Inpatient Capsule Endoscopy Leads to Frequent Incomplete Small Bowel Examinations

Abstract

Background: Capsule endoscopy (CE) is an important diagnostic tool to evaluate small bowel pathology. A major problem with CE is incomplete exams due to failure of the capsule to reach the cecum. While some predictors of exam completion have been evaluated, there are limited data on whether inpatient (IP) versus outpatient (OP) status at the time of the CE is predictive. We hypothesized that inpatient CE exams are more often incomplete, which may be due to factors such as lack of ambulation, medications, and/or underlying illness. Methods: All CE exams done at our institution between 3/03 - 10/05 were retrospectively reviewed (n = 356). Patients with capsule malfunction (n = 6), prior gastric surgery (n = 3), or endoscopic capsule placement (n = 3) were excluded. Patients lacking sufficient data for analysis were also excluded (8 OP, 1 IP). In the remaining 335 exams (264 OP, 71 IP), patient characteristics such as age and gender, presence of gastric retention of the capsule, completeness of the examination (whether or not the capsule reached the cecum), gastric and small bowel transit times were recorded. Results were statistically analyzed using Chi-square, t-test, and a multivariate logistic regression model. Results: The mean age of the study population was 55 (11-92) with 130 males and 205 females. The capsule never reached the cecum in 31% of IP (n = 22/71) vs. 9.5% of OP (n = 25/264) (p < 0.001). The proportion of patients with incomplete exams was higher in the ICU setting (n = 7/13, 54%) as compared to studies done on the general floor (n=15/58, 26%) (p=.049). Mean gastric transit times were prolonged in IP as compared to OP (62 min vs. 47 min respectively; p = 0.041). Gastric retention of the capsule was also higher in IP (n = 6/71, 30%) vs. OP (n = 8/264, 8.5%) (p = 0.043). In a multivariate logistic regression model, patient location (IP vs. OP) and gastric transit times were independent predictors of incomplete exams. Conclusions: We have shown that inpatient CE exams are associated with a significant reduction in complete examination of the small bowel as compared to exams done in the outpatient setting. This finding is a consequence of prolonged gastric transit times and a higher incidence of gastric retention. Similarly, studies done in the ICU are more often incomplete as compared to those done on the general floor. Efforts to improve GI motility (i.e. prokinetics, ambulation) or the use of capsules with longer data acquisition capabilities may be worth considering for inpatient CE exams. Further prospective data are needed to delineate the most important factors that contribute to incomplete exams in the IP setting.