Oral Contrast is no Longer Needed
The authors attribute only a secondary role to abdominal ultrasound in the diagnosis of ileus (1). This is asserted on the basis of a study that reports sensitivity and specificity of 83% and 100% respectively for ultrasound. A recent meta-analysis found a sensitivity of 92% and a specificity of 96% for ultrasound, based on a total of 11 studies (2). This shows that ultrasound is a very good first-line method for this issue and one that can point the way for further diagnosis and treatment immediately after history and clinical examination, within a few minutes. Finally, we come across many patients in whom mechanical ileus is only one of several differential diagnoses, but for whom ultrasound can nevertheless provide swift clarification. Naturally, computed tomography (CT) is the gold standard that can diagnose the site and cause of ileus (usually better than ultrasound). However, for a number of our patients the cause of ileus is already known thanks to prior history and diagnosis (relapsing ileus or subileus) and does not need to be confirmed by computed tomography.
However, the statement that prior oral contrast is needed is outdated. The literature by Branco et al. referred to on this subject concerns the value of oral contrast to evaluate intestinal transit (Gastrografin tracing). Oral contrast does not increase the diagnostic value of CT; this has been shown several times very recently (3, 4). It merely prolongs diagnosis, as the passage of contrast medium is substantially delayed in these patients. It also hinders the evaluation of mural uptake of contrast medium, which does, as explained, play a part in the Schwenter risk score.
Dr. med. Egbert Knöpfle
Radiologische Abteilung , Kliniken an der Paar
Conflict of interest statement
The author declares that no conflict of interest exists.
|1.||Vilz TO, Stoffels B, Straßburg C, Schild HH, Kalff JC: Ileus in adults—pathogenesis, investigation and treatment. Dtsch Arztebl Int 2017; 114: 508–18 VOLLTEXT|
|2.||Gottlieb M, Peksa GD, Pandurangadu AV, et al.: Utilization of ultrasound for the evaluation of small bowel obstruction: a systematic review and meta-analysis. Am J Emerg Med 2017; 17: 30635–6 CrossRef|
|3.||Kammerer S, Höink AJ, Wessling J, et al.: Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study. Eur Radio 2015; 25: 669–78 CrossRef MEDLINE|
|4.||Schuur JD, Chu G, Sucov A: Effect of oral contrast for abdominal computed tomography on emergency department length of stay. Emerg Radiol 2010; 17: 267–73 CrossRef MEDLINE|