Intravascular iodinated contrast media and the anaesthetist

Periprocedural management of patients presenting for neurointerventional procedures using flow diverters for complex intracranial aneurysms: An anesthetist's perspective - A narrative review

Complex intracranial aneurysms pose significant challenges in the realm of neurointervention, necessitating meticulous planning and execution. This article highlights the crucial roles played by anesthetists in these procedures, including patient assessment, anesthesia planning, and continuous monitoring and maintaining hemodynamic stability, which are pivotal in optimizing patient safety. Understanding these complex procedures and their complications will aid the anesthetist in delivering optimal care and in foreseeing and managing the potential associated complications. The anesthetist's responsibility extends beyond the procedure itself to postprocedure care, ensuring a smooth transition to the recovery phase. Successful periprocedural anesthetic management in flow diverter interventions for complex intracranial aneurysms hinges on carefully orchestrating these elements. Moreover, effective communication and collaboration with the interventional neuroradiologist and the procedural team are emphasized, as they contribute significantly to procedural success. This article underscores the essential requirement for a multidisciplinary team approach when managing patients undergoing neurointerventions. In this collaborative framework, the expertise of the anesthetist harmoniously complements the skills and knowledge of other team members, contributing to the overall success and safety of these procedures. By providing a high level of care throughout the periprocedural period, anesthetists play a pivotal role in enhancing patient outcomes and minimizing the risks associated with these intricate procedures. In conclusion, the periprocedural anesthetic management of neurointervention using flow diverters for complex intracranial aneurysms is a multifaceted process that requires expertise, communication, and collaboration.

Crosstalk among apoptosis, inflammation, and autophagy in relation to melatonin protective effect against contrast-induced nephropathy in rats

Contrast medium (CM) is a chemical substance that is used for imaging anatomical boundaries and to explore normal and abnormal physiological findings; the use of CM was associated with kidney injury and acute renal failure. Melatonin (M) possesses antioxidant, anti-inflammatory, and antiapoptotic effects in addition to autophagy modulation. This study aimed to investigate the protective effect of M against contrast-induced nephropathy (CIN) and its impact on the crosstalk between inflammasome, apoptosis, and autophagy in CIN. Male albino rats received M (10, 20, and 40 mg/kg/day, intraperitoneally) for 3 days. One hour after the last administration, rats were subjected to CIN induction (10 mg/kg indomethacin, double doses of l-NAME 10 mg/kg, i.v., and meglumine diatrizoate 60% 6 mL/kg, i.v.). CIN-induced kidney damage was evidenced through elevated kidney function biomarkers and induced renal histopathological changes. Pretreatment with M caused a significant decrease in nephrotoxicity biomarkers and histopathological alterations. Moreover, CIN-induced oxidative stress, NLRP3 inflammasome, and apoptosis were attenuated by M. Furthermore, M modulates autophagy in CIN rats. M inhibits CIN-induced NLRP3-inflammasome activation and apoptosis as well as enhances autophagy.

Effect of iodinated radiographic contrast media on radioimmunoassay for measuring thyroid hormones

Radioimmunoassay (RIA) is one of the most routine laboratory tests for diagnosing thyroid disease. Patients might receive iodine in the form of intravenous iodinated radiographic contrast media (IRCM) before testing of serum thyroxin (T4) or triiodothyronine (T3) concentration by RIA. The objective was to determine the effect of IRCM on T4 and T3 hormone tests in normal, hypothyroid, and hyperthyroid hormone conditions by RIA. IRCMs (0, 2.5, 5 and 10 mgI/mL) used in this study were iopromide and iodixanol. RIA was determined by commercial T4 RIA kit and T3 RIA kits. The method suggested by the manufacturer was followed. Normal, hypothyroid, and hyperthyroid hormones condition were 1.2 ng/mL, 0.2 ng/mL and 2.2 ng/mL for T3 hormone concentration and 70 ng/mL, 30 ng/mL and 140 ng/mL for T4 hormone concentration, respectively. %Bound values were compared between IRCM-incubated groups and non-incubated group. The data showed that iopromide-incubated groups did not statistically significant change %bound values of T3 and T4 hormone tests in normal, hypothyroid, and hyperthyroid conditions, compared to the non-incubated group. In the same way, %bound values of T3 and T4 hormone tests in iodixanol-incubated groups did not change at all conditions when compared to the non-incubated group. This finding suggested that iodinated radiographic contrast media was unlikely to result in significant problems with radioimmunoassay for measuring T3 and T4 thyroid hormones.

