Impact on clinical practice of updated guidelines on iodinated contrast material: CINART.

OBJECTIVE: Guidelines on safe use of iodinated contrast material recommend intravenous prophylactic hydration to prevent post-contrast adverse (renal) effects. Recently, guidelines have been updated and standard prophylaxis is no longer recommended for the majority of patients. The current study aims to evaluate the consequences for clinical practice of the updated guidelines in terms of complications, hospitalisations, and costs. METHODS: The Contrast-Induced Nephropathy After Reduction of the prophylaxis Threshold (CINART) project is a retrospective observational study. All elective procedures with intravascular iodinated contrast administration at Maastricht University Medical Centre (UMC+) in patients aged > 18 years, formerly eligible for prophylaxis (eGFR 30-44 ml/min/1.73 m2 or eGFR 45-59 ml/min/1.73 m2 in combination with diabetes or > 1 predefined risk factor), and currently eligible for prophylaxis (eGFR < 30 ml/min/1.73 m2) were included. Data were used to calculate relative reductions in complications, hospitalisations, and costs associated with standard prophylactic intravenous hydration. CINART is registered with Clinicaltrials.gov: NCT03227835. RESULTS: Between July 1, 2017, and July 1, 2018, 1992 elective procedures with intravascular iodinated contrast in patients formerly and currently eligible for prophylaxis were identified: 1808 in patients formerly eligible for prophylaxis and 184 in patients currently eligible for prophylaxis. At Maastricht UMC+, guideline updates led to large relative reductions in numbers of complications of prophylaxis (e.g. symptomatic heart failure; - 89%), extra hospitalisations (- 93%), and costs (- 91%). CONCLUSION: Guideline updates have had a demonstrable impact on daily clinical practice benefiting patient, hospital, and health care budgets. Clinical practice varies between institutions and countries; therefore, a local estimation model is provided with which local impact on costs, hospitalisations, and complications can be calculated. KEY POINTS: • Clinical practice guidelines recommend prophylactic intravenous hydration to prevent post-contrast adverse outcomes such as contrast-induced acute kidney injury. • Clinical practice guidelines have recently been updated, and standard prophylaxis is no longer recommended for the majority of patients. • The guideline updates have a large impact on daily clinical practice: relative reductions at Maastricht UMC+ were - 89% prophylaxis complications, - 93% hospitalisations, and - 91% costs, and similar reductions are expected for Dutch and adherent European medical centres.

The influence of arm positions on abdominal image quality of whole-body computed tomography in trauma: systematic review.

PURPOSE: Whole-body computed tomography (WBCT) is the standard diagnostic method for evaluating polytrauma patients. When patients are unable to elevate their arms, the arms are placed along the body, which affects the image quality negatively. Aim of this systematic review is to evaluate the influence of below the shoulder arm positions on image quality of WBCT. METHODS: Literature in PubMed and Scopus databases was systematically searched. Results of the papers were stratified into 4 categories: arms elevated, 1 arm up 1 arm down, arms ventrally supported, arms along the body. A qualitative analysis was performed on subjective image quality and a quantitative analysis on objective quality (image noise). RESULTS: Eight studies were included with 1421 participants. Various studies reported significantly higher quality scores with arms elevated, compared to arms along the body. Significant differences in objective image quality were found between the arms elevated and the arms ventrally on support group. The arms ventrally supported group had a significantly higher image quality than the arms along the body group. A statistically significant difference was found in objective image quality between the 1 arm up 1 arm down and arms along the body group. No preferential below the shoulders position could be identified. CONCLUSION: Positioning the arms alongside the body results in a poor image quality. Placing the arms on a pillow ventrally to the chest improves image quality. Interestingly, asymmetrical arm positioning has potential to improve the image quality for patients that are unable to elevate the arms.

[Serious complications of umbilical venous catheterisation]. / Ernstige complicaties van een navelvenelijn.

Three male newborns, born at 30 weeks, 36 weeks and at term, respectively, developed serious complications related to umbilical venous catheters. The first patient had persistent bacteraemia due to a cardiac thrombus. He recovered after treatment. In the second patient, the umbilical venous catheter was placed in the pericardial sac, causing accumulation of parenteral nutrition and fatal cardiac tamponade. In the third patient, the umbilical catheter was positioned in the liver, leading to extravasation of parenteral nutrition in the liver and peritoneal cavity. At follow-up, he had developed an atrial septum defect, hypotonia and developmental retardation. Umbilical venous catheterisation has been used in neonatal intensive care units for more than 50 years to allow continuous infusion of medication, fluids and nutrition. However, the use of umbilical venous catheters can be associated with severe infectious, thrombotic and traumatic complications. Therefore, umbilical venous catheterisation requires a critical assessment of the need, alternatives and possible complications.

