# Unexpected Life‐Threatening Reactions During Surgical Management of Deep Neck Infections

## TL;DR

This paper reports three cases of severe, life-threatening reactions in patients after using undiluted povidone-iodine during surgery for deep neck infections.

## Contribution

The study highlights a previously under-recognized risk of undiluted povidone-iodine in confined head and neck surgical spaces.

## Key findings

- Three patients developed severe complications minutes after intraoperative irrigation with undiluted povidone-iodine.
- Complications included facial nerve palsy, airway edema, and cardiac arrest.
- The reactions occurred despite no known iodine allergy or prior adverse reactions.

## Abstract

Odontogenic infections may extend into deep neck spaces, posing a serious risk of airway compromise and systemic complications. Povidone‐iodine (PVI) is frequently used intraoperatively for its broad antimicrobial activity; however, data regarding its safety in confined head and neck spaces remain scarce.

We describe three patients treated at Soroka University Medical Center between 2020 and 2024, whose cases were reviewed in 2024 and who developed severe complications immediately following intraoperative irrigation of deep neck spaces with undiluted PVI. One patient developed transient facial nerve palsy, another experienced extensive airway edema requiring prolonged intubation, and the third suffered a cardiac arrest during surgery that necessitated an emergency cesarean delivery. None of the patients had a known allergy to iodine or prior adverse reactions to iodinated contrast media, and all events occurred within minutes of PVI exposure.

The consistent temporal relationship between PVI irrigation and the onset of severe complications raises concern for a possible localized toxic or osmotic effect. Although the exact mechanism remains uncertain, potential explanations include osmotic tissue injury due to the hypertonicity of undiluted PVI, chemical cytotoxicity, and, less likely, hypersensitivity reactions.

This case series highlights the potential for rare, but life‐threatening reactions following PVI irrigation in the deep fascial spaces of the neck. Caution is warranted when using antiseptic irrigants in anatomically confined regions, and diluted PVI solutions should be preferred. Further studies are needed to elucidate the underlying pathophysiology and to establish safe intraoperative irrigation protocols.