Low-osmolar Contrast Media Research Articles

Effect of Nonionic Iodinated Contrast Media on Blood Pressure during Contrast-enhanced Computed Tomography of Abdomen Examination: A Cross-sectional Study

ABSTRACT Introduction: Computed tomography (CT) scan has high sensitivity and specificity for numerous conditions. The images produced by a CT scanner can be enhanced using iodinated contrast media. Significant hemodynamic changes are seen with rapid intravenous contrast media injection. The average acceptable blood pressure (BP) value is 120/80 mmHg. Many studies have related hypertensive crises with high-osmolar contrast media, whereas its relation with low-osmolar contrast media is still unclear. This study aims to evaluate the effect of nonionic iodinated contrast media on BP during contrast-enhanced CT (CECT) of the abdomen. Materials and Methods: A cross-sectional study was conducted from April 2022 to August 2023. A total of 146 subjects (73 males and 73 females were included in the study). Statistical analysis of data was done using SPSS 23.0. A comparison of systolic BP and diastolic BP across the three periods was done using repeated measures of ANOVA. A between-group comparison was performed by unpaired t-test. The level of significance was set as 5%. All subjects underwent a CECT abdomen, including a plain, arterial, and venous phase. A bolus of 80 mL of Ultravist was administered. BP was measured before the contrast injection (baseline value), between the arterial and venous phases, and 3 min after the contrast injection. Results: Injection of nonionic contrast media caused a decrease in BP among subjects. The mean systolic BP readings before contrast injection in males and females were 127.5 ± 8 mmHg and 122.8 ± 8.4 mmHg, respectively. The mean diastolic BP before contrast injection was 79.2 ± 6.4 and 76 ± 6.4 mmHg among males and females, respectively. For systolic, these values decreased to 123 ± 10.3 mmHg in males and in females to 115 ± 14.6 mmHg when measured between arterial and venous phases. Similarly, for diastolic BP, the mean values recorded between the arterial-venous phase reduced to 76.7 ± 9.3 mmHg and 72.3 ± 10 mmHg, respectively. The BP readings, however, increased near baseline value when measured 3 min after the injection. The mean systolic BP measured 126.1 ± 8.5 mmHg and 124.9 ± 11.8 mmHg for males and females at 3 min after injection. Similarly, the mean diastolic BP values taken after 3 min of contrast injection were 78.3 ± 6.5 mmHg and 76.2 ± 7 mmHg in males and females, respectively, P < 0.001. BP in both male and female groups was affected similarly. Conclusion: Bolus administration of 80 mL of Ultravist reduced BP. This reduction was short-term and got back to normal within a few minutes. The contrast media similarly affected both genders. The BP changes had no clinical significance.

Iso-osmolar vs low-osmolar contrast agents for coronary optical coherence tomography: a blinded prospective randomized controlled study.

The impact of contrast type on coronary optical coherence tomography (OCT) imaging has received limited research. We conducted a blinded, prospective, single-center, randomized, controlled crossover study comparing iso-osmolar contrast media (IOCM) with low-osmolar contrast media (LOCM) in patients undergoing clinically indicated coronary OCT imaging. Patients were randomly assigned to undergo OCT imaging with either IOCM or LOCM as the initial contrast medium. Following a washout period, a second run of OCT imaging of the same coronary vessel was performed using the other contrast medium. A total of 62 patients were randomized to IOCM first (n = 31) or LOCM first (n = 31). Mean patient age was 65.9 ± 11.2 years and 74.2% were male, with high prevalence of dyslipidemia (82.3%) and prior myocardial infarction (41.9%). Percutaneous coronary intervention was performed in 60 cases (96.8%) and the left anterior descending artery was the most common target vessel (53.3%). The contrast volume used for OCT imaging was similar for IOCM and LOCM (8.0 [6.9, 9.0] mL vs 8.0 [6.7, 9.0] mL; P = .89), as was the length of clear OCT images (70.0 [62.8, 74.0] mm for IOCM vs 70.0 [64.0, 74.0] mm for LOCM; P = .65). Electrocardiographic changes were observed in 11 runs with IOCM (ventricular repolarization changes in 9 runs and premature ventricular contractions [PVCs] in 2 runs) vs 12 runs with LOCM (ventricular repolarization changes in 9 runs and PVCs in 3 runs). The use of IOCM in coronary OCT is associated with similar contrast volume and clear imaging length when compared with LOCM.

Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy - the Difference between Iso-Osmolar and Low-Osmolar Contrast Media.

Symptomatic intracranial hemorrhage (SICH) after mechanical thrombectomy (MT) is generally considered a critical complication. Hemorrhagic transformation after ischemic stroke has also been associated with contrast media administration. The objective of our study was to evaluate correlations between contrast media type and incidence of SICH after MT. Ninety-three consecutive patients (41 men; mean age, 80.2 years; range, 44-98 years) underwent MT reperfusion (expanded thrombolysis in cerebral infarction score, 2a-3) for acute large-vessel occlusion ischemic stroke within 8 h after symptom onset between April 2020 and July 2023 were retrospectively reviewed. Correlations between contrast media type (iso-osmolar or low-osmolar medium) and incidence of SICH were assessed. Contrast media were iso-osmolar in 60 cases or low-osmolar in 33 cases. The overall incidence of SICH was 5.5%. The frequency of SICH was significantly lower in the iso-osmolar group (1.7%) than in the low-osmolar group (12.1%; P = 0.033). Iso-osmolar contrast media was associated with a lower incidence of SICH compared with low-osmolar contrast media in patients after MT.

Effects of Low-Osmolar Contrast Media on Long-Term Renal Impairment After Coronary Angiography: Iohexol Versus Iopromide

To investigate the long-term effects of 2 commonly used low-osmolar contrast media, iohexol and iopromide, on renal function and survival in patients who underwent coronary angiography. A total of 14,141 cardiology patients from 2006 to 2013 were recruited, of whom 1,793 patients (679 patients on iohexol and 1,114 on iopromide) were evaluated for long-term renal impairment and 5,410 patients (1,679 patients on iohexol and 3,731 on iopromide) were admitted for survival analyses spanning as long as 15years. Univariate and multivariate logistic regression were used to explore the risk factors for long-term renal impairment. Cox proportional hazard regression was used to investigate the risk factors affecting survival. Propensity score matching and inverse probability of treatment weighting were applied to balance the baseline clinical characteristics. Patients receiving iohexol demonstrated a greater occurrence of renal impairment compared with those who received iopromide. Such difference remained consistent both before and after propensity score matching or inverse probability of treatment weighting, with a statistical significance of p <0.05. Among clinical variables, receiving contrast-enhanced contrast tomography/magnetic resonance imaging during follow-up, antihypertensive medication usage, presence of proteinuria, and anemia were identified as risk factors for long-term renal impairment (p = 0.041, 0.049, 0.006, and 0.029, respectively). During survival analyses, the difference was insignificant after propensity score matching and inverse probability of treatment weighting. In conclusion, administration of iohexol was more likely to induce long-term renal impairment than iopromide, particularly among patients diagnosed with anemia and proteinuria and those taking antihypertensive medication and with additional contrast exposure. The all-cause mortality, however, showed no significant difference between iohexol and iopromide administration.

Efficacy and Safety of Iodixanol in Computed Coronary Tomographic Angiography and Cardiac Catheterization.

Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

Different outcomes between iso-osmolar and low-osmolar contrast media in acute myocardial infarction with renal impairment.

