Use Of Water-soluble Contrast Agents Research Articles

Feasibility of Gastrografin Use for Adhesive Small Bowel Obstruction in Low-Income Countries

IntroductionSmall bowel obstruction (SBO) is one of the most common causes for hospital admission in Ethiopia. The use of water-soluble contrast agents (WSCAs) such as Gastrografin to manage adhesive SBO can predict nonoperative resolution of SBO and reduce decision time to surgery and length of hospital stay. However, nothing is known about practice patterns and Gastrografin use in low-income settings. We sought to characterize current management practices, including use of WSCAs, as well as outcomes for patients with SBO in Addis Ababa, Ethiopia. MethodsWe conducted a mixed-methods study consisting of a survey of surgeons throughout Ethiopia and a retrospective record review at five public, tertiary care–level teaching hospitals in Addis Ababa. ResultsOf the 76 surgeons who completed the survey, 63% had heard of the use of WSCAs for SBO and only 11% used oral agents for its management. Chart review of 149 patients admitted with SBO showed the most common etiology was adhesion (39.6% of admissions), followed by small bowel volvulus (20.8%). Most patients (83.2%) underwent surgery during their admission. The most common diagnosis in patients who did not require surgery was also adhesion (68.0%), as well as for those who had surgery (33.9%), followed by small bowel volvulus (24.2%). ConclusionsThe etiology of SBO in Ethiopia may be changing, with postoperative adhesions becoming more common than other historically more prevalent causes. Although a Gastrografin protocol as a diagnostic and potentially therapeutic aid for SBO is feasible in this population and setting, challenges can be anticipated, and future studies of protocol implementation and effectiveness are needed to further inform its utility in Ethiopia and other low-income and middle-income countries.

Compliance on the use of water-soluble contrast agent in adhesional small bowel obstruction

Objectives: Small bowel obstruction is associated with significant morbidity and mortality. This study aimed to map outcomes of patients admitted with adhesional small bowel obstruction (ASBO ) with a view evaluating the effectiveness of water-soluble contrast agents (WSCA). Materials and Methods: A retrospective review of all emergency admissions coded for operative and non-operative treatment of small bowel obstruction between January 2018 and June 2020. Electronic patient records were utilized to confirm cases of ASBO. Patient demographics, hospital administrative data, treatment and surgery-related data are collected. Results: A total of 110 patients were admitted with ASBO initiated with conservative management. Median time to computed tomography (CT) scan was 12 h (Range: 3–115 h). Oral contrast was administered in only 11%; of these, 58% (7/12) resolved spontaneously compared to 52% (51/98) in those without contrast. About 43% (47/110) of all patients necessitated surgical intervention. Median time from admission to surgery was 43.5 h (Range: 10– 288 h). There were one 30-day re-admissions in patients surgically managed compared to two in those conservatively managed. Conclusion: Early CT scan facilitates initiation of non-operative management in stable patients with ASBO. In this series, the scant use of WSCA despite international guidelines did not compromise patient outcomes or length of stay.

Pantopaque: Does It Still Migrate With Gravity After 30 Years?

Pantopaque was an oil-based positive contrast media used in central nervous system imaging before the use of water-soluble contrast agents. It is no longer used due to side effects, including arachnoiditis. Prior studies have indicated that remnants of pantopaque can be seen in modern radiographic imaging, including CT and MRI. With its use obsolete, these remnants have been increasingly mislabeled from “tumor” to “shot gun pellets”. An understanding of this historic modality will usually lead to the correct diagnosis.

