Background: Point of care ultrasound (POCUS) has a demonstrated sensitivity of 89.8% and specificity of 88.0% for identification of cholelithiasis and has a proven negative predictive value for ruling out other acute biliary pathology such as acute cholecystitis.1 It is a quickly deployable and easily interpreted study that can be done in real time to guide decisions in the Emergency Department. However, many institutions’ surgical teams still require or request a formal study over a bedside exam, likely due to a lack of confidence in the accuracy of POCUS, resulting in longer ED stays.
Article: Hilsden R, Mitrou N, Hawel J, Leeper R, Thompson D, Myslik F. Point of care biliary ultrasound in the emergency department (BUSED) predicts final surgical management decisions. Trauma Surg Acute Care Open. 2022;7(1):e000944. Published 2022 Sep 2. PMID: 36111140
Clinical Question: In adult patients presenting to the emergency department with suspected biliary disease diagnosed by POCUS, does subsequent confirmatory RUS imaging change surgical management plan compared to decisions made based solely on POCUS findings?
What They Did:
- Investigators performed a prospective cohort study
- At a single University-affiliated tertiary care center (London Health Sciences Centre) in London, Ontario, Canada.
Workflow:
- Patient presents with abdominal pain to ED
- ED physician performs POCUS RUQ US
- The surgeon presented with H&P, bloodwork, and POCUS results
- The surgeon completes a survey on what they would do for the patient
- The patient is sent to radiology for formal RUQ US
- Formal RUQ US revealed to the surgeon
-
The surgical team proceeds based on the available information:
- Offer surgery
- ERCP or MRCP
- No surgery
-
At this institution, surgeons from all subspecialties take ED general surgery call:
- Acute care/Trauma (ACS)
- Colorectal
- Hepatobiliary (HPB)
- Surgical Oncologists
- Minimally invasive/bariatric (MIS)
Population:
Inclusion Criteria:
- Patient over the age of 18
- Clinically suspected of having acute biliary disease
- POCUS findings consistent with biliary disease
Exclusion Criteria:
- Emergency surgery prior to confirmatory ultrasound
- Inability to understand or offer consent to the study
Intervention:
The surgical decision made by the consulting surgeon after reviewing the patient’s history, physical examination, laboratory work, and POCUS results recorded prior to receiving RUS results.
Comparator:
The final management plan made by the consulting surgeon after reviewing RUS results compared to the initial plan based on POCUS findings.
Outcomes:
Primary: Percent change in management decisions after introducing the Radiology Department RUQ US.
Secondary:
- Evaluation of the clinical decision based on the surgeon’s subspecialty
- Biochemical markers
- Vital signs
- Patient demographics
Results:
- 103 patients were recruited, though only 100 were included in the final analysis.
- All baseline characteristics were similar between groups, with the exception of total and direct bilirubin levels
- Total bilirubin was 8.4±6.5 μmol/L in the surgery group, 34±22 μmol/L in the duct clearance group, and 16±12μmol/L in the no surgery group (p=1.12×10−12).
- ACS surgeons appeared to select surgery as their initial choice substantially more frequently than other subspecialties.
- ACS surgeons would have sent 6/43 patients for ERCP or MRCP (14%), whereas surgical oncologists would have sent a higher percentage of patients for ERCP or MRCP (7/18 or 38.9%).
Critical Findings:
- 10 out of 100 patients (10%) had a change in their management plan after RUQ US was obtained.
- Of note, it was a clinical change that appeared to drive the shift in decision-making by surgeons, not the imaging itself.
- A change in clinical course resulting from a discrepancy between POCUS and radiology department imaging only occurred in 2% of patients (not 10%).
Strengths:
- Prospective study
- Baseline characteristics, including age, BMI, temp, HR, MAP, and WBCs, were similar between all groups.
- All patients received both a POCUS and RUQ US
- Sonographers were fellowship-trained
- Surgeons blinded to formal RUQ US interpretation prior to the formation of their plan
- Relatable surgical decisions for what ultrasound can reflect
- The trial focused on surgical decision-making
Limitations:
- Small patient population, age >18, very little patient demographic information, single-center, single country
- Patient enrollment was at the discretion of the ED physician based on US findings, physical exam, and history
- The difference in total and direct bilirubin levels between groups
- Individuals performing POCUS were fellowship trained, which does not accurately reflect the entire population of ED attendings.
