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Open Access Publications from the University of California

Scholarly Works (5 results)

  • Article
  • Peer Reviewed
Clinical Practice and Cases in Emergency Medicine, Volume 1, Issue 1 (2017)
The authors present a case of orbital trapdoor fracture with entrapment in an adult patient along with brief summary of the literature.
    Cover page: Orbital Trapdoor Fracture: An Open-and-shut Case?Creative Commons 'BY' version 4.0 license
    • Article
    • Peer Reviewed
    UC Irvine Previously Published Works (2015)

    Background

    Cholelithiasis affects an estimated 20 million people in the United States yearly; 20% of symptomatic patients will develop acute cholecystitis (AC). A recent single-center study estimating test characteristics of point-of-care ultrasonography (POCUS) for the detection of AC, as defined by gallstones plus sonographic Murphy's or pericholecystic fluid or gallbladder wall-thickening, resulted in a sensitivity and specificity of 87% (95% confidence interval [CI] 66-97) and 82% (95% CI 74-88), respectively. No prior studies have been conducted to estimate the test characteristics of POCUS for the purpose of excluding acute calculous cholecystitis.

    Objective

    To determine whether the finding of gallstones alone on POCUS has high sensitivity, high negative predictive value, and low negative likelihood ratio for the exclusion of AC.

    Methods

    We conducted an analysis using data from a prospective cross-sectional single-center study of POCUS test to estimate the test characteristics using a simplified definition of a positive test - the presence of gallstones alone. Clinical follow-up and pathology reports were used as the reference standard. Test characteristics were calculated and compared to the standard definition, gallstones plus one secondary finding.

    Results

    The overall prevalence of AC was 14% (23 pathology-confirmed cases of 164 included patients). The sensitivity of the simplified definition was 100% (95% CI 85.7-100), negative predictive value 100% (95% CI 92.2-100), and negative likelihood ratio was < 0.1, compared to a sensitivity of 87% (95% CI 66-97%), negative predictive value 97% (95% CI 93-99%), and negative likelihood ratio of 0.16 (95% CI 0.06-0.5).

    Conclusion

    Simplifying the definition of the test findings on POCUS to gallstones alone has excellent sensitivity and negative predictive value for the exclusion of AC. This finding, if broadly validated prospectively, confirms the practice of excluding acute calculous cholecystitis using POCUS in emergency department patients.
      Cover page: The Absence of Gallstones on Point-of-Care Ultrasound Rules Out Acute Cholecystitis
      • Article
      • Peer Reviewed
      UC Irvine Previously Published Works (2010)

      Study objective

      We assess the diagnostic accuracy of emergency physician-performed bedside ultrasonography and radiology ultrasonography for the detection of cholecystitis, as determined by surgical pathology.

      Methods

      We conducted a prospective, observational study on a convenience sample of emergency department (ED) patients presenting with suspected cholecystitis from May 2006 to February 2008. Bedside gallbladder ultrasonography was performed by emergency medicine residents and attending physicians at an academic institution. Emergency physicians assessed for gallstones, a sonographic Murphy's sign, gallbladder wall thickness, and pericholecystic fluid, and the findings were recorded before formal imaging. The test characteristics of bedside and radiology ultrasonography were determined by comparing their respective results to pathology reports and clinical follow-up at 2 weeks.

      Results

      Of the 193 patients enrolled, 189 were evaluated by bedside ultrasonography. Forty-three emergency physicians conducted the ultrasonography, and each physician performed a median of 2 tests. After the bedside ultrasonography, 125 patients received additional radiology ultrasonography. Twenty-six patients underwent cholecystectomy, 23 had pathology-confirmed cholecystitis, and 163 were discharged home to follow-up. Twenty-five were excluded (23 lost to follow-up and 2 unavailable pathology). The test characteristics of bedside ultrasonography were sensitivity 87% (95% confidence interval [CI] 66% to 97%), specificity 82% (95% CI 74% to 88%), positive likelihood ratio 4.7 (95% CI 3.2 to 6.9), negative likelihood ratio 0.16 (95% CI 0.06 to 0.46), positive predictive value 44% (95% CI 29% to 59%), and negative predictive value 97% (95% CI 93% to 99%). The test characteristics of radiology ultrasonography were sensitivity 83% (95% CI 61% to 95%), specificity 86% (95% CI 77% to 92%), positive likelihood ratio 5.7 (95% CI 3.3 to 9.8), negative likelihood ratio 0.20 (95% CI 0.08 to 0.50), positive predictive value 59% (95% CI 41% to 76%), and negative predictive value 95% (95% CI 88% to 99%).

