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Division of Emergency Medicine, Stanford University School of Medicine.
The California journal of emergency medicine 10/2005; 6(4):74-5.
Source: PubMed
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    ABSTRACT: Recently, limited abdominal computed tomography (CT) scans have been reported (Rao, New England Journal of Medicine, 1998) to have accuracy as high as 98%. We compare our hospital's CT accuracy ordered by emergency room (ER) physicians with that of experienced surgeons provided only with the ER history and physical examination in the evaluation of appendicitis. All charts of patients 16 years or older with limited CT scans ordered by ER from January 1, 1996, through February 28, 1998, were reviewed. CT scans ordered when appendicitis was not in the differential were excluded from analysis. Pathology and clinical follow-up were criterion standards. Four surgeons reviewed ER history and physical and placed them into one of three categories: appendectomy, observe to rule out appendicitis, or discharge with follow-up (included admitting to another service or treating for another disorder). A total of 526 charts were reviewed; 129 met the criteria for the study. The accuracy of CT scans as used by our ER was not as high as reported in the literature. In addition, surgeon accuracy approached that of the CT scan even without the ability to evaluate the patients in person. Noncontrast CTs were ordered before surgical evaluation in contrast to the Rao protocol, likely reducing their accuracy. Ordering CT scans to evaluate for appendicitis prior to surgical evaluation is of limited value.
    The American Journal of Surgery 06/2002; 183(5):547-50. DOI:10.1016/S0002-9610(02)00850-4 · 2.29 Impact Factor
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    ABSTRACT: Whole cell vaccines, consisting of relatively crude preparations of Salmonella typhi administered parenterally, are effective but have a high incidence of adverse effects. Two vaccines have been developed more recently. Ty21a (an attenuated strain of S. typhi administered orally) and Vi (the purified bacterial capsule, given parenterally), have appeared less toxic than the older whole cell vaccines and are thought to be equally effective. The objective of this review was to assess the effects of typhoid fever vaccines. We searched the Cochrane Library, Medline, Index Medicus, Embase and reference lists of articles. Randomised trials comparing typhoid vaccines to other types of vaccine or placebo. Two reviewers independently assessed trial quality and extracted data. Seventeen studies, involving nearly two million people, were included. For the whole cell vaccines single dose regimens provided significant protection for the first two years. Two dose regimens provided significant protection for five years. For the Ty21a vaccine, both two and three dose regimens provided statistically significant protection for two years. The three dose regimen provided protection in the third and fourth years, but protection was not statistically significant in the fifth year. The Vi vaccine provided protection for two years, but the protection in the third year was not significant. The three year cumulative efficacy of two doses of whole cell vaccines was 73% (95% confidence interval 65-80), three doses of Ty21a was 51%, (95% confidence interval 35 to 63) and one dose of Vi was 55% (95% confidence interval 30 to 71). Data on adverse effects were limited, but indicate that whole cell vaccines are more toxic than the newer Ty21a and Vi vaccines. The whole cell vaccines provided more prolonged protection than either the Ty21a vaccine or the Vi vaccine. However whole cell vaccines are associated with higher toxicity.
    Cochrane database of systematic reviews (Online) 02/2000; DOI:10.1002/14651858.CD001261 · 6.03 Impact Factor
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    ABSTRACT: The total white blood cell (WBC) count and temperature are often expected to be elevated in patients with appendicitis. Clinicians often use the results of these parameters in making a judgment about the presence or absence of disease. The objective of this study was to assess the discriminatory value of the total WBC count and presenting body temperature in patients presenting to the emergency department (ED) with signs and symptoms suggestive of appendicitis. This was a prospective consecutive case series in a university ED with an annual census of 38,000. All patients presenting to the ED in whom the diagnosis of appendicitis was the attending physician's primary consideration were enrolled. Measures included age, gender, symptoms, physical findings, patient temperature as taken in the ED, initial total WBC count, and discharge diagnosis. Admitted patients were followed up until surgical or clinical outcomes, and discharged patients were followed up by telephone two weeks after the initial visit. All statistical analysis was performed using StatsDirect version 1.9.8. A total of 293 patients were enrolled over a two-year study period. The total WBC count was measured in 274 cases, and the temperature was measured in 293 cases. There were 130 male patients and 163 female patients. The mean age of the patients was 30.8 years (range, 7-75 years). Appendicitis was confirmed in 92 patients. In this study group of patients, a total WBC count >10,000 cells/mm(3) had a sensitivity of 76% (95% confidence interval [95% CI] = 65% to 84%) and a specificity of 52% (95% CI = 45% to 60%). The positive predictive value (PPV) was 42% (95% CI = 35% to 51%), and the negative predictive value (NPV) was 82% (95% CI = 74% to 89%). The positive likelihood ratio (LR) was 1.59 (95% CI = 1.31 to 1.93), and the negative LR was 0.46 (95% CI = 0.31 to 0.67). A temperature >99.0 degrees F had a sensitivity of 47% (95% CI = 36% to 57%) and a specificity of 64% (95% CI = 57% to 71%). The PPV was 37% (95% CI = 29% to 46%), and the NPV was 72% (95% CI = 65% to 79%). The positive LR was 1.3 (95% CI = 0.97 to 1.72), and the negative LR was 0.82 (95% CI = 0.65 to 1.01). The areas under the curve for the receiver-operating characteristic (ROC) curve were 0.72 (95% CI = 0.65 to 0.79) and 0.59 (95% CI = 0.52 to 0.66) for an elevated total WBC count and an elevated temperature, respectively. An elevated total WBC count >10,000 cells/mm(3), while statistically associated with the presence of appendicitis, had very poor sensitivity and specificity and almost no clinical utility. There was minimal statistical association between a temperature of >99 degrees F and the presence of appendicitis. The ROC curve suggests there is no value of total WBC count or temperature that has sufficient sensitivity and specificity to be of clinical value in the diagnosis of appendicitis. Clinicians should be wary of reliance on either elevated temperature or total WBC count as an indicator of the presence of appendicitis.
    Academic Emergency Medicine 10/2004; 11(10):1021-7. DOI:10.1197/j.aem.2004.04.011 · 2.01 Impact Factor

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