Assessment of the radio-contrast media-induced self-reported adverse drug reactions in a tertiary care hospital of North India: A prospective study

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Shelling the myth: allergies to Iodine containing substances and risk of reaction to Iodinated contrast media

PURPOSE

In excess of 100 million procedures using iodinated radio-contrast media are conducted each year. There is a common misunderstanding regarding the links between allergy to iodinated substances and the risk of allergic reaction to intravenous iodinated contrast agents. These perceived risks are managed via administration of corticosteroids or avoidance of iodinated contrast altogether.

METHODS

An extensive review of published literature on scientific databases and international guidelines was conducted in order to inform the research question. A questionnaire was formulated and distributed to hospital doctors in four tertiary centres. Within this questionnaire, hospital doctors were presented with six different scenarios of bona fide allergy to iodinated substances (e.g. shellfish) and asked to select the treatment response option which they deemed to be the most suitable from a choice of three (standard contrast scan/delay scan with pre-medication/change to non-contrast scan).

RESULTS

Eighty-seven questionnaire responses were received. Contrast (standard protocol) was the most appropriate regimen in the setting of all the listed allergies. This was identified correctly by 76%, 69%, 44%, 32%, 18% and 14% for kiwi, fish, poly-food, shellfish, betadine and tincture of iodine allergies, respectively.

CONCLUSIONS

There is a lack of understanding amongst local junior medical staff regarding administration of iodinated contrast media to patients with a history of allergy to iodinated substances. These misconceptions may potentiate the unnecessary usage of pre-medication and ordering of non-contrast scans in the setting of a gold-standard enhanced scan. Findings from this study suggest that there is a need for future education efforts targeted during the basic specialty training stage.

Intrathecal iodinated contrast-induced transient spinal shock

Transient spinal shock is a previously unreported complication of intrathecal contrast. A 63-year-old man presented with the chief complaint of worsening back pain. Computed topography of lumbar spine without contrast showed a lytic lesion. After international normalized ratio (INR) correction, patient was sent for CT myelogram. After intrathecal contrast injection, the patient dropped his blood pressure profoundly and developed clinical manifestations of spinal shock. Emergent intravenous bolus fluids were initiated resulting in improvement in blood pressure. Patient's spinal shock resolved within hours. CT myelogram was normal except previously known lytic lesion. It was concluded that the transient shock was most likely due to contrast injection. We believe that this is the first reported case of transient spinal shock following CT myelogram using water-soluble iodinated non-ionic contrast agent administered intrathecally.

The Effects of Iodinated Radiographic Contrast Media on Multidrug-resistant K562/Dox Cells: Mitochondria Impairment and P-glycoprotein Inhibition

Iodinated radiographic contrast media is used in cancer radiography for cancer diagnosis. The aim of this present study was to examine five iodinated radiographic contrast media (IRCM) (i.e., iohexol, iopamidol, iobitridol, ioxaglate, and iodixanol) in terms of their cytotoxicity, mitochondria membrane potential (ΔΨm), and P-glycoprotein function in multidrug resistant K562/Dox cancer cells and corresponding sensitive cancer cells. The cytotoxicity was determined by colorimetric resazurin reduction assay. The ΔΨm and P-glycoprotein function was measured using a noninvasive functional spectrofluorometry. Rhodamine B, fluorescence probe, was used to estimate ΔΨm. The kinetic of P-glycoprotein-mediated efflux pirarubicin was used to monitor P-glycoprotein function in multidrug resistant (MDR) cancer cells. The results showed that ioxaglate and iodixanol show similar efficacy in MDR cancer cells and for their corresponding sensitive cancer cells. Iopamidol, iohexol, and iobitridol showed higher efficacy in MDR cancer cells than for the corresponding sensitive cancer cells by approximately 2 fold. The results also showed no significant change in the |ΔΨm| values in treated K562 and K562/Dox cancer cells when compared to the non-treated K562 and K562/Dox cancer cells. However, there were notable changes detected for iobitridol and iodixanol at 50 mgI/mL. Similarly, the results showed significant differences in P-glycoprotein function of K562/Dox cancer cells after treatment with IRCM when compared to the non-treated K562/Dox cancer cells, with iohexol and iodixanol being the notable exceptions once again. In this present study, IRCM exhibited cytotoxicity on MDR cancer cells and their corresponding sensitive cancer cells. IRCM also showed potential as an anticancer agent in the future.

