Hrev_master [page 50] [Emergency Care Journal 2015; 11:5528] Is there still a role for abdominal plain X-ray in acute abdomen? Ciro Paolillo,1 Ilenia Spallino,1 Gianfranco Cervellin,2 Fausto Catena3 1Emergency Department, Udine University Hospital, Udine; 2Emergency Department, Parma University Hospital, Parma; 3Emergency Surgery Department, Parma University Hospital, Parma, Italy Abstract The imaging workup of patients with acute abdominal pain still starts with abdominal X- ray in several clinical settings and facilities. Unfortunately, conventional plain film is of limited utility if performed as a routine inves- tigation. Abdominal radiography is valuable only in patients with suspected perforated vis- cus and large bowel obstruction. Ultrasound is mostly valuable in the vast majority of abdomi- nal pain presentations, whereas computed tomography scan should be considered as sec- ond level test. Introduction Approximately 10% of emergency depart- ment visits are due to acute abdominal pain, making it one of the most encountered com- plaints.1-3 Several studies have demonstrated that a diagnosis based solely on a patient’s medical history, physical examination, and laboratory tests is not reliable enough, despite the fact that these aspects are essential parts of the workup of a patient presenting with acute abdominal pain.4 Imaging workup traditionally starts with abdominal radiography series: supine and upright abdominal and erect chest radiography. Unfortunately, X-ray has limited utility in abdominal imaging. In 2011 the van Randen’s group5 published the results of a multicenter prospective trial. The study com- pared the initial diagnosis, after clinical evalu- ation alone, with the final diagnosis, in patients with abdominal pain presented at the ED. The primary clinical diagnosis correspond- ed with the final diagnosis in less than half patients. After radiographs, primary diagnosis corresponded with final diagnosis in half cases; the improvement in accuracy of plain abdominal radiography combined with clinical examination was not significant (P=0.14). Treating physician changed primary diagnosis from initial clinical diagnosis in 11% after plain abdominal radiography, and these changes were accurate in only 22% of the patients. This study showed that clinical diag- nosis after routine plain radiographs did not change significantly the primary diagnosis based on clinical evaluation alone. The Authors concluded that plain radiography should be omitted from routine diagnostic workup. The American College of Radiology, The Royal College of Radiologists and the Italian Society of Radiology, published indica- tions for abdominal radiography that include only suspicion of perforated viscus or bowel obstruction.6-8 Detection of free air The identification of a small amount of free intra-abdominal gas remains one of the most significant signs in medicine. Advocates of conventional radiography state that plain abdominal X-ray should be the first diagnostic modality used in suspicion of a perforated vis- cus. With a well done radiographic technique it is possible to detect small quantities of free gas, but a great experience is necessary. In Baker ’s study,9 plain radiography demonstrat- ed pneumoperitoneum in only 51% of the patients with documented visceral perforation. Van Randen5 found a sensitivity of plain radi- ographs for perforated viscus of only 15%. Furthermore, when in reports of 1980s plain radiographs typically revealed free intraperi- toneal air originated from perforated peptic ulcers (59-69%) or colonic diverticulitis (37- 46%), in recent years an increase of small bowel and colon perforation and a decline in the incidence of gastroduodenal perforation has seen, as the Kumar’s study evidenced in 2012.10 If abdominal X-ray evidences a massive pneumoperitoneum other imaging are unnec- essary. If plain radiography delineates minimal pneumoperitoneum and the clinical is not clear an additional computed tomography (CT) scan is often needed to adopt the specific oper- ative strategy. Bowel obstruction Clinical findings in bowel obstruction include crampy abdominal pain, distension, increased bowel sounds and vomiting. The results of a prospective study published in 19984 evidenced that the combination of that variables has low sensitivity. Furthermore history and clinical examination are neither sufficiently sensitive nor specific to determine a coexistent ischemia. This uncertainty has led to the widespread use of imaging, above all to detect complication. If there is a suspect of bowel obstruction the diagnostic evaluation should focus on the fol- lowing goals: distinguishing mechanical obstruction from ileus; determining the etiolo- gy of the obstruction; discriminating from par- tial to complete obstruction; and discriminat- ing from simple to strangulating obstruction. X-ray has conventionally been used as the first step in the diagnostic imaging evaluation of a patient with suspected bowel obstruction.11 The diagnostic accuracy of plain radiographs is low varying from 55 to 80%. The diagnosis relies on two primary findings: dilated loops and air-fluid levels. Their