Exploring the evidence-practice gap in the use of plain radiography for acute abdominal pain and intestinal obstruction: a systematic review and meta-analysis

AIM

Previous studies, some dating back several decades, have recommended that the use of plain abdominal radiography should be curbed, particularly with the growth of more accurate imaging modalities. However, evidence from referral data suggests that plain abdominal radiography continues to be a commonly requested examination. The aim of this review was to explore the gap between evidence and practice by re-examining the evidence using a robust methodology, investigating the diagnostic accuracy of plain abdominal radiography.

METHODS

Studies were identified from electronic databases and reference lists. Eligible studies provided data as to the sensitivity and specificity of plain abdominal radiography for either acute abdominal pain (Group A) or suspected intestinal obstruction (Group B). Version 2 of the Quality Assessment of Diagnostic Accuracy Studies was used to assess the quality of studies and hierarchical summary receiver operator characteristic curves and coupled forest plots were generated.

RESULTS

Four studies evaluated plain abdominal radiography for acute abdominal pain (Group A) and 10 for suspected intestinal obstruction (Group B). Two studies investigated both presentations and were included in both groups. Methodological quality of studies was moderately high, though incorporation bias was a common limitation. Sensitivity for Group A studies ranged from 30 to 46%, with specificity from 75 to 88%. For Group B, the range of sensitivity was 48 to 96% and specificity from 50 to 100%.

CONCLUSION

The results suggest that use of plain abdominal radiography could be substantially reduced, particularly for patients with undifferentiated acute abdominal pain. While some guidelines exist, there is sound argument for clinical decision rules for abdominal imaging to inform evidence-based clinical decision-making and radiology referrals.

The value of the erect abdominal radiograph for the diagnosis of mechanical bowel obstruction and paralytic ileus in adults presenting with acute abdominal pain

INTRODUCTION

There is discord on the value of the erect abdominal radiograph for diagnosing acute abdominal pathologies. The erect radiograph can be uncomfortable for patients in pain and increases patient radiation dose.

AIM

To determine if including the erect abdominal radiograph in plain abdominal radiography (PAR) improved diagnostic accuracy for identifying mechanical bowel obstruction and/or paralytic ileus in adults presenting with acute abdominal pain.

METHODS

PAR of 40 consecutive adults presenting with suspected bowel obstruction or paralytic ileus was retrospectively sampled and independently reviewed by two emergency department (ED) consultants and two radiology consultants for bowel obstruction and paralytic ileus across two sessions. In session 1, the assessors assessed the supine abdominal radiographs (PAR 1) and clinical details in a randomised order, and session 2, at least 6 weeks later, they assessed the supine and erect radiographs (PAR 2) and clinical details of the randomly re-ordered cases. Computed tomography was the reference standard. Pair-wise comparisons of receiver operating characteristic curves were calculated to assess for significant differences in participants' diagnostic accuracy using MedCalc 16.4.3.

RESULTS

Average sensitivity, specificity and area under the receiver operating characteristic curves (AUROC) were 69.7%, 61.0% and 0.642 for PAR 1, respectively, and 80.0%, 53.4% and 0.632 for PAR 2 respectively. For AUROC there were no significant differences (P > 0.05) between PAR 1 and PAR 2. Intra-rater and inter-rater agreement improved in PAR 2.

CONCLUSION

There was no statistically significant improvement in diagnostic accuracy when including the erect radiograph in PAR for the acute abdomen.

Abdominal radiograph pearls and pitfalls for the emergency department radiologist: a pictorial review

Abdominal plain films are often the first imaging examination performed on a patient with abdominal pain in the emergency department. Radiograph findings can help guide clinical management and the need for advanced imaging. A pictorial review of a range of abdominal radiograph findings is presented, including bowel gas patterns, abdominal organ evaluation, pathologic gas, calcifications, implanted devices, and foreign bodies.

Early diagnosis of bowel obstruction and strangulation by computed tomography in emergency department

BACKGROUND

Closed loop bowel obstruction is a specific type of mechanical obstruction with a high risk of strangulation and bowel infarction, especially in the small bowel. It is associated with a high mortality rate. Hence, it is important for emergency physicians to identify the presence of strangulation, while making the diagnosis of closed loop small bowel obstruction.

METHODS

We reported three patients with strangulated closed loop small bowel obstruction associated with severe abdominal pain, who had been treated at the emergency department. Urgent computerized tomography was performed in the patients.

RESULTS

Two patients were discharged with stable conditions, and one patient died after hemodialysis.

CONCLUSION

Urgent computerized tomography of the abdomen serves as an important diagnostic tool in view of its ability to detect the site, level and cause of obstruction along with the distinctive CT appearance of closed loop small bowel obstruction and signs of ischemia. Early definitive diagnosis will guide subsequent management and improve outcomes.