Doctor I Have an Iodine Allergy

Endophthalmitis after Anti-VEGF Intravitreal Injections with Aqueous Chlorhexidine versus Povidone-Iodine as Ocular Antiseptics

PURPOSE

To compare the rates and outcomes of endophthalmitis after intravitreal injections (IVIs) for patients pretreated with 5% povidone-iodine (PI) and 0.05% chlorhexidine (CHX).

DESIGN

A retrospective, single-center, comparative cohort study.

PARTICIPANTS

A total of 8686 patients were included in the study, and a total of 67 695 anti-VEGF injections were performed from January 1, 2019, to November 30, 2021.

SETTING

A private retina practice of 13 retina specialists in Colorado.

METHODS

Using electronic health records, patients with preinjection preparation with PI or CHX were compiled retrospectively. Use of prefilled versus nonprefilled syringes was also tabulated. Patients with postinjection endophthalmitis (PIE) were identified among the 2 groups. Postinjection endophthalmitis is defined as an inflammation of the eye from infectious agents after an IVI. Logarithm of the minimum angle of resolution (logMAR) visual acuity (VA) was determined at the time of causative anti-VEGF injection, endophthalmitis presentation, and 3-month follow-up.

RESULTS

A total of 67 695 IVIs were administered by 13 retina specialists during the study period. A total of 13 of 32 802 (0.0396%; 1 in 2523 injections) cases of presumed endophthalmitis occurred in the PI group, and 9 of 34 893 (0.0258%; 1 in 3877 injections) cases in the CHX group (P = 0.395). For the PI group, there were 2 culture-positive endophthalmitis cases (0.0061%, 1 in 16 401), compared with 2 cases in the CHX group (0.00573%, 1 in 17 447) (P = 1.000). No significant difference was observed in the average logMAR VA of PI and CHX at causative injection (P = 0.3851), endophthalmitis encounter (P = 0.7718), and 3-month follow-up (P = 0.6152). A significant reduction in presumed endophthalmitis (P = 0.0445) and culture-positive cases (P = 0.0130) was present for prefilled IVI compared with nonprefilled injections.

CONCLUSIONS

No significant difference in the rate of endophthalmitis or visual outcomes were found in the CHX group compared with the PI group. Prefilled syringes were associated with a significant reduction in endophthalmitis rate. Further multicenter studies are needed to validate the efficacy and safety of CHX compared with PI for IVI preparation.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Hidden risk of gadolinium-based contrast agents during interventional pain medicine procedures: a retrospective chart review

INTRODUCTION

Epidural steroid injections and epidural blood patches commonly involve the injection of a small amount of radiocontrast media under fluoroscopy to properly identify the target tissue or anatomic space and prevent off-target or intravascular delivery of therapeutic or diagnostic drugs. Iodinated low osmolar non-ionic contrast media is the standard preparation used as it is considered safe and cost-effective, but gadolinium-based preparations have been used as an alternative for patients with an 'iodine'-related or radiocontrast media allergy label to prevent hypersensitivity reactions. The risk of neurotoxic events when gadolinium is inadvertently injected into the intrathecal space has been reported in recent years, raising concerns when gadolinium-based contrast media is used in lieu of iodinated low osmolar non-ionic contrast media.

METHODS

A retrospective review was conducted of patients who received gadolinium-based contrast media for procedures with risk of inadvertent intrathecal access from January 1, 2019 to May 1, 2022. Information on patient demographics, allergy label information, and procedure description was documented for all patients who received gadolinium-based contrast media for axial spine procedures (including epidural steroid injections, epidural blood patch procedures, and selective nerve root blocks), and all side effects reported within 1 month of the procedure were recorded. Saved fluoroscopy images of all procedures for which there was concern for possible gadolinium-based contrast media-related side effect were reviewed for evidence of inadvertent intrathecal gadolinium-based contrast media administration. Descriptive statistical analysis was performed using REDCap and IBM SPSS Statistics V.28.

RESULTS

We identified 508 patients who received gadolinium-based contrast media during a fluoroscopically guided axial spine procedure. These patients underwent 697 epidural procedures and 23 patients were identified as experiencing an adverse event that could be consistent with possible, probable, or clear signs of exposure to intrathecal gadolinium. Our calculated adverse event rate was 3.3%. Ten patients required additional medical evaluation or treatment.

DISCUSSION

Almost all patients in our cohort had an allergy label on their chart that guided the provider to switch to gadolinium-based contrast media, but most were incomplete, ill-defined, or related to allergy to iodine but not iodinated contrast media. Such practice is not recommended based on current guidelines. The current study raises concern regarding the use of gadolinium-based contrast media in axial spine procedures, with the risk of potential severe adverse events, without evidence-based need for avoiding iodinated contrast media.

Antimicrobial Mouthwashes: An Overview of Mechanisms-What Do We Still Need to Know?

This narrative literature review is the first in a 6-section supplement on the role of mouthwashes in oral care. This introduction briefly summarises current knowledge on antimicrobial mechanisms, relating to some of the most common over-the-counter mouthwash products available worldwide: chlorhexidine, hydrogen peroxide, cetylpyridinium chloride, povidone iodine, and essential oils. The aim of this first article is to describe how mouthwashes "kill" pathogenic microbes when used adjunctively and thus provide a basis for their widespread use to manage key oral diseases, namely caries, gingivitis, and periodontal disease. This article therefore sets the scene for subsequent, more detailed exploration of mouthwashes regarding their clinical effectiveness, impact on the oral microbiome, and possible effects on systemic health as well as natural alternatives and future directions. Other than the clinical effectiveness (for certain agents) of mouthwashes, on many topics there remains insufficient evidence for systematic review or formulation of robust national guidelines. The supplement, therefore, compiled by an international task team, is aimed at general dental practitioners across the globe, as an easy-to-read guide for helping to advise patients on mouthwash use based on the current best available evidence.

The Use of Iodophor-Impregnated Drapes in Patients With Iodine-Related Allergies: A Case Series and Review of the Literature

Background

The use of iodophor-impregnated adhesive drapes have become almost universally incorporated into standard practice of arthroplasty draping technique. Iodine-related allergies in patients planned for joint replacement present a challenge in terms of the best course of action to minimize complications and optimize outcomes.

Methods

This is a retrospective case series of patients that received an iodophor-impregnated drape as part of draping for a total hip or knee arthroplasty at a single orthopaedic-specific hospital with documented iodine-related allergies. From 2015 to 2023, 9816 total hip arthroplasty and total knee arthroplasty cases were reviewed, and 135 were documented to have an iodine-related allergy for a prevalence of 1.38%. Intraoperative and postoperative records were reviewed to screen for an allergic reaction or wound healing issues that may have been related to an adverse reaction to the use of the iodophor-impregnated drape.

Results

Of the 135 patients, 43 had iodine listed as an allergy, 85 had shellfish, 20 had iodinated contrast media, and 3 had povidone iodine. Sixteen patients had a cluster of iodine-related allergies. There were no intraoperative reports of an allergic reaction to this drape. There were four superficial wound problems, none of which were documented to relate to an allergic dermatitis reaction, and none required further surgery.

Conclusions

Patients reporting iodine-related allergies were present in 1.38% of patients undergoing hip or knee arthroplasty in our series. We encountered no allergic reactions or adverse outcomes that could be attributed to the use of iodiphor impregnated drapes in these patients.