Reduction of reperfusion injury of human myocardium by allopurinol: a clinical study.

To determine the possibility of myocardial protection against reperfusion injury by allopurinol, 22 aortocoronary bypass patients were studied. Eight patients received allopurinol (200 mg during induction of anesthesia and 100 mg after starting extracorporeal circulation) during surgery (group B), and 14 patients served as a control (group A). Blood samples and myocardial biopsies were taken before and 10 min after aortic cross-clamping. No statistically significant difference between the two groups was observed considering gender, age, prior myocardial infarction, left ventricular end diastolic pressure (LVEDP), and aortic cross-clamp time. Preservation of cardiac tissue was assessed by the measurement of quantitative birefringence (QBR) changes upon the addition of adenosine 5'-triphosphate (ATP) plus calcium in biopsies and the need for postoperative inotropes. The synthesis of peroxides was estimated by the measurement of leukotriene B4 and C4 (LTB4, LTC4). LTB4 was below the level of detection (< 1.5 ng/l) before and after cross-clamping in both groups, while the LTC4 level for group A increased from < 1.5 to 27 +/- 17 ng/l compared to an increase of < 1.5 to 11 +/- 8 ng/l for group B after 10 min of reperfusion (p = .036). The decrease in QBR value in group A was 1.26 +/- 0.28 and 0.35 +/- 0.23 for group B (p < .003). Postoperatively, 11 out of 14 patients in group A needed inotropic support (dopamine or dobutamine), whereas two patients out of eight did so in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of hepatic lipogenesis by salicylate.

Salicylate has been found to be an inhibitor of fatty acid synthesis in isolated rat hepatocytes. Half-maximal inhibition of fatty acid synthesis occurs at approximately 2 mM. The inhibitory effect of salicylate on fatty acid synthesis is not relieve by the addition of acetate, suggesting that salicylate inhibits the conversion of acetate into fatty acids. Acetyl-CoA carboxylase activity in homogenates of hepatocytes is not influenced by previous exposure of the intact cells to salicylate. Partially purified acetyl-CoA carboxylase, isolated and assayed in the absence of citrate, is markedly inhibited by salicylate. However, in the presence of 0.5 mM citrate, which is the concentration of this metabolite in the cytosol of the liver cell, salicylate activates the enzyme. Upon treatment of acetyl-CoA carboxylase with salicylate (in the absence or presence of citrate), followed by separation of enzyme and effector on a Sephadex G-25 column, the enzyme activity is enhanced as compared to the salicylate-free control, demonstrating that the inhibitory effect of salicylate (in the absence of citrate) is reversible, but not the stimulatory effect (in the presence of citrate). Salicylate inhibition of fatty acid synthesis by hepatocytes is not rapidly reversible; hepatocytes preincubated with salicylate followed by a wash procedure (centrifugation and resuspension) still show depressed rates of fatty acid synthesis from acetate upon further incubation. Salicylate was found to prevent pyruvate accumulation in hepatocyte suspensions observed in the absence of this compound; salicylate even induces the disappearance of pyruvate and lactate initially present in the cell suspension. This suggests that salicylate activates pyruvate and lactate consumption, which is most likely related to the well-known fact that salicylate uncouples oxidative phosphorylation. The latter action of the drug will stimulate citric acid-cycle activity. This causes an inhibition of fatty acid and cholesterol synthesis since acetyl units will be specifically channelled into the citric acid cycle and not into the lipogenic pathway. It is concluded that part of the inhibitory effect of salicylate on fatty acid biosynthesis is exerted at (a) step(s) in the conversion of acetate into fatty acids, acetyl-CoA carboxylase not being a target of this compound. In addition, salicylate prevents that pyruvate, generated by glycolysis, enters the lipogenic pathway. The latter effect of salicylate would also explain the observed inhibition of cholesterol synthesis by this compound.

Inhibition of lipogenesis in isolated hepatocytes by 3-amino-1,2,4-triazole.

3-Amino-1,2,4-triazole has been found to be an inhibitor of fatty acid synthesis by isolated rat hepatocytes. Half-maximal inhibition of fatty acid synthesis occurs at approximately 20mM. Acetyl-CoA carboxylase activity in homogenates of hepatocytes is not affected by previous exposure of the intact cells to 3-amino-1,2,4-triazole. The drug opposes the activation of partially purified acetyl-CoA carboxylase by citrate, but does not influence enzyme activity in the absence of citrate. As compared to fatty acid synthesis, cholesterol synthesis by the hepatocytes is more drastically depressed by incubation of the cells with 3-amino-1,2,4-triazole. Half-maximal inhibition of cholesterogenesis occurs at approximately 5 mM 8-amino-1,2,4-triazole.

