Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study.

OBJECTIVES: Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria. METHODS: Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses. RESULTS: A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up. CONCLUSIONS: Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds.

Value of point-of-care blood testing in emergent trauma management.

BACKGROUND: No prospective study demonstrates the value of point-of-care laboratory testing (POCT) in the management of major trauma. METHODS: In a prospective, noninterventional, study of 200 major trauma patients, we evaluated the influence of a blood POCT profile (hemoglobin, Na+, K+, Cl-, blood urea nitrogen, glucose, pH, PCO2, PO2, HCO3-, base deficit, and lactate) on emergent diagnostic and therapeutic interventions. Physicians responded to a standardized set of questions on their diagnostic and therapeutic plans before and after the availability of POCT results. Management plan changes were deemed emergently appropriate, if they were influenced by the POCT results and, within the ensuing 30 minutes, the change in management was likely to reduce morbidity or conserve resources. RESULTS: For emergently appropriate plan changes, Na+, Cl-, K+, and blood urea nitrogen were never influential, whereas in each of 6.0% of cases (95% confidence interval [CI], 3.5%-10.2%) at least one of the remaining POCT parameters was influential. An emergently appropriate change was based on hemoglobin in 3.5% of cases (95% CI, 1.0%-6.1%), blood gas parameters in 3.0% of cases (95% CI, 0.64%-5.7%), lactate in 2.5% of cases (95% CI, 1.1%-5.7%), and glucose in 0.5% of cases (95% CI, 0.1%-2.8%). All of these cases involved blunt injury. CONCLUSION: Na+, Cl-, K+, and blood urea nitrogen levels do not influence the initial management of major trauma patients. In patients with severe blunt injury, hemoglobin, glucose, blood gas, and lactate measurements occasionally result in morbidity-reducing or resource-conserving management changes.

Occupational exposures to blood among emergency medicine residents.

OBJECTIVES: To investigate the epidemiologic characteristics of potentially infectious occupational exposures to blood among emergency medicine (EM) residents. METHODS: A SAEM-sponsored multiple-choice survey was administered anonymously to all EM residents participating in the 1998 American Board of Emergency Medicine in-service examination. Survey questions included resident demographics, use of universal precautions, frequency and types of exposures to blood, and exposure reporting. Residents who experienced at least one exposure were then asked to complete an additional set of questions referring only to their latest exposure. Mean values were calculated for each variable and differences between groups were compared by chi-square analysis. RESULTS: Three thousand one hundred sixty-two surveys were distributed to the resident participants, and 2,985 surveys (94.4%) were returned. Of the participants, 56.1% reported at least one exposure to blood during their EM training. The frequency of this self-reported exposure increased with advancing EM level of training (43% EM-1, 58% EM-2, 64% EM-3, 76% EM-4, p<0.001). Of these residents, 36.6% always followed universal precautions, 54% frequently, and 9.4% sometimes, rarely, or never. Those individuals who "always" followed universal precautions reported significantly fewer exposures than those who did not (p<0.005). The latest exposures were most commonly caused by a solid needle or sharp object (39.4%), by a hollow-bore needle (30.6%), or by eye splashes (17.2%). Of these exposures, 71.7% occurred in the ED setting, and only 46.7% of these exposures were reported to health care providers. CONCLUSION: Emergency medicine residents are frequently exposed to blood, most commonly due to puncture injuries by sharp objects. The rate of exposure reporting is low, which may compromise appropriate postexposure counseling and prophylaxis.

Tuberculosis exposure risk in emergency medicine residents.

OBJECTIVES: To assess purified protein derivative (PPD) test surveillance and respiratory protection practices of emergency medicine (EM) residents, along with the prevalence of PPD test conversion and the development of active tuberculosis (TB) in EM residents. METHODS: The study instrument was an anonymous, self-reporting, multiple-choice survey administered to U.S. and Canadian EM residents. It was distributed for voluntary completion in conjunction with the American Board of Emergency Medicine's annual in-service examination, which was administered February 25, 1998. RESULTS: A total of 89.3% (n = 2,985) of residents eligible to complete the survey completed at least part of it. The majority of residents are PPD-tested once a year. The prevalence of PPD test conversions in EM residents was between 1.4% (36/2,575) and 2.0% (52/2,575). Of the residents who PPD test-converted, the ED was most often the perceived area of TB source exposure (n = 15). Two residents (0.08%) reported having developed active TB, including chest radiographic findings or clinical infection, which equals a 0.14% (95% CI = 0.005 to 0.31) risk of developing active TB over a three-year residency. Half of all the residents do not routinely wear National Institute for Occupational Safety and Health (NIOSH)-approved particulate filtration respirator (PFR) masks in patient encounters at risk for TB exposure. While more than a third of EM residents have not undergone fit testing for a NIOSH-approved PFR mask, the lack of routine easy availability of such masks is the most common reason they are not routinely worn by EM residents during at-risk encounters for TB transmission. CONCLUSIONS: Most surveillance PPD testing of EM residents is performed at intervals recommended by the CDC. TB control programs at institutions sponsoring EM residencies need to improve both compliance with PFR mask fit testing by EM residents and availability of approved PFR masks in appropriate areas of the ED. Despite poor compliance with personal respiratory protection in ED patient encounters at risk for TB transmission, the risk of an EM resident's developing active TB over a three-year residency is low.

Radiographic presentation of pulmonary tuberculosis in severely immunosuppressed HIV-seropositive patients.

Although the presence of typical postprimary or "reactivation" pattern tuberculosis (TB) on chest radiograph (CXR) strongly suggests TB infection in adults, the sensitivity of this finding, particularly in severely immunosuppressed human immunodeficiency virus (HIV) patients, is unclear. To investigate this issue, HIV status, CD4 counts, and CXR findings of all adult patients with culture-proven TB admitted to a tertiary-care hospital over a 2-year period were retrospectively studied. CXRs were classified as typical for postprimary TB if they showed upper lobe opacities with or without cavitation. No attempt was made to correlate the actual clinical phase of TB infection (primary versus postprimary) with CXR patterns, largely because differentiating primary from postprimary TB in HIV patients is difficult due to high anergy rates and inability to skin-test-convert. Of 46 patients who had chest radiographs and medical records documenting HIV status available for review, 23 were HIV-seropositive and 23 were HIV-seronegative. Of 22 HIV-seropositive patients whose CD4 counts were available, 18 (82%) had CD4 counts of < 200 cells/microL. Only 2 of these 18 (11%) had CXRs showing a typical postprimary TB pattern, whereas all 4 (100%) patients with CD4 counts of > 200 cells/microL and 18 of 23 (78%) non-HIV patients had CXRs typical for postprimary TB (P < .005). It was concluded that HIV-seropositive patients with TB and CD4 counts of < 200 cells/microL frequently present with chest radiographs atypical for postprimary TB, including normal CXRs. Typical postprimary TB CXR findings are not sensitive for diagnosing pulmonary TB in this population.