Association of biliary distention with a diagnosis of acute cholecystitis.

BACKGROUND: Gallbladder distention has been described in radiology literature but its value on point-of-care ultrasound (PoCUS) performed by emergency physicians is unclear. We sought to determine the test characteristics of gallbladder distention on PoCUS for cholecystitis (acute or chronic), and secondarily whether distention was associated with an obstructing stone-in-neck (SIN), acute cholecystitis on subsequent pathology report, and longer cholecystectomy operative times. METHODS: This was a dual-site retrospective cohort study of all Emergency Department (ED) patients that underwent diagnostic biliary PoCUS and were subsequently admitted from 11/1/2020 to 10/31/2022. Patients with pregnancy, liver failure, ascites, hepatobiliary cancer, prior cholecystectomy, or known cholecystitis were excluded. Gallbladder distention was defined as a width ≥4 cm or a length ≥10 cm. Saved ultrasound images were reviewed by three independent reviewers who obtained measurements during the review. Test characteristics, Cohen's kappa (κ), and strength of association between distention and our variables (acute cholecystitis on pathology report and SIN on PoCUS) were calculated using a Chi Square analysis, where intervention (cholecystectomy, percutaneous cholecystostomy, or intravenous antibiotics) was used as the reference standard for AC. A one-tail two sample t-test was calculated for mean operative times. RESULTS: Of 280 admitted patients who underwent ED biliary PoCUS, 53 were excluded, and 227 were analyzed. Of the 227 patients, 113 (49.8%) had cholecystitis according to our reference standard, and 68 (30.0%) had distention on PoCUS: 32 distended by both width and length, 16 distended by width alone, and 20 distended by length alone. Agreement between investigators was substantial for width (κ 0.630) and length (κ 0.676). Distention was 85.09% (95% CI 77.20-91.07%) specific and 45.1% (95% CI 35.8-54.8%) sensitive for cholecystitis. There was an association between distention and SIN; odds ratio (OR) 2.76 (95% CI 1.54-4.97). Distention of both length and width was associated with acute over chronic cholecystitis; OR 4.32 (95% CI 1.42-13.14). Among patients with acute cholecystitis, mean operative times were 114 min in patients with distention and 89 min in patients without distention (p = 0.03). CONCLUSION: Gallbladder distention on PoCUS was specific for cholecystitis (acute or chronic), and associated with SIN, acute cholecystitis on subsequent pathology report, and longer cholecystectomy operative times. Measurement of gallbladder dimensions as part of the assessment of cholecystitis may be advantageous.

Point-of-care ultrasound associated with shorter length of stay than computed tomography for renal colic.

BACKGROUND: Despite similar diagnostic effectiveness for renal colic, computed tomography (CT) is more resource intensive than point-of-care ultrasound (PoCUS). We sought to compare Emergency Department (ED) length of stay (LOS) among patients with renal colic according to imaging modality utilized. We secondarily compared rates of infection, return ED visits, missed significant pathology, and urologic intervention. METHODS: This was a 12-month (1/1/22-12/31/22) multi-site retrospective cohort study of all patients diagnosed with renal colic who presented to the ED on days when at least one patient had a billable renal PoCUS examination performed. Patients with a history of genitourinary malignancy, pregnancy, renal transplant, hemodialysis, single kidney, prior visit for renal colic in the previous 30 days, or an incomplete workup were excluded. Median ED LOS was compared using a Wilcoxon rank sum test, and the 95% confidence limits for the difference between medians was calculated. Secondary outcomes were compared using a Fisher's Exact test. RESULTS: Of 415 patients screened, 325 were included for analysis: 150 had CT alone, 80 had PoCUS alone, 54 had PoCUS plus CT, and 41 had neither. Median LOS for PoCUS alone was 75.0 (95% CI 39.3-110.7) minutes shorter than CT alone (231.5 vs. 307.0 min, p < 0.0001). Similar rates of infection, return visits, and missed pathology occurred across all groups (p > 0.10). Urologic interventions were higher in the PoCUS plus CT (25.9%) group compared to CT alone (7.3%), PoCUS alone (2.5%), and neither (7.3%), p < 0.0001. CONCLUSION: Among patients with renal colic, PoCUS was associated with shorter ED LOS compared to CT, without differences in infection rates, return visits, or missed pathology. Patients with PoCUS plus CT had a higher rate of urologic interventions, suggesting PoCUS may have a role in identifying patients who would most benefit from CT.

Radiology Imaging Adds Time and Diagnostic Uncertainty when Point of Care Ultrasound Demonstrates Cholecystitis.

BACKGROUND: Point of care ultrasound (POCUS) is specific for acute cholecystitis (AC), but surgeons request radiology imaging (RI) prior to admitting patients with POCUS-diagnosed AC. OBJECTIVES: We sought to determine the test characteristics of POCUS for AC when performed and billed by credentialed emergency physicians (EPs), the accuracy rate of RI when performed after POCUS, and the time added when RI is requested after POCUS demonstrates AC. METHODS: We performed a dual-site retrospective cohort study of admitted adult ED patients who had received biliary POCUS from November 1, 2020 to April 30, 2022. Patients with previously diagnosed AC, liver failure, ascites, hepatobiliary cancer, or cholecystectomy were excluded. Descriptive statistics and 95% confidence intervals for point estimates were calculated. Medians were compared using a Wilcoxon signed-rank test. Test characteristics of POCUS for AC were calculated using inpatient intervention for AC as the reference standard. RESULTS: Of 473 screened patients, 143 were included for analysis: 80 (56%) had AC according to our reference standard. POCUS was positive for AC in 46 patients: 44 true positives and two false positives, yielding a positive likelihood ratio of 17.3 (95%CI 4.4-69.0) for AC. The accuracy rate of RI after positive POCUS for AC was 39.0%. Median time from ED arrival to POCUS and ED arrival to RI were 115 (IQR 64, 207) and 313.5 (IQR 224, 541) minutes, respectively; p < 0.01. CONCLUSION: RI after positive POCUS performed by credentialed EPs takes additional time and may increase diagnostic uncertainty.