databases using previously validated search algorithms. Medical charts were reviewed from patients hospitalized were for major hemorrhage (intracranial, fatal, requiring >or=2 units of transfused blood, or involving a critical anatomic site). Age was categorized into four categories (<60, 60-69, 70-79, and >or=80), and multivariable Poisson regression was used to assess whether major hemorrhage rates increased with age, stratified by warfarin use and adjusted for other clinical risk factors for hemorrhage. RESULTS: A total of 170 major hemorrhages were identified during 15,300 person-years of warfarin therapy and 162 major hemorrhages during 15,530 person-years off warfarin therapy. Hemorrhage rates rose with older age, with an average increase in hemorrhage rate of 1.2 (95% confidence interval (CI) 1.0-1.4) per older age category in patients taking warfarin and 1.5 (95% CI=1.3-1.8) in those not taking warfarin. Intracranial hemorrhage rates were significantly higher in those aged 80 and older (adjusted rate ratio=1.8, 95% CI=1.1-3.1 for those taking warfarin, adjusted rate ratio=4.7, 95% CI=2.4-9.2 for those not taking warfarin) than in those younger than 80. CONCLUSION: Older age increases the risk of major hemorrhage, particularly intracranial hemorrhage, in patients with atrial fibrillation, whether or not they are taking warfarin. Hemorrhage rates were generally comparable with those reported in previous randomized trials, indicating that carefully monitored warfarin therapy can be used with reasonable safety in older patients.

Age Factors↗

PubMed2006

Stimulation of the posterior cord predicts successful infraclavicular block.

Infraclavicular (IC) block is often performed by localizing one cord within the brachial plexus sheath and placing all the local anesthetic solution at that location. We hypothesized that posterior cord stimulation would be associated with a greater likelihood of IC block success. We enrolled 369 patients scheduled for surgery to the lower arm or hand in a prospective, nonrandomized observational trial. All underwent IC blocks using a standard technique, and the cord stimulated immediately before drug injection was recorded. Motor and sensory functioning were evaluated 15 min after injection. Compared with stimulation of either the lateral or medial cord, stimulation of the posterior cord was associated with rapid onset of motor block in significantly more nerves, as well as a decreased likelihood of block failure (motor and sensory block inadequate to perform surgery). Failure rates were 5.8% for posterior cord, 28.3% for lateral (P < 0.05), and 15.4% for medial (P < 0.05). The differences were highly significant when adjusted for multiple possible confounders, such as gender, body mass index, location of the incision, and level of training of the individual performing the block (P < 0.001, lateral versus posterior; P = 0.003, medial versus posterior). A low failure rate was also predicted by stimulation of more than one cord simultaneously (P < 0.05). We conclude that injection after locating the posterior cord or multiple cords predicts successful IC block.

Adult↗

PubMed2005

Synergism of epidermal growth factor receptor-targeted immunotherapy with photodynamic treatment of ovarian cancer in vivo.

BACKGROUND: Epithelial ovarian cancer often develops resistance to standard treatments, which is a major reason for the high mortality associated with the disease. We examined the efficacy of a treatment regimen that combines immunotherapy to block the activity of epidermal growth factor receptor (EGFR), overexpression of which is associated with the development of resistant ovarian cancer, and photodynamic therapy (PDT), a mechanistically distinct photochemistry-based modality that is effective against chemo- and radioresistant ovarian tumors. METHODS: We tested a combination regimen consisting of C225, a monoclonal antibody that inhibits the receptor tyrosine kinase activity of EGFR, and benzoporphyrin derivative monoacid A (BPD)-based PDT in a mouse model of human ovarian cancer. Therapeutic efficacy was evaluated in acute treatment response and survival studies that used 9-19 mice per group. Analysis of variance and Wilcoxon statistics were used to analyze the data. All statistical tests were two-sided. RESULTS: Mice treated with PDT + C225 had the lowest mean tumor burden compared with that in the no-treatment control mice (mean percent tumor burden = 9.8%, 95% confidence interval [CI] = 2.3% to 17.3%, P < .001). Mean percent tumor burden for mice treated with C225 only or PDT only was 66.6% (95% CI = 58.7% to 74.4%, P < .001) and 38.2% (95% CI = 29.3% to 47.0%, P < .001), respectively. When compared with PDT only or C225 only, PDT + C225 produced synergistic reductions in mean tumor burden (P < .001, analysis of variance) and improvements in survival (P = .0269, Wilcoxon test). Median survival was approximately threefold greater for mice in the PDT + C225 group than for mice in the no-treatment control group (80 days versus 28 days), and more mice in the PDT + C225 group were alive at 180 days (3/9; 33% [95% CI = 7% to 70%]) than mice in the C225-only (0/12; 0% [95% CI = 0% to 22%]) or PDT-only (1/10; 10% [95% CI = 0.2% to 44%]) groups. CONCLUSION: A mechanistically nonoverlapping combination modality consisting of receptor tyrosine kinase inhibition with C225 and BPD-PDT is well tolerated, effective, and synergistic in mice.

