Emergency room patients referred for esophago-gastro-duodenoscopy (EGD) often have many
possible causes for their symptoms. These inevitably undergo further testing if EGD is
inconclusive, which adds costs and inevitably prolongs emergency room length of stay (LOS).
Endoscopic ultrasound (EUS) combines EGD with high-resolution ultrasound imaging of pancreas,
liver and biliary system and is the best test to diagnose bile duct stones, early chronic
pancreatitis, and small [<2cm] pancreatic cancers (all of which cannot be seen by regular
ultrasound or CT scanning or MRI, yet are included in the differential diagnosis of
EGD-negative abdominal pain).
EUS has traditionally been used after EGD, due to lack of availability, increased cost, and
to increased risk due to larger scope diameter. However, the latest generation of EUS scopes
have the same outer diameter as conventional gastroscopes, there is much wider availability
of EUS in university and community hospital settings, and the cost per procedure is lower,
due to increased procedural numbers and reduced maintenance costs.
In experienced hands, diagnostic EUS is now as safe and as accurate as EGD for diagnosing
mucosal pathology and takes approximately 1 minute longer.(1; 2) Previously published work by
our group suggests that EUS may reduce resource consumption in patients with unexplained
abdominal pain.(3) The investigators also showed that in refractory dyspepsia with normal EGD
and CT, EUS identified signs of occult chronic pancreatitis in up to 20% of cases.(4) More
recently, EUS was found to identify previously undiagnosed, potential causes of unexplained
abdominal pain in up to 9% of patients, or at least provides the same, if not more
information than EGD and abdominal US alone.(2; 5; 6)
There are no previous studies that have prospectively compared the yield of EGD and PEUS in
emergency room patients. The investigators hypothesize that adding EUS to EGD ("primary EUS"
[PEUS]) can safely and more efficiently diagnose or exclude significant gastro-intestinal and
pancreatico-biliary pathology in emergency room patients in whom EGD has been requested. The
investigators therefore propose a prospective pilot study to perform a preliminary analysis
of the potential impact of PEUS on the ability to make an early GI diagnosis (EGID), length
of stay (LOS) and resource utilisation in emergency room patients referred for EGD. If there
is sufficient evidence of a clinically useful impact, an appropriately powered study to
determine whether PEUS is clinically superior to EGD with respect to these variables will be
performed.