The selection of appropriate contrast media (CM) remains an important issue in terms of renal preservation in patients with acute myocardial infarction (AMI) and renal impairment scheduled for percutaneous coronary intervention (PCI). We compared the clinical outcomes of patients with AMI and renal impairment, depending on the CM type (iso-osmolar CM [IOCM] vs. low-osmolar CM [LOCM]) that was used during PCI. From the Convergent Registry of Catholic and Chonnam University for Acute Myocardial Infarction, 3174 post-PCI patients with AMI and renal impairment were subdivided into two groups (IOCM [n = 2101] and LOCM [n = 1073]). Regarding in-hospital clinical outcomes, the IOCM group had a higher peak creatinine (Cr) level and lower "Cr differential" than the LOCM group. A higher proportion of dialysis was noted in the IOCM group. In 30-day clinical outcomes, the IOCM group showed higher incidence of new-onset heart failure (HF) but lower incidence of revascularization than the LOCM group. The differences in in-hospital and 30-day clinical outcomes were attenuated after inverse probability of treatment weighting, except for new-onset HF. All other variables in 30-day clinical outcomes, including all-cause death, non-fatal myocardial infarction, cerebrovascular accidents, stent thrombosis, and any dialysis events, were similar between the two groups. IOCM use did not prevent future incidence of dialysis compared to LOCM use in AMI patients with renal impairment.

Stroke in a patient of anaphylaxis—a case report and brief review

BackgroundThe use of nonionic low-osmolar contrast media has significantly reduced the risk of hypersensitivity reactions. Despite this, severe reactions continue to occur unpredictably. An ischemic stroke in the setting of anaphylaxis is extremely rare.Case reportA 64-year-old male with no prior allergies went into anaphylactic shock following the administration of iohexol which improved after treatment. He later developed a multi-territorial ischemic stroke.ConclusionAn ischemic stroke in the setting of an anaphylaxis is a rare occurrence, which can be attributed to multiple factors in our patient.

A Study of Management of Adverse Reaction to Iodinated Contrast Media used in Computed Tomography at UCMS-TH

INTRODUCTION: Iodinated contrast media is used in computed tomography imaging to enhance the visibility of blood vessels and tissues. They have distinct clinical effectiveness and toxicity profiles. Although low osmolar contrast media have made iodinated contrast media safer in recent years, adverse reactions can sometimes occur. The management of adverse reactions to iodinated contrast media is an important aspect of patient care during computed tomography examinations. The purpose of this study was to evaluate the management of adverse reactions to iodinated contrast media during contrast-enhanced computed tomography examinations at Universal College of Medical Sciences and Teaching Hospital, Bhairahawa, Nepal. MATERIALS AND METHODS: A prospective, observational study was conducted on 323 patients at Department of Radiodiagnosis and Medical Imaging, Universal College of Medical Sciences and Teaching Hospital, Bhairahawa, Nepal, from December 15, 2022 to May 15, 2023. All data was obtained from the Department of Radiodiagnosis and Medical Imaging, as per the study inclusion criteria. The data were analyzed with statistical package for the social sciences version 20. RESULTS: The mean age of study participants was 48.49±19.78 years. There were 34.67% male and 65.33% female patients involved in this study. Universal College of Medical Sciences and Teaching Hospital favoured a more strict approach, to determine the normal renal function and withhold metformin before iodinated contrast media exposure. 36.84% of patients had a history of previous adverse reactions, before undergoing contrast-enhanced computed tomography scans. Following iodinated contrast media administration, 94.74% experienced nausea and vomiting which was followed by mild urticarial (88.54%) and dyspnea (19.81%). Premedication protocol was predominantly implemented with antihistamine, pheniramine (73.1%), and corticosteroid, hydrocortisone (26.9%). Mild urticaria was treated with pheniramine (87.1%), nausea and vomiting was treated with metoclopramide (83.01%), dyspnea was treated by epinephrine, hydrocortisone and oxygen (9.38%). CONCLUSIONS: Universal College of Medical Sciences and Teaching Hospital has established a standard protocol for the management of adverse reactions experienced by patients during iodinated contrast media administration. Premedication with antihistamines and corticosteroids was recommended for highrisk patients.