evidence is correlat- ed with the severity of obstruction (partial or complete) and with the time of onset until X- ray is performed; an abdominal X-ray obtained just after the onset of the obstruction may not yet evidence dilated bowel proximal to the obstruction and may not yet evidence the absence of gas distal to the obstruction. Already the presence of more than two air-fluid level, air-fluid levels wider than 2.5 cm, and air-fluid levels differing more than 5 mm from one another in the same small-bowel loop, have reported to be sensitive and specific to differentiate high-grade of small bowel obstruction from low grade.12 The sensitivity of the plain films is high when there is a high grade bowel obstruction, in this case X-ray is as sensitive as CT (86 vs 82%).13 Unfortunately the number of symptomatic patients encoun- tered with either low grade or no obstruction is considerably greater than the number of patients with a high-grade partial or complete bowel obstruction. In patients for whom clini- cal suspect of an intestinal obstruction is high and abdominal radiographs are insufficient to confidently confirm diagnosis or to reasonably assess the severity of obstruction, additional diagnostic imaging becomes necessary. Emergency Care Journal 2015; volume 11:5528 Correspondence: Ciro Paolillo, Emergency Department, Udine University Hospital, piazzale Santa Maria della Misericordia 15, 33100 Udine, Italy. Tel: +39.0432.552360. E-mail: ciropaolillo@gmail.com Key words: Abdominal X ray; Acute abdomen; Plain radiography; Bowel occlusion; Pneumoperitoneum. Conflict of interest: the authors declare no poten- tial conflict of interest. Received for publication: 22 September 2015. Revision received: 19 November 2015. Accepted for publication: 27 November 2015. This work is licensed under a Creative Commons Attribution 3.0 License (by-nc 3.0). ©Copyright C. Paolillo et al., 2015 Licensee PAGEPress, Italy Emergency Care Journal 2015; 11:5528 doi:10.4081/ecj.2015.5528 Non co mmerc ial us e o nly [Emergency Care Journal 2015; 11:5528] [page 51] Conclusions The routinely use of abdominal X-ray as the first assessment after clinical examination in abdominal pain is striking considering the low diagnostic yield of this imaging test.14 However, performing abdominal CT in all patients presenting to the ED complaining for abdominal pain is an insane way, and it could be considered the Waterloo of the emergency system, indeed. So, is there still a role for abdominal plain X-ray in acute abdomen? The choice of imaging test is part of the strategy.15 After clinical evaluation, only in the suspect of perforation or bowel obstruction a plain radi- ography should be performed, while in differ- ent contests it is of poor value. References 1. Gans SL, Pols MA, Stoker J, Boermeester MA. Guidelines for the diagnostic pathway in patients with acute abdominal pain. Digest Surg 2015;32:23-31. 2. McNamara R, Dean AJ. Approach to acute abdominal pain. Emerg Med Clin N Am 2011;29:159-73. 3. Gans SL, Stoker J, Boermeester MA. Plain abdominal radiography in acute abdomi- nal pain; past, present, and future. Int J Gen Med 2012;4:525-33. 4. Bohner H, Yang Q, Franke Claus, et al. Simple data from history and physical examination help to exclude bowel obstruction and to avoid radiographic studies in patients with acute abdominal pain. Eur J Surg 1998;164:777-84. 5. Van Randen A, Laméris W, Luitse JSK, et al. The role of plain radiographs in patients with acute abdominal pain at the ED. Am J Emerg Med 2011;29:582-9. 6. American College of Radiology. ACR-SPR practice parameter for the performance of abdominal radiography. Available from: http://www.acr.org/~/media/79a594819bbd 4631a7e31404daa66ef6.pdf 7. Smith JE, Hall EJ. The use of plain abdom- inal x rays in the emergency department. Emerg Med J 2009;26:160-3. 8. Società Italiana di Radiologia Medica. SIRM guidelines. Available from: http://www. sirm.org/documenti/cat_view/ 66-linee-guida 9. Baker SR. Unenhanced helical CT versus plain abdominal radiography: a dissenting opinion. Radiology 1997;1:45-7. 10. Kumar A, Muir MT, Cohn SM, et al. The eti- ology of pneumoperitoneum in the 21st century. J Trauma Acute Care Surg 2012;73:542-8. 11. Rachel E, Musson, Bickle I, Ram KPV. Gas patterns on plain abdominal radiographs: a pictorial review. Postgrad Med J 2011;87:274-87. 12. Lappas JC, Reyes BL, Maglinte DD. Abdominal radiography findings in small bowel obstruction: relevance to triage for additional diagnostic imaging. Am J Roentgenol 2001; 176:167-74. 13. Magliette DD, Reyes BL, Harmron BH, et al. Reliability and role of plain film radiog- raphy and CT in the diagnosis of small- bowel obstruction. Am J Roentgenol 1996; 167:1451-5. 14. Morris-Stiff G, Stiff RE, Morris-Stiff H. Abdominal radiograph requesting in the setting of acute abdominal pain: temporal trends and appropriateness of requesting. Ann R Coll Surg Engl 2006;88:270-4. 15. Lameris W, van Randen A, van Es FW, et al. Imaging strategies for detection of urgent conditions in patients with acute abdomi- nal pain: diagnostic accuracy study. Brit Med J 2009;339:2431. Opinion Report Non co mmerc ial us e o nly