A73 PERFORMANCE OF ASGE AND ESGE CRITERIA FOR RISK STRATIFICATION FOR CHOLEDOCHOLITHIASIS IN A REAL-WORLD SETTING

Background

Choledocholithiasis (CDL) is a common clinical entity and can lead to serious complications, such as pancreatitis or ascending cholangitis. Endoscopic retrograde cholangio-pancreatography (ERCP) is generally the first-line procedure for definitive management of CDL. ERCP has well-established adverse events. Given the risks, patients can be stratified by likelihood of finding CDL on ERCP, thus potentially avoiding an unnecessary procedure in low probability patients. There are three commonly used criteria for this – the American Society for Gastrointestinal Endoscopy (ASGE) 2010 criteria, the ASGE 2019 criteria, and the European Society of Gastrointestinal Endoscopy (ESGE) 2019 criteria. These criteria use a mixture of biliary imaging, clinical condition, and liver biochemistry to stratify patients into low, intermediate, and high probability for CDL.

Aims

To test the performance characteristics of the ASGE 2010, ASGE 2019, and ESGE 2019 criteria for probability of CDL on a real-world sample.

Methods

We identified all adult patients who had ERCP done at our local centre for suspected CDL between 2012/01/01 and 2018/10/07. A sample of 1000 cases were chosen. We obtained the patients’ pre-procedural liver biochemistries, pre-procedural imaging in the preceding 6 months, and their ERCP reports. We used a semi-automated algorithm to determine confirmation of CDL. We inferred clinical gallstone pancreatitis using the surrogate of serum lipase at or greater than three times upper limit of normal. We could not capture clinical ascending cholangitis from the collected data. We stratified each patient according to the three guidelines and calculated their performance characteristics.

Results

After manually reviewing visits with incomplete ERCP or repeat ERCP, we analyzed 879 ERCP visits. There were 622 with stone or sludge found on ERCP. The performance characteristics of the high-probability and intermediate-probability criteria of the three guidelines are listed in the table below.

Conclusions

Our results for the 2010 ASGE guidelines high probability patients are in keeping with previous validation studies. There have been only one validation study each of the 2019 ASGE guidelines and the 2019 ESGE guidelines, and our results are different in sensitivity and negative predictive value. Future directions in refining these risk stratification tools are needed, and our project in ongoing in assessing the additional value of trends in liver biochemistry.

Funding Agencies

None

Isolation of Ross River virus from mosquitoes and from horses with signs of musculo-skeletal disease

OBJECTIVE

To report clinical and clinicopathological findings in horses naturally infected with Ross River virus (RRV) and identify likely mosquito arbovirus vector species.

PROCEDURES

Veterinarians submitted serum samples from 750 horses because they suspected Ross River virus (RRV) infection. The samples were tested for the presence of IgM and IgG antibody to RRV and for the presence of virus. Mosquitoes were trapped, differentiated to species level and tested for the presence of RRV by virus isolation.

RESULTS

RRV was isolated from six species of mosquitoes (Ochlerotatus camptorhyncus, Culex globocoxitus, Cx. australicus, Cx. annulirostris, Cx. quinquefasciatus, Anopheles annulipes) and from 13 horses with clinical signs of musculo-skeletal disease. Antibody to RRV was detected in 420 of the 750 serum samples; 307 contained IgG only; 76 contained both IgM and IgG and 37 contained only IgM antibody to RRV. Virus was isolated from horses with IgM antibody only.

CONCLUSIONS

RRV can be isolated from infected horses during the short time period when there is an overlap of clinical signs, positive IgM serology and viraemia. Early spring infections of horses may occur if RRV infected mosquito vectors are present. RRV has not been shown to cause clinical disease in horses. This is the first report of isolation of RRV from Oc. camptorhyncus in the Murray region and indicates a potential for infection of humans and animals in autumn as well as in spring.

Competence of medical students in history taking during the clinical course

Twelve students were selected from each of the three clinical undergraduate years, two from each year interviewing one of six simulated patients. The interviews were video recorded and scored by two clinicians on a rating system involving sixteen criteria. In addition to the expected differences between individual students, when the scores were placed in rank order a pattern of differences between years of study emerged. Students of the third clinical year performed better than those of first year and both were better than those of the intermediate second year. Junior students displayed more personal concern for the patients, while senior students tended to conduct a more controlled and structure interview.