Should patients with risk factors be tested for hypersensitivity to contrast media: a prospective study

BACKGROUND

Previous hypersensitivity reactions to contrast media (CM), atopy, atopic disease, drug allergy, and age (20-29 or >55) are risk factors for CM hypersensitivity reactions. Our aim was to evaluate whether these risk factors should prompt skin testing for diagnosing CM allergy.

METHODS

The study was conducted among patients referred for allergy testing with CM. Skin tests were performed with non ionic or gadolinium CM, recommended by a radiologist. After completion of tests patients were telephonically queried on their symptoms of reactions.

RESULTS

151 risk patients (53 men, 98 women; mean age 55.2) were included in the study. Only 13 (9 %) had a history of hypersensitivity reaction to CM. Compared with the other patients, atopy was significantly more common in patients with a history of CM hypersensitivity reactions. Female gender and mean age were also higher, but not significant. All of the tests with CMs were negative. Only one patient reported urticaria within 1-2 min after administration of CM (telephonically).

CONCLUSIONS

Atopy can increase the risk of CM allergy. However, skin tests with CMs may be inefficient, unnecessary, and time-consuming, except in cases with a history of CM allergy. Premedication protocols appear to be beneficial in patients with a history of CM allergy and cannot be recommended for patients with well-controlled asthma, rhinitis, atopic dermatitis or history of drug allergy.

How accurate is the label "allergic to iodinated contrast agents"?

BACKGROUND

Iodinated contrast agents (ICAs) are crucial to the use of many imaging studies. Reported allergies to ICAs in the medical record can interfere with optimal diagnostic imaging workups.

PURPOSE

To investigate the accuracy with which the label "allergic to ICAs" is applied.

MATERIAL AND METHODS

The medical records of 500 patients labeled "allergic to ICAs" at a single tertiary care hospital were reviewed. Patients were separated into three groups based on documentation in their medical records, as follows: Group 1, documented hypersensitivity reaction to ICAs; Group 2, documented ICA exposure with non-hypersensitivity adverse event (Group 2a) or without documented reaction (Group 2b); and Group 3, no documented prior exposure to an ICA. We then further reviewed the EMR to determine whether or not patients had subsequent administration of an ICA, whether or not they were given specific premedication, and whether or not they had a subsequent ICA-related event.

RESULTS

A total of 16.6% of patients (n = 83) listed as "allergic to ICAs" had a documented hypersensitivity reaction following ICA administration (Group 1) while 58.6% (n = 293) of patients (Group 2) had a documented exposure to ICAs with either: (i) a non-hypersensitivity adverse event (23.5%, n = 69) or (ii) no record of a reaction to ICAs (76.5%, n = 224). The remaining 24.8% (n = 124), Group 3, had no record of exposure to an ICA, yet still carried the label.

CONCLUSION

The majority of patients carrying the label "allergic to ICAs" had no record of a prior hypersensitivity reaction to ICAs.

Clinical pharmacology, uses, and adverse reactions of iodinated contrast agents: a primer for the non-radiologist

Iodinated contrast agents have been in use since the 1950s to facilitate radiographic imaging modalities. Physicians in almost all specialties will either administer these agents or care for patients who have received these drugs. Different iodinated contrast agents vary greatly in their properties, uses, and toxic effects. Therefore, clinicians should be at least superficially familiar with the clinical pharmacology, administration, risks, and adverse effects associated with iodinated contrast agents. This primer offers the non-radiologist physician the opportunity to gain insight into the use of this class of drugs.