- POCUS Image storage as a permanent medical record is different from most clinical settings
- Not an RCT
- Surgeons knew they were reviewing POCUS reports versus formal department reports.
- Certain surgical groups seemed to prefer certain treatment options. For instance, ACS surgeons preferred to offer surgery, whereas surgical oncologists preferred duct clearance.
Discussion:
Bias:
- In this study, selection bias had a significant impact. Physicians trained in POCUS evaluated and selected the patients for possible biliary disease, potentially skewing the cohort toward more definitive ultrasound findings. Additionally, the patient selection may have been such that their management plans were unlikely to change regardless of ultrasound results. For instance, patients showing signs of jaundice and elevated bilirubin, indicative of choledocholithiasis, would more likely undergo MRCP and ERCP. Similarly, surgeons might hesitate to operate on older patients with multiple comorbidities due to higher associated risks.
- Surgical teams also seemed to prefer different management plans, with ACS surgeons selecting surgery more often and oncological surgeons preferring duct clearance more often.
Pragmatic:
- The study methodology lacks pragmatism and may not be generalizable to many healthcare settings. In the study, all POCUS ultrasounds were performed by a fellowship-trained emergency medicine physician, which is not reflective of most clinical settings. Physicians less facile in POCUS would likely have difficulty obtaining and interpreting US images. Furthermore, images were stored in a PACS system, allowing ED physicians to interpret the images and store them in the patient’s electronic medical record. However, many facilities lack this advanced infrastructure, making it difficult to adopt similar practices. Moreover, surgeons may seek “official” documentation in a patient’s chart before surgery. This hesitancy adds an extra layer of complexity, further limiting its applicability in real-world settings.
Author’s Conclusions: “This study showed that fewer than 10% of patients with biliary disease seen on POCUS had a change in surgical decision-making based on the addition of RUS imaging. In uncomplicated cases of biliary disease, relying on POCUS imaging for surgical decision-making has the potential to improve patient flow.”
Our Conclusion:
The study has a number of important flaws. The authors claim that biliary POCUS has the potential to improve flow but did not explicitly measure flow in any meaningful way. The trial was heavily influenced by selection bias as patients were evaluated and enrolled by physicians specifically trained in POCUS, which could skew the results. Moreover, the study’s reliance on a PACS system for storing and interpreting ultrasound images may not be applicable to many healthcare facilities that lack such infrastructure. The single-center, unblinded study decision and small sample size further restrict generalizability. Overall, while the study provides some insights regarding the utility and accuracy of POCUS, its accuracy compared to formal studies, and its role in surgical decision-making, its limitations make it difficult to apply its findings broadly across different settings.
References:
- Ross M, Brown M, McLaughlin K, Atkinson P, Thompson J, Powelson S, Clark S, Lang E. Emergency physician-performed ultrasound to diagnose cholelithiasis: a systematic review. Acad Emerg Med. 2011 Mar;18(3):227-35. PMID: 21401784.
- Hilsden R, Mitrou N, Hawel J, Leeper R, Thompson D, Myslik F. Point of care biliary ultrasound in the emergency department (bused) predicts final surgical management decisions. Trauma Surgery Acute Care Open. 2022;7(1). PMID: 36111140
- Dumbrava BD, Bass GA, Jumean A, Birido N, Corbally M, Pereira J, Biloslavo A, Zago M, Walsh TN. The Accuracy of Point-of-Care Ultrasound (POCUS) in Acute Gallbladder Disease. Diagnostics (Basel). 2023 Mar 26;13(7):1248. PMID: 37046466
Guest Post By:
Andrew Michalak, MD
PGY-1, Emergency Medicine Resident
Vassar Brothers Hospital, Poughkeepsie, New York
E-mail: Andrew.Michalak@nuvancehealth.org
Joseph Felice MD
Assistant Professor, Emergency Medicine
Vassar Brothers Hospital, Poughkeepsie, New York
E-mail: joseph.felice@nuvancehealth.org
Marco Propersi, DO FAAEM
Vice-Chair, Emergency Medicine
Assistant Emergency Medicine Program Director
Vassar Brothers Hospital, Poughkeepsie, New York
Twitter: @marco_propersi
Post Peer Reviewed By: Salim R. Rezaie, MD (Twitter/X: @srrezaie)
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