Preprocedure and Postprocedure Predictive Values of Serum ß2-Microglobulin for Contrast-Induced Nephropathy in Patients Undergoing Coronary Computed Tomography Angiography: A Comparison With Creatinine-Based Parameters and Cystatin C.

OBJECTIVE: This study aimed to investigate the values of serum ß2-microglobulin to predict contrast-induced nephropathy (CIN) before and early after coronary computed tomography angiography (CCTA), comparing with creatinine-based parameters and cystatin C. METHODS: A total of 424 patients were enrolled. Serum ß2-microglobulin, cystatin C, and creatinine were measured at 0, 24, and 48 hours of CCTA. Contrast-induced nephropathy was defined as an elevation of serum creatinine level by 25% or higher or 0.5 mg/dL or greater from baseline within 48 hours. The estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease study equation. Receiver operating characteristic curves and multivariate logistic regression analysis were used to detect the efficiency of biomarkers in predicting CIN. RESULTS: Fifty-two subjects (12.26%) developed CIN. Before CCTA, CIN was predicted by both baseline ß2-microglobulin (area under the receiver operating characteristic curve [AUC], 0.791; P < 0.001) and cystatin C (AUC, 0.781; P < 0.001), whereas creatinine and eGFR were not predictive. After CCTA, CIN was predicted by both the absolute post-CCTA levels of ß2-microglobulin, cystatin C, creatinine, and eGFR (AUC, 0.842 vs 0.961 vs 0.691 vs 0.688 at 24 hours, P < 0.001; and 0.937 vs 1.000 vs 0.908 vs 0.898 at 48 hours, P < 0.001) and their relative changes (Δ) to baseline (AUC, 0.677 vs 0.846 vs 0.850 vs 0.844 at 24 hours, P < 0.001; and 0.731 vs 0.968 vs 0.984 vs 0.966 at 48 hours, P < 0.001). Multivariate regression analysis confirmed that baseline ß2-microglobulin (odds ratio, 2.137; 95% confidence interval, 1.805-3.109; P < 0.001) and cystatin C (odds ratio, 1.873; 95% confidence interval, 1.667-2.341; P = 0.003) were independent predictors for CIN. CONCLUSIONS: Serum ß2-microglobulin, with values superior to creatinine-based parameters and similar with cystatin C, was a useful biomarker for the prediction of CIN at pre-CCTA and early post-CCTA.

Rapid determination of X-ray contrast agent iomeprol in human plasma by on-line solid-phase extraction coupled with phase optimized liquid chromatography.

Phase optimized liquid chromatography (POPLC) allows for the optimized combination of column segments of any length and stationary phases with different functionalities. In this study, a simple and rapid method using POPLC coupled with on-line solid-phase extraction (SPE) for the analysis of X-ray contrast media agent iomeprol (IOM) in human plasma was developed. Because the phenyl (PH) stationary phase has strong hydrophobic and π-π interactions with IOM and iopromide (IOP, internal standard), the best separation efficiency was achieved with a 250mm×3mm homogenous PH POPLC-column. Different kinds of on-line SPE sorbents were studied, including restricted access material-alkyl diol silica (ADS), LiChrolut EN with excellent absorption capacity and hydrophilic-lipophilic-balanced Oasis HLB. The most efficient on-line sample clean-up was carried out using a fast-flow on-line purification approach with an Oasis HLB pre-column ((20mm×2mm, 30µm). This pre-column showed excellent durability and reproducibility. At least 400 samples could be analyzed with one pre-column. Each plasma sample was directly injected and analyzed within 15min. The calibration curves were linear in the range of 10-1000µg/mL. The limit of quantitation was 2.26µg/mL. The inter-day precision of this method was excellent and less than 1.44%, and the intra-day precision was less than 4.44%. The inter-day and intra-day accuracy ranged from 94.33% to 104.36% and 94.60% to 101.71%, respectively. This validated method is expected to be useful in the analysis of human plasma samples for glomerular filtration rate (GFR) measurements and assessment of kidney function.

The incidence of contrast medium-induced nephropathy following endovascular aortic aneurysm repair: assessment of risk factors.

PURPOSE: The aim of the study was to investigate the incidence of contrast medium-induced nephropathy (CIN) and risk factors for CIN following endovascular abdominal aortic aneurysm repair or thoracic endovascular aortic aneurysm repair. MATERIALS AND METHODS: After exclusion criteria, 139 (121 males, 18 females) patients aged 20-86 (median 65.5) years who underwent endovascular aortic aneurysm repair between January 2002 and September 2013 were included in this retrospective study. CIN, with ≥25% increase in serum creatinine levels within 3 days after contrast medium administration, was compared to the patients' demographics, risk factors, type and complexity of the endovascular operation, parameters regarding to the contrast medium, preoperative estimated glomerular filtration rate (eGFR), and preoperative and early postoperative serum parameters. Statistical analyses were performed with Kolmogorov-Smirnov, χ (2) and Student's t tests. RESULTS: CIN, detected in 39 of 139 patients (28%), was correlated with preoperative eGFR <60 ml/min/1.73 m(2) (P = 0.04) and high preoperative and postoperative serum urea and creatinine levels. Postoperative serum urea levels (P < 0.001) were significant in multivariate analysis. CONCLUSION: In patients undergoing endovascular aortic aneurysm repair, CIN was correlated with preoperative and postoperative renal impairment, while it was not correlated with the contrast medium dose.