Inhibition of hepatic cholesterol biosynthesis by chloroquine.

Chloroquine is shown to be a potent inhibitor of cholesterol biosynthesis by isolated rat hepatocytes. Half-maximal inhibition of cholesterogenesis occurs at ca. 10 micro M chloroquine. Chloroquine does not affect fatty acid synthesis by isolated hepatocytes. This suggests that chloroquine acts on the cholesterol biosynthetic pathway beyond the cytosolic acetyl-coA branchpoint of cholesterol and fatty acid synthesis.

Small bowel metastases from malignant melanoma.

Metastases of malignant melanoma to the small bowel are only rarely seen by the radiologist. In the majority of cases small bowel invasion causes only aspecific symptoms. Gastro-intestinal bleeding is frequently the first specific complaint. Enteroclysis is the most appropriate technique for demonstrating mucosal abnormalities. CT however is not only more sensitive but it also better delineates local and mesenteric involvement.

Randomised trial of no hydration vs. sodium bicarbonate hydration in patients with chronic kidney disease undergoing acute computed tomography-pulmonary angiography.

BACKGROUND: Hydration to prevent contrast-induced acute kidney injury (CI-AKI) induces a diagnostic delay when performing computed tomography-pulmonary angiography (CTPA) in patients suspected of having acute pulmonary embolism. AIM: To analyze whether withholding hydration is non-inferior to sodium bicarbonate hydration before CTPA in patients with chronic kidney disease (CKD). METHODS: We performed an open-label multicenter randomized trial between 2009 and 2013. One hundred thirty-nine CKD patients were randomized, of whom 138 were included in the intention-to-treat population: 67 were randomized to withholding hydration and 71 were randomized to 1-h 250 mL 1.4% sodium bicarbonate hydration before CTPA. Primary outcome was the increase in serum creatinine 48-96 h after CTPA. Secondary outcomes were the incidence of CI-AKI (creatinine increase > 25%/> 0.5 mg dL(-1) ), recovery of renal function, and the need for dialysis within 2 months after CTPA. Withholding hydration was considered non-inferior if the mean relative creatinine increase was ≤ 15% compared with sodium bicarbonate. RESULTS: Mean relative creatinine increase was -0.14% (interquartile range -15.1% to 12.0%) for withholding hydration and -0.32% (interquartile range -9.7% to 10.1%) for sodium bicarbonate (mean difference 0.19%, 95% confidence interval -5.88% to 6.25%, P-value non-inferiority < 0.001). CI-AKI occurred in 11 patients (8.1%): 6 (9.2%) were randomized to withholding hydration and 5 (7.1%) to sodium bicarbonate (relative risk 1.29, 95% confidence interval 0.41-4.03). Renal function recovered in 80.0% of CI-AKI patients within each group (relative risk 1.00, 95% confidence interval 0.54-1.86). None of the CI-AKI patients developed a need for dialysis. CONCLUSION: Our results suggest that preventive hydration could be safely withheld in CKD patients undergoing CTPA for suspected acute pulmonary embolism. This will facilitate management of these patients and prevents delay in diagnosis as well as unnecessary start of anticoagulant treatment while receiving volume expansion.

A national survey on radiation dose in CT in The Netherlands.

OBJECTIVES: To assess radiation exposure due to CT in the Netherlands. METHODS: Twenty-one hospitals participated in a dose survey for the 21 most frequently used CT protocols. Hospitals completed a Web survey with detailed parameters for one patient per protocol, including the dose length product (DLP) from the scanner dose report. Only standard-sized patients (1.74 m and 77 kg and BMI 25.4 kg/m(2) ± 15 %) for each protocol and available scanner were considered. Effective dose (E) per protocol was estimated using ICRP-103-based E/DLP coefficients. Dose levels were compared to surveys from other countries and to diagnostic reference levels. RESULTS: Data of 186 patients (247 scan phases) from 14 hospitals and 19 scanners were used for final analysis of DLP and E. Effective doses varied from 0.2 mSv in sinus CT to 19.4 mSv for multiphase liver. The most frequent exams were brain (1.5 mSv), abdomen (8.0 mSv), and thorax-abdomen (11.5 mSv). These results are lower than in Germany and comparable to those in the UK, and are within reference levels. Results between hospitals varied, with per protocol minimum/maximum E ratios ranging from 1.1-5.4. CONCLUSIONS: Compared to surrounding countries, CT in the Netherlands is associated with relatively low radiation doses in standard patients. Important differences remain between hospitals. MAIN MESSAGES: • A national dose survey providing updated, detailed data for patient dose in the most frequently used CT protocols. • CT in the Netherlands is associated with relatively low individual radiation doses in standard patients compared to surrounding European countries. • Considerable differences remain between hospitals for the most frequently used CT protocols, indicating the need for further optimisation.