Analysis of Variance↗

PubMed2005

Gender differences in the risk of ischemic stroke and peripheral embolism in atrial fibrillation: the AnTicoagulation and Risk factors In Atrial fibrillation (ATRIA) study.

BACKGROUND: Previous studies provide conflicting results about whether women are at higher risk than men for thromboembolism in the setting of atrial fibrillation (AF). We examined data from a large contemporary cohort of AF patients to address this question. METHODS AND RESULTS: We prospectively studied 13,559 adults with AF and recorded data on patients' clinical characteristics and the occurrence of incident hospitalizations for ischemic stroke, peripheral embolism, and major hemorrhagic events through searching validated computerized databases and medical record review. We compared event rates by patient sex using multivariable log-linear regression, adjusting for clinical risk factors for stroke, and stratifying by warfarin use. We identified 394 ischemic stroke and peripheral embolic events during 15,494 person-years of follow-up off warfarin. After multivariable analysis, women had higher annual rates of thromboembolism off warfarin than did men (3.5% versus 1.8%; adjusted rate ratio [RR], 1.6; 95% CI, 1.3 to 1.9). There was no significant difference by sex in 30-day mortality after thromboembolism (23% for both). Warfarin use was associated with significantly lower adjusted thromboembolism rates for both women and men (RR, 0.4; 95% CI, 0.3 to 0.5; and RR, 0.6; 95% CI, 0.5 to 0.8, respectively), with similar annual rates of major hemorrhage (1.0% and 1.1%, respectively). CONCLUSIONS: Women are at higher risk than men for AF-related thromboembolism off warfarin. Warfarin therapy appears be as effective in women, if not more so, than in men, with similar rates of major hemorrhage. Female sex is an independent risk factor for thromboembolism and should influence the decision to use anticoagulant therapy in persons with AF.

Aged↗

PubMed2005

The sensitivity of cardiac markers stratified by symptom duration.

We compared the sensitivity of three commonly used cardiac markers between two subpopulations, those who came to the Emergency Department (ED) late (6-24 h) after their symptoms began, and those who arrived earlier (<6 h), in a prospective comparative trial. Among all adult patients who presented to our ED with symptoms suggestive of acute myocardial infarction (MI), we drew serum for myoglobin, CK-MB, and troponin I upon arrival (time 0) and 2 h later. Outcomes, including acute MI, were determined. Sensitivities for all three markers between the subpopulations who arrived fewer than 6 h from symptom onset were compared to those who arrived later (6-24 h). We enrolled 346 eligible subjects, 36% of whom described cardiac symptoms as beginning 6 or more hours earlier; 14% suffered acute MIs. For time 0, the sensitivity of all three markers for acute MI was significantly higher among those subjects with symptoms of 6 or more hours' duration as compared to those with less. For troponin I, the increase in sensitivity between these two subpopulations approached 300%. At the time of the 2-h sample, the differences in sensitivities were much less and were not statistically significant. We conclude that cardiac marker values obtained at time 0 among Emergency Department patients who arrive 6 or more hours after cardiac symptom onset provide significantly higher sensitivities as compared to those obtained in patients who arrive earlier. For troponin I, the increase in sensitivity approaches threefold.

Adult↗

PubMed2005

Measuring provider adherence to tobacco treatment guidelines: a comparison of electronic medical record review, patient survey, and provider survey.

An accurate method of measuring primary care providers' tobacco counseling actions is needed for monitoring adherence to clinical practice guidelines. We compared three methods of measuring providers' tobacco counseling practices: electronic medical record (EMR) review, patient survey, and provider survey. We mailed a survey to 1,613 smokers seen by 114 Boston-area primary care providers during a 2-month period to assess what tobacco counseling actions had occurred at the visit (N = 766; 47% response rate). Smokers' reports were compared with the EMR and with their providers' self-reported usual tobacco counseling practices, derived from a provider survey (N = 110; 96% response rate). Patients reported receiving each counseling action more frequently than providers documented it in the EMR. Agreement between the patient survey and the EMR was poor for all 5A steps (kappa statistic = 0.01-0.22). Providers reported that they often or always performed each 5A action at a higher rate than indicated by EMR or patient report. However, providers who said they often or always performed individual 5A steps did not have consistently higher mean rates of EMR documentation or patient report than those who said they performed the 5A's less frequently. Little agreement was found among the three methods of measuring primary care providers' tobacco counseling actions. Implementing an EMR does not necessarily improve providers' documentation of tobacco interventions, but EMR adaptations that would standardize provider documentation of tobacco counseling might make the EMR a more reliable tool for monitoring providers' delivery of tobacco treatment services.