508 Conservative Management of Small Bowel Obstruction: A Local Experience

Abstract Introduction Post-operative intra-abdominal adhesions remain the leading cause of small bowel obstruction (SBO) representing one of the main diagnoses warranting emergency laparotomies. The National Audit in Small Bowel Obstruction advocates the use of water-soluble contrast agents (WSCA) as initial management of SBO. We aim to assess the role and outcomes of WSCA and its rate in successfully managing SBO non-operatively. Method We conducted a 2-year retrospective analysis including all patients admitted with adhesive SBO. Outcomes of patients who received WSCA were compared to those who hadn’t. Results 118 patients were included, 27(23%) of which required immediate surgery while 91(77%) were initially managed conservatively. From the latter group, 53(58.2%) received WSCA whilst 38(41.8%) didn’t. Of the group that received WSCA, 36(39.5%) were successfully managed non-operatively, compared to 26(28.5%) that didn’t, this however lacked statistical significance. LOS didn’t differ between these two groups (5 days vs. 5.5 days, p = 0.805). 32% of the patients required eventual surgical intervention needing longer LOS regardless of receiving WSCA (6.6 days vs. 13.6 days p < 0.001). Conclusions Adhesive SBO can be managed conservatively in up to two-thirds of patients. WSCA usage has a positive impact but needs further assessment in larger studies.

Current management of small bowel obstruction in the UK: results from the National Audit of Small Bowel Obstruction clinical practice survey.

Small bowel obstruction (SBO) is associated with high rates of morbidity and mortality. The National Audit of Small Bowel Obstruction (NASBO) is a collaboration between trainees and specialty associations to improve the care of patients with SBO through national clinical audit. The aim of this study was to define current consultant practice preferences in the management of SBO in the UK. A survey was designed to assess practice preferences of consultant surgeons. The anonymous survey captured demographics, indications for surgery or conservative management, use of investigations including water-soluble contrast agents (WSCA), use of laparoscopy and nutritional support strategies. The questionnaire underwent two pilot rounds prior to dissemination via the NASBO network. A total of 384 responses were received from 131 NASBO participating units (overall response rate 29.2%). Abdominal CT and serum urea and electrolytes were considered essential initial investigations by more than 80% of consultants. Consensus was demonstrated on indications for early surgery and conservative management. Three hundred and thirty-eight (88%) respondents would consider use of WSCA; of these, 328 (97.1%) would use it in adhesive SBO. Two hundred (52.1%) consultants considered a laparoscopic approach when operating for SBO. Oral nutritional supplements were favoured in operatively managed patients by 259 (67.4%) respondents compared with conservatively managed patients (186 respondents, 48.4%). This survey demonstrates consensus on imaging requirements and indications for early surgery in the management of SBO. Significant variation exists around awareness of the need for nutritional support in patients with SBO, and on strategies to achieve this support.

Oil-soluble contrast agents for NMR

In well logging applications, nuclear magnetic resonance (NMR) is recognized as a powerful tool to differentiate various fluids inside porous media. However, it can be challenging to do so in complex situations, e.g. when fluid peaks overlap with each other. Water-soluble contrast agents, such as MnCl2 or Gd-EDTA, have been proposed for use to accelerate the water relaxation, thus separating the water signal from those of other fluids. Together with these contrast agents, the log-inject-log method is used and the difference between the two logs is attributed to the doped water phase. This application only works with water-based mud. To extend its use to oil-based mud (OBM), it is desirable to find alternatives to water-soluble contrast agents that are compatible with OBM.In this work, we introduce a new group of doping agents: oil-soluble contrast agents. We selected several iron-based complex compounds that are oil-soluble, and tested and evaluated their effects on oil signal relaxation using a laboratory NMR apparatus. We also tested hydrophobic iron oxide nanoparticles as a contrast agent. The results showed that both the complex compounds and nanoparticles were able to reduce the transverse relaxation time of oil from longer than 2 s to less than 20 ms. To demonstrate their applicability in porous media, we injected doped oil into gas-saturated Berea sandstone and limestone core plugs. With conventional 1D NMR measurements or the use of water-soluble contrast agents, it is not straightforward to discern the gas signal from the OBM signal. Our experiments showed that the gas signal could be easily identified in the presence of doped oil via simple T2 scans. We also performed experiments to demonstrate that the peaks of water and doped oil could be readily differentiated.The use of oil-soluble doping agents can significantly enhance the contrast of the NMR signals originated from different formation fluids, thus facilitating the fluid typing process. It provides a key alternative to the current water-doping technique. It is particularly advantageous when changing the oil relaxation is desired, such as for eliminating signal interferences from OBM invasion and differentiating heavy oil from clay-bound water. It also provides the possibility of speeding up the logging process by dramatically reducing the oil relaxation time. In addition, they can be employed in the laboratory for various purposes such as water saturation determination and fluid displacement monitoring. These contrast agents can also be of useful when oil-soluble contrast agents are desired in other fields, such as medical imaging applications.

