Late and acute adverse reactions to iohexol in a pediatric population

Radiocontrast Media Hypersensitivity Reactions in Children

Hypersensitivity reactions to radiocontrast media seem to be rare in children. Furthermore, the use of radiocontrast media in children remains quite safe in terms of the severity of reactions. Since pediatric guidelines are lacking, the diagnostic workup employed in adults could be adapted to children, taking into account that results have not yet been validated in this age group. Specific protocols for risk stratification and management of severe reactions have been proposed so far.

Patterns of intravenous contrast material use and corticosteroid premedication in children--a survey of Society of Chairs of Radiology in Children's Hospitals (SCORCH) member institutions

BACKGROUND

There are few data available concerning the use of intravenous contrast materials in children.

OBJECTIVE

To assess patterns of intravenous iodinated/gadolinium-based contrast material (ICM/GBCM) use in children.

MATERIALS AND METHODS

Society of Chairs of Radiology in Children's Hospitals (SCORCH) members were invited to complete a Web-based survey regarding intravenous contrast material use at their institutions.

RESULTS

Sixty-six percent (42/64) of SCORCH member institutions responded, 76% of which are academic hospitals. Ioversol and gadopentetate dimeglumine are the most commonly used ICMs and GBCMs (52% and 81%, respectively). Premedication policies to mitigate risk of allergic-like contrast reactions are more common for ICMs than GBCMs (71% vs. 32%). For both ICMs and GBCMs, most institutions premedicate or avoid contrast material in the setting of a prior allergic-like contrast reaction of any severity. Policies regarding ICM and GBCM use in children with renal insufficiency are in place at 74% and 88% of institutions, respectively, but are variable.

CONCLUSION

Policies concerning premedication for prevention of allergic-like contrast agent reactions and administration of contrast materials in children with renal insufficiency are variable and not consistently present at all pediatric institutions. This highlights the need for standardization of practice patterns and pediatric-specific research on these topics.

Evaluation of image quality and radiation dose of thoracic and coronary dual-source CT in 110 infants with congenital heart disease

BACKGROUND

There are only a few reports on the diagnostic accuracy, and the technical and clinical feasibility, of multidetector CT (MDCT) in infants with congenital heart disease (CHD).

OBJECTIVE

To evaluate the image quality and radiation dose of DSCT in babies with CHD.

MATERIALS AND METHODS

From November 2006 to November 2007, 110 consecutive infants with CHD referred for pre- or postoperative CT evaluation were included. All these infants had a spiral angiothoracic DSCT scan after injection of 300 mg/ml iopromide at 0.5-1 ml/s with a power injector using a low-dose protocol (80 kVp and 10 mAs/kg). Of these infants, 34 also underwent an ECG-gated coronary CT scan for evaluation of the course of the coronary arteries.

RESULTS

No serious adverse events were recorded. The mean dose-length product was 8+/-6 mGy x cm (effective dose 0.5+/-0.2 mSv) and 21+/-9 mGy x cm (effective dose 1.3+/-0.6 mSv) during the non-ECG-gated spiral acquisition and ECG-gated acquisition, respectively. Diagnostic quality images were achieved with the spiral acquisition in 89% of cases. Compared to the spiral mode, ECG-gated acquisition significantly improved the visualization of the coronary arteries, with a diagnostic rate of 91% and 84% for the left and right coronary arteries, respectively.

CONCLUSION

DSCT together with iopromide at 300 mg/ml is a valuable tool for the routine clinical evaluation of infants with CHD. ECG-gated acquisition provides reliable visualization of the course of the coronary arteries.

Incidence and severity of acute allergic-like reactions to i.v. nonionic iodinated contrast material in children

OBJECTIVE

The purpose of this study was to evaluate the incidence and severity of acute allergic-like reactions related to i.v. administration of low-osmolality nonionic iodinated contrast material in children.

MATERIALS AND METHODS

Department of radiology contrast material reaction forms involving pediatric (younger than 19 years) imaging examinations performed from January 1, 1999, through June 30, 2006, were retrospectively evaluated for type of acute allergic-like reaction, severity of reaction, and patient outcome. The electronic medical record was reviewed for pertinent medical history related to each acute reaction, including previous contrast material reaction, premedication before administration of i.v. iodinated contrast material, previous allergic-like reaction to substances other than contrast material, and history of asthma.

RESULTS

In our department during the time period specified, 11,306 pediatric i.v. administrations of low-osmolality nonionic iodinated contrast material were performed. Acute allergic-like reactions to the contrast material were documented in 20 (0.18%) of the patients. Sixteen (80%) of the acute allergic-like reactions were categorized as mild, one (5%) as moderate, and three (15%) as severe. No deaths were attributed to i.v. nonionic iodinated contrast material. Six (30%) of the patients had a history of allergic-like reaction, including two patients who had a history of reaction to iodinated contrast material. Five (25%) of the patients had a history of asthma.

CONCLUSION

Acute allergic-like reactions to i.v. administration of low-osmolality nonionic iodinated contrast material in children are rare. As in the adult population, most pediatric reactions are mild; however, severe reactions do occur.

