Should Oral Contrast Be Omitted in Patients with Suspected Appendicitis?

Optimizing Outpatient Oral Contrast Use in Abdominal CT-A Radiology Pandemic Response Initiative to Reduce Patient Time in the Waiting Room and Reduce Costs, While Improving Patient Experience

Purpose: The aim was to reduce outpatient wait time and improve patient experience by optimising oral contrast use. Methods: Our multidisciplinary stakeholder collaboration implemented two simultaneous interventions: (1) Creation of 'oral contrast policy', limiting recommended indications. (2) Creation of a new shorter oral contrast regime (30 vs 60 min). We conducted a retrospective service evaluation of oral contrast use in outpatient (OP) abdominal CT at baseline and post-intervention. Patient wait times were measured and per-patient cost-savings were reported. An image quality review was performed by 2 blinded abdominal radiologists. Patient experience was evaluated with a standard voluntary survey. Statistical analysis was performed comparing baseline and evaluation outcomes using Chi-square or Fisher Exact test for categorical variables and Student's t-test or ANOVA for continuous data. Results: Over 1-month periods, OP CT scans were assessed in baseline (pre-pandemic) n = 575, baseline (pandemic) n = 495 and post-intervention n = 545 groups. Oral contrast use reduced from 420/575, 73.0% at baseline to 178/545, 32.7% post intervention. The turn-around time reduced by 15.8 minutes per patient from 70.3 to 54.5 minutes, P < .001 (Interventions 1 and 2). The diagnostic quality did not differ between the oral contrast regimes (Intervention 2, P = 1.0, P = .08). No repeat CTs were needed due to lack of oral contrast (Intervention 1) or poor opacification (Intervention 2). There was oral contrast cost reductions of 69.1-78.4% (P < .001). Patients reported their overall experience was improved post-intervention (Interventions 1 and 2). Conclusions: Optimising the CT oral contrast service through judicious use and a shorter regime, reduced patient wait times, improved patient experience and preserved diagnostic quality.

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.