CARD24: Protective Effect of HemoTech - Blood Substitute Against Contrast Media-Induced Endothelial Toxicity: An In Vitro Study

Background: Although the most common complication after intravascular administration of iodinated contrast media (CM) is contrast-induced nephropathy (CIN) there is some evidence suggesting CM toxicity to endothelial cells (EC). CIN mechanism is well defined and includes medullary ischemia and direct toxicity to renal tubular cells. The mechanism of CM-associated EC damage is still unclear. The purpose of this study was twofold: (1) to determine the response of normal and ischemic coronary artery EC to low-osmolar nonionic CM commonly used in percutaneous coronary interventions (PCI) and (2) to evaluate the protective effect of HemoTech used concomitantly with CM. HemoTech is Hb-based blood substitute pharmacologically modified with vasodilators, anti-inflammatory and antioxidant agents: ATP, adenosine and reduced glutathione (GSH), and is in the preclinical development phase of its intended use as perfusion fluid for PCI. Methods: In this study human coronary artery EC (Clonetics, Bio-Whittaker, San Diego, CA) were subcultured in EGM-MV medium to confluence on cover slips and 6-well cell cultured plates in a humidified atmosphere of 5% CO2 and 37 deg C. To mimic ischemia, EC were depleted from GSH by 24 hr treatment with 200 uM of BSO (L-buthionine-[S,R]-sulphoximine).Then, normal and ischemic EC were exposed for 1, 2, 4 and 18 hrs to 50 uL/mL of low-osmolar nonionic iodinated CM Optiray 350 (Ioversol Injection 74%, Mallinckrodt Pharmaceuticals) alone or with 0.4 mM of HemoTech and assessed for cellular redox state and oxidative stress (GSH, TBARS), inflammatory response (VCAM-1) and early and late apoptosis. Results: The results demonstrate a different response of normal and ischemic EC to CM. While normal EC showed delayed mild reaction, a response of ischemic EC was immediate and intensifies with time. In normal EC there was a depletion of GSH from 24.1±1.5 to 18.5±1.1 nM/mg protein (p<0.05) at 18 hr; however without changes in TBARS and only insignificant expression of VACAM-1 in the absence of apoptosis. On the contrary, CM showed to strongly affect ischemic EC causing further redox imbalance. At 2 hr GSH dropped from 13.6±0.9 to 10.3±0.6 (p<0.05) and progressively decreased to 9.1±0.5 (p<0.01) at 4 hr and 7.5±0.4 (p<0.001) at 18 hr. TBARS progressively increased from 0.84±0.03 to 0.98±0.04 nM/mg protein (p<0.05) at 2 hr, 1.1±0.07 (p<0.01) at 4 hr and 1.44±0.12 (p<0.001) at 18 hr. A slight expression of VACAM-1 was noted at 4 hr that reached the peak at 18 hr (p<0.01). Early apoptosis was detected at 18 hr. HemoTech treatment effectively restored the redox balance in ischemic EC and alleviated inflammatory and apoptotic responses to CM. All tested parameters were in normal range. Conclusions: Low-osmolar nonionic iodinated CM is well tolerated by normal but not ischemic coronary artery EC. HemoTech blood substitute with pharmacological properties of ATP, adenosine and GSH protects ischemic EC against CM-induced toxicity.

Surgical Mortality Risk Scores in Transcatheter Aortic Valve Implantation: Is Their Early Predictive Value Still Strong?

