Optimizing the Previs Device for Prediction of Postoperative Ileus

The research proposed in this study will develop a noninvasive prototype device that will capture intestinal sounds, process signals, and display predictive information in real-time at the point-of-care using algorithms already developed at this institution.

Following major abdominal surgery, up to 30% of patients develop a poorly understood condition known as ileus. When ileus occurs, the bowels shut down and patients often develop abdominal dissension, nausea, vomiting, and even more serious complications. Because this condition does not develop until many days after surgery has been completed, clinicians do not know if they should begin allowing patients to eat or withhold nutrition until they show signs of bowel function such as passing gas or having bowel movements. Clinicians have different approaches but none are ideal: 1) feed all patients early and the ones that develop an ileus will have their diets reverse, suction tube placed in their stomach, and hopefully don't get develop more serious complications, or 2) don't feed patients until they pass gas or have a bowel movement, which delays nutrition and prolongs hospital stays for the 70% of patients who will not develop an ileus Participants in this study will be asked to wear a 3-ounce device that adheres to the skin of the abdominal wall for 10 days. They will also be asked to answer questions each day of their hospital stay regarding how they have tolerated eating.

Device: Entac Medical device application Other: Patient Daily Assessment Other: Patient Discharge Assessment

Subjects will wear a 3-inch by 3-inch stethoscope device that adheres to the skin of the abdomen via FDA approved adhesive material. It will be applied either in the operating room at the completion of surgery or in the recovery room. The device will remain on the abdomen until discharge or for 10 days, whichever comes first.

The research team will ask questions of the subject regarding nausea, vomiting, passage of flatus, return of bowel function, and satisfaction with the device every day that the subject is hospitalized.

The research team will ask questions of the subject regarding satisfaction or dissatisfaction with having the device placed and attached to their abdomen.

The signal processing algorithm will be modified iteratively to maximize the negative predictive value of the device while maintaining the highest PPV The sensitivity, specificity, positive predictive value, negative predictive value, AUC, and accuracy of the device for each 10-30 patients (dependent upon the incidence of GI impairment in each group) will be measured. The signal processing algorithm will be modified iteratively to maximize the negative predictive value of the device while maintaining the highest PPV possible. Our goal is for the AUC for the final algorithm to be greater than 0.8.

Each patient's data will be evaluated after 14 days. Each group of 10-30 patients' data will be analyzed. Final analysis will occur after 225 patients are enrolled.

Inclusion Criteria: Patients undergoing elective intestinal resection surgery by the colorectal surgery service at UIHC. Age 18 to 100. Exclusion Criteria: Allergies to any of the device components. Inability to have prototype device applied to their abdominal wall due to a condition (ie:fistulas, stomas, drains, etc).