Does limiting oral contrast decrease emergency department length of stay?

Root Cause Analysis of Delayed Emergency Department Computed Tomography Scans

Introduction

A solution for emergency department (ED) congestion remains elusive. As reliance on imaging grows, computed tomography (CT) turnaround time has been identified as a major bottleneck. In this study we sought to identify factors associated with significantly delayed CT in the ED.

Methods

We performed a retrospective analysis of all CT imaging completed at an urban, tertiary care ED from May 1-July 31, 2021. During that period, 5,685 CTs were performed on 4,344 patients, with a median time from CT order to completion of 108 minutes (Quartile 1 [Q1]: 57 minutes, Quartile 3 [Q3]: 182 minutes, interquartile range [IQR]: 125 minutes). Outliers were defined as studies that took longer than 369 minutes to complete (Q3 + 1.5 × IQR). We systematically reviewed outlier charts to determine factors associated with delay and identified five factors: behaviorally non-compliant or medically unstable patients; intravenous (IV) line issues; contrast allergies; glomerular filtration rate (GFR) concerns; and delays related to imaging protocol (eg, need for IV contrast, request for oral and/or rectal contrast). We calculated confidence intervals (CI) using the modified Wald method. Inter-rater reliability was assessed with a kappa analysis.

Results

We identified a total of 182 outliers (4.2% of total patients). Fifteen (8.2%) cases were excluded for CT time-stamp inconsistencies. Of the 167 outliers analyzed, 38 delays (22.8%, 95% confidence interval [CI] 17.0-29.7) were due to behaviorally non-compliant or medically unstable patients; 30 (18.0%, 95% CI 12.8-24.5) were due to IV issues; 24 (14.4%, 95% CI 9.8-20.6) were due to contrast allergies; 21 (12.6%, 95% CI 8.3-18.5) were due to GFR concerns; and 20 (12.0%, 95% CI 7.8-17.9) were related to imaging study protocols. The cause of the delay was unknown in 55 cases (32.9%, 95% CI 26.3-40.4).

Conclusion

Our review identified both modifiable and non-modifiable factors associated with significantly delayed CT in the ED. Patient factors such as behavior, allergies, and medical acuity cannot be controlled. However, institutional policies regarding difficult IV access, contrast administration in low GFR settings, and study protocols may be modified, capturing up to 42.6% of outliers.

Using Body Mass Index and Bioelectric Impedance Analysis to Assess the Need for Positive Oral Contrast Agents Before Abdominopelvic CT

OBJECTIVE

The objective of this study was to determine whether body fat percentage, measured using a portable handheld bioelectric impedance analysis (BIA) device, and body mass index (BMI, weight in kilograms divided by the square of height in meters) can estimate the amount of intraabdominal and intrapelvic fat and thereby predict the need for oral contrast material before abdominopelvic CT.

SUBJECTS AND METHODS

A prospective, institutional review board-approved study consisting of 101 patients who presented to the emergency department of a level I trauma center was conducted between June 1, 2016, and July 19, 2016. A medical student calculated patients' BMI and obtained body fat measurements from a handheld BIA device. Three fellowship-trained and board-certified radiologists who were blinded to the collected data then assigned a score of 1-5 on the basis of the amount of intraabdominal and intrapelvic fat seen on CT images. A McNemar test was used to compare overall sensitivity and specificity of this method, and a weighted Fleiss kappa score was used to determine interobserver variability between the three radiologists.

RESULTS

Nearly all (97%) of the patients with high BMI (BMI ≥ 25) had sufficient amounts of intraabdominal and intrapelvic fat to allow delineation of anatomic structures without the use of oral contrast material. Of the patients with low BMI (BMI ≤ 21), 83% had inadequate amounts of fat to separate intraabdominal and intrapelvic structures. For patients with intermediate BMIs (21 < BMI < 25), BIA-determined body fat percentage of 30% or more can be used to predict whether a patient will have sufficient intraabdominal and intra-pelvic fat to obviate oral contrast material for CT.

CONCLUSION

Using BIA in addition to BMI accurately predicts amount of intraabdominal and intrapelvic fat. This information may help guide the decision to use oral contrast material in patients presenting for abdominopelvic CT.