Surgical mortality risk scores, even if not properly designed and rarely tested in the transcatheter aortic valve implantation (TAVI) setting, still guide the heart team in managing significant aortic stenosis. After splitting 1763 consecutive patients retrospectively based on their mortality risk thresholds, the composite endpoint early safety (ES) was adjudicated according to Valve Academic Research Consortium (VARC)-2 and -3 consensus documents. ES incidence was higher if VARC-2 rather than VARC-3 defined. Despite only patients showing VARC-2 ES had significantly lower absolute values of all three main risk scores, these last still failed to foresee both VARC-2 and -3 ES in intermediate-risk patients. The receiver operating characteristic analysis also showed a significant correlation, but with poor diagnostic accuracy, among the three scores and only VARC-2 ES; moreover, the absence of VARC-2 ES and low-osmolar contrast media administration were identified as independent predictors of 1-year mortality and absence of VARC-3 ES, respectively. Finally, even a single complication included in the ES definition could significantly affect 1-year mortality. Currently, the most used mortality risk scores do not have adequate diagnostic accuracy in predicting ES after TAVI. The absence of VARC-2, instead of VARC-3, ES is an independent predictor of 1-year mortality.

Incidence and severity of nonionic low-osmolar iodinated contrast medium-related adverse drug reactions in the Republic of Korea: Comparison by generic.

We aimed to report the incidence and severity of nonionic low-osmolar iodine contrast medium (ICM)-related adverse drug reactions (ADRs) in the Republic of Korea, by analyzing data from our single tertiary institution and published Korean reports, and to determine whether there is a difference in the incidence of ICM-related ADR by ICM generics. A total of 1,161,419 consecutive contrast-enhanced computed tomography (CT) examinations between January 2016 and December 2021 at Asan Medical Center were included. A systematic search of the literature investigating the incidence of ICM-related ADR in the Republic of Korea published up to December 31, 2021 was performed. We pooled these outcomes with those of our study using a binomial-normal model, and the pooled incidences of ADRs were compared among ICM generics using chi-square tests. Seven studies with a total of 2,570,986 contrast-enhanced CT examinations from 12 institutions were included. The pooled incidences of overall, mild, moderate, and severe ICM-related ADRs in the Republic of Korea were 0.82% (95% CI: 0.61%-1.10%), 0.72% (95% CI: 0.50%-1.04%), 0.11% (95% CI: 0.08%-0.15%), and 0.013% (95% CI: 0.010%-0.018%), respectively. In multiple pairwise comparisons, there were no significant differences in the overall incidence of ADRs between ICM generics, except iomeprol versus iobitridol and iomeprol versus iohexol. For moderate and severe ADRs, there were no significant differences in ADR incidence between ICM generics. The incidence of moderate and severe ICM-related ADRs did not differ among ICM generics. Our results suggest that no restriction is required for selection among nonionic low-osmolar ICMs.

Preventing contrast-induced acute kidney injury with probucol and hydration in patients with coronary heart disease: A systematic review and meta-analysis of randomized controlled trials.

Preventing contrast-induced acute kidney injury (CI-AKI) is critical because of its association with poor clinical outcomes, including extended hospital stays and increased mortality. The effects of probucol on preventing CI-AKI have been controversial. Therefore, this systematic review and meta-analysis evaluated the influence of probucol combined with hydration on the CI-AKI risk in patients with coronary heart disease undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI). We retrieved data from the following databases from their inception to May 29, 2022: PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database (Sinomed), Wanfang Database, and Chinese Scientific Journal Database. The methodological quality of the trials was assessed following the Cochrane Handbook guidelines, and Review Manager 5.3 and Stata 14.0 software were used for the data analysis. We included 14 trials comprising 3306 patients in the analysis. All included trials reported the CI-AKI incidence rate (the primary outcome). Probucol with hydration significantly reduced the CI-AKI incidence compared to hydration alone (odds ratio [OR]: 0.33, 95% confidence interval [CI]: 0.25-0.44, P < .001). Subgroup analyses were performed based on the contrast medium type (iso-osmolality vs low-osmolality contrast medium [LOCM]) and volume (less than or more than 200 mL); the effects of probucol with hydration versus hydration-only on CI-AKI were comparable within each subgroup. Additionally, the serum creatinine (Scr) concentration 24 hours, 48 hours, and 72 hours and the estimated glomerular filtration rate (eGFR) 72 hours after contrast exposure were better in the probucol with hydration group than the hydration-only group. Finally, major clinical adverse events and adverse drug reactions were comparable between the probucol with hydration and hydration-only groups. Probucol with hydration decreases the CI-AKI incidence compared to hydration only in patients with coronary heart disease undergoing CAG or PCI. However, more high-quality, large-sample, multicenter randomized trials are needed to confirm this conclusion.