Washing of banked blood by three different blood salvage devices.

BACKGROUND: Storage lesions in red blood cells (RBCs) lead to an accumulation of soluble contaminants that can compromise the patient. Organ failures, coagulopathies, and cardiovascular events including lethal cardiac arrest have been reported, especially with massive transfusion or in pediatric patients. Washing improves the quality of stored RBCs, and autotransfusion devices have been proposed for intraoperative processing, but these devices were designed for diluted wound blood, and limited data on their performance with RBCs are available. STUDY DESIGN AND METHODS: Three autotransfusion devices (Electa, Sorin; CATS, Fresenius; OrthoPAT, Haemonetics) differing in function of their centrifugation chambers were evaluated with RBCs at the end of their shelf life and with dilutions thereof. Elimination rates of potassium, plasma free hemoglobin, total protein, citrate, acid equivalents, and iomeprol added as a marker substance were analyzed, in addition to RBC recoveries. RESULTS: Product hematocrit (Hct) levels ranged between 54.8 and 72.6%. RBC recovery rates were between 62.7 and 95.0%, the lowest being with the OrthoPAT processing of undiluted RBCs. Plasma elimination rates increased with predilution and ranged from 46.6% to 99.5%, the lowest being with the CATS and undiluted RBCs. Washing did not change pH and buffering capacity of RBCs. CONCLUSION: Autotransfusion devices offer a practical and obviously economical option to wash banked RBCs intraoperatively to prevent hyperkalemia and other disturbances in massive transfusion or pediatric patients. Predilution improves elimination rates, especially in devices that produce high product Hct levels. With a Y-tubing the RBCs should bypass reservoir and vacuum, and the procedure should be guarded by a policy and procedure manual and a quality management system.

Conditions of iodine contrast transfer from lumbosacral CSF to blood.

PURPOSE: To determine conditions which influence transfer of iopamidol from lumbosacral cerebrospinal fluid (CSF) to blood. METHODS: Iopamidol transfer was measured in 32 patients over 180 min after radiculography and compared with patient variables. RESULTS: Iopamidol transfer began early in 12 patients, more slowly in 13 patients, and was not detected during sample period in 7 patients. Transfer of sequential samples correlated highly with each other (r>0.8). Transfer was more pronounced in patients with prominent nerve root sleeves on radiculogram (p=0.006, t test), and correlated inversely with body weight (r=-0.4258), and with albumin CSF/serum quotient (r=-0.4702). CONCLUSION: Early iopamidol transfer probably indicates transfer through spinal arachnoid villi and granulations with CSF bulk flow. Prominent nerve root sleeves may facilitate access to transfer sites. No transfer during sample period suggests no such spinal transfer, possibly due to sparse access to or presence of spinal transfer sites. Inverse correlation of transfer with body weight may reflect influence of body weight on retroperitoneal venous pressure, which regulates outflow of CSF and of compounds dissolved in it. Awareness of wide interindividual transfer variation and steady intraindividual transfer may help to specify dosage and effect expectation of intrathecal drug therapy.

Pharmacokinetics of lopamidol after intrathecal administration in humans.

The kinetics of iopamidol, a new nonionic radiocontrast agent, were evaluated in 10 patients undergoing lumbar myelography. The doses of iopamidol administered intrathecally were 11 and 15 ml of a 200-mg iodine per ml solution in one and nine patients, respectively. Radiographs were made within 30 to 40 min and CTs were taken at about 1, 6, and 23 hr after iopamidol administration. The diagnostic quality and usefulness of the conventional and CT myelograms were considered excellent. In the lumbosacral subarachnoid space, the densitometry CT readings were maximal at 1 hr, whereas in the cervical subarachnoid space, peak CT values were reached at 6 hr. Plasma and urine samples were taken at frequent intervals up to 48 hr after the contrast agent was administered. Peak plasma levels of iopamidol were observed at 2.9 hr and were no longer detectable at 48 hr. The 48-hr urinary recovery for all patients averaged 66 +/- 8% of the dose. In all but one patient, iopamidol was cleared almost completely from the CSF within 24 hr. Side effects after iopamidol administration were transient and minor, and were not related to the CT readings or its systemic clearance.