Introduction

Upper gastrointestinal bleeding (UGIB) is a common emergency associated with high resource utilization, morbidity, and mortality. The gold standard for diagnosis is Esophagogastroduodenoscopy (EGD). However, timely EGD can be challenging from a time, personnel, and access perspective. PillSense, an FDA-approved device, is a novel swallowed bleeding sensor (PillSense, EnteraSense Ltd, Galway, Ireland) developed to provide rapid and accurate blood detection, aid in triage, and guide clinical decision-making for patients with suspected UGIB.

Aims & Methods

This was the first U.S. and largest open-label, single-arm comparative clinical trial of a novel bleeding sensor for patients with suspected UGIB. The PillSense System consists of an optical sensor capsule intended to detect the presence of blood by measuring the absorption of multiple wavelengths of light and an external receiver that processes and displays data relayed wirelessly from the capsule as simply “Blood Detected” or “No Blood Detected”. Patients underwent EGD within 4 hours of capsule administration, and results of both modalities were compared; participants were followed for 21 ±3 days to confirm capsule passage through the gastrointestinal tract. Endoscopists were blinded to the capsule result.

Results

131 patients were enrolled (59.5% males, mean age 62.4 ± 14.3 years), 5 withdrew consent before capsule ingestion, and 2 had missing primary endpoint data due to device malfunction. The most common presenting symptoms for UGIB were melena (52%), anemia (41%), and hematemesis (15%). The capsule correctly detected presence of blood in 26/28 and absence in 87/96. Sensitivity and specificity were 92.9% (p = 0.024) and 90.6% (p < 0.0001), respectively. The capsule's positive and negative predictive values were 74.3% and 97.8%, respectively. Positive (+) and negative (-) likelihood ratios (LR) were 9.9 and 0.08, respectively. PillSense recording time was 6.71 ±1.17 minutes. Capsule passage from the patient was confirmed radiographically or visually on stool inspection in 110 patients, and 16 were lost to follow-up. The average capsule transit time was 3.6 days, and no capsule retention was documented. No adverse events or death occurred related to the PillSense System. The PillSense capsule detected various types and amounts of bleeding, ranging from new blood to older, darker blood, as well as small spots of bleeding to larger, more active episodes. The capsule was able to identify bleeding coming from the esophagus, stomach, and duodenum.

Conclusion

The PillSense System is safe and effective for detecting blood in patients evaluated for UGIB prior to upper endoscopy. This tool is rapidly deployed, safe to use, easy-to-interpret, and may therefore assist in the efficient diagnosis of UGIB with the goal of improving patient outcomes and reducing healthcare costs.