Early acute kidney injury after transcatheter aortic valve implantation: predictive value of currently available risk scores.

Acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI) is a frequent complication associated with adverse outcomes and mortality. Various scores have been developed to predict this complication in the coronary setting. However, none have ever been tested in a large TAVI population. This study aimed to evaluate the power of four different scores in predicting AKI after TAVI. Overall, 1535 consecutive TAVI patients from the observational multicentric "Magna Graecia" TAVI registry were included in the analysis. Of the study population, 235 (15.31%) developed AKI early. The Mehran, William Beaumont Hospital, CR4EATME3AD3, and ACEF scores were calculated retrospectively. The patients who developed TAVI-related AKI had significantly higher absolute values of all risk scores than those who did not. The receiver-operating characteristic analysis also showed a significant correlation between these four scores and AKI, but without a significant difference among all of them (p value=0.176). Nevertheless, based on their area under the curve values (≤0.604 for all), none had adequate diagnostic accuracy in predicting TAVI-related AKI. Importantly, multivariate analysis identified myocardial revascularization close to the TAVI procedure and implantation of self-expanding prostheses, as well as atrial fibrillation, low-osmolar contrast media administration, corrected contrast medium volume, and any transfusion (p value<0.05 for all) as independent risk factors for AKI. Although high values of current AKI risk scores are significantly associated with the development of this complication, these are not sufficiently accurate. Further studies are needed so that a TAVI-dedicated AKI risk score may be created.

Differential renal proteomics analysis in a novel rat model of iodinated contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI), which occurs after the use of iodinated contrast media, has become the third leading cause of hospital-acquired acute kidney injury (AKI). It is associated with prolonged hospitalization and increased risks of end-stage renal disease and mortality. The pathogenesis of CI-AKI is unclear and effective treatments are lacking. By comparing different post-nephrectomy times and dehydration times, we constructed a new, short-course CI-AKI model using dehydration for 24 h two weeks after unilateral nephrectomy. We found that the low-osmolality contrast media iohexol caused more severe renal function decline, renal morphological damage, and mitochondrial ultrastructural alterations compared to the iso-osmolality contrast media iodixanol. The shotgun proteomics based on Tandem Mass Tag (TMT) was used to conduct proteomics research on renal tissue in the new CI-AKI model, and 604 distinct proteins were identified, mainly involving complement and coagulation cascade, COVID-19, PPAR signalling pathway, mineral absorption, cholesterol metabolism, ferroptosis, staphylococcus aureus infection, systemic lupus erythematosus, folate biosynthesis, and proximal tubule bicarbonate reclamation. Then, using parallel reaction monitoring (PRM), we validate 16 candidate proteins, of which five were novel candidates (Serpina1, Apoa1, F2, Plg, Hrg) previously unrelated to AKI and associated with an acute response as well as fibrinolysis. The pathway analysis and 16 candidate proteins may help to discover new mechanisms in the pathogenesis of CI-AKI, allowing for early diagnosis and outcome prediction.

Acute severe thrombocytopenia following iodinated radiographic contrast medium infusion: a case report.

The authors report the case of a 79-year-old male patient with severe, life-threatening thrombocytopenia after administration of intravenous nonionic low-osmolarity contrast medium. His platelet count dropped from 179×109/l to 2×109/l after 1h of radiocontrast infusion. Which has returned gradually to normal level within days with corticosteroid administration and platelet transfusion. Iodinated contrast-induced thrombocytopenia is a rare complication with an unknown causative mechanism. There is no definitive treatment for this condition, with corticosteroids being used in most cases. The platelet count normalizes within a few days regardless of any interventions, but supportive treatment is important to avoid any unwanted complications. Further studies are still needed for a better understanding of the exact mechanism of this condition.