Nephrogenic systemic fibrosis and the role of gadolinium contrast media.

Nephrogenic system fibrosis is a rare disease affecting patients with severe renal insufficiency or dialysis. Its aetiology is incompletely understood. Evidence is growing that gadolinium contrast media is a major risk factor, whereby risk increases with larger cumulative doses. The role of other risk factors, such as inflammation or electrolyte disturbances, is less clear. All published cases to date received gadodiamide, gadopentetate or gadoversetamide, which are considered to be less stable due to a linear molecular structure. The aetiological significance of stability differences between the non-ionic linear, ionic linear and macrocyclic agents remains to be shown. For prevention, strict indications for MRI in risk patients can be combined with Food and Drug Administration (FDA) or European Medicines Agency (EMEA) guidelines. These recommend checking for renal impairment by history or laboratory tests. The FDA recommends avoidance of all gadolinium contrast media in patients with renal insufficiency grades 4 and 5 (glomerular filtration rate <30 mL/min per 1.73 m(2)) or any grade of acute renal failure in liver transplantation patients or candidates. The EMEA differentiates between agents and advises avoidance of only gadodiamide and gadopentetate in the same patient categories. Other gadolinium contrast media should only be used after careful consideration of risks versus benefits. Post-procedural haemodialysis is only indicated in patients on regular dialysis.

16-slice CT: achievable effective doses of common protocols in comparison with recent CT dose surveys.

The aim of the study was to investigate achievable dose levels in 16-slice CT by evaluating CT dose indices (CTDI) and effective doses of dose-optimized protocols compared with 4-slice dose surveys. Normalized CTDI free in air and in 16 cm and 32 cm diameter phantoms were measured on four different 16-slice CT scanners in the Netherlands. All collimation and tube potential settings were analysed. Volume CTDI was calculated for adult protocols for brain, chest, pulmonary angiography (CTPA), abdomen and biphasic liver CT. Effective doses were calculated first using volume CTDI with conversion factors and second from CTDIair values using the ImPACT dose calculator. Average results of the 16-slice scanners were correlated to results of dose surveys with predominantly 4-slice scanners. Statistical analysis was done with Student t-tests with a Bonferroni correction; therefore p < 0.017 was significant. The results of CTDIair and weighted CTDI were documented for all scanners. Effective doses averaged over four scanners for brain, chest, CTPA, abdomen and biphasic liver protocols were 1.9+/-0.4, 3.8+/-0.4, 3.0+/-0.2, 7.2+/-0.9 and 10.2+/-1.3 mSv, respectively. Compared with dose surveys achievable effective doses were equal (p = 0.069) to significantly lower (p < 0.017) for chest and abdomen protocols. For 16-slice spiral brain CT there was a trend of equal doses compared with sequential brain CT in the dose surveys. Thus, with dose-optimized protocols 16-slice CT can achieve equal to lower effective doses in examinations of the chest and abdomen compared with 4-slice CT, while doses can remain stable in the brain.

The effects of lactate and acetate on fatty acid and cholesterol biosynthesis by isolated rat hepatocytes.

1. The present study demonstrates that lactate and acetate stimulate fatty acid synthesis and inhibit cholesterogenesis by isolated rat hepatocytes. 2. Exposure of the intact cells to lactate increases the activity of acetyl-CoA carboxylase, as can be measured in homogenates of these cells. A similar effect by acetate was not observed. 3. Both acetate and lactate drastically increase the cellular level of citrate. 4. Possible mechanisms underlying the difference in response of fatty acid and cholesterol synthesis to an increase in substrate availability are discussed. Futhermore, a mechanism is proposed for the lactate effect on acetyl-CoA carboxylase.

Reduction of patient motion artifacts in digital subtraction angiography: evaluation of a fast and fully automatic technique.

The performance of an automatic technique for the reduction of patient motion artifacts in digital subtraction angiography was evaluated. Four observers assessed the quality of 104 cerebral digital subtraction angiographic images that were processed by means of both the automatic technique and manual pixel shifting. The automatic technique resulted in better image quality and was considerably less time-consuming.