Imaging of renal scarring

Children with urinary tract infection should be investigated and followed up, as those with pyelonephritis may develop renal scarring. In this review, after discussing the advantages and disadvantages of various imaging modalities for diagnosis of renal scarring, it is concluded that DMSA scintigraphy and urography can both be used to detect significant renal scarring. With DMSA scintigraphy, small renal lesions (functional uptake defects) not seen at urography will also be detected. The long-term clinical significance of these lesions is, as yet, unknown. A normal DMSA scintigraphy after infection indicates low risk for clinically significant damage. In order to allow acute, reversible lesions to first disappear, a follow-up DMSA examination should not be performed until at least 6 mo after the acute infection. Ultrasonography in isolation cannot be recommended for the diagnosis of renal scarring.

Delayed-type hypersensitivity to a nonionic, radiopaque contrast medium

BACKGROUND

True allergic reactions to iodinated radiocontrast media are rare, and only a few well-documented cases of delayed-type hypersensitivity reactions caused by contrast media have been described.

METHODS

We report a 61-year-old patient in whom percutaneous transluminal coronary angioplasty (PTCA) was performed with iopamidol, a nonionic contrast medium. Seven days later, the patient developed generalized maculopapular exanthema. Repeated patch tests with several iodinated agents were performed.

RESULTS

A first patch test with iopamidol was positive. Repetition of the patch tests showed positive results to iopamidol as well as to iohexol and ioversol, two other nonionic contrast media, but not to other iodinated substances. Three months later, PTCA was repeated, and iopamidol was used again. Despite premedication, pruritic macular exanthema developed 1 day later. Whether iopamidol or trometamol -- an additive substance in the contrast medium -- was causative could not be determined, since a third set of patch tests was negative.

CONCLUSIONS

Delayed-type hypersensitivity reactions to iodinated contrast media are rare. We recommend that patients with delayed exanthematous reactions undergo patch or intradermal tests with different contrast media and their additives, and that readings be performed immediately and later at days 2 and 3.

Potential intrathecal leakage of solutions injected into the epidural space following combined spinal epidural anaesthesia

A combined spinal epidural anaesthetic (CSE), by design, produces a deliberate multicompartment block across a breached dural membrane. Since the lateral holes of the epidural catheter may lie in close proximity to the dural puncture site, a bolus solution of drug injected via the epidural catheter has the potential to leak through the dural puncture into the subarachnoid space. The aim of this study was to determine the incidence of intrathecal leak by performing an epidurogram. Fifteen patients undergoing surgery with a CSE anaesthetic using a 16 gauge Tuohy/26 gauge pencil point needle were studied. Within three hours of catheter insertion, 12 ml of contrast (iohexol 300 mg/ml) was injected via the epidural catheter under fluoroscopic control with screen recording and exposure of lateral and anteroposterior X-ray plates. All films were later reviewed for evidence of intrathecal spread. We did not observe any evidence of intrathecal spread of contrast. However, caution should be observed during administration of an intraoperative bolus dose of analgesic agent via a catheter inserted as part of a combined spinal epidural anaesthetic technique, particularly with the use of hydrophilic opiods.

Delayed adverse reactions to nonionic monomeric contrast-enhanced media

RATIONALE AND OBJECTIVES

A delayed adverse reaction is one occurring more than an hour after injection of contrast media. The frequency and symptoms of delayed adverse reaction to nonionic contrast media still are not well established. The purpose of the study is to clarify the frequency and symptoms of delayed adverse reactions using nonionic monomeric contrast media.

METHODS

Patients studied by computed tomography (CT) were the subject of the investigation. Delayed adverse reactions were compared between the group receiving CT without contrast injection and the group receiving contrast injection.

RESULTS

Delayed adverse reactions were noted in 293 of 2370 patients (12.4%) in the group with enhanced CT and in 93 of 907 patients (10.3%) in the group with unenhanced CT. The frequency of delayed adverse reaction to nonionic contrast media was 2.1% (12.4% - 10.3%; P = 0.094). None of the risk factors were related with the incidence of delayed adverse reaction. The most common delayed adverse reaction was a mild skin reaction, which occurred within 24 hours after injection of contrast media.

CONCLUSIONS

The frequency of delayed adverse reaction to nonionic monomeric contrast media was 2.1%; the most common reactions were itching and limited urticaria.

Intravenous contrast media: are they being administered safely in radiology departments?

A recent Royal College of Radiologists (RCR) publication is entitled Advice on The Management of Reactions to Intravenous Contrast Media. This study aims to determine whether radiology departments are adhering to the essential points, covered in the guidelines, regarding prevention, early recognition and prompt treatment of adverse reactions, and whether they are adequately equipped for the proposed contrast media reaction management protocols. A questionnaire was formulated and sent to the superintendent radiographers of 295 radiology departments in the United Kingdom of whom 233 (79%) replied. This was specifically directed at the use of intravenous contrast media in intravenous urography. In almost all departments there was provision for basic life support training, regular checking of equipment and drugs, and prompt access to emergency medical help. Certain "first line" drugs and monitoring equipment were not instantly accessible in the majority of institutions. Most departments did not adequately supervise post-injection patients and did not conform to the guidelines referring to the administration of intravenous contrast to children. Certain areas of the guidelines are being neglected by many radiology departments and there is still much to be done to improve the safety of intravenous contrast medium injection.