A retrospective evaluation of point of care ultrasound for acute cholecystitis in a tertiary academic hospital setting

Background In 2008 the Council of Emergency Medicine Residency Directors delineated consensus recommendations for training in biliary ultrasound for the “detection of biliary pathology”. Objectives While studies have looked at the accuracy of emergency provider performed clinical ultrasound (ECUS), we sought to evaluated if ECUS could be diagnostic for acute cholecystitis and thus obviate the need for follow-up imaging. Method We reviewed all ECUS performed between 2012 and 2017 that had a matching radiology performed ultrasound (RADUS) and a discharge diagnosis. 332 studies were identified. The sensitivity and specificity of both ECUS and RADUS were compared to the patient’s discharge diagnosis. The agreement between the ECUS and RADUS was assessed using an unweighted Cohen’s Kappa. The time from patient arrival to diagnosis by ECUS and RADUS was also compared. Results Using discharge diagnosis as the gold standard ECUS was 67% (56–78%) sensitive, 88% (84–92%) specific, NPV 90% (87–95%), PPV 60% (50–71%), +LR 5.6 (3.9–8.2), −LR 0.37 (0.27–0.52) for acute cholecystitis. RADUS was 76% (66–87%) sensitive, 97% (95–99%) specific, NPV 95% (092–97%), PPV 86% (76–95%), +LR 25.6 (12.8–51.4), and −LR 0.24 (0.15–0.38). ECUS was able to detect gallstones with 93% (89–96%) sensitivity and 94% (90–98%) specificity leading to a NPV 90% (85–95%), PPV of 95% (92–98%), +LR 14.5 (7.7–27.4), −LR 0.08 (0.05–0.13). The unweighted kappa between ECUS and RADUS was 0.57. The median time between obtaining ECUS vs. RADUS diagnosis was 124 min. Conclusions ECUS can be beneficial in ruling out acute cholecystitis, but lacks the test characteristics to be diagnostic for acute cholecystitis.

Point-of-care Ultrasound Diagnosis of Emphysematous Cholecystitis

A 49-year-old male presented to the emergency department with abdominal pain and generalized weakness. The physical examination was positive for right upper quadrant tenderness and positive Murphy’s sign. Point-of-care biliary ultrasound revealed signs of emphysematous cholecystitis. Emphysematous cholecystitis is a rare biliary pathology with a high mortality rate. It differs from acute cholecystitis is many ways. It has unique ultrasound characteristics. This case highlights the use of point-of-care ultrasound to diagnose a rare biliary condition.

P152: Point of care biliary ultrasound in the emergency department (BUSED): implications for surgical referral and emergency department wait times

Introduction: Patients with uncomplicated biliary disease frequently present to the emergency department for assessment. To improve bedside clinical decision making many emergency medicine physicians have pursued specialized training to perform point of care biliary ultrasound in the emergency department (BUSED). The purpose of this study was to determine the usefulness of BUSED in predicting the need for surgical consultation and intervention for biliary disease. Methods: A retrospective study of 283 consecutive patients visiting the emergency department who received a BUSED scan from December 1, 2016 to July 16, 2017. Physician interpretations of the BUSED scans were collected from the electronic image storage and interpretation system. Additional data was collected from the electronic health record including lab values, the subsequent use of diagnostic imaging, and outcomes data including disposition, surgical consultation or intervention, and 28 day follow up for representation or complication. Descriptive statistics and logistic regression were performed. Results: Of the patients who received a biliary POCUS scan, 29% were referred to general surgery, and 43% of those referred proceeded to eventual cholecystectomy. Factors found to be independently predictive of surgical intervention on point of care BUSED scans included presence of gall stones (OR 13.01, 95%CI 5.02 to 27.1) and increased gallbladder wall thickness (OR 6.01, 95%CI 1.7 to 11.1). A total of 30% of patients receiving BUSED required at least one additional, radiology based imaging test (CT or diagnostic US). Average emergency department length of stay was substantially longer for those who required additional imaging as compared to those who were able to be diagnosed by BUSED alone (16.1 versus 5.2 hours, 10.9 hours 95%CI 10.6 11.2, p<0.05) . Conclusion: Point of care biliary ultrasound performed by emergency physicians provides timely access to diagnostic information. Positive findings of gall stones and increased gall bladder wall thickness are highly predictive of the need for surgical intervention. Future, prospective studies are warranted to determine if point of care sonography is sufficient to proceed to surgery in select cases of uncomplicated biliary disease.