Acute appendicitis in childhood: oral contrast does not improve CT diagnosis

INTRODUCTION

We compared the diagnostic accuracy of CT performed without and with oral contrast for suspected appendicitis in children.

METHODS

In this retrospective cohort study, we reviewed abdomen/pelvis CT scans with IV contrast performed between 2011 and 2015 for suspected appendicitis. Oral contrast was used routinely before August 2013 and eliminated from the CT protocol thereafter. Diagnostic accuracy of CT was compared with operative/pathology reports, and included a 30-day follow-up period for non-surgical patients. For a secondary analysis, the oral contrast group was subdivided into "complete" (contrast extending into the cecum) or "partial" contrast. We also compared groups for CT turnaround time, the frequency of appendiceal perforation and abscess, and the potential influence of a prior appendix ultrasound.

RESULTS

Five hundred fifty-eight patients were included: 51.6% (n = 288) without oral contrast and 48.4% (n = 270) with oral contrast (of which 52% (n = 140/270) had "complete" contrast). There was no difference in diagnostic accuracy between the oral contrast and non-contrast groups (p = 0.903), with sensitivity/specificity of 93.8% (95% CI 84.8-98.3)/98.5% (CI 95.8-99.7) and 94.6% (CI 84.9-98.9)/98.3% (CI 95.7-99.5), respectively. Similarly, there was no difference in accuracy when comparing only "complete" contrast vs. non-contrast groups (p = 0.755). CT turnaround time for the non-contrast group was significantly faster (43.8 ± 37.6 min), on average, than the oral contrast group (137.4 ± 47.5 min).

CONCLUSION

For children evaluated by CT with IV contrast for suspected appendicitis, administering oral contrast increased wait time by > 90 min, did not reach the cecum in 48% of cases, and did not improve diagnostic accuracy. Oral contrast for pediatric CT appendicitis evaluation is not warranted.

Evaluating the Patient with Right Lower Quadrant Pain

Right lower quadrant pain is one of the most common indications for imaging evaluation of the abdomen in the emergency department setting. This article reviews important imaging findings associated with acute appendicitis as well as major differential considerations including: mesenteric adenitis, Meckel diverticulum, neutropenic colitis, right-sided diverticulitis, epiploic appendagitis, omental infarction, and inflammatory bowel diseaseRight lower quadrant pain is one of the most common indications for imaging evaluation of the abdomen in the emergency department setting. This article reviews important imaging findings associated with acute appendicitis as well as major differential considerations including: mesenteric adenitis, Meckel diverticulum, neutropenic colitis, right-sided diverticulitis, epiploic appendagitis, omental infarction, and inflammatory bowel disease.

Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients with Acute Abdominal Pain?

Purpose

The purpose of our study was to validate the hypothesis that eliminating the use of oral contrast for multidetector computed tomography (MDCT) would not affect the detection of acute abdominal abnormalities in emergency room patients.

Methods

We conducted a retrospective study to assess the effect of discontinuing oral contrast use for MDCT scans of the abdomen and pelvis for patients presenting with acute abdominal pain and body mass index (BMI) >25. Patients with BMI <25 continued to receive oral contrast. The medical records were reviewed to determine the rate of repeat imaging within 7 days from the initial CT scan, as well as delayed or missed diagnoses related to the absence of oral contrast. The study was approved by the research ethics board at our institution.

Results

A total of 1378 patients had an MDCT examination of the abdomen and pelvis between November 1, 2012, and October 31, 2013. 375 patients met the inclusion criteria (174 males and 201 females; mean age 57 years; range 18-97 years). Seven of 375 (1.9%) patients had a repeat CT examination with oral contrast within 7 days. Of these 7 patients, none had a change in the course of their management due to the utilization of oral contrast. No delayed or missed diagnoses related to the absence of oral contrast were identified.

Conclusion

Omitting oral contrast for imaging patients with BMI >25 presenting with acute abdominal pain resulted in no delayed or missed diagnoses, in our retrospective study. The benefits of prompt imaging diagnosis outweigh the unlikely need for repeat imaging.