A novel contrast-induced acute kidney injury mouse model based on low-osmolar contrast medium

The contrast-induced acute kidney injury (CI-AKI) has been becoming the third common cause of hospital-acquired acute kidney injury. An ideal animal model is essential for understanding the pathophysiology of CI-AKI. Previous CI-AKI studies were mostly performed on rats with high-osmolar contrast medium (HOCM), which is unsuitable for transgenic researches. This study provides a novel, efficient and reproducible CI-AKI model which was developed in mouse by administrating a low-osmolar contrast medium (LOCM). First of all, we applied the frequently used pretreatments (uninephrectomy and water deprivation), which combined with HOCM on rats could induce CI-AKI, on mice with LOCM. Secondly, we attempted to find a novel pretreatment suitable for mouse and LOCM by combining two classic pretreatments(uninephrectomy, water deprivation and furosemide administration). Finally, we evaluate the kidney damage of the novel model. We found that this mouse model possessed a significant reduction in renal function, severe renal tissue damage, and increased renal tubular cells apoptosis, indicating that LOCM is a feasible inducer for CI-AKI mice model. Taken together, we found that uninephrectomy (UPHT) combined with 24 h water deprivation and furosemide administration 20 min before LOCM (iohexol, 10 ml/kg) application is a feasible pretreatment to establish a novel CI-AKI mouse model.

Urinary excretion of low-osmolar contrast media during small-bowel follow-through studies in infants is not definitive evidence of bowel perforation.

Presence of contrast agent in the urinary system in infants after small-bowel follow-through study with low-osmolar contrast media has been described as a sign of bowel perforation. To evaluate how often the presence of contrast agent in the bladder after small-bowel follow-through is a reliable sign of bowel perforation or necrosis. From the radiology information system, we retrieved imaging reports of infants evaluated with small-bowel follow-through and findings of contrast agent in the bladder. We retrieved demographic and clinical information from the medical records. Presence of bladder contrast medium was considered true-positive evidence of bowel perforation or necrosis if confirmed by pneumoperitoneum, extraluminal contrast agent, surgery or pathology within 3days of the small-bowel follow-through. False-positives for bowel perforation or necrosis were based on surgical findings or clinical follow-up. Of the 207 infants who had small-bowel follow-through, 18 infants (12 boys; mean age 50days, range 14days to 8.5months) had contrast medium in the bladder after the small-bowel follow-through. Fifteen of the 18 (83.3%) had a history of prematurity and 11 had prior abdominal surgery. Four of the 18 (22.2%) had bowel perforation or necrosis at surgery or pathology performed more than 3days after the small-bowel follow-through and were considered indeterminate and excluded. Eight of the remaining 14 infants (57.1%) had bowel perforation or necrosis based on surgical evidence of perforation or pathology confirmation of necrosis (n=6), pneumoperitoneum (n=1) or contrast agent leakage from enterocutaneous fistula (n=1). Six of the 14 (42.9%) were false-positives, without evidence of bowel perforation or necrosis based on clinical follow-up (n=4) or surgery (n=2). Demonstration of urinary contrast agent post small-bowel follow-through with low-osmolar contrast medium in newborns/infants with complex medical problems is not a definitive indication of bowel perforation or necrosis. More than one-third of our patients with contrast medium in the bladder did not have bowel perforation or necrosis.

EE272 Economic Burden Associated with ISO-Osmolar Versus Low Osmolar Iodinated Contrast Media during Peripheral Endovascular Procedures: Evidence from Premier Database

Iodinated contrast media are used in most interventional revascularization procedures. Several prior studies have demonstrated lower incidence of adverse clinical outcomes associated with iso-osmolar iodinated contrast media (IOCM) compared with low-osmolar contrast media (LOCM), including a recent analysis in comorbid patients with peripheral arterial disease (PAD). The objective of this study was to evaluate association of IOCM and LOCM use with direct costs and length of hospital stay in PAD patients undergoing endovascular interventions.