Adult↗

PubMed2005

Rapid absorption of tumescent lidocaine above the clavicles: a prospective clinical study.

BACKGROUND: Tumescent local anesthesia has been adapted for surgery of the face and neck, but there are no data regarding drug absorption when tumescent injection is used in this region. The aim of this study was to characterize the changes in plasma lidocaine concentrations over time when a tumescent solution is injected into the subcutaneous tissue of the neck. The study was carried out in human volunteer subjects, and injection of lidocaine to the thighs provided control data. METHODS: Eight healthy female volunteer subjects were studied twice using a prospective, crossover design. Tumescent lidocaine solution was injected into the subcutaneous tissue of the neck in one session and the thighs in another session. The order of injection was randomized. Blood samples were collected for 14 hours after injection, and the plasma concentration of lidocaine measured. The injected solution consisted of lidocaine 0.1%, NaHCO3 12.5 mEq/L, and epinephrine 1:1,000,000 in normal saline. A standardized dose of lidocaine (7 mg/kg) was used for each injection and no surgical procedure was performed. RESULTS: All subjects completed the study. Subject weight was 66.1 +/- 12.8 kg, body fat was 29.0 +/- 4.7 percent, and body mass index was 23.8 +/- 3.1 kg/m2. The average time to reach peak lidocaine concentration after neck injection was 5.8 hours, whereas peak lidocaine concentration after thigh injection did not occur until 12.0 hours. This difference of 6.2 hours was highly significant (p = 0.009). The average peak concentration after neck injection was 16 percent greater than that after thigh injection (0.94 microg/ml versus 0.81 microg/ml), with the difference approaching significance (p = 0.06). No adverse reactions were noted. CONCLUSIONS: Tumescent injection above the clavicles results in a rapid rise in plasma lidocaine concentration when compared with injection to the lower extremities. Toxic symptoms could occur much earlier than expected for lower extremity tumescent anesthesia. In addition, dangerous plasma levels could occur if tumescent anesthesia in the lower extremities is followed by tumescent injection above the clavicles, because the absorption curves would be superimposed.

Absorption↗

PubMed2005

The effect of surgical and nonsurgical treatment on longitudinal outcomes of lumbar spinal stenosis over 10 years.

OBJECTIVES: To assess the relative effect of initial surgical and nonsurgical treatment on longitudinal outcomes of patients with lumbar spinal stenosis over a 10-year follow-up period. DESIGN: A prospective observational cohort study. SETTING: Enrollment from community-based specialist practices throughout Maine. PARTICIPANTS: One hundred forty-four patients with lumbar spinal stenosis who had at least one follow-up: 77 initially treated surgically and 67 initially treated nonsurgically. INTERVENTION: Initial surgical or nonsurgical treatment. MEASUREMENTS: Clinical data were obtained at baseline and outcomes followed at regular intervals over 10 years with mailed questionnaires including patient-reported symptoms of back pain, leg symptoms, back-specific functional status, and satisfaction. Longitudinal data were analyzed using general linear mixed models. In addition to treatment (initial surgical or nonsurgical care), time period, and the interaction between treatment and time, the models included baseline score, patient age and sex, and a time-varying general health status score. The effects of these covariates in explaining differences between treatment groups were also examined. The effect of subsequent surgical procedures was assessed using different analysis strategies. RESULTS: The 10-year rate of subsequent surgical procedures was 23% and 38% for patients initially treated surgically and nonsurgically, respectively, and the overall 10-year survival rate was 69%. Patients undergoing initial surgical treatment had worse baseline symptoms and functional status than those initially treated nonsurgically. For all outcomes and at each time point, surgically treated patients reported greater improvement in symptoms and functional status and higher satisfaction scores, indicative of better outcomes, than nonsurgically treated patients. However, the relative magnitude of the benefit diminished over time such that the relative differences for low back pain and satisfaction were no longer significant over long-term follow-up (both P=.08 for treatment effect between 5 and 10 years after controlling for covariates). Regardless of initial treatment received, patients undergoing subsequent surgical procedures reported less improvement in outcomes over time than patients who did not undergo subsequent procedures, but the relative differences between treatment groups were similar in analyses that controlled for outcomes after subsequent procedures. CONCLUSION: After controlling for covariates, patients initially treated surgically demonstrated better outcomes on all measures than those initially treated nonsurgically. Although outcomes of initial surgical treatment remained superior over time, the relative benefit of surgery diminished in later years, especially for low back pain and satisfaction. Patients undergoing subsequent surgery had worse outcomes regardless of initial treatment received, but excluding them did not change overall treatment group comparisons. The analytical methods described may be helpful in the design and analysis of future studies comparing treatment outcomes for patients with lumbar spinal stenosis.

Aged↗