Pain in femoral arteriography. A double-blind, randomized, clinical study comparing safety and efficacy of the iso-osmolar iodixanol 270 mgI/ml and the low-osmolar iomeprol 300 mgI/ml in 9 European centers

Prevention of Contrast-Induced Nephropathy (CIN) in Interventional Radiology Practice

Contrast-induced nephropathy (CIN) is a widely recognized and clinically significant problem in patients undergoing an increasing number of minimally invasive procedures that require contrast administration. Contrast-induced nephropathy is the third most common cause of hospital-acquired renal failure and has significant prognostic implications on patient outcomes. Interventional practitioners are faced with challenging decisions regarding prophylaxis and patient management. The major risk factor for developing CIN is preexisting renal dysfunction, particularly in association with diabetes. Patients are considered to be at risk when estimated glomerular filtration rate (eGFR) or estimated creatinine clearance (eC(Cr)) is less than 60. The cornerstone of prevention of CIN is appropriate risk stratification, intravenous hydration with normal saline or sodium bicarbonate, appropriate withholding of nephrotoxic medications, use of low or iso-osmolar contrast media, and various intraprocedural methods for iodinated contrast dose reduction. Although N-acetylcysteine administration is popular, it remains unproven. Practitioners must be familiar with prevention strategies and diagnosis of CIN to minimize its clinical impact.

Comparison of allergic adverse effects and contrast enhancement between iodixanol and iopromide

Background

Iodinated X-ray contrast media are the most commonly used contrast agents in the world with an annual application of 40-50 million. New non-ionic contrast agents are subdivided into low osmolar agents such as iopromide and iso-osmolar agents such as iodixanol. Regarding different biochemical characteristics, these agents are different in the allergic reactions and contrast enhancement and final lesion conspicuity.

Objectives

This study was carried out to compare allergic adverse effects and contrast enhancement between iodixanol and iopromide.

Patients and Methods

One-hundred and twenty patients who were referred for abdominal CT scan to Besat Hospital were included in this study. Patients were randomly divided into two groups (A and B). Group A received 100 cc iodixanol (300 mgI/mL) and group B received 100 cc iopromide (300 mgI/ml) by power injector. CT examination was performed using Helical CT Scanner (Somatom, Siemens, Germany). Sixty seconds after injection, images were obtained and enhancement of port, liver and aorta were determined. Allergic adverse effects were recorded one hour and up to one week after injection.

Results

Iodixanol produced a significantly greater enhancement of the hepatic, aorta and portal vein than iopromide (P < 0.01). Sixty seconds after injection, associated pain and heat sensation were less frequent in iodixanol in comparison with iopromide (P = 0.03). Immediate reactions such as nausea and vomiting were less frequent in iodixanol (P = 0.01). Late skin reactions such as rash was more frequent in iodixanol (P < 0.01).

Conclusions

Iodixanol is safe and is better tolerated in the early phase of injection with better contrast enhancement and lesion conspicuity. Mild late skin rash is its disadvantage.

Patient discomfort associated with the use of intra-arterial iodinated contrast media: a meta-analysis of comparative randomized controlled trials

Background

Discomfort characterized by pain and warmth are common adverse effects associated with the use of intra-arterial iodinated contrast media (CM). The objective of this review was to pool patient-reported outcomes available from head-to-head randomized controlled trials (RCTs) and to compare the discomfort rates associated with iso-osmolar contrast media (IOCM; i.e., iodixanol) to those reported with various low-osmolar contrast media (LOCM).

Methods

A review of the literature published between 1990 and 2009 available through Medline, Medline Preprints, Embase, Biological Abstracts, BioBase, Cab Abstracts, International Pharmaceutical Abstracts, Life Sciences Collection, Inside Conferences, Energy Database, Engineering Index and Technology Collection was performed to compare rates of discomfort associated with the use of the IOCM (iodixanol) vs. various LOCM agents in head-to-head RCTs. All trials with a Jadad score ≥2 that reported patient discomfort data following intra-arterial administration of CM were reviewed, coded, and extracted.