The Influence of Low and Iso-osmolar Contrast Media on Diagnostic Performance of Contrast Fractional Flow Reserve Measurement.

For fractional flow reserve measurement, contrast media can be used as an alterna- tive for adenosine. However, contrast media with different physical characteristics (e.g., osmo- lality and viscosity) may have different effects on hyperemia. This study aimed to determine if the diagnostic accuracy of contrast fractional flow reserve was influenced by 2 commonly used contrast media (Visipaque and Ultravist). In this diagnostic study, candidates for coronary angiography with intermediate cor- onary lesion were enrolled and randomized to receive either an iso-osmolar contrast media (Visipaque) or a low osmolar contrast media (Ultravist) for fractional flow reserve measure- ment. The gold standard was fractional flow reserve measured by adenosine fractional flow reserve. Then cFFR and adenosine fractional flow reserve were compared between the groups, and the diagnostic values of both contrasts were calculated. Finally, the cut-point for diagnos- ing adenosine fractional flow reserve ≤ 0.8 was calculated for cFFR in both groups. In this study, 46 patients were studied (24 patients received Ultravist and 22 patients received Visipaque). There was no significant difference between the groups in adenosine frac- tional flow reserve. Also, the mean cFFR was not different from the mean adenosine fractional flow reserve in both groups. There was a strong correlation between cFFR and adenosine frac- tional flow reserve for each of the contrasts (r = 0.937 for Ultravist and r = 0.927 for Visipaque). Both contrasts had high specificity to diagnose fractional flow reserve ≤ 0.8 (specificity = 1), and the sensitivities of cFFR for Ultravist and Visipaque were 83.3% and 94.7%. The cut-point to predict adenosine fractional flow reserve ≤ 0.80 was 0.845 for Ultravist and 0.835 for Visipaque. Both iso-osmolar or low osmolar contrast media have an acceptable diagnostic accuracy in measuring cFFR.

Evaluating the Effectiveness of Pretreatment With Intravenous Fluid in Reducing the Risk of Developing Contrast-Induced Nephropathy: A Systematic Review and Meta-Analysis.

Contrast media administration to patients during cardiac events increases the risk of developing contrast-induced nephropathy (CIN). CIN is among some complications usually associated with the percutaneous coronary intervention and may result in acute renal failure. Several risk factors are associated with CIN. These risk factors include; age (elderly patients), pre-existing renal impairment, diabetes mellitus, and the use of high osmolar contrast media. Studies have shown that several measures such as using low osmolar contrast media, N-acetylcysteine, intravenous sodium bicarbonate, and hydration through oral or intravenous fluid administration play a significant role in CIN incidence reduction. Hydration using intravenous fluid, especially saline solution, has been critical in preventing CIN. Prehydration using the intravenous fluid before contrast media administration is vital.A systematic literature search with meta-analysis for relevant and original articles was carried out from 2000 to 2022 on databases such as PubMed, Cochrane Library, Google Scholar, ScienceDirect, Web of Science, and Embase. The search on the databases was based on various keywords related to intravenous fluid and CIN. The studies that met the inclusion criteria were critically analyzed, and data such as study design, interventions, participants, and outcomes of the research were retrieved.Out of the 784 results yielded during the initial search, ten articles met the eligibility criteria and were included in the study. The data analysis obtained from the included studies showed that pretreatment using intravenous fluid has conflicting results. Some studies showed that hydrating patients using intravenous fluid before contrast media administration significantly reduces the risk of CIN. In contrast, others claimed that intravenous fluid has minimal impact on preventing CIN.Despite the different investigations conducted on CIN, it remains insufficiently understood. From the analysis, most of the studies support that intravenous fluid administration decreases the occurrence of CIN in patients that receive contrast media. The analysis also has established that oral hydration is similar to intravenous fluid administration in reducing CIN incidence.