      Conclusion

      The test characteristics of emergency physician-performed bedside ultrasonography for the detection of acute cholecystitis are similar to the test characteristics of radiology ultrasonography. Patients with a negative ED bedside ultrasonography result are unlikely to require cholecystectomy or admission for cholecystitis within 2 weeks of their initial presentation.
        Cover page: A Prospective Evaluation of Emergency Department Bedside Ultrasonography for the Detection of Acute CholecystitisCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health, Volume 18, Issue 6 (2017)

        Introduction: Our goal was to determine if heated gel for emergency department (ED) bedsideultrasonography improves patient satisfaction compared to room-temperature gel.

        Methods: We randomized a convenience sample of ED patients determined by their treating physicianto require a bedside ultrasound (US) study to either heated gel (102.0° F) or room-temperature gel(82.3° F). Investigators performed all US examinations. We informed all subjects that the study entailedinvestigation into various measures to improve patient satisfaction with ED US examinations but didnot inform them of our specific focus on gel temperature. Investigators wore heat-resistant gloves whileperforming the examinations to blind themselves to the gel temperature. After completion of the US,subjects completed a survey including the primary outcome measure of patient satisfaction as measuredon a 100-mm visual analogue scale (VAS). A secondary outcome was patient perceptions of sonographerprofessionalism measured by an ordinal scale (1-5).

        Results: We enrolled 124 subjects; 120 completed all outcome measures. Of these, 59 underwentrandomization to US studies with room-temperature gel and 61 underwent randomization to heated USgel. Patient 100-mm VAS satisfaction scores were 83.9 among patients undergoing studies with roomtemperaturegel versus 87.6 among subjects undergoing studies with heated gel (effect size 3.7, 95%confidence interval -1.3-8.6). There were similarly no differences between the two arms with regard topatient perceptions of sonographer professionalism.

        Conclusion: The use of heated ultrasound gel appears to have no material impact on the satisfaction ofED patients undergoing bedside ultrasound studies.

          Cover page: Heated Ultrasound Gel and Patient Satisfaction with Bedside Ultrasound Studies: The HUGS TrialCreative Commons 'BY' version 4.0 license
          • Article
          • Peer Reviewed
          Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health, Volume 17, Issue 2 (2016)

          Introduction: Bedside thoracic ultrasound (US) can rapidly diagnose pneumothorax (PTX) with improved accuracy over the physical examination and without the need for chest radiography (CXR); however, US is highly operator dependent. A computerized diagnostic assistant was developed by the United States Army Institute of Surgical Research to detect PTX on standard thoracic US images. This computer algorithm is designed to automatically detect sonographic signs of PTX by systematically analyzing B-mode US video clips for pleural sliding and M-mode still images for the seashore sign. This was a pilot study to estimate the diagnostic accuracy of the PTX detection computer algorithm when compared to an expert panel of US trained physicians.

          Methods: This was a retrospective study using archived thoracic US obtained on adult patients presenting to the emergency department (ED) between 5/23/2011 and 8/6/2014. Emergency medicine residents, fellows, attending physicians, physician assistants, and medical students performed the US examinations and stored the images in the picture archive and communications system (PACS). The PACS was queried for all ED bedside US examinations with reported positive PTX during the study period along with a random sample of negatives. The computer algorithm then interpreted the images, and we compared the results to an independent, blinded expert panel of three physicians, each with experience reviewing over 10,000 US examinations.

          Results: Query of the PACS system revealed 146 bedside thoracic US examinations for analysis. Thirteen examinations were indeterminate and were excluded. There were 79 true negatives, 33 true positives, 9 false negatives, and 12 false positives. The test characteristics of the algorithm when compared to the expert panel were sensitivity 79% (95 % CI [63-89]) and specificity 87% (95% CI [77-93]). For the 20 images scored as highest quality by the expert panel, the algorithm demonstrated 100% sensitivity (95% CI [56-100]) and 92% specificity (95% CI [62-100]).

          Conclusion: This novel computer algorithm has potential to aid clinicians with the identification of the sonographic signs of PTX in the absence of expert physician sonographers. Further refinement and training of the algorithm is still needed, along with prospective validation, before it can be utilized in clinical practice.

            Cover page: Computerized Diagnostic Assistant for the Automatic Detection of Pneumothorax on Ultrasound: A Pilot StudyCreative Commons 'BY' version 4.0 license
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