Results

A total of 22 RCTs (n = 8087) were included. Overall discomfort (regardless of severity) was significantly different between patients receiving IOCM and various LOCMs (risk difference [RD] -0.049; 95% confidence interval [CI]: -0.076, -0.021; p = 0.001). IOCM was favored over all LOCMs combined with a summary RD value of -0.188 (95% CI: -0.265, -0.112; p < 0.001) for incidence of pain, regardless of severity. A greater reduction in the magnitude of pain was observed with IOCM (iodixanol), particularly with selective limb and carotid/intracerebral procedures. Similarly, the meta-analysis of warmth sensation, regardless of severity, favored IOCM over LOCMs with an RD of -0.043 (95% CI: -0.074, -0.011; p = 0.008). A positive linear relationship was observed between the discomfort effect size and age and a negative relationship with increasing proportion of women. The opposite trends were observed with warmth sensation.

Conclusions

IOCM was associated with less frequent and severe patient discomfort during intra-arterial administration. These data support differences in osmolality as a possible determinant of CM discomfort.

Contrast-induced acute kidney injury: specialty-specific protocols for interventional radiology, diagnostic computed tomography radiology, and interventional cardiology

Contrast-induced acute kidney injury (AKI) (also known as contrast-induced nephropathy) is an abrupt deterioration in renal function that can be associated with use of iodinated contrast medium. Although the increase in serum creatinine concentration is transient in most cases, contrast-induced AKI may lead to increased morbidity and mortality rates in selected at-risk populations. This review summarizes the findings of a multidisciplinary panel composed of computed tomography radiologists, interventional radiologists, cardiologists, and nephrologists convened to address the specialty-specific issues associated with minimizing the incidence of contrast-induced AKI. As part of this initiative, the panel developed specialty-specific protocols for preventing contrast-induced AKI, taking into account, for example, the variations in patient risk profile, inpatient or outpatient status, and staffing resources that characterize various clinical settings. The 3 protocols, each reflecting a consensus of expert opinion, address the prevention of contrast-induced AKI in interventional radiology, diagnostic computed tomography radiology, and interventional cardiology settings. The protocols are presented in the context of a review of recent guidelines and published reports of trials that discuss contrast-induced AKI and its prevention. The panel reviewed materials retrieved by a PubMed search covering the period January 1990 through January 2008 and used combinations of key words associated with the prevention and treatment of contrast-induced AKI. In addition, the panel reviewed the reference lists of selected articles and the tables of contents posted on the Web sites of selected journals for relevant publications not retrieved in the PubMed searches.

Changes in osmolality modulate voltage-gated calcium channels in trigeminal ganglion neurons

Voltage-gated calcium channels (VGCCs) participate in many important physiological functions. However whether VGCCs are modulated by changes of osmolarity and involved in anisotonicity-induced nociception is still unknown. For this reason by using whole-cell patch clamp techniques in rat and mouse trigeminal ganglion (TG) neurons we tested the effects of hypo- and hypertonicity on VGCCs. We found that high-voltage-gated calcium current (I(HVA)) was inhibited by both hypo- and hypertonicity. In rat TG neurons, the inhibition by hypotonicity was mimicked by Transient Receptor Potential Vanilloid 4 receptor (TRPV4) activator but hypotonicity did not exhibit inhibition in TRPV4(-/-) mice TG neurons. Concerning the downstream signaling pathways, antagonism of PKG pathway selectively reduced the hypotonicity-induced inhibition, whereas inhibition of PLC- and PI3K-mediated pathways selectively reduced the inhibition produced by hypertonicity. In summary, although the effects of hypo- and hypertonicity show similar phenotype, receptor and intracellular signaling pathways were selective for hypo- versus hypertonicity-induced inhibition of I(HVA).