Water-Soluble Contrast Agents in Small Bowel Obstruction: A Useful Discriminator

AJR 2012; 199:W783 0361–803X/12/1996–W783 © American Roentgen Ray Society Water-Soluble Contrast Agents in Small Bowel Obstruction: A Useful Discriminator We read with great interest the review article, “Small Bowel Obstruction,” by Mullan et al. [1] in the February 2012 issue of the AJR. The article provides a practical overview of a frequently occurring situation in abdominal diagnostic radiology. However, we disagree with the authors on a significant topic: namely, the usefulness of abdominal radiography after ingestion of a water-soluble contrast agent. We would like to suggest the use of water-soluble contrast agents not only for diagnostic but also for therapeutic purposes. This practice may eliminate the need for surgery and decrease the length of hospital stays. Over the past decade, the use of watersoluble contrast agents in small bowel obstruction caused by adhesions has been the subject of several randomized controlled trials published in surgical journals. Its use has therefore been incorporated in the diagnostic workup of patients who present with small bowel obstruction suspected to be due to adhesions. Consequently, we receive an increasing number of requests for a conventional abdominal radiography in patients who have ingested a water-soluble contrast agent. The appearance of contrast medium in the colon within 24 hours after ingestion of a water-soluble contrast agent predicts resolution of the obstruction without the need for surgery with high sensitivity (0.97), specificity (0.96), and receiver operating characteristic value (0.98) [2]. The administration of watersoluble contrast agents significantly reduced the length of hospital stay. A reduction in the need for surgery is claimed by some authors [3, 4] but denied by others [2]. Figure 1 shows that contrast medium has progressed to the jejunum at 8 hours after administration and the ascending colon at 24 hours. The proposed therapeutic mechanism of water-soluble contrast agents is related to their hyperosmolarity (approximately six times that of extracellular fluid). This promotes shifting of fluid into the bowel lumen, which decreases the pressure gradient over the obstruction, which distends collapsed bowel segments, dilutes the contents, and facilitates passage of water that is attracted to the hyperosmolar contrast medium [3]. Water-soluble contrast agents are relatively safe to use, even if a perforation occurs. Barium contrast material does not appear to be a useful alternative. The use of barium holds risks because it may lead to complete obstruction by decreasing the viscosity of bowel contents. Moreover, in case of perforation, leakage of barium to the abdominal cavity is potentially lethal [3]. In conclusion, the use of water-soluble contrast agents can be of diagnostic and therapeutic effect in cases of adhesive small bowel obstruction. Hein P. Stallmann Jaap Borstlap Thomas L. Bollen St. Antonius Hospital, Nieuwegein, The Netherlands

Iopamidol in Peripheral Angiography

ABSTRACTThe development of new low-osmolality contrast media represents a major advance in the use of water-soluble contrast agents in clinical practice, especially in arteriography. The pain and discomfort experienced in peripheral angiography is largely related to the very high osmolalities of con

The Radiological Diagnosis of Herniated Lumbar Intervertebral Disk

LUMBAR disk herniation was not fully recognized as a disease entity until 1934, when Mixter and Barr¹published their now classic description. Only two years later, Hampton and Robinson²described the myelographic criteria for the diagnosis of this entity. For almost 50 years, myelography with radiopaque contrast media has been the diagnostic method of choice for detection and localization of herniated lumbar intervertebral disk.^3-8The recent development of nonionic water-soluble iodinated contrast media with relatively low toxicity (eg, metrizamide)^9,10has added a new dimension to the myelographic evaluation of disk herniation by allowing direct visualization of the compressed nerve root.⁶ Although the use of water-soluble contrast agents has now become widely accepted and has likely improved the diagnostic accuracy of the myelographic method,⁶Williams and colleagues" have recently suggested that the diagnosis of herniated lumbar